Academic literature on the topic 'Phytodepuration'

The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls.

Wastewaters generated by the pyrolytic process require treatments to reduce the risks of contamination in rivers, lakes, and coastal waters. Utilizing constructed wetlands is one of the possible approaches according to a Circular Economy System. Plant Growth-Promoting Bacteria (PGPB) and Arbuscular Mycorrhizal Fungi (AMF) can improve plant growth and enhance the bioremediation of wastewater. Two experiments were set up: in the first, a pilot mesocosm was designed to evaluate the effects of a consortium of AM fungi and a PGPB strain on Phragmites australis. After 60 days, the highest plant growth was obtained after inoculation with the combination of microorganisms. In the second experiment, a constructed wetland was built to remediate wastewaters from gasification plant. The plants were efficient in scavenging biological oxygen demand (BOD5), chemical oxygen demand (COD), total fat and oils, hydrocarbons, phenols, aldehydes, surfactants, fluorides, sulfites, sulfates, nitrate, and phosphorus. These data suggest that inoculation of P. australis with AMF and PGPB strains significantly improve the depuration process of wastewaters from gasification plants via constructed wetlands.

Water pollution by excessive amounts of nitrate (NO3−) has become a global issue. Technologies to clean up nitrate-contaminated water bodies include phytoremediation. In this context, this research aimed to evaluate four tree species (Salix alba L., Populus alba L., Corylus avellana L. and Sambucus nigra L.) to remediate nitrate-contaminated waters (100 and 300 mg L−1). Some physiological parameters showed that S. alba L. and P. alba L. increased particularly photosynthetic activity, chlorophyll content, dry weight, and transpired water, following the treatments with the above NO3− concentrations. Furthermore, these species were more efficient than the others studied in the phytodepuration of water contaminated by the two NO3− levels. In particular, within 15 days of treatment, S. alba L. and P. alba L. removed nitrate quantities ranging from 39 to 78%. Differently, C. avellana L. and S. nigra L. did not show particular responses regarding the physiological traits studied. Nonetheless, these species removed up to 30% of nitrate from water. In conclusion, these data provide exciting indications on the chance of using S. alba L. and P. alba L. to populate buffer strips to avoid NO3− environmental dispersion in agricultural areas.

It was evaluated the feasibility of growing lettuce intercropped with Nile tilapia farming in a hydroponic system and the efficiency upon the improvement of the quality of the effluent. The experimental structure was composed of one module for fish production and other for plant production in the hydroponic system. It was used production technique NFT (Nutrient Film Technique), and the nutrient solution used was the effluent of fish farming. It was used a randomized block experimental design with four treatments and three replications, considering each repetition an 8-day cycle in hydroponics. The treatments were: 20; 40, 60 and 80 plants for the first, second, third and fourth treatments, respectively. Electrical conductivity, pH, temperature and dissolved oxygen did not change (P>0.05) in relation to the input effluent and they were not affected (P>0.05) by the number of plants. We observed a linear effect of number of plants on the parameters orthophosphate and nitrite, ie the higher the number the greater the removal of plants for these parameters in the water. The percentage of nitrogen in leaves and roots of lettuce was not influenced by the number of plants. There was a linear effect of the number of plants on the accumulation in lettuce leaves parameters dry matter, nitrogen and phosphorus. There was a linear effect of the number of plants on the accumulation of dry matter and phosphorus and quadratic effect on nitrogen accumulation in roots of lettuce.There is a technical feasibility of integrating the intensive Nile tilapia farming in a closed system of recirculating water in the production of hydroponic lettuce, with nutrients remotion such as nitrogen and phosphorus from the effluents and their incorporation in leaves and roots of lettuce.

The intensification of Italian pig breeding over the years has resulted in high livestock concentrations in some parts of the country, especially in the north, increasing environmental pollutions threats. The potential environmental hazards caused by these activities regard surface water or groundwater eutrophication, emission of ammonia with consequent problems of acid deposition due to rainfall, other gases, odours, and accumulation risk of heavy metals and salts in agricultural soils. In addition, the proliferation over time of biogas plants in the livestock and agricultural field has led to a rapid and significant increase in the digestate quantities produced. The wastewaters from these activities are distributed on fields according to the European Directive (91/676 EC), which often results in an increase in the demand for available surfaces for the distribution of the effluent. However, when the land for spreading is not sufficient, other solutions must be found, that breeders solve by relocating the wastewater in other areas, incurring high transport costs. In recent years phytodepuration has proved to be of substantial interest as a system for the treatment of animal wastewater liquid fraction, representing a valid solution for its disposal when the surface area is not adequate. This work examined phytodepuration intensified systems for the treatment of agricultural and livestock wastewaters, based on low-cost solutions and reduction of the area required for treatment. The research concerned in particular the study of pilot filter systems using recycled and sustainable materials for the pretreatment of piggery wastewater and digestate, in order to purify wastewater for the phytodepuration treatment. A vertically arranged phytodepuration system was also investigated, where both wetland and halophytic plant species have been tested for the treatment of piggery wastewater. Lastly, a secondary part of this research was devoted to the hydraulics study of filters used for phosphorus treatment, and to the growth of algae on pretreated piggery wastewater to analyze the chemical removal and possible accumulation of astaxanthin. The pretreatment systems proved to be suitable for digestate and piggery wastewater depuration, with higher removal for NH4-N, COD and total N than other chemicals. The phytodepuration highlighted the potential of several plants and the weaknesses of others for the treatment of piggery wastewater, showing highest concentration abatements of NH4-N (69-99%) and lower abatements of the other chemicals.
Il processo di intensificazione dell’allevamento suino in Italia ha portato negli anni ad un alta concentrazione di animali in alcune parti del paese, specialmente al nord, accrescendo i rischi di inquinamento ambientale. I potenziali danni sull’ambiente causati da queste attività riguardano l’eutrofizzazione delle acque superficiali e sotterranee, le emissioni di ammoniaca con conseguenti problemi di deposizioni acide in seguito a precipitazioni e di altri gas, gli odori, e il rischio di accumulo di metalli pesanti e di sali nei suoli agricoli. Inoltre la forte crescita negli ultimi anni del biogas nel settore agro-zootecnico ha generato un altrettanto rapido ed importante incremento dei quantitativi di digestato prodotto. I reflui derivanti da queste attività devono distribuiti secondo la normativa italiana (Direttiva CE 91/676), che si traduce spesso in un aumento della richiesta di superfici disponibili per la distribuzione dei reflui. Tuttavia, quando la superficie per lo spandimento è insufficiente, c’è la necessità di trovare altre soluzioni, che l’allevatore ovvia delocalizzando i reflui in altri terreni, sostenendo costi di trasporto non esigui. In questi ultimi anni la fitodepurazione si è rivelata di considerevole interesse come sistema di trattamento della frazione liquida dei reflui animali, rappresentando una valida soluzione per il loro smaltimento quando la superficie è insufficiente. Questo lavoro ha esaminato sistemi intensivi di fitodepurazione per il trattamento di reflui agro-zootecnici, basati sull’economicità e sulla riduzione della superficie per la depurazione. La ricerca ha riguardato principalmente lo studio di sistemi pilota filtranti per il pretrattamento di refluo suino e digestato, allo scopo di depurare il refluo prima del trattamento di fitodepurazione, in cui sono utilizzati materiali sostenibili e di scarto. Inoltre è stato investigato un sistema di fitodepurazione sviluppato verticalmente, ove sono state testate diverse specie vegetali per il trattamento del refluo suino. Infine, una minor parte della ricerca è stata dedicata allo studio dell’idraulica di filtri, usati per il trattamento del fosforo,e alla crescita di alghe su refluo suino pretrattato per analizzare la rimozione chimica e l’eventuale accumulo di astaxantina. I sistemi di pretrattamento si sono rivelati abili nella depurazione del digestato e del refluo suino, con maggiori abbattimenti per N-NH4, COD e TN, rispetto agli altri composti chimici. La fitodepurazione ha risaltato le potenzialità di alcune piante e le debolezze di altre per il trattamento del refluo suino, mostrando i maggiori abbattimenti di concentrazione per N-NH4 (69-99%) e più bassi per gli altri parametri chimici.

Water scarcity is one of the major worldwide problems affecting in particular agriculture, an intensive water consumer activity. In the frame of the EU H2020 MADFORWATER project, aimed to develop integrated technological and management solutions to reduce water footprint in agriculture, this PhD thesis focused on plant-associated bacteria to improve the productivity of crops growing under drought conditions and wastewater phytodepuration efficiency to allow water reuse for irrigation purposes. A large collection of 681 bacterial strains was isolated from the root apparatus of six plants species adapted to dry soils or other unconventional environmental conditions. The isolates have been taxonomically identified and functionally characterized in order to select the most promising strains exploitable in in vivo experimentations. The isolate collection was compared with a literature-derived dataset of bacterial families identified in the plant microbiome by molecular methods. The comparison demonstrated that we were able to bring into culture members of 20% of the bacterial families detected by culture-independent approaches, partially confirming on the plant biome recent concepts emerged on others environmental microbiota. Moreover, the collection included ubiquitous and potentially beneficial core members of the plant microbiota and satellite taxa, which could have a role in sustaining plant growth under peculiar environmental conditions. The bacterial community associated to Argania spinosa, a drought tolerant tree relevant for the ecology and economy of Morocco, was described for the first time, by culture dependent and independent approaches. The Plant Growth Promoting (PGP) potential of isolates obtained from the root and soil environment of Argan revealed a particular abundance of PGP related traits in strains isolated from the residuesphere fraction, providing a putative explanation to the tradition of local farmers of using argan litter as soil amendment. A selection of strains was tested in in vivo experiments aimed to evaluate their potential to improve plant growth, water use efficiency and fruit productivity. Five PGP bacteria were applied on tomato plants, cultivated in greenhouse under optimal and deficit irrigation and plant physiology, biomass and fruit yield were compared with control, not bacterized plants. All the bacterial inocula showed at different extent to have the potential capacity to alleviate plant water stress, improving different plant and soil parameters, but no statistically significant effect was reported on plant productivity. Further experiments are needed to confirm the results, nevertheless it was demonstrated the importance of performing long-term experiments to obtain reliable and applicable data about the real efficacy of PGP crop application. A second selection of PGP strains significantly showed in microcosm constructed wetlands the ability to tolerate metal contaminated wastewaters and to enhance the azo-dye phytodepuration capacity of Juncus acutus plants. These bacteria have thus the potential to improve the quality of water treated in low cost systems, and will be selected in the project for experimentation at higher pilot scale. This work demonstrated the relevance of the plant microbiota in sustaining plant growth, and provided a collection of strains which need to be further evaluated but could potentially be exploited to mitigate water shortage effects in agriculture.

In in contesto di carenza idrica e di inquinamento delle acque superficiali causato dalle attività agricole, devono essere identificate nuove pratiche di gestione delle risorse idriche che rispondano a queste problematiche e possano essere utilizzate in diversi ambienti. Il bacino idrografico della Laguna di Venezia (nell'Italia nord-orientale) è un'area sensibile all'inquinamento delle acque superficiali. La prevalenza di terreni pianeggianti e la presenza di una falda freatica superficiale, tuttavia, suggeriscono condizioni idonee per la realizzazione di due pratiche di gestione idrica per la riduzione dei carichi di N e P provenienti dalle aree agricole: il drenaggio controllato (controlled drainage: CD) e le wetland artificiali a flusso superficiale (surface flow constructed wetlands: SFCWs). Il monitoraggio di lungo periodo delle performance di queste pratiche è necessario per fornire risultati di validità generale, che non siano condizionati dalla variabilità meteorologica annuale. Questo lavoro valuta le performance di un sistema di CD e di SFCW in un esperimento di lungo periodo. Il CD è stato monitorato durante i periodi 1995-2002 e 2006-2013, in termini di bilancio idrico e di resa delle colture, e dal 2007 al 2013 anche per le perdite di N e P. La SFCW è stata monitorata dal 2007 al 2013 per la riduzione dei carichi di N e P. Il CD ha permesso di ridurre i deflussi idrici del 69% e ha determinato un aumento complessivo della resa di granella di mais del 26,3%, e della resa di mais da insilato del 4,0%. Le perdite di NO3-N e PO4-P nelle acque superficiali sono state ridotte rispettivamente del 92% e del 65%. La SFCW ha mostrato tassi di rimozione annui apparenti dell'83% e del 79% rispettivamente per NO3-N e N totale, e del 48% e del 67% rispettivamente per PO4-P e P totale. Sia il CD che la SFCW si sono rivelati efficaci nel ridurre i carichi inquinanti di N e P, ed il CD ha anche contribuito ad aumentare la resa delle colture attraverso il risparmio idrico. Per questi motivi, l'applicazione di queste due pratiche di gestione idrica è da prendersi in considerazione in questo ambiente.
In the context of increasing water scarcity and surface water pollution caused by agricultural activities, new water management practices that tackle these issues and that could be used in different environments should be identified. The Venice Lagoon drainage basin (in north-eastern Italy) is a sensitive area to surface water pollution. The prevalence of flat lands and the presence of shallow phreatic groundwaters, however, create suitable conditions for the implementation of two water management practices that can reduce N and P loads coming from agricultural fields: controlled drainage (CD) and surface flow constructed wetlands (SFCWs). Long-term monitoring of the performances of these practices is required to provide sound results that are not contingent on annual weather variability. This work evaluates the performances of a CD and SFCW system in a long-term experiment. CD was monitored during the periods 1995-2002 and 2006-2013 for water balance and crop yield, and from 2007 to 2013 for N and P losses. The SFCW was monitored from 2007 to 2013 for N and P removal loads. CD permitted to reduce water outflows of 69%, and provided an overall increase in maize grain yield of 26.3% and in silage maize yield of 4.0%. NO3-N and PO4-P losses to surface waters were reduced by 92% and 65%, respectively. The SFCW showed annual apparent removal rates of 83% and 79% respectively for NO3-N and total N, and of 48% and 67% respectively for PO4-P and total P. Both CD and SFCW proved effective in reducing N and P loads, and CD helped increasing crop yield through water saving. For these reasons, the application of these two water management practices is advisable in this environment.

The scarcity of resources in recent decades has increased the search for new alternative and renewable forms of energy to fossil fuels. However, this transition must be carried out to achieve a more diversified energy system based on sustainability and environmental protection. In recent years, hydrothermal carbon-ization (HTC) has been considered an alternative process for processing value added products. This alter-native method is a thermochemical process that converts high moisture organic feedstock into carbon rich solids. However, during this process toxic organic and inorganic compounds present in the feedstock, such as hydrocarbons, are leached to a liquid phase that needs to be depurated. Phytodepuration is a technology based on the use of plants in the remediation of contaminated effluents, thus it’s a sustainable option that allows to simultaneously clean the contaminated waters obtained in the hydrothermal carbonization process and produce biomass that can be used in multiple applications. Camelina sativa is an energy crop that has the potential to produce biofuels, as well as, value added products from its oil. Several studies have shown that energy crops are tolerant to irrigation with contaminated waters. In this work we evaluated the phy-todepuration capacity of Camelina sativa (winter and spring varieties) when subjected to the irrigation of contaminated effluents obtained in hydrothermal carbonization process, as well as, the productivity and quality of biomass. The hydrothermal carbonization effluent (HTC) used in this study (360 mg / L O2) was diluted 1:3 (WW1: 120 mg / L O2), 1:2.4 (WW2: 150 mg / L O2) and 1:2 (WW3: 180 mg / L O2) to obtain the chemical oxygen demand (CDO) equal to 0.8, 1.0 and 1.2 times the limit value for wastewater dis-charges established by Decree Law 236/98. Also, the pots were irrigated with tap water as a control treat-ment. The results obtained led to the conclusion that the soil-biomass system was able to depurate the contaminated waters from the HTC process, decreasing by circa 63-72% for WW1, 69-75% for WW2 and 68-76% for WW3 the initial oxidability values and thus, avoiding the contamination of groundwater. Re-garding biomass productivity, it’s was concluded that the winter variety of Camelina sativa was the least affected by the contaminated waters of the HTC effluent. In addition, the winter variety obtained the highest productivity, namely in the aboveground and siliquae yields (loss of siliquae yield: 9-45% for the winter variety; 11-67% for the spring variety). Ash, nitrogen, metals and phosphorus content in the plant were also affected by the contaminated effluents from the HTC process.