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1
Mongitore, Rodolfo. "Lo spazio della musica nel teatro kabuki." AsiaTeatro 2023, no. 1 (2023): 23–35. http://dx.doi.org/10.55154/vkoq1037.
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Sulla organizzazione degli spazi dedicati ai diversi organici strumentali che compongono l’orchestra del teatro Kabuki e la logica che governa la visibilita' o invisibilita' degli interpreti alla vista del pubblico.
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Dalmar Chaka. "Utilizzo della nanotecnologia Nello sviluppo di fertilizzanti organici e pesticide." International Journal of Science and Society 4, no. 2 (July 12, 2022): 355–64. http://dx.doi.org/10.54783/ijsoc.v4i2.479.
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Non si può negare che lo sviluppo della tecnologia e il suo utilizzo sia strettamente correlato all'aumento della competitività dell'industria di un paese. È necessaria una maggiore conoscenza e padronanza delle nuove tecnologie per vincere la concorrenza nell'era del commercio globale sia da parte del governo che dell'industria. Un esempio di tecnologia che viene discussa caldamente è la nanotecnologia. L'uso della nanotecnologia è ben noto, anche nei settori della salute, della cosmesi e dell'agricoltura. Fondamentalmente, il principio della scoperta delle nanotecnologie è massimizzare la resa o la produzione delle colture riducendo al minimo l'uso di fertilizzanti, pesticidi e altri bisogni monitorando le condizioni del suolo come le radici e applicandole direttamente al bersaglio in modo che nulla venga sprecato. Per i pesticidi, se applicato, sarà in grado di ridurre al minimo l'uso di pesticidi sulle piante perché solo gli insetti bersaglio sono interessati. L'uso della nanotecnologia nei fertilizzanti consentirà il rilascio dei nutrienti contenuti nel fertilizzante può essere controllato. Quindi vengono rilasciati solo i nutrienti che verranno effettivamente assorbiti dalle piante, in modo che non ci sia perdita di nutrienti ci siano bersagli indesiderati come suolo, acqua e microrganismi. Nei nano fertilizzanti, i nutrienti possono essere sotto forma di incapsulamento di nanomateriali, ricoperti da un sottile strato protettivo o rilasciati sotto forma di emulsione da nanoparticelle.
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Oddo, Giuseppe. "Costituzione dei Derivati Solforati, Azotati etc. Degli Acidi Organici nel Gruppo Carbossilico." Recueil des Travaux Chimiques des Pays-Bas 48, no. 9 (September 3, 2010): 875–79. http://dx.doi.org/10.1002/recl.19290480904.
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Osculati, Franco. "La finanza comunale in provincia di Pavia tra gli anni Sessanta e Settanta del Novecento." STORIA IN LOMBARDIA, no. 1 (April 2022): 92–109. http://dx.doi.org/10.3280/sil2021-001006.
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Nella provincia di Pavia erano, e sono, presenti numerosi comuni, molti dei quali di piccole e piccolissime dimensioni. L'industrializzazione del dopoguerra e la connessa immigrazione non sconvolsero il territorio; tuttavia, tra gli anni Sessanta e i primi anni Settanta si manifestava un forte fabbisogno di infrastrutture. Pur aumentando gli investimenti e gli organici, i comuni mantennero una condotta finanziaria prudente anche dopo la riforma tributaria del 1974 che abolì quasi totalmente i tributi locali. La maggioranza dei comuni era di sinistra, ma non sembra che i diversi colori politici abbiano caratterizzato significativamente i comportamenti delle giunte. Il presente saggio cerca di collocare la situazione locale nelle tendenze economiche generali di un periodo contraddistinto da inflazione e dalla formazione di un primo nucleo di debito pubblico nazionale, un lascito fastidioso ma inevitabile.
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Cenati, Giuliano. "Il fumetto grassroots: gli antipodi convergenti di Dr. Pira e Sio." ENTHYMEMA, no. 30 (January 2, 2023): 8–26. http://dx.doi.org/10.54103/2037-2426/19530.
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I processi di trasformazione che hanno interessato il campo fumettistico al crocevia del secolo si allacciano strettamente alla digitalizzazione e all’integrazione del sistema mediale. Accanto all’affermazione del graphic novel, che permette al fumetto di convergere verso archi narrativi organici di matrice romanzesca, si delineano tendenze al riscatto dei generi brevi del fumetto classico: la striscia umoristica, la vignetta fulminante, la tavola autoconclusiva. L’accrescimento vertiginoso dei flussi sviluppati dal web favorisce la trasposizione, il ricircolo, la stratificazione di simili schegge fumettistiche, tra comunicazione analogica e comunicazione digitale. Si tratta di proposte che insorgono dal basso, da protagonisti della compartecipazione creativa socialmediale o da rinnovatori della cultura underground. L’intreccio fra interazione estetica istituzionale e medialità autogestita, pur vincolato all’oligopolio delle piattaforme, dischiude originali opportunità di differenziazione e arricchimento dell’esperienza fumettistica.
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Locati, Ilaria, Mary Bottarel, Maria Teresa Gervasi, and Lenio Rizzo. "Gruppi di donne in ostetricia. Il lavoro psichico con le donne ricoverate per gravidanza a rischio." GRUPPI, no. 1 (October 2010): 113–26. http://dx.doi.org/10.3280/gru2010-001010.
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Gli autori descrivono la nascita e l'evoluzione di gruppi di donne in un reparto di ostetricia a partire da una considerazione integrata degli aspetti biologico-organici e di quelli psicologico- relazionali delle pazienti ricoverate. Ritenendo che l'esperienza del ricovero per patologia ostetrica puň aggravare i fattori di rischio psicologico ed incidere negativamente sul benessere psicofisico della donna, si č cercato di favorire la mentalizzazione di aspetti angoscianti e spesso non detti della maternitŕ mediante il lavoro col gruppo omogeneo. L'articolo descrive le fasi evolutive dei lavori di gruppo che hanno coinvolto le unitŕ operative di neuropsichiatria infantile ed ostetricia, le ostetriche del reparto e le pazienti ricoverate. L'esperienza svolta suggerisce che questa modalitŕ di lavoro possa favorire un processo di mentalizzazione di quegli aspetti della maternitŕ che, se rimangono bloccati nel soma, possono ostacolare l'evoluzione della maternitŕ psichica e del rapporto madre-bambino.
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Malone, Caroline, and Simon Stoddart. "The neolithic site of San Marco, Gubbio (Perugia), Umbria: survey and excavation 1985–7." Papers of the British School at Rome 60 (November 1992): 1–69. http://dx.doi.org/10.1017/s006824620000979x.
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RICOGNIZIONE E SCAVO DEL SITO NEOLITICO DI SAN MARCO, GUBBIO (PERUGIA), UMBRIA, 1985–7La ricognizione e lo scavo dell'insediamento di San Marco rappresenta uno dei pochi esempi di studio interdisciplinare compiuti nell'Italia centrale e riguardante un sito neolitico. Sono stati studiati in maniera approfondita i vari aspetti geologici ed ambientali del sito, collocato su un conoide alluvionale. Sono state inoltre ottenute date al 14C, eseguite con l'AMS direttamente su materiali organici associati con la sussistenza umana, che hanno permesso di attribuire il sito ad una prima fase dell'età neolitica (fine del sesto-inizio del quinto millennio a.C, date calibrate). L'industria litica mostra una chiara continuità con la precedente tecnologia epipaleolitica, mentre le ceramiche rinvenute possono essere attribuite alle correnti stilistiche della Ceramica Impressa e a quella di Sasso-Fiorano. Le analisi dei prodotti di sussistenza (fauna e resti botanici) rivelano un'economia basata principalmente sull'agricoltura, integrata a sua volta con prodotti ottenuti tramite attività di caccia e raccolta.
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D’Onofrio, F., and U. De Fanis. "Ma esiste il terzo sesso?" Medicina e Morale 48, no. 4 (August 31, 1999): 709–19. http://dx.doi.org/10.4081/mem.1999.796.
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La diffusione dell’omosessualità, specie in questi ultimi decenni, ha richiamato l’attenzione di molti ricercatori che hanno formulato varie ipotesi per spiegare la sua genesi.
La teoria psicoanalitica sostiene che l’omosessualità sarebbe un disturbo acquisito della pulsione sessuale.
Invece, secondo la teoria biologica, vi sarebbero meccanismi organici e genetici alla base dell’omosessualità. Infatti alcuni studi avrebbero evidenziato differenze anatomiche tra il cervello degli eterosessuali e quello degli omosessuali ed inoltre sarebbe stata evidenziata una ricorrenza familiare dell’omosessualità.
Tuttavia, l’ipotesi biologica è stata contestata da diversi studi che non solo non hanno riscontrato differenze sostanziali tra il cervello di omosessuali e quello degli eterosessuali, ma hanno anche sottolineato il fatto che i pochi soggetti esaminati erano affetti da AIDS e sottoposti a lunghi periodi di terapie ormonali. Inoltre, il mancato riscontro di sequenze geniche alterate nonché i metodi utilizzati per la ricerca di coppie di fratelli omosessuali, sono le principali contestazioni mosse all’origine genetica dell’omosessualità.
Il problema dell’omosessualità, in attesa di altre ricerche, deve ancora essere considerato come una scelta individuale di orientamento sessuale condizionato da esperienze maturate per lo più nell’ambito familiare e relazionale favorita da una cultura permissivistica e non come una scelta obbligata condizionata da variazioni anatomiche e genetiche.
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Paull, John. "Organics Olympiad 2016: Global Indices of Leadership in Organic Agriculture." Journal of Social and Development Sciences 7, no. 2 (July 6, 2016): 79–87. http://dx.doi.org/10.22610/jsds.v7i2.1309.
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Organic production (including agriculture, wild culture, forestry and aquaculture) is a worldwide phenomenon that is practiced in at least 172 countries. The Organics Olympiad presents 14 indices of global organics leadership, each at three levels (Gold, Silver and Bronze). The Organics Olympiad of 2016 yields 29 countries as global organics leaders, and confirms that organics leadership is diversely distributed across countries, large and small, rich and poor, developed and less so, and cuts across linguistic, ethnic and cultural boundaries. Australia continues to lead the world in organic agriculture hectares. Australia also leads in the increase of organic hectares over the past four years (since the Organics Olympiad 2012) and in the number of WWOOF (Willing Workers on Organic Farms) hosts. Finlandleads in organic wild culture hectares. Vietnam leads in organic aquaculture hectares, and Tunisia leads in organic forest hectares. Germany leads in biodynamic hectares, as well as with the number of members of IFOAM-Organics International. India leads for the number of organic producers. The Falkland Islands (Malvinas) leads in terms of the percentage agricultural land dedicated as organic. Switzerland leads with the value of organics consumption per capita. USA leads in the value of the organics market. Denmark leads in the publishing of organics research papers over the past four years. Namibia leads in the percentage increase in organic hectares over the past four years. The overall global organics leaders, on the basis of aggregated scores, are Australia, Germany, and Switzerland, in positions one, two and three, respectively. This study demonstrates the successful global diffusion of organics, and identifies that leadership lessons can be available from a broad diversity of countries. Key implications are identified.
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Paull, John. "Organics Olympiad 2011: Global Indices of Leadership in Organic Agriculture." Journal of Social and Development Sciences 1, no. 4 (May 15, 2011): 144–50. http://dx.doi.org/10.22610/jsds.v1i4.638.
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Organic agriculture is now a worldwide phenomenon which is practiced in 160 countries. The Organics Olympiad presents 12 indices of global organics leadership, each at three levels. It yields 26 countries as global organics leaders, and reveals that organics leadership is diversely distributed across countries, large and small, rich and poor, developed and less so, as well as across linguistic and cultural barriers. Australia leads the world in organic agriculture hectares, Finland leads in organic wild culture hectares, China leads in organic aquaculture hectares, and Portugal leads in organic forest hectares. Germany leads in biodynamic hectares, as well as with the number of members of the International Federation of Agriculture Movements (IFOAM), and in the publishing of organics research papers. India is in the lead position for the number of organic producers, the Falkland Islands (Malvinas) leads in terms of the percentage of agricultural land dedicated as organic, and Denmark leads with the value of organics consumption per capita. Uruguay leads in the relative increase in organic hectares over the past decade, and Japan leads in the number of organics certifiers. The overall global organics leaders, on the basis of aggregated scores, are Germany, India and Denmark, in positions one, two and three, respectively. The successful global diffusion of organics, as demonstrated in this study, means that leadership lessons are available from a diversity of social, geographical, political, and ecological situations for both existing and aspiring organics leaders.
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Jolly, Desmond A., and Kim Norris. "Marketing prospects for organic and pesticide-free produce." American Journal of Alternative Agriculture 6, no. 4 (December 1991): 174–79. http://dx.doi.org/10.1017/s0889189300004227.
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AbstractThe March 1989 food safety episodes involving Alar on apples and the cyanide tainted grapes found in a Chilean shipment were seminal events in the history of U.S. organic agriculture. Demand for organic produce soared as a consequence of these events, and mainstream supermarkets began adding more organic produce to their traditional product lines. But when organic supplies proved scarce, and as prices increased, consumer purchases decreased and many marketing managers began to question the rationality of allocating scarce shelf space to organic products. In fact, many supermarket chains either drastically reduced their organic offerings or dropped them altogether. Some analysts proclaimed that organics had failed the market test. However, two surveys we carried out in 1989 and 1991 among major California supermarket chains show that forecasts of the demise of organic produce in mainstream markets may have been premature. Of 16 chains responding to our survey, 12 continue to carry organic produce. All had carried organics for more than six months, two-thirds of them for more than a year. Of the 12 that carry organics, six rate organics as worse overall than conventional produce. But, interestingly, six rate organics as “about the same” as conventional produce. This is a significant achievement for organics. Organics rated better on environmental impact and residues, worse on appearance and shelf life, and “about the same” on flavor and nutritive value. Despite the constraints and difficulties encountered in marketing organic foods, 8 of the 12 chains that carry organics would carry more organic fruits and vegetables if supplies were available. The prospects for certified “pesticide free” produce are less definite.
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Farmer, D. K., A. E. Perring, P. J. Wooldridge, D. R. Blake, A. Baker, S. Meinardi, L. G. Huey, D. Tanner, O. Vargas, and R. C. Cohen. "Impact of organic nitrates on urban ozone production." Atmospheric Chemistry and Physics Discussions 10, no. 10 (October 11, 2010): 23423–48. http://dx.doi.org/10.5194/acpd-10-23423-2010.
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Abstract. Urban O3 is produced by photochemical chain reactions that amplify background O3 in mixtures of gaseous nitrogen oxides (NOx) and organic molecules. Current thinking treats NOx and organics as independent variables that limit O3 production depending on the NOx to organic ratio; in this paradigm, reducing organics either has no effect or reduces O3. We describe a theoretical counterexample where NOx and organics are strongly coupled and reducing organics increases O3 production, and illustrate the example with observations from Mexico City. This effect arises from chain termination in the HOx and NOx cycles via organic nitrate production. We show that emission reductions that inadvertently reduce organic nitrate production rates will be counterproductive without concurrent reductions in NOx or other organics.
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Farmer, D. K., A. E. Perring, P. J. Wooldridge, D. R. Blake, A. Baker, S. Meinardi, L. G. Huey, D. Tanner, O. Vargas, and R. C. Cohen. "Impact of organic nitrates on urban ozone production." Atmospheric Chemistry and Physics 11, no. 9 (May 4, 2011): 4085–94. http://dx.doi.org/10.5194/acp-11-4085-2011.
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Abstract. Urban O3 is produced by photochemical chain reactions that amplify background O3 in mixtures of gaseous nitrogen oxides (NOx) and organic molecules. Current thinking treats NOx and organics as independent variables that limit O3 production depending on the NOx to organic ratio; in this paradigm, reducing organics either has no effect or reduces O3. We describe a theoretical counterexample where NOx and organics are strongly coupled and reducing organics increases O3 production, and illustrate the example with observations from Mexico City. This effect arises from chain termination in the HOx and NOx cycles via organic nitrate production. We show that reductions in VOC reactivity that inadvertently reduce organic nitrate production rates will be counterproductive without concurrent reductions in NOx or other organics.
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Yong, Raymond N., and Diana Mourato. "Extraction and characterization of organics from two Champlain Sea subsurface soils." Canadian Geotechnical Journal 25, no. 3 (August 1, 1988): 599–607. http://dx.doi.org/10.1139/t88-066.
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The focus of this investigation is to establish whether organic materials are present in subsurface soils in measurable and significant quantities. Two subsurface soils from the Champlain Sea region were chosen for study. Organic carbon concentrations of 0.5% as total organic carbon (TOC) were detected in the soils studied at depths up to 14.2 m. The extraction and subsequent analyses of organic compounds permitted one to classify these as humic acids, fulvic acids, humins, and nonhumic materials. Extraction of these subsurface soil organics was achieved using a modified HCl–NaOH extraction method. The extracted organics were analyzed for TOC to confirm their organic nature as well as for study of their surface chemistry. The compositional and structural characteristics of the extracts were investigated using infrared spectroscopy and scanning electron microscopy. Key words: subsurface soil organics, humic materials, nonhumic organics, organics extraction, Champlain Sea clays.
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Zhang, Feng, Shuai Li, Chang Qing Liu, Xing Sheng Kang, and Yan Li. "The Component and Characteristic Analysis of Organic Matters in Inflow Water of one Wastewater Treatment Plant in Qingdao." Advanced Materials Research 518-523 (May 2012): 2886–90. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2886.
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The concentration of soluble inert organics and the mass distribution of organic matter in inflow wastewater of one wastewater treatment plant (WWTP) in Qingdao city in China were studied in this paper. The results showed that the concentration of soluble inert organics in the influent which cannot be degraded by microbe was about 20 mg/L, accounts for 2%～5% of all dissolved organic matter. The small organic molecules (<1 ku) took up the largest proportion of all organics in influent, which was about 40% of dissolved organic carbon (DOC). Moreover, the residual organic molecules after biological treatment process and coagulation sedimentation process might be transformed into disinfection by-products (DBPs) by chlorination in advanced treatment process, so the combined process of ozone and activated carbon was suggested to be used to remove the small organic molecules in inflow water in this WWTP.
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Lee, A. K. Y., K. L. Hayden, P. Herckes, W. R. Leaitch, J. Liggio, A. M. Macdonald, and J. P. D. Abbatt. "Characterization of aerosol and cloud water at a mountain site during WACS 2010: secondary organic aerosol formation through oxidative cloud processing." Atmospheric Chemistry and Physics Discussions 12, no. 2 (February 24, 2012): 6019–47. http://dx.doi.org/10.5194/acpd-12-6019-2012.
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Abstract. The water-soluble fractions of aerosol samples and cloud water collected during Whistler Aerosol and Cloud Study (WACS 2010) were analyzed using an Aerodyne aerosol mass spectrometer (AMS). This is the first study to report AMS organic spectra of re-aerosolized cloud water, and to make direct comparison between the AMS spectra of cloud water and aerosol samples collected at the same location. In general, the aerosol and cloud organic spectra were very similar, indicating that the cloud water organics likely originated from secondary organic aerosol (SOA) formed nearby. By using a photochemical reactor to oxidize both aerosol filter extracts and cloud water, we find evidence that fragmentation of aerosol water-soluble organics increases their volatility during oxidation. By contrast, enhancement of AMS-measurable organic mass by up to 30% was observed during aqueous-phase photochemical oxidation of cloud water organics. We propose that additional SOA material was produced by functionalizing dissolved organics via OH oxidation, where these dissolved organics are sufficiently volatile that they are not usually part of the aerosol. This work points out that water-soluble organic compounds of intermediate volatility (IVOC), such as cis-pinonic acid, produced via gas-phase oxidation of monoterpenes, can be important aqueous-phase SOA precursors in a biogenic-rich environment.
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Karadima, Katerina S., Vlasis G. Mavrantzas, and Spyros N. Pandis. "Insights into the morphology of multicomponent organic and inorganic aerosols from molecular dynamics simulations." Atmospheric Chemistry and Physics 19, no. 8 (April 29, 2019): 5571–87. http://dx.doi.org/10.5194/acp-19-5571-2019.
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Abstract. We explore the morphologies of multicomponent nanoparticles through atomistic molecular dynamics simulations under atmospherically relevant conditions. The particles investigated consist of both organic (cis-pinonic acid – CPA, 3-methyl-1,2,3-butanetricarboxylic acid – MBTCA, n-C20H42, n-C24H50, n-C30H62 or mixtures thereof) and inorganic (sulfate, ammonium and water) compounds. The effects of relative humidity, organic mass content and type of organic compound present in the nanoparticle are investigated. Phase separation is predicted for almost all simulated nanoparticles either between organics and inorganics or between hydrophobic and hydrophilic constituents. For oxygenated organics, our simulations predict an enrichment of the nanoparticle surface in organics, often in the form of islands depending on the level of humidity and organic mass fraction, giving rise to core–shell structures. In several cases the organics separate from the inorganics, especially from the ions. For particles containing water-insoluble linear alkanes, separate hydrophobic and hydrophilic domains are predicted to develop. The surface partitioning of organics is enhanced as the humidity increases. The presence of organics in the interior of the nanoparticle increases as their overall mass fraction in the nanoparticle increases, but this also depends on the humidity conditions. Apart from the organics–inorganics and hydrophobics–hydrophilics separation, our simulations predict a third type of separation (layering) between CPA and MBTCA molecules under certain conditions.
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Fang, Hua, De Fu Xu, Xiao Ru Fu, Yuan Wang, and Ji Lai Lu. "Molecular Weight Distribution of Organics in Raw and Treated Water." Advanced Materials Research 255-260 (May 2011): 2731–35. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.2731.
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Levels of organic matters in raw water from Huangpu River and treated water from different processes have been investigated. Dissolved organic carbon (DOC) and assimilable organic carbon (AOC) have been determined on ultrafiltrate (UF) (MW cut-off of 1K and 10K Daltons) samples. The organics in raw water are majority of lower MW (<1K Daltons) fractions. The conventional treatment processes are effective in removing higher MW (>10K Daltons) organics, while granular activated carbon (GAC) adsorption can reduce organics with lower MW significantly. The lower MW fractions correspond to 60%~70% of the AOC in raw and treated waters, and much higher than other MW fractions. This indicates that the AOC is mainly related to organics with lower MW. In order to decrease AOC level to achieve biostability in drinking water, the processes which can reduce lower MW organics effectively must be employed.
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Chen, Jing, Sri Hapsari Budisulistiorini, Takuma Miyakawa, Yuichi Komazaki, and Mikinori Kuwata. "Secondary aerosol formation promotes water uptake by organic-rich wildfire haze particles in equatorial Asia." Atmospheric Chemistry and Physics 18, no. 11 (June 4, 2018): 7781–98. http://dx.doi.org/10.5194/acp-18-7781-2018.
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Abstract. The diameter growth factor (GF) of 100 nm haze particles at 85 % relative humidity (RH) and their chemical characteristics were simultaneously monitored at Singapore in October 2015 during a pervasive wildfire haze episode that was caused by peatland burning in Indonesia. Non-refractory submicron particles (NR-PM1) were dominated by organics (OA; approximating 77.1 % in total mass), whereas sulfate was the most abundant inorganic constituent (11.7 % on average). A statistical analysis of the organic mass spectra showed that most organics (36.0 % of NR-PM1 mass) were highly oxygenated. Diurnal variations of GF, number fractions of more hygroscopic mode particles, mass fractions of sulfate, and mass fractions of oxygenated organics (OOA) synchronized well, peaking during the day. The mean hygroscopicity parameter (κ) of the haze particles was 0.189 ± 0.087, and the mean κ values of organics were 0.157 ± 0.108 (κorg, bulk organics) and 0.266 ± 0.184 (κOOA, OOA), demonstrating the important roles of both sulfate and highly oxygenated organics in the hygroscopic growth of organics-dominated wildfire haze particles. κorg correlated with the water-soluble organic fraction insignificantly, but it positively correlated with f44 (fraction of the ion fragment at m∕z 44 in total organics) (R = 0.70), implying the oxygenation degree of organics could be more critical for the water uptake of organic compounds. These results further suggest the importance of sulfate and secondary organic aerosol formation in promoting the hygroscopic growth of wildfire haze particles. Further detailed size-resolved as well as molecular-level chemical information about organics is necessary for the profound exploration of water uptake by wildfire haze particles in equatorial Asia.
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Narkis, Nava, and Menahem Rebhun. "Flocculation in presence of organic macromolecules of natural water and secondary effluents." Water Science and Technology 36, no. 4 (August 1, 1997): 85–91. http://dx.doi.org/10.2166/wst.1997.0092.
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Flocculation processes were studied in three types of water representing turbid natural surface water, controlled synthetic systems of reference clay minerals suspensions in the presence of humates and fulvates at various degrees of interactions, and municipal wastewater treatment plant effluents. These systems contain suspended and colloidal dispersed solids accompanied by organic substances in dissolved or colloidal form. The presence of organic anionic macromolecules and soluble organics in water affects flocculation processes by raising the flocculant demand appreciably and hence affects the final water quality. Extraction and elimination of the organics from natural suspended solids, and removal of soluble organics from effluents reduced the organic content, thus decreasing considerably the flocculant demand. The addition of the extracted and separated organics to pure clay dispersions increased accordingly the cationic polyelectrolyte flocculant demand.
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Al Namazi, Mohammed, Sheng Li, Noreddine Ghaffour, TorOve Leiknes, and Gary Amy. "A Fouling Comparison Study of Algal, Bacterial and Humic Organic Matters in Seawater Desalination Pretreatment Using Ceramic UF Membranes." Membranes 13, no. 2 (February 15, 2023): 234. http://dx.doi.org/10.3390/membranes13020234.
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This study investigates three types of organic matter, namely algal organic matter (AOM), bacterial organic matter (BOM), and humic organic matter (HOM). These organics are different in properties and chemical composition. AOM, BOM and HOM were compared in terms of organic content, fouling behavior, and removal efficiency in ceramic UF filtration. UF experiments were conducted at a constant flux mode using 5 kDa and 50 kDa ceramic membranes. Results showed that 5 kDa membrane removed more transparent exopolymer particles (TEP)/organics than 50 kDa membranes, but less fouling formation for all the three types of organic matters tested. Membranes exhibited the lowest trans-membrane pressure (TMP) during the filtration of HOM, most probably due to the high porosity of the HOM cake layer, contributed by big HOM aggregates under Ca bridging effect. AOM shows the highest MFI-UF (modified fouling index-ultrafiltration) and TMP (transmembrane pressure) values among the three organics and during all filtration cycles for both membranes. The AOM fouling layer is well known for having high fouling potential due to its compressibility and compactness which increase the TMP and eventually the MFI values. AOM and BOM organics exhibited a similar fouling behavior and mechanism. Furthermore, the divalent cations such as calcium showed a significant impact on membrane fouling. That is probably because calcium ions made the membranes and organic matter less negatively charged and easier to deposit on membranes, thus, enhancing the membrane fouling significantly.
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Yasui, H., and Y. Miyaji. "A Novel Approach to Removing Refractory Organic Compounds in Drinking Water." Water Science and Technology 26, no. 7-8 (October 1, 1992): 1503–12. http://dx.doi.org/10.2166/wst.1992.0594.
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A basic study has been conducted on the treatment of refractory organics in river water in order to produce safe drinking water. Through ozonation of refractory organics, assimilable carboxylic acids are produced with a slight decrease in total organic carbon(TOC) concentration. The amount of newly formed assimilable organic carbon corresponds to nearly 35% of the initial TOC in sample water. Re-ozonation after biological treatment of the formed assimilable organics makes it possible to reduce TOC to a much lower level by transforming the residual refractory organic carbon to an assimilable one. The repeated treatment of ozonation-biodegradation processes can minimize TOC and trihalomethane formation potential to below the detectable level with a minimum of ozone consumption.
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Wonaschütz, A., S. P. Hersey, A. Sorooshian, J. S. Craven, A. R. Metcalf, R. C. Flagan, and J. H. Seinfeld. "Impact of a large wildfire on water-soluble organic aerosol in a major urban area: the 2009 Station Fire in Los Angeles County." Atmospheric Chemistry and Physics 11, no. 16 (August 15, 2011): 8257–70. http://dx.doi.org/10.5194/acp-11-8257-2011.
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Abstract. This study examines the nature of water-soluble organic aerosol measured in Pasadena, CA, under typical conditions and under the influence of a large wildfire (the 2009 Station Fire). During non-fire periods, water-soluble organic carbon (WSOC) variability was driven by photochemical production processes and sea breeze transport, resulting in an average diurnal cycle with a maximum at 15:00 local time (up to 4.9 μg C m−3). During the Station Fire, primary production was a key formation mechanism for WSOC. High concentrations of WSOC (up to 41 μg C m−3) in smoke plumes advected to the site in the morning hours were tightly correlated with nitrate and chloride, numerous aerosol mass spectrometer (AMS) organic mass spectral markers, and total non-refractory organic mass. Processed residual smoke was transported to the measurement site by the sea breeze later in the day, leading to higher afternoon WSOC levels than on non-fire days. Parameters representing higher degrees of oxidation of organics, including the ratios of the organic metrics m/z 44:m/z 57 and m/z 44:m/z 43, were elevated in those air masses. Intercomparisons of relative amounts of WSOC, organics, m/z 44, and m/z 43 show that the fraction of WSOC comprising acid-oxygenates increased as a function of photochemical aging owing to the conversion of aliphatic and non-acid oxygenated organics to more acid-like organics. The contribution of water-soluble organic species to the organic mass budget (10th–90th percentile values) ranged between 27 %–72 % and 27 %–68 % during fire and non-fire periods, respectively. The seasonal incidence of wildfires in the Los Angeles Basin greatly enhances the importance of water-soluble organics, which has implications for the radiative and hygroscopic properties of the regional aerosol.
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Patoulias, D., C. Fountoukis, I. Riipinen, and S. N. Pandis. "The role of organic condensation on ultrafine particle growth during nucleation events." Atmospheric Chemistry and Physics Discussions 14, no. 22 (December 9, 2014): 30761–98. http://dx.doi.org/10.5194/acpd-14-30761-2014.
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Abstract. A new aerosol dynamics model (DMANx) has been developed that simulates the aerosol size/composition distribution and includes the condensation of organic vapors on nanoparticles through the implementation of the recently developed Volatility Basis Set framework. Simulations were performed for Hyytiala (Finland) and Finokalia (Greece), two locations with different organic sources where detailed measurements were available to constrain the new model. We investigate the effect of condensation of organics and chemical aging reactions of secondary organic aerosol (OA) on ultrafine particle growth and particle number concentration. This work highlights the importance of the pathways of oxidation of biogenic volatile organic compounds and the production of extremely low-volatility organics. At Hyytiala, organic condensation dominates the growth process of new particles. The low-volatility secondary OA contributes to particle growth during the early growth stage, but after a few hours most of the growth is due to semi-volatile secondary OA. At Finokalia, simulations show that organics have a complementary role to new particle growth contributing 45% to the total mass of new particles. Condensation of organics increases the number concentration of particles that can act as CCN (N100) by 13% at Finokalia and 25% at Hyytiala. The sensitivity of our results to the surface tension used is discussed.
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Amundson, N. R., A. Caboussat, J. W. He, A. V. Martynenko, C. Landry, C. Tong, and J. H. Seinfeld. "A new atmospheric aerosol phase equilibrium model (UHAERO): organic systems." Atmospheric Chemistry and Physics Discussions 7, no. 3 (June 22, 2007): 8709–54. http://dx.doi.org/10.5194/acpd-7-8709-2007.
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Abstract. In atmospheric aerosols, water and volatile inorganic and organic species are distributed between the gas and aerosol phases in accordance with thermodynamic equilibrium. Within an atmospheric particle, liquid and solid phases can exist at equilibrium. Models exist for computation of phase equilibria for inorganic/water mixtures typical of atmospheric aerosols; when organic species are present, the phase equilibrium problem is complicated by organic/water interactions as well as the potentially large number of organic species. We present here an extension of the UHAERO inorganic thermodynamic model (Amundson et al., 2006c) to organic/water systems. Phase diagrams for a number of model organic/water systems characteristic of both primary and secondary organic aerosols are computed. Also calculated are inorganic/organic/water phase diagrams that show the effect of organics on inorganic deliquescence behavior. The effect of the choice of activity coefficient model for organics on the computed phase equilibria is explored.
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Amundson, N. R., A. Caboussat, J. W. He, A. V. Martynenko, C. Landry, C. Tong, and J. H. Seinfeld. "A new atmospheric aerosol phase equilibrium model (UHAERO): organic systems." Atmospheric Chemistry and Physics 7, no. 17 (September 14, 2007): 4675–98. http://dx.doi.org/10.5194/acp-7-4675-2007.
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Abstract. In atmospheric aerosols, water and volatile inorganic and organic species are distributed between the gas and aerosol phases in accordance with thermodynamic equilibrium. Within an atmospheric particle, liquid and solid phases can exist at equilibrium. Models exist for computation of phase equilibria for inorganic/water mixtures typical of atmospheric aerosols; when organic species are present, the phase equilibrium problem is complicated by organic/water interactions as well as the potentially large number of organic species. We present here an extension of the UHAERO inorganic thermodynamic model (Amundson et al., 2006c) to organic/water systems. Phase diagrams for a number of model organic/water systems characteristic of both primary and secondary organic aerosols are computed. Also calculated are inorganic/organic/water phase diagrams that show the effect of organics on inorganic deliquescence behavior. The effect of the choice of activity coefficient model for organics on the computed phase equilibria is explored.
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Fuentes, E., H. Coe, D. Green, and G. McFiggans. "On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity." Atmospheric Chemistry and Physics Discussions 10, no. 11 (November 4, 2010): 26157–205. http://dx.doi.org/10.5194/acpd-10-26157-2010.
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Abstract. The effect of colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator. The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 5–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN) activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics. The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles increased with increasing seawater organic concentration, with the highest organic enrichment found for the diatomaceous exudate. These findings are indicative that, besides the differences induced by the aerosol generator employed, discrepancies between different studies in the behaviour of the organics-enriched primary seaspray could partly be explained by the difference in the nature and concentration of the organic material in the source seawater employed. Consistently across the experiments, theoretical analysis based on the Köhler model predicted a reduction in the primary seaspray CCN activity upon the incorporation of marine organics into the particle composition. This effect is consequence of the replacement of small inorganic sea salt molecules by large molar mass organic molecules, together with a moderate suppression of the surface tension at the point of activation of 5–0.5%, which leads to a dominance of the reduction in the dissolved solute in the Raoult term.
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Wang, J., Y. N. Lee, P. H. Daum, J. Jayne, and M. L. Alexander. "Effects of aerosol organics on cloud condensation nucleus (CCN) concentration and first indirect aerosol effect." Atmospheric Chemistry and Physics Discussions 8, no. 3 (May 28, 2008): 9783–818. http://dx.doi.org/10.5194/acpd-8-9783-2008.
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Abstract. Aerosol microphysics, chemical composition, and CCN properties were measured on the Department of Energy Gulfstream-1 aircraft during the Marine Stratus/Stratocumulus Experiment (MASE) conducted over the coastal waters between Point Reyes National Seashore and Monterey Bay, California, in July 2005. Aerosols measured during MASE included free tropospheric aerosols, marine boundary layer aerosols, and aerosols with high organic concentration within a thin layer above the cloud. Closure analysis was carried out for all three types of aerosols by comparing the measured CCN concentrations at 0.22% supersaturation to those predicted based on size distribution and chemical composition using Köhler theory. The effect of aerosol organic species on predicted CCN concentration was examined using a single hygroscopicity parameterization. For aerosols with organics volume fraction up to 70%, such as the marine boundary layer and free troposphere aerosols, CCN concentration and the corresponding first indirect aerosol effect are insensitive to the properties of organics, and can be accurately predicted with a constant hygroscopicity for all organic species. This simplification can facilitate the prediction of indirect aerosol effects using physically-based parameterizations in large scale models. However, for the aerosols within the thin layers above clouds, organics contributed up to 90% of the total aerosol volume, and a detailed knowledge of organic hygroscopicity is required to accurately predict CCN concentrations. Derivations of organic properties in future closure studies, when aerosols are dominated by organic species, would help constrain the descriptions of organics and aerosol-cloud parameterizations in large scale models.
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Patoulias, D., C. Fountoukis, I. Riipinen, and S. N. Pandis. "The role of organic condensation on ultrafine particle growth during nucleation events." Atmospheric Chemistry and Physics 15, no. 11 (June 11, 2015): 6337–50. http://dx.doi.org/10.5194/acp-15-6337-2015.
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Abstract. A new aerosol dynamics model (DMANx) has been developed that simulates aerosol size/composition distribution and includes the condensation of organic vapors on nanoparticles through the implementation of the recently developed volatility basis set framework. Simulations were performed for Hyytiälä (Finland) and Finokalia (Greece), two locations with different organic sources where detailed measurements were available to constrain the new model. We investigate the effect of condensation of organics and chemical aging reactions of secondary organic aerosol (SOA) precursors on ultrafine particle growth and particle number concentration during a typical springtime nucleation event in both locations. This work highlights the importance of the pathways of oxidation of biogenic volatile organic compounds and the production of extremely low volatility organics. At Hyytiälä, organic condensation dominates the growth process of new particles. The low-volatility SOA contributes to particle growth during the early growth stage, but after a few hours most of the growth is due to semi-volatile SOA. At Finokalia, simulations show that organics have a complementary role in new particle growth, contributing 45% to the total mass of new particles. Condensation of organics increases the number concentration of particles that can act as CCN (cloud condensation nuclei) (N100) by 13% at Finokalia and 25% at Hyytiälä during a typical spring day with nucleation. The sensitivity of our results to the surface tension used is discussed.
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Hu, J. Y., and J. H. Shan. "Control of RO/NF organic fouling by monitoring and modification of organic polarity of feed water." Water Supply 8, no. 4 (October 1, 2008): 467–72. http://dx.doi.org/10.2166/ws.2008.092.
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The organics in surface water and treated wastewater were analyzed for their polarity by a modified natural organic matter polarity rapid assessment method (NOM-PRAM). Selected water samples were then introduced to reverse osmosis (RO) and nanofiltration (NF) membrane system to study the relationship between organics polarity and membrane fouling. Results showed that the more organic fractions with non-polar property, the more serious fouling found for both RO and NF. Pre-treatment with KMnO4 was then conducted to modify the organics polarity in feed water. Under the optimum dosage, where more non-polar organics were converted to polar or negatively charged fractions, the subsequent membrane fouling was found to be reduced.
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Li, Xiaoxiao, Shaojie Song, Wei Zhou, Jiming Hao, Douglas R. Worsnop, and Jingkun Jiang. "Interactions between aerosol organic components and liquid water content during haze episodes in Beijing." Atmospheric Chemistry and Physics 19, no. 19 (October 1, 2019): 12163–74. http://dx.doi.org/10.5194/acp-19-12163-2019.
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Abstract. Aerosol liquid water (ALW) is ubiquitous in ambient aerosol and plays an important role in the formation of both aerosol organics and inorganics. To investigate the interactions between ALW and aerosol organics during haze formation and evolution, ALW was modelled based on long-term measurement of submicron aerosol composition in different seasons in Beijing. ALW contributed by aerosol inorganics (ALWinorg) was modelled by ISORROPIA II, and ALW contributed by organics (ALWorg) was estimated with κ-Köhler theory, where the real-time hygroscopicity parameter of the organics (κorg) was calculated from the real-time organic oxygen-to-carbon ratio (O∕C). Overall particle hygroscopicity (κtotal) was computed by weighting component hygroscopicity parameters based on their volume fractions in the mixture. We found that ALWorg, which is often neglected in traditional ALW modelling, contributes a significant fraction (18 %–32 %) to the total ALW in Beijing. The ALWorg fraction is largest on the cleanest days when both the organic fraction and κorg are relatively high. The large variation in O∕C, from 0.2 to 1.3, indicates the wide variety of organic components. This emphasizes the necessity of using real-time κorg, instead of fixed κorg, to calculate ALWorg in Beijing. The significant variation in κorg (calculated from O∕C), together with highly variable organic or inorganic volume fractions, leads to a wide range of κtotal (between 0.20 and 0.45), which has a great impact on water uptake. The variation in organic O∕C, or derived κorg, was found to be influenced by temperature (T), ALW, and aerosol mass concentrations, among which T and ALW both have promoting effects on O∕C. During high-ALW haze episodes, although the organic fraction decreases rapidly, O∕C and derived κorg increase with the increase in ALW, suggesting the formation of more soluble organics via heterogeneous uptake or aqueous processes. A positive feedback loop is thus formed: during high-ALW episodes, increasing κorg, together with decreasing particle organic fraction (or increasing particle inorganic fraction), increases κtotal, and thus further promotes the ability of particles to uptake water.
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Roelofs, G. J. "A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation." Atmospheric Chemistry and Physics Discussions 7, no. 2 (April 27, 2007): 5675–700. http://dx.doi.org/10.5194/acpd-7-5675-2007.
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Abstract. With the global aerosol-climate model ECHAM5-HAM we investigate the potential influence of organic aerosol originating from the ocean on aerosol mass and chemical composition and the droplet concentration and size of marine clouds. We present sensitivity simulations in which the uptake of organic matter in the marine aerosol is prescribed for each aerosol mode with varying organic mass and mixing state, and with a geographical distribution and seasonality similar to the oceanic emission of dimethyl sulfide. Measurements of aerosol mass and chemical composition serve to evaluate the representativity of the model initializations. Good agreement with the measurements is obtained when organic matter is added to the Aitken, accumulation and coarse modes simultaneously. Representing marine organics in the model leads to higher cloud drop number concentrations, smaller cloud drop effective radii, and a better agreement with remote sensing measurements. The mixing state of the organics and the other aerosol matter, i.e., internal or external depending on the formation process of aerosol organics, is an important factor for this. We estimate that globally about 75 Tg C yr−1 of organic matter from marine origin enters the aerosol phase. An approximate 35% of this occurs through formation of secondary organic aerosol and 65% through emission of primary particles.
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Roelofs, G. J. "A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation." Atmospheric Chemistry and Physics 8, no. 3 (February 13, 2008): 709–19. http://dx.doi.org/10.5194/acp-8-709-2008.
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Abstract. With the global aerosol-climate model ECHAM5-HAM we investigate the potential influence of organic aerosol originating from the ocean on aerosol mass and chemical composition and the droplet concentration and size of marine clouds. We present sensitivity simulations in which the uptake of organic matter in the marine aerosol is prescribed for each aerosol mode with varying organic mass and mixing state, and with a geographical distribution and seasonality similar to the oceanic emission of dimethyl sulfide. Measurements of aerosol mass, aerosol chemical composition and cloud drop effective radius are used to assess the representativity of the model initializations. Good agreement with the measurements is obtained when organic matter is added to the Aitken, accumulation and coarse modes simultaneously. Representing marine organics in the model leads to higher cloud drop number concentrations and thus smaller cloud drop effective radii, and this improves the agreement with measurements. The mixing state of the organics and the other aerosol matter, i.e. internal or external depending on the formation process of aerosol organics, is an important factor for this. We estimate that globally about 75 Tg C yr−1 of organic matter from marine origin enters the aerosol phase, with comparable contributions from primary emissions and secondary organic aerosol formation.
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Wang, J., Y. N. Lee, P. H. Daum, J. Jayne, and M. L. Alexander. "Effects of aerosol organics on cloud condensation nucleus (CCN) concentration and first indirect aerosol effect." Atmospheric Chemistry and Physics 8, no. 21 (November 3, 2008): 6325–39. http://dx.doi.org/10.5194/acp-8-6325-2008.
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Abstract. Aerosol microphysics, chemical composition, and CCN properties were measured on the Department of Energy Gulfstream-1 aircraft during the Marine Stratus/Stratocumulus Experiment (MASE) conducted over the coastal waters between Point Reyes National Seashore and Monterey Bay, California, in July 2005. Aerosols measured during MASE included free tropospheric aerosols, marine boundary layer aerosols, and aerosols with high organic concentration within a thin layer above the cloud. Closure analysis was carried out for all three types of aerosols by comparing the measured CCN concentrations at ~0.2% supersaturation to those predicted based on size distribution and chemical composition using Köhler theory. The effect of aerosol organic species on predicted CCN concentration was examined using a single hygroscopicity parameterization. For aerosols with organics volume fraction up to 70%, such as the marine boundary layer and free troposphere aerosols, CCN concentration and the corresponding first indirect aerosol effect are insensitive to the properties of organics, and can be accurately predicted with a constant hygroscopicity for all organic species. This simplification can facilitate the prediction of indirect aerosol effects using physically-based parameterizations in large scale models. However, for the aerosols within the thin layers above clouds, organics contributed up to 90% of the total aerosol volume, and an accurate knowledge of the overall organic hygroscopicity is required to accurately predict CCN concentrations. Derivations of organic properties in future closure studies, when aerosols are dominated by organic species, would help constrain the descriptions of organics and aerosol-cloud parameterizations in large scale models.
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Duff, Barbara. "639 Organic Alliance." HortScience 34, no. 3 (June 1999): 557F—557. http://dx.doi.org/10.21273/hortsci.34.3.557f.
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Organics is the fastest growing trend in the food industry, increasing at an annual rate of more than 20% per year for the past 7 years. In the upper midwestern United States, a pilot project aimed at increasing the sales of organics in mainstream supermarkets has had an even higher success rate. We'll take a look at how this program was developed and implemented and the ways in which consumers, farmers, and grocers were educated about organic food. We'll discuss trends in organics, what consumers want, and how grocers can best promote organic products and increase their sales.
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Mumma, Michael J. "Organics In Comets." International Astronomical Union Colloquium 161 (January 1997): 121–42. http://dx.doi.org/10.1017/s0252921100014640.
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AbstractThe birth-endowed organic fraction of the newly formed (hot) Earth was destroyed by thermal decomposition during the cooling epoch. After Earth cooled sufficiently, an early organic inventory was likely replenished by the impact of comets and asteroids — a process which continues even today. The present organic composition of comets and asteroids can provide information relevant to this secondary organic seeding of the planets, for comparison with scenarios leading to self-replicating organic entities. Although impacts no longer deliver organics in significant quantities, compared with the existing terrestrial inventory, small bodies can deliver their organics intact to Earth‘s surface while giant impacts may cause punctuated extinction of living species (and create opportunities for renewed speciation). Hence, the exogenous organic flux has great importance for life’s origins and terminations. Current knowledge of the organic composition of comets is reviewed, and recent progress in our understanding of the chemical evolution of organic material from its formation to its incorporation into comets and later into planets is outlined. The need for detailed quantitative chemical analysis of material obtained directly from the cometary nucleus is indicated.
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Gruenheid, S., U. Huebner, and M. Jekel. "Impact of temperature on biodegradation of bulk and trace organics during soil passage in an indirect reuse system." Water Science and Technology 57, no. 7 (April 1, 2008): 987–94. http://dx.doi.org/10.2166/wst.2008.207.
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Investigations on the behavior of bulk organics and trace organic compounds in a temperature controlled soil column system are reported. Objective of the research was to assess the importance of temperature for the degradation of bulk and trace organics. The analysis of the bulk organic behavior showed a fast mineralization of easily degradable organic carbon in the first few centimetres of the columns, which does not seem to be temperature-dependent. Along the further infiltration path an influence of the different temperatures on the bioactivity was clearly visible. However, a significant increase of mineralization potential of bulk organic compounds with increasing temperature was shown. The monitoring of the single organic pollutants Iopromide, Sulfamethoxazole and naphthalenedisulfonic acids showed that temperature has an influence on the degradation behavior of the monitored compounds. In most cases higher temperatures increased the mineralization potential.
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Chung, S. J., S. Balaji, M. Matheswaran, T. Ramesh, and I. S. Moon. "Preliminary studies using hybrid mediated electrochemical oxidation (HMEO) for the removal of persistent organic pollutants (POPs)." Water Science and Technology 55, no. 1-2 (January 1, 2007): 261–66. http://dx.doi.org/10.2166/wst.2007.055.
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This study investigates the hybrid mediated electrochemical oxidation (HMEO) technology, which is a newly developed non thermal electrochemical oxidation process for organic destruction. A combination of ozone and ultrasonication processes to the mediated electrochemical oxidation (MEO) process is termed as hybrid mediated electrochemical oxidation. The electrochemical cell was developed in this laboratory. In the present study, several organic compounds, such as phenol, benzoquinone and ethylenediaminetetraacetic acid (EDTA), were chosen as the model organic pollutants to be destructed by the hybrid process. The organic destruction was monitored based on the CO2 generation and total organic carbon (TOC) reduction. The HMEO process was found to be extremely effective in the destruction of all the target organics chosen in this study. The information obtained from this study will provide an insight in adopting this technique for dealing with more recalcitrant organics (POPs).
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Nairn, Carol, Iván Rodríguez, Yolanda Segura, Raúl Molina, Natalia González-Benítez, Mari Carmen Molina, Raquel Simarro, Juan Antonio Melero, Fernando Martínez, and Daniel Puyol. "Alkalinity, and Not the Oxidation State of the Organic Substrate, Is the Key Factor in Domestic Wastewater Treatment by Mixed Cultures of Purple Phototrophic Bacteria." Resources 9, no. 7 (July 20, 2020): 88. http://dx.doi.org/10.3390/resources9070088.
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Domestic wastewater treatment by purple phototrophic bacteria (PPB) is based on the assimilative uptake of organics and nutrients into the bacterial biomass. Thereby, it strongly depends on the carbon/nutrients ratio of the wastewater. The physiological COD/N/P ratio for PPB growth in domestic wastewater makes the addition of an external organic carbon source necessary in order to allow for an efficient process. However, PPB need a source of alkalinity (as CO2) to grow on reduced organics that serves as an electron acceptor since biohydrogen production (an alternative electron sink) is inhibited by ammonium. A preliminary experiment showed that high nutrients-loading wastewater was limited by CO2 imbalance, leading to poor removal efficiencies. Subsequently, the effect of the oxidation state of the organics added as external organic carbon sources to PPB reactors treating low nutrients-loading domestic wastewater has been analyzed. Three organics were used as additives to PPB development in four consecutive batches: acetate (more oxidized), ethanol and butyrate (more reduced). The PPB population was settled and the general performance under the three situations, in terms of organics, N and P assimilation, and growth kinetics was not significantly different irrespective of the external organic carbon source. The reactors were dominated by PPB, though reduced organics allowed for dominance of Rhodopseudomonas palustris, whereas oxidized organics caused co-dominance of R. palustris and Rhodobacter capsulatus. Thereby, alkalinity (as bicarbonate), and not the oxidation state of the organics, is the key parameter for the efficient treatment of domestic wastewater by PPB.
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Wang, Jian, John E. Shilling, Jiumeng Liu, Alla Zelenyuk, David M. Bell, Markus D. Petters, Ryan Thalman, Fan Mei, Rahul A. Zaveri, and Guangjie Zheng. "Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight, not water solubility." Atmospheric Chemistry and Physics 19, no. 2 (January 24, 2019): 941–54. http://dx.doi.org/10.5194/acp-19-941-2019.
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Abstract. Aerosol particles strongly influence global climate by modifying the properties of clouds. An accurate assessment of the aerosol impact on climate requires knowledge of the concentration of cloud condensation nuclei (CCN), a subset of aerosol particles that can activate and form cloud droplets in the atmosphere. Atmospheric particles typically consist of a myriad of organic species, which frequently dominate the particle composition. As a result, CCN concentration is often a strong function of the hygroscopicity of organics in the particles. Earlier studies showed organic hygroscopicity increases nearly linearly with oxidation level. Such an increase in hygroscopicity is conventionally attributed to higher water solubility for more oxidized organics. By systematically varying the water content of activating droplets, we show that for the majority of secondary organic aerosols (SOAs), essentially all organics are dissolved at the point of droplet activation. Therefore, for droplet activation, the organic hygroscopicity is not limited by solubility but is dictated mainly by the molecular weight of organic species. Instead of increased water solubility as previously thought, the increase in the organic hygroscopicity with oxidation level is largely because (1) SOAs formed from smaller precursor molecules tend to be more oxidized and have lower average molecular weight and (2) during oxidation, fragmentation reactions reduce average organic molecule weight, leading to increased hygroscopicity. A simple model of organic hygroscopicity based on molecular weight, oxidation level, and volatility is developed, and it successfully reproduces the variation in SOA hygroscopicity with oxidation level observed in the laboratory and field studies.
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Hong, Juan, Mikko Äijälä, Silja A. K. Häme, Liqing Hao, Jonathan Duplissy, Liine M. Heikkinen, Wei Nie, et al. "Estimates of the organic aerosol volatility in a boreal forest using two independent methods." Atmospheric Chemistry and Physics 17, no. 6 (March 31, 2017): 4387–99. http://dx.doi.org/10.5194/acp-17-4387-2017.
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Abstract. The volatility distribution of secondary organic aerosols that formed and had undergone aging – i.e., the particle mass fractions of semi-volatile, low-volatility and extremely low volatility organic compounds in the particle phase – was characterized in a boreal forest environment of Hyytiälä, southern Finland. This was done by interpreting field measurements using a volatility tandem differential mobility analyzer (VTDMA) with a kinetic evaporation model. The field measurements were performed during April and May 2014. On average, 40 % of the organics in particles were semi-volatile, 34 % were low-volatility organics and 26 % were extremely low volatility organics. The model was, however, very sensitive to the vaporization enthalpies assumed for the organics (ΔHVAP). The best agreement between the observed and modeled temperature dependence of the evaporation was obtained when effective vaporization enthalpy values of 80 kJ mol−1 were assumed. There are several potential reasons for the low effective enthalpy value, including molecular decomposition or dissociation that might occur in the particle phase upon heating, mixture effects and compound-dependent uncertainties in the mass accommodation coefficient. In addition to the VTDMA-based analysis, semi-volatile and low-volatility organic mass fractions were independently determined by applying positive matrix factorization (PMF) to high-resolution aerosol mass spectrometer (HR-AMS) data. The factor separation was based on the oxygenation levels of organics, specifically the relative abundance of mass ions at m∕z 43 (f43) and m∕z 44 (f44). The mass fractions of these two organic groups were compared against the VTDMA-based results. In general, the best agreement between the VTDMA results and the PMF-derived mass fractions of organics was obtained when ΔHVAP = 80 kJ mol−1 was set for all organic groups in the model, with a linear correlation coefficient of around 0.4. However, this still indicates that only about 16 % (R2) of the variation can be explained by the linear regression between the results from these two methods. The prospect of determining of extremely low volatility organic aerosols (ELVOAs) from AMS data using the PMF analysis should be assessed in future studies.
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Zander, Katrin, Susanne Padel, and Raffaele Zanoli. "EU organic logo and its perception by consumers." British Food Journal 117, no. 5 (May 5, 2015): 1506–26. http://dx.doi.org/10.1108/bfj-08-2014-0298.
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Purpose – With the introduction of the mandatory European Union (EU) organic logo for all organic food products in 2010, the European Commission aimed at fostering the internal organic food market. This needs consumers’ knowledge of the logo. According to earlier research consumers’ knowledge of the EU organic logo is low. Thus, the purpose of this paper is to elicit consumers’ attitudes towards organic certification and labelling and to develop recommendations on how to improve consumers’ knowledge of the EU organic logo. Design/methodology/approach – By means of an online survey with 3,000 participants in six European countries, knowledge of the logo and attitudes towards organic farming and European labelling, as well as organic food purchase behaviour and socio-demographic indicators were elicited. Factor and cluster analysis based on several statements on the test persons’ attitudes towards organic farming and corresponding EU legislation were conducted in order to segment consumers. Findings – The results indicate that knowledge of the logo is low. Only about 15 per cent of all respondents knew its meaning. Four clusters of consumers could be identified: “Committed organics”, “Pragmatic organics”, “Organic sceptics” and Organic disinterested’. With reference to the EU organic legislation’s aim of promoting the organic market, particularly “Organic sceptics” should be addressed by emphasising the trustworthiness of the organic certification and labelling system. Originality/value – Segmenting consumers according to their attitude towards organic farming, its labelling and certification allows for targeted and efficient communication and organic market development.
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Fuentes, E., H. Coe, D. Green, and G. McFiggans. "On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity." Atmospheric Chemistry and Physics 11, no. 6 (March 18, 2011): 2585–602. http://dx.doi.org/10.5194/acp-11-2585-2011.
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Abstract. The effect of nanogel colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator. The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 8–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN) activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics. The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles was found to correlate with the seawater organic concentration, without observing saturation of the particle organic mass fraction even for unrealistically high organic matter concentration in seawater. These findings are indicative that discrepancies on the composition of the primary aerosol between different studies could partly be explained by the difference in the nature and concentration of the organic matter in the source seawater employed. Consistently across the experiments, theoretical analysis based on the Köhler model predicted a reduction in the primary marine aerosol CCN activity upon the incorporation of marine organics into the particle composition. This effect is consequence of the replacement of small inorganic sea salt molecules by large molar mass organic molecules, together with a moderate suppression of the surface tension at the point of activation of 5–0.5%, which leads to a dominance of the reduction in the dissolved solute in the Raoult term.
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Pozzer, Andrea, Simon F. Reifenberg, Vinod Kumar, Bruno Franco, Matthias Kohl, Domenico Taraborrelli, Sergey Gromov, et al. "Simulation of organics in the atmosphere: evaluation of EMACv2.54 with the Mainz Organic Mechanism (MOM) coupled to the ORACLE (v1.0) submodel." Geoscientific Model Development 15, no. 6 (April 1, 2022): 2673–710. http://dx.doi.org/10.5194/gmd-15-2673-2022.
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Abstract. An updated and expanded representation of organics in the chemistry general circulation model EMAC (ECHAM5/MESSy for Atmospheric Chemistry) has been evaluated. First, the comprehensive Mainz Organic Mechanism (MOM) in the submodel MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) was activated with explicit degradation of organic species up to five carbon atoms and a simplified mechanism for larger molecules. Second, the ORACLE submodel (version 1.0) now considers condensation on aerosols for all organics in the mechanism. Parameterizations for aerosol yields are used only for the lumped species that are not included in the explicit mechanism. The simultaneous usage of MOM and ORACLE allows an efficient estimation of not only the chemical degradation of the simulated volatile organic compounds but also the contribution of organics to the growth and fate of (organic) aerosol, with the complexity of the mechanism largely increased compared to EMAC simulations with more simplified chemistry. The model evaluation presented here reveals that the OH concentration is reproduced well globally, whereas significant biases for observed oxygenated organics are present. We also investigate the general properties of the aerosols and their composition, showing that the more sophisticated and process-oriented secondary aerosol formation does not degrade the good agreement of previous model configurations with observations at the surface, allowing further research in the field of gas–aerosol interactions.
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Feenstra, Stan. "Screening / Indicator Parameters for Organic Contaminants in Groundwater." Water Quality Research Journal 22, no. 1 (February 1, 1987): 73–84. http://dx.doi.org/10.2166/wqrj.1987.006.
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Abstract Parameters such as total organic carbon (TOC), chemical oxygen demand (COD), oil and grease, total kjeldahl nitrogen (TKN), Microtox Toxicity, total phenolics, total organic halogen (TOX), total aromatic hydrocarbons (TAH), total chromatographable organics (TCO) and total volatile organics (TVO) have been used as screening/indicator parameters for the monitoring of organic contaminants in groundwater. The suitability of these various parameters will depend on the selectivity of the analysis method to the organic contaminants of interest, the detection limit of the method relative to the concentrations of interest, the background concentrations of the screening/indicator parameters in the groundwater and any analytical interferences. There are no screening/indicator parameters currently available which are suitable for all situations in which toxic organic contaminants are of concern at sub-milligram per litre concentrations. Suitable screening/indicator parameters must be selected on a case-by-case basis depending on the organic contaminants of interest, the concentrations at which they are a concern, and the presence of any interferences. However, in general, because the organic contaminants which are most frequently of concern in groundwater are chlorinated compounds, total organic halogen (TOX) will likely be the most commonly applicable screening/indicator parameter.
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Yoon, J., S. Cho, Y. Cho, and S. Kim. "The characteristics of coagulation of fenton reaction in the removal of landfill leachate organics." Water Science and Technology 38, no. 2 (July 1, 1998): 209–14. http://dx.doi.org/10.2166/wst.1998.0141.
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The need to improve the Fenton process, which is one of the leachate treatment trains at Metropolitan Landfill in Korea was raised. This study was intended to compare the Fenton reaction with coagulation in removing landfill leachate organics of specific size. The organics fractionated by ultrafiltration and measured by TOC, were selected for evaluating the characteristics of the removal of organics. From this study it was found that the organic removal pattern in the Fenton reaction was quite similar to coagulation. Both reactions removed large leachate organics more readily and selectively. For example, coagulation removed 59~73% of organics larger than molecular weight (MW) of 500 and only up to 18% of organics less than MW of 500. On the other hand, the Fenton process removed 72-89% of organics larger than MW of 500 and only up to 43% of organics less than MW of 500. It was interpreted that the coagulation step in the Fenton process had a primary role in selective removal of leachate organics, though the Fenton reaction is not coagulation. However, since the efficiency of organic removal in the Fenton reaction was higher than coagulation, the Fenton process in Metropolitan Landfill leachate treatment process may be called “a type of enhanced coagulation”.
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Oh, S. E., M. S. Bum, Y. B. Yoo, A. Zubair, and I. S. Kim. "Nitrate removal by simultaneous sulfur utilizing autotrophic and heterotrophic denitrification under different organics and alkalinity conditions: batch experiments." Water Science and Technology 47, no. 1 (January 1, 2003): 237–44. http://dx.doi.org/10.2166/wst.2003.0061.
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The effect of various organic compounds were tested using lab-scale batch reactors. At sufficient alkalinity, the initial nitrate nitrogen concentration of 100 mg/L was completely reduced in all batch reactors. Sulfate production decreased by the addition of organics. The concentration range of organics used in this experiment did not inhibit autotrophic denitrification except for propionate. Propionate inhibited autotrophic denitrification a little, indicated by a lower sulfate production rate. Biomass in suspension increased with higher initial organic concentrations, showing higher DOC consumption. As the concentration of organics increased, alkalinity increased accordingly. Under the conditions of low alkalinity, in the case of a control reactor without organics, only about 30% of the initial nitrate was reduced. With half the theoretically required dosage of methanol, the denitrification rates increased slightly. When ethanol, acetate, and propionate were used, denitrification went to completion. When excess organics was added, however, sulfate production was significantly decreased. Interestingly, even when small amounts of organics were added, autotrophic denitrification was promoted as indicated by the sulfate production.
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Zheng, Guangjie, Chongai Kuang, Janek Uin, Thomas Watson, and Jian Wang. "Large contribution of organics to condensational growth and formation of cloud condensation nuclei (CCN) in the remote marine boundary layer." Atmospheric Chemistry and Physics 20, no. 21 (November 1, 2020): 12515–25. http://dx.doi.org/10.5194/acp-20-12515-2020.
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Abstract. Marine low clouds strongly influence global climate, and their radiative effects are particularly susceptible to the concentration of cloud condensation nuclei (CCN). One major source of CCN is the condensational growth of pre-CCN particles, and sulfate has long been considered the major condensing species in the remote marine boundary layer. While some studies have suggested that secondary organic species can contribute to particle growth, its importance remains unclear. Here we present the first long-term observational evidence that organics play an important role in particle growth over remote oceans. To the contrary of traditional thinking, sulfate dominated condensational growth for only a small (∼18 %) fraction of the 62 observed growth events, even fewer than the organic-dominated events (24 %). During most (58 %) growth events, the major condensing species included both organics and sulfate. Potential precursors of the secondary organics are volatile organic compounds from ocean biological activities and those produced by the air–sea interfacial oxidation. Our results indicate that the condensation of secondary organics contributes strongly to the growth of pre-CCN particles and thereby the CCN population over remote oceans.
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Wang, Shutao, Xingwen Zhang, Zhi-Wu Wang, Xiangkun Li, and Jun Ma. "In-depth characterization of secondary effluent from a municipal wastewater treatment plant located in Northern China for advanced treatment." Water Science and Technology 69, no. 7 (January 25, 2014): 1482–88. http://dx.doi.org/10.2166/wst.2014.040.
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This study provided insight into the characterization of secondary effluent from a wastewater treatment plant located in northeastern China. The secondary effluent was separated into three fractions, the dissolved, the near-colloidal and the suspended, to study their individual characteristics. It revealed that most of the organics in the secondary effluent existed in the dissolved form, accounting for 78.1–86.5% of the total chemical oxygen demand and 82.6–86.6% of the total organic carbon. Results from the molecular weight distribution study further indicated that organics with MW < 1k Da constituted 56.3–62.7% of total organics. Moreover, the particle size distribution study suggested that particles between 2.0 and 6.8 μm in diameter made up 80.0% of the total suspended solids. Both biological oxygen demand/chemical oxygen demand and biological dissolved organic carbon/dissolved organic carbon were measured ranging from 0.2 to 0.3, suggesting the most secondary effluent organics were biologically refractory. This conclusion was further strengthened by the functional groups information obtained from the GC/MS (gas chromatography/mass spectrometry) analysis. The characteristics information revealed from this study will help the design and selection of water quality-specific tertiary treatment technologies for secondary effluent water purification and reuse.
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Ye, Lin, Nirmala N. Khandan, and Findlay G. Edwards. "Biological treatment of airstreams contaminated with organic vapors." Water Science and Technology 30, no. 7 (October 1, 1994): 71–74. http://dx.doi.org/10.2166/wst.1994.0311.
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Increases in regulatory control of discharges of organic vapors require improvement of traditional methods of removal and treatment of organic vapors from airstreams. The traditional methods of removal, various forms of adsorption, only change the phase of the pollutants. Subsequent treatment of the pollutants has proven to be energy intensive and therefore expensive. Biological treatment of organics has proven to be inexpensive but requires that the organics be in dissolved form, in the liquid phase, and at a concentration above a minimum concentration. Adsorption of organics in the gas phase onto activated carbon, which is suspended in water, will remove the pollutants from the gas phase and can increase the aqueous concentration, in the region around each activated carbon particle, above the required minimum for biological degradation. The organic pollutants can then be biodegraded leaving harmless by-products. Design of a reactor to provide for the phase change and the biodegradation of the pollutant requires development of a theoretical model and validation of the model.