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Assessment of Nitrates and Nitrites in Borehole Water from the Southern and the Northern Region of Côte d’Ivoire (West Africa)

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Open Journal of Modern Hydrology 2024年第2期14卷 87-105页

作者： Jean Stéphane Claon Kouassi Kouakou Serge Sérikipré Laurent Seka M’Bassidjé Arsène N’Guettia Kossonou Roland Traoré Aïcha Djamanallico Joseph Kouadio Kouakou Luc Analytical Sciences and Public Health Department University of Félix Houphou&#235t-Boigny Abidjan C&#244te d’Ivoire Water Quality Control and Analysis Laboratory (LACQUE) Office National de l’Eau Potable (ONEP) Abidjan C&#244te d’Ivoire Biology and Health Laboratory University of Félix Houphou&#235t-Boigny Abidjan C&#244te d’Ivoire Department of Medical and Fundamental Biochemistry Institut Pasteur of C&#244te d’Ivoire Abidjan C&#244te d’Ivoire Laboratory of Environmental Sciences (LSE) University of Nangui Abrogoua Abidjan C&#244te d’Ivoire

This study aimed to evaluate the quality of water from village boreholes by measuring physicochemical parameters such as nitrates, nitrites, and total organic carbon (TOC). Forty-five (45) village pumps from the Southern (Basse Côte) and the Northern (Korhogo) region of Cte d’Ivoire (west Africa) were sampled. Physicochemical parameters such as temperature, pH, conductivity at 25˚C, and turbidity were determined in situ, while nitrite and nitrate were analyzed according to ISO 10304-1 (2007) standard and total organic carbon (TOC) by NF EN 1484 (1997) standard. The results showed that the borehole waters of the Basse Côte and Korhogo analyzed are acidic, with an average temperature of 27.51˚C ± 0.16˚C and 29.95˚C ± 0.51˚C respectively for the Basse Côte and Korhogo regions. The borehole waters of the Basse Côtedo not contain nitrites, while those of Korhogo have average nitrite contents of 0.32 mg/l. The average nitrate rate in the waters of the Basse Côte and Korhogo are 12.08 ± 2.11 mg/l and 11.03 ± 3.18 mg/l respectively. The average TOC concentration of the waters of the Basse Côte is 1.28 ± 0.32 mg/l and that of Korhogo is 0.56 ± 0.09 mg/L. The study showed that the borehole waters of the Basse Côte and Korhogo have average temperatures between 27.4˚C and 29.95˚C with a slightly acidic pH value and acceptable salinity. The TOC concentrations obtained at the different sampling points were all below the French standard (2 mg/L) except for certains pumps of the Basse Côte. The water samples from the Basse Côte were devoid of nitrite. On the other hand, those from Korhogo revealed the presence of nitrite. Also, the borehole waters of the regions of the Basse Côte and Korhogo contain relatively high nitrate contents, presumably due to anthropometric activity. Overall, our study on the quality of drinking water showed that the waters analyzed are in compliance with international standards and safe for consumption.

关键词： Drinking Water pH turbidity TOC Nitrates Nitrites Health Effect

The treatment of black-odorous water using tower bipolar electro-flocculation including the removal of phosphorus,turbidity,sulfion,and oxygen enrichment

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Frontiers of Environmental Science & Engineering 2021年第2期15卷 19-31页

作者： Huan He Qinjin Yu Chaochao Lai Chen Zhang Muhan Liu Bin Huang Hongping Pu Xuejun Pan Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China Yunnan Provincial Key Laboratory of Carbon Sequestration and Pollution Control in Soils Kunming 650500China

The large amount of municipal wastewater discharged into urban rivers sometimes exceeds the rivers’self-purification capacity leading to black-odorous polluted water.Electro-flocculation has emerged as a powerful remediation technology.Electro-flocculation in a bubble column tower with a bipolar electrode(BPE)was tested in an attempt to overcome the high resistance and weak gas-floatation observed with a monopolar electrode(MPE)in treating such water.The BPE reactor tested had a Ti/Ta2O_(5)-IrO_(2)anode and a graphite cathode with an iron or aluminum bipolar electrode suspended between them.It was tested for its ability to reduce turbidity,phosphate and sulphion and to increase the concentration of dissolved oxygen.The inclusion of the bipolar electrode was found to distinctly improved the system’s conductivity.The system’s electro-flocculation and electrical floatation removed turbidity,phosphate and sulphion completely,and the dissolved oxygen level improved from 0.29 to 6.28 mg/L.An aluminum bipolar electrode performed better than an iron one.Changes in the structure of the microbial community confirmed a significant improvement in water quality.

关键词： Black-odorous water Bipolar electrodes Flocculation Floatation Oxygen enrichment turbidity

Correlations between silt density index,turbidity and oxidation-reduction potential parameters in seawater reverse osmosis desalination

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Water Science and Engineering 2019年第2期12卷 115-120页

作者： Seyed Mohammad Hossein Fayaz Roya Mafigholami Fatemeh Razavian Karim Ghasemipanah Department of Environment West Tehran BranchIslamic Azad UniversityTehran ***Iran Department of Environment Parand BranchIslamic Azad UniversityParand ***Iran Research Institute of Petroleum Industry Tehran ***Iran

The reverse osmosis method is one of the most widely used methods of seawater desalination at present.Hydrophilic and desalting membranes in reverse osmosis systems are highly susceptible to the input pollutants.Various contaminants,including suspended organic and inorganic matter,result in membrane fouling and membrane degradation.Fundamental parameters such as the turbidity,the amount of chlorine injection,and silt density index (SDI) are the most predominant parameters of fouling control in the membranes.In this study,the operation system included a water intake unit,a pretreatment system,and an RO system.The pretreatment system encompassed a clarifier,a gravity sand filter,pressurized sand filters,and a cartridge filter.The correlation between the amount of chlorine injection in terms of the oxidation-reduction potential (ORP) and the SDI value of the input water was investigated at a specified site next to the Persian Gulf.The results showed that,at certain intervals of inlet turbidity,injection of a certain amount of chlorine into the raw water has a distinct effect on the decrease of SDI.

关键词： Silt density index Oxidation-reduction potential turbidity Reverse osmosis Membrane fouling

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Modeling of turbidity dynamics caused by wind-induced waves and current in the Taihu Lake

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International Journal of Sediment Research 2013年第2期28卷 139-148页

作者： Ting-feng WU Bo-qiang QIN Guang-wei ZHU Meng-yuan ZHU Wei LI Cheng-mei LUAN State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences Jiangsu Province Hydrology and Water Resource Investigation Bureau

A simple turbidity model was developed with a sound physical basis based on in situ high-frequency observations of short-term,strong wind-induced sediment suspension in Taihu Lake,China.The validation results show that the model could successfully simulate turbidity caused by strong wind events,despite the relatively poor simulation accuracy for high values of turbidity caused by the entrainment of cyanobacteria by turbulence. The in situ observations and model simulation results indicate that the wind waves were within a narrow spectral band,with spectral energy mainly distributed within the 0.28-0.75 Hz band on opposite sides of the peak frequency.These high-frequency and low-energy wind waves are sensitive to depth filtering.However,the average depth of the lake is only 1.9 m,and wind waves still represent the main force of sediment suspension at the sediment-water interface.Moreover,lake currents were of significance to the maintenance of background turbidity in calm waves or ripples and in the determination of critical shear stress.By considering the spatial distribution of hydrodynamics and sediment,the model can be used to simulate the turbidity of the entire lake as well as boundary conditions for three-dimensional numerical models.

关键词： Taihu Lake Wind-driven current Wind wave frequency spectrum turbidity Critical shear stress Model

C haracteristics of turbulent kinetic energy dissipation rate and turbidity near the coast of East China Sea

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Chinese Journal of Oceanology and Limnology 2016年第5期34卷 1134-1142页

作者：张艳伟许惠平覃如府徐昌伟范代读 State Key Lab of Marine Geology Tongji University

The East China Sea(ECS) has a high suspended-sediment concentration because of the influence of the Changjiang River,indicated by high turbidity in the water.Considering the islands off the coast and the complex topography,and the strong influence of tides and wind,the coast off the ECS is a typical region with strong oceanic mixing processes.The changes in the dynamic processes near the bottom play an important role in the control of water turbidity.The turbulent kinetic energy dissipation rate(ε) is a parameter that shows the strength of ocean mixing.This is estimated based on a structure method using current velocity that is measured by a high-frequency Acoustic Doppler Current Profiler(ADCP) from a seafloor observatory in the ECS.The results indicate strong ocean mixing processes with a mean e value of 5.7×10^(-5) W/kg and distinct tidal variations in the dissipation rate.Conversely,the variation of the water turbidity leads to changes in the water dynamical structure near the bottom.Comparing the dissipation rate with the turbidity near the bottom boundary layer,we find that the high turbidity mimics strong ocean mixing.

关键词： turbulent kinetic energy dissipation rate turbidity tides near bottom boundary East China Sea

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Noninvasive Fetal Lung Maturity Prediction Based on Amniotic Fluid turbidity Using Ultrasonic Histogram Measurement Function

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Open Journal of Obstetrics and Gynecology 2023年第1期13卷 26-36页

作者： Kensuke Matsumoto Kaoru Yamawaki Kazufumi Haino Koji Nishijima Department of Obstetrics and Gynecology Niigata University Medical and Dental Hospital Niigata Japan

Background: Amniotic fluid turbidity increases with fetal lung maturation due to vernix and lung surfactant micelles suspended in the amniotic fluid. This study focused on this phenomenon and evaluated the presence or absence of respiratory distress syndrome (RDS)/transient tachypnea of the newborn (TTN) by quantitatively assessing the brightness of the amniotic fluid turbidity using a noninvasive ultrasound histogram measurement function. Methods: We included cases of singleton pregnancies managed at the Niigata University Medical and Dental Hospital between November 2020 and March 2022. Histograms of amniotic fluid turbidity were measured at the center of the amniotic fluid depth, avoiding the fetus, placenta, and umbilical cord, with the gain setting set to 0, and the average value was obtained after three measurements. Histograms of fetal urine in the bladder were measured similarly. The value obtained by subtracting the fetal bladder brightness value from the amniotic brightness value based on histogram measurements was used as the final amniotic fluid brightness value. Results: We included 118 cases (16 of RDS/TTN and 102 of control). The gestational age of delivery weeks was correlated with amniotic fluid brightness (Spearman’s rank correlation coefficient was 0.344;p = 0.00014). Amniotic fluid brightness values were significantly lower in the RDS/TTN group than in the control group (RDS/TTN: 16.2 ± 13.5, control: 26.3 ± 16.3;p = 0.020). The optimal cutoff value of amniotic fluid brightness to predict RDS/TTN was 20.3. For predicting RDS/TTN, the sensitivity, specificity, positive predictive value, and negative predictive value were 91.7%, 69.6%, 26.2%, and 94.1%, respectively. Conclusions: The quantitative value of the amniotic fluid brightness by histogram measurements may provide an easy and objective index for evaluating the presence or absence of RDS/TTN.

关键词： Amniotic Fluid Brightness Fetal Lung Histogram turbidity

Response of nephelometric turbidity to hydrodynamic particle size of fine suspended sediment

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International Journal of Sediment Research 2020年第5期35卷 444-454页

作者： Christina Bright Sarah Mager Sophie Horton School of Geography University of Otago

turbidity is used as a surrogate for suspended sediment concentration(SSC),and as a regulatory tool for indicating land use disturbance and environmental protection.turbidity relates linearly to suspended material,however,can show non-linear responses to particulate organic matter(POM),concomitant with changes in particle size distribution(PSD).In the paper the influence of ultra-fine particulate matter(UFPM) on specific turbidity and its association with POM in suspended sediment are shown for alpine rivers in the Southern Alps of New Zealand.The approach was two-fold:a field-based investigation of the relations between SSC,POM,and turbidity sampled during event flow;and experimental work on hydrodynamic particle size effects on SSC POM,PSD,and turbidity.Specific turbidity changes over event flow and are sensitive to increasing proportional amounts of sand,UFPM,and POM in suspension.Furthermore,the UFPM is the size fraction(turbidity-SSC relations are undesirable in locations that may be dominated by cyclic release of POM or distinct pulses of fine-grained material.At locations where the turbidity-SSC slopes approximate 2,the POM proportion is usually turbidity-SSC slopes are turbidity as a proxy for determining SSC may have serious consequences for the measurement of representative suspended sediment data,particularly in locations where POM may be a significant contributor to overall suspended load.

关键词： turbidity Nephelometry Suspended sediment concentration Particle size distribution Particulate organic matter

The vertical attenuation of irradiance as a function of turbidity: a case of the Huanghai (Yellow) Sea in spring

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Acta Oceanologica Sinica 2009年第5期28卷 66-75页

作者： LIN Shaoying ZOU Tao GAO Huiwang GUO Xinyu Key Laboratory of Marine Environment and Ecology Ministry of Education of China Ocean University of China Qingdao 266100 China Center for Marine Environmental Studies Ehime University 2-5 Bunkyo-Cho Matsuyama 790-8577 Japan

The planar photosynthetically available radiation （PAR）, turbidity and concentration of chlorophyll a （chl a）, were measured at 26 stations in the Huanghai （Yellow） Sea during a cruise of China SOLAS from 19 to 27 March 2005. Due to low chl a （〈0.35 mg · m^-3 ） in upper layers （above 5 m）, suspended particulate matter became the major factor that influenced the turbidity in early spring. The calculated vertical diffuse attenuation coefficient of PAR, K PAR , varied with water depths with a maximum value in the upper 5 m layer. The mean K PAR in survey area was 0.277 ± 0.07 m^-1 that is considerably higher than most of the other case 2 waters. Within the survey area, K PAR also showed distinct regional characteristics, corresponding to the distribution of turbidity. Based on measurements, the relationship between K PAR and turbidity as well as chl a was established. It was suggested that suspended particulate matter plays an important role in light attenuation in the Huanghai （Yellow） Sea in spring.

关键词： Photosynthetically available radiation Diffuse attenuation coefficient turbidity Chlorophyll a the Huanghai （Yellow） Sea

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A methodological approach for estimating turbidity in a river

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International Journal of Sediment Research 2011年第1期26卷 112-119页

作者： Annamaria De VINCENZO Bruno MOLINO Rosa VIPARELLI Pompilio CARAMUSCIO Department of Environmental Physics and Engineering University of Basilicata85100 PotenzaItaly SAVA Department University of Molise86100 CompobassoItaly 3. ENEL R&D Department72020 Tutorano(Br)Italy

During the operations of purging and disposal of sediments of a reservoir it is necessary to know the values of turbidity in the river downstream in natural condition,in the absence of dams or river training works.The paper shows that under these conditions the ratio of the average values of sediment discharge to the annual maximum value of water discharge is a function of the average annual turbidity.turbidity can be considered as representative synthetic index of the climatic conditions,the lithological features and the land cover of the basin,and the geometric characteristics of the river network.The proposed relationship of sediment discharge as a function of water discharge were validated on the basis of data collected from different Italian regions that have very different morphological,geo-lithological and rainfall features and that are characterised by a basin area changing between a few dozen and thousands of square kilometres.The results can be considered satisfying.

关键词： Soil erosion Reservoir siltation Flushing turbidity Sediment transportation