Littérature scientifique sur le sujet « PH sesnor »

Large quantities of seston are among the most important indicators of eutrophication in aquatic ecosystems. The present study aimed to elucidate the role seston plays in the general limnological dynamics of a cluster of eighteen tropical karstic lakes with different anthropic impacts (non-impacted, oligotrophic, clear-water lakes, and impacted, eutrophic, turbid-water lakes) of the “Lagunas de Montebello” National Park lake district. The seston concentration was measured twice, in the warm/rainy and the cold/dry season. Vertical profiles of temperature, dissolved oxygen, electrical conductivity, pH, and photosynthetic active radiation (PAR) were recorded at each lake. Water samples were taken along the water column to evaluate seston and chlorophyll a (Chl-a) concentration. Impacted lakes displayed higher seston (4.1-21.0 mg/L) and Chl-a (8.1-129.8 μg/L) concentrations, reduced euphotic zone (ZEU = 2.6-6.3 m), and superficial thermo- (gradient = 0.8 ± 0.2 °C/m) and oxyclines (gradient = 4.7 ± 2.4 mg DO/m). Non-impacted lakes had lower seston (1.0-2.1 mg/L) and Chl-a (0.4-5.2 μg/L) concentrations, wide ZEU (10.1-33.4 m), and deeper thermo- (gradient = 0.5 ± 0.1 °C/m) and oxyclines (gradient = 0.6 ± 0.4 mg DO/m). The changes reported in impacted lakes linked with the increase in the seston and Chl-a concentrations are most likely related to the eutrophication process asso¬ciated with anthropogenic activities (agriculture, urban development, land-use change) in the NW part of the area. This research highlights the fragility of the tropical karst lake ecosystems worth protecting to preserve the aquatic ecosystem’s health.

Daerah penelitian secara administratif berada pada Desa Jepitu, Desa Karangawen, Desa Tileng, Desa Balong, Desa Purwodadi, dan Desa Tepus, Kecamatan Girisubo, Kabupaten Gunungkidul, Provinsi Daerah Istimewa Yogyakarta. Metode yang digunakan dalam penelitian ini terdiri atas pemetaan geologi permukaan, Measuring Section (MS), pemetaan hidrogeologi, dan pengambilan conto batuan serta air tanah. Arah aliran air bawah tanah sepanjang teluk Wediombo dipengaruhi oleh sesar mendatar orde 1, dengan arah aliran yang berarah tenggara pada sisi barat dan berarah barat daya pada sisi timur. Pada bagian tengah, arah aliran air bawah tanah ke selatan dipengaruhi oleh sesar orde 2 (Sesar Pokgunung). Batugamping memengaruhi tingginya unsur Ca2+, HCO3-, dan CO32- pada air tanah. Lava lapuk (teralterasi) memengaruhi tingginya unsur Mg2+, Na+, K+, dan Cl- pada air tanah. Kontak breksi-batugamping memengaruhi tingginya unsur Mg2+, Na+, dan Cl- pada air tanah. Batugamping memengaruhi tingginya nilai daya hantar listrik, dan kekeruhan, serta dicirikan dengan debit yang tinggi. Lava segar dan kontak breksi-batugamping memengaruhi rendahnya nilai pH air tanah

<p>Reduksi ketersediaan energi konvensional menuntut pengembangan energi alternatif, salah satunya panas bumi. Danau Ranau memiliki potensi panas bumi direpresentasikan dengan manifestasi mata air panas di permukaan. Sasaran identifikasi awal potensi panas bumi terkait asosiasinya dengan struktur rekahan dan patahan. Observasi ini dikembangkan dengan studi pustaka, penginderaan jauh dengan pendekatan melalui satelit citra, survei manifestasi, dan analisis studio. Berdasarkan analisis ini didapati pola kelurusan dominan barat laut – tenggara dan dipengaruhi oleh gaya kompresi dengan arah relatif utara – selatan. Pola kelurusan ini berasosiasi dengan struktur geologi sebagai <em>play zone </em>dari reservoir <em>geothermal</em>. Tipe kelurusan juga diinterpretasikan bahwa Danau Ranau merupakan <em>discharge zone </em>yang dihasilkan oleh sesar mendatar yaitu Sesar Kumering dengan pola serupa Sesar Semangko. Hasil survei permukaan ditemukan dua lokasi manifestasi Air Panas Ranau (APR) dan Air Panas Lumbok (APL). Lokasi APR ditemukan dua titik manifestasi dengan suhu sekitar 54^oC dan 60^oC, kadar pH netral, dan litologi penyusun batuan sampingnya berupa endapan piroklastik yaitu <em>welded tuff </em>dan batuan beku andesit. Pada APL terdapat dua titik manifestasi air panas dengan suhu sekitar 45^oC hingga 59^oC dengan pH relatif netral. Potensi energi sekitar 37 Mwe diduga terdapat pada reservoir panas bumi pada daerah Danau Ranau</p>

Daerah panasbumi “Z” dalam tatanan tektoniknya termasuk pada jalur back-arc Sumatera, tepat pada salah satu segmen sesar Sumatera bagian selatan, disusun oleh batuan vulkanik dan sedimen klastik yang berumur Tersier hingga Kuarter (Andesit-Basalt). Gejala adanya potensi sistem panasbumi pada daerah penelitian ditandai dengan kemunculan manifestasi permukaan berupa alterasi dan lima mata air panas bersuhu 44,4 – 92,5 oC dan pH antara 8,19 – 9,43. Pengolahan Data gravitasi menggunakan teknik pemisahan Complete Bouguer Anomali (CBA), filtering First Horizontal Derivative (FHD) dan filtering Second Vertical Derivative (SVD) untuk mengetahui kemungkinan lokasi sumber panas dan letak bidang kontak terjadinya anomali serta jenis sesarnya. Berdasarkan slicing lintasan FHD dan SVD, struktur pada peta geologi didominasi oleh sesar naik dan sesar normal yang bersifat regional, serta struktur dengan kompleksitas tinggi yang bersifat lokal. Kemunculan manifestasi permukaan sistem panasbumi berada disekitar nilai anomali residual gravitasi tinggi (8 – 24 mgal) yang mengindikasikan terdapatnya batuan yang kompak dan massif. Diperkirakan sistem panasbumi daerah penelitian termasuk jenis tektonik fracture zone serta anomali tinggi yang berada di sekitar APZ1-APZ2-APZ3 tersebut terdapat batuan intrusi yang berperan penting sebagai sumber panas.

Pada pemeliharaan ikan didalam akuarium membutuhkan perawatan guna menjaga kelangsungan hidup ikan dan vegetasi air yang terdapat didalamnya. Selain rutinitas pemberian pakan, nilai parameter lingkungan akuarium juga perlu selalu diawasi dan dijaga pada rentang tertentu. Tujuan utama yang ingin dicapai untuk memonitoring pH dan kekeruhan pada akuarium sehingga kualitas air akuarium bisa terjaga. pH yang baik untuk ikan hias di akuarium yaitu lebih dari 7 dan kurang dari 8, kemudian kekeruhan yang baik untuk ikan hias di akuarium yaitu dibawah 25 ntu. Pada penelitian ini menggunakan mikrokontroler NodeMCU ESP32 digunakan sebagai pusat kendali sistem, kemudian sensor pH untuk mendeteksi nilai pH air, kem Pada pemeliharaan ikan didalam akuarium membutuhkan perawatan guna menjaga kelangsungan hidup ikan dan vegetasi air yang terdapat didalamnya. Selain rutinitas pemberian pakan, nilai parameter lingkungan akuarium juga perlu selalu diawasi dan dijaga pada rentang tertentu. Tujuan utama yang ingin dicapai untuk memonitoring pH dan kekeruhan pada akuarium sehingga kualitas air akuarium bisa terjaga. pH yang baik untuk ikan hias di akuarium yaitu lebih dari 7 dan kurang dari 8, kemudian kekeruhan yang baik untuk ikan hias di akuarium yaitu dibawah 25 ntu. Pada penelitian ini menggunakan mikrokontroler NodeMCU ESP32 digunakan sebagai pusat kendali sistem, kemudian sensor pH untuk mendeteksi nilai pH air, kemudian sensor turbidity untuk mendeteksi nilai kekeruhan air, kemudian Buzzer berfungsi sebagai alarm dan yang terakhir LCD berfungsi untuk menampilkan hasil dari pembacaan sensor tersebut. Pada penelitian ini metode yang digunakan yaitu metode regresi linear untuk mengetahui keakuratan dari pembacaan sensor pH. Pada penelitian ini terdapat pengujian sensor turbidity untuk menguji hasil sensor, pengujian sensor pH untuk menguji nilai ADC / tegangan output dan akurasi sesnsor pH, Pengujian regresi linear pada sensor pH dan pengujian QOS untuk mengetahui beberapa nilai parameter diantara lain delay, throughput, packet loss dan jitter. Pada sistem ini digunakan android ntuk monitoring dan notifikasi dengan implementasi internet of things. Berdasarkan hasil pengujian pada sensor pH dengan kondisi pH 4,2, 7,1 dan 9,4, pada pembacaan sensor dengan kondisi pH 9,4 tingkat rata-rata errornya yaitu 2%. Namun setelah diuji denngan metode regresi linier dengan persamaan y=-0,2540+1,0468X nilai rata-rata errornya menjadi 0%, dapat disimpulkan bahwa metode regresi linier dapat diterpakan pada penelitian ini. Pada hasil pengujian QOS delay didapatkan nilai rata-rata pengujian delay sebesar 975,9470 ms dimana termasuk dalam kategori jelek, packet loss didapatkan rata-rata sebesar 15,126 % dimana termasuk dalam kategori sedang, throughput didapatkan rata-rata sebesar 694,661 bit/s dimana termasuk dalam kategori sangat bagus dan Jitter didapatkan rata-rata sebesar 473,9918 ms dimana masuk dalam kategori jelek. Kata kunci : Akuarium, Sensor pH, Sensor Turbidity, NodeMCU ESP32, Buzzer, LCD.

An investigation into bryophyte communities in karst Jankovac Stream (Papuk Nature Park, Croatia) was carried out once a month from July 2008 to June 2009. Samples were taken from two lotic microhabitats: (i) Jankovac Spring (JS), a hypocrenal habitat with dense bryophyte clusters (90% bottom cover) and (ii) Jankovac Waterfall (JW), with scattered bryophyte clusters (50% bottom cover). At the same time, seston samples were collected during the spring as the source site and after the JW, as the outflow site. The goals of this study were to understand the (i) algal, protozoan and metazoan bryophyte community assemblages in these two lotic microhabitats, (ii) influence of environmental factors on the structuring of the bryophyte community and (iii) structure of seston along the longitudinal profile. A total of 172 taxa were determined: 68 algae, 55 protozoa, 24 meiofauna and 25 macroinvertebrates. Statistically significant differences between two microhabitats differing in percentage of bryophyte cover were established testing 13 environmental parameters. In dense bryophyte clusters, community structure was determined by flow velocity and pH, and macroinvertebrates achieved higher diversity and abundance. On the contrary, in scattered bryophyte coverage algae, protozoa and meiofauna reached higher abundance and diversity governed by the amount of suspended organic matter and epiphyton. In contrast to previous studies, the inverse ratio of community diversity and abundanceversuspercentage of bryophyte cover was established. We assume this to be the result of an enrichment of the scattered bryophyte clusters by upstream seston. Additionally, the effects of anthropogenic hydromorphological disturbance are reflected in macroinvertebrate diversity and abundance reduction.

The need for prediction is widely recognized in limnology. In this study, data from 25 lakes of the Upper Paraná River floodplain were used to build models to predict chlorophyll-a and dissolved oxygen concentrations. Akaike's information criterion (AIC) was used as a criterion for model selection. Models were validated with independent data obtained in the same lakes in 2001. Predictor variables that significantly explained chlorophyll-a concentration were pH, electrical conductivity, total seston (positive correlation) and nitrate (negative correlation). This model explained 52% of chlorophyll variability. Variables that significantly explained dissolved oxygen concentration were pH, lake area and nitrate (all positive correlations); water temperature and electrical conductivity were negatively correlated with oxygen. This model explained 54% of oxygen variability. Validation with independent data showed that both models had the potential to predict algal biomass and dissolved oxygen concentration in these lakes. These findings suggest that multiple regression models are valuable and practical tools for understanding the dynamics of ecosystems and that predictive limnology may still be considered a powerful approach in aquatic ecology.

The present study aimed to evaluate the water quality of the Icaraí Sewage Outfall (ISEO) area. Sampling was conducted during winter and summer, and water samples were analyzed for dissolved oxygen, pH, temperature, salinity, dissolved inorganic nutrients (DIN), seston, particulate organic matter (POM), and pigments. Results showed that the water chemistry of the area suffers temporal and spatial variation. Great variability was also seen in the C:N:P ratios of POM (August, 112:30:1; December, 59:11:1) and in the DIN concentrations. Chlorophyll-a and ammonium concentrations (4.5 µg L-1 - 71.2 µg L-1, and 0.20 µM - 52,6 µM, respectively) characterized the ISEO area as eutrophic. The dispersal of the material was not effective under certain oceanographic conditions.

Abstract. Increasing atmospheric carbon dioxide (CO2) is changing seawater chemistry towards reduced pH, which affects various properties of marine organisms. Coastal and brackish water communities are expected to be less affected by ocean acidification (OA) as these communities are typically adapted to high fluctuations in CO2 and pH. Here we investigate the response of a coastal brackish water plankton community to increasing CO2 levels as projected for the coming decades and the end of this century in terms of community and biochemical fatty acid (FA) composition. A Baltic Sea plankton community was enclosed in a set of offshore mesocosms and subjected to a CO2 gradient ranging from natural concentrations ( ∼ 347 µatm fCO2) up to values projected for the year 2100 ( ∼ 1333 µatm fCO2). We show that the phytoplankton community composition was resilient to CO2 and did not diverge between the treatments. Seston FA composition was influenced by community composition, which in turn was driven by silicate and phosphate limitation in the mesocosms and showed no difference between the CO2 treatments. These results suggest that CO2 effects are dampened in coastal communities that already experience high natural fluctuations in pCO2. Although this coastal plankton community was tolerant of high pCO2 levels, hypoxia and CO2 uptake by the sea can aggravate acidification and may lead to pH changes outside the currently experienced range for coastal organisms.

We quantified total mercury in surficial sediments (uppermost 5 cm) of six small seepage lakes. Fifty cores were taken from each lake, based on a random sampling design stratified by water depth. Volumetric concentrations (mass per volume of wet sediment) more accurately portrayed the depth distribution of mercury in the lakes than did dry-weight concentrations, which underrepresented the significance of the shallow-water sediments as a reservoir of potentially available mercury. Estimates of whole-lake burdens (masses) of mercury in the surficial sediment, which represent the maximum amount of sedimentary mercury available for methylation, ranged from 45 to 149 g. These sedimentary pools of mercury greatly exceeded the inventories of the metal in water, seston, and fish, and the release of mercury from the sediments could significantly increase its bioaccumulation. Areal burdens of mercury (mass per unit of lake area) varied fivefold among lakes (1.65–7.84 g/ha) and were strongly correlated with lake pH, but were not correlated with dissolved organic carbon, conductance, or chlorophyll a of lakes. We hypothesize that the observed variation in areal burdens of mercury was partly due to variation among lakes in the pH-related efflux of gaseous mercury (Hg0) from the lakes to the atmosphere.