Regular Water Quality Monitoring Research Articles

Physical and chemical features of hydro-geologically connected wetlands in the Abbay River basin, Ethiopia

Physico-chemical water quality assessment is vital for wetland characterization, detecting environmental stress affecting the ecosystem and wetland management interventions. Therefore, this study aimed at comprehensive analysis of water quality parameters of six hydro-geologically connected wetlands in West Gojjam zone, Amhara region, Ethiopia. Water quality data was collected for one year (from June 2022 to April 2023) during four sampling seasons (pre-rainy, main-rainy, post-rainy and dry seasons) from twelve purposively selected sampling sites. In-situ measurements and nutrient analysis were carried out following standard procedures. Water quality index (WQI) was also computed by the weighted arithmetic water quality index method (WAWQI) based on selected parameters. Phosphate ranged from 0.24 mg/l (Kurt Bahir) to 1.80 mg/l (Zindib) and nitrate ranged from 2.12 mg/l (at Gudera) to 3.25 mg/l (at Geray). This increased nutrient concentration and the decreasing trend in DO level clearly indicates their ecological degradation. There was a statistically significant difference (P < 0.05, One-way ANOVA) in the mean measurements of some of the parameters among the study wetlands and among the study seasons. The PCA also clearly shows the most influential variables responsible for the variation among the wetlands. The study concluded that the wetlands water quality has been degraded. Therefore, regular water quality monitoring is recommended to reduce further deterioration.

Hydrochemical Characteristics and Suitability Assessment of Groundwater Quality for Irrigation

The hydrochemical properties of groundwater play a crucial role in crop growth and soil health, as well as the maintenance of irrigation equipment. To ensure suitable water quality for irrigation, the present study was conducted to evaluate the hydrochemical properties of irrigation groundwater in a typical agricultural region of Serbia. Groundwater was sampled at three monitoring locations in the Srem region in Republic of Serbia between 2011 and 2020. Examined parameters included electrical conductivity (EC), total dissolved salts (TDS), pH values, and the concentrations of cations (sodium (Na+), calcium (Ca2+), magnesium (Mg2+) and potassium (K+)) and anions (bicarbonate (HCO3−), chloride (Cl−), sulfate (SO42−), and nitrate (NO3−)). Further assessment was done using three classification systems; Nejgebauer’s, the US USSL, and the FAO classification. To obtain a more detailed assessment, additional indices were included, such as Soluble Sodium Percentage (SSP), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly’s Ratio (KR), Magnesium Adsorption Ratio (MAR), and Total Hardness (TH). The PCA analysis detected that the concentration of K+, Ca2+, and Na+ in the irrigation water were lower in recent years, while the concentration of Cl− was higher. The cluster analysis grouped the parameters into three clusters; I—electroconductivity, II—dry residue and HCO3−, and III—other water parameters for all three monitoring localities. According to the applied classifications, the majority of underground water samples were suitable for irrigation. However, some samples fell out of the range of the first class, indicating the need for regular water quality monitoring. In light of climate changes that influence water deficiency, the urgent need for wise and sustainable water use implies the application of a comprehensive approach to irrigation water quality assessment, as shown in this study.

Assessments of microbial and heavy metal contaminations in water supply systems at the University of Environment and Sustainable Development in Ghana

The main component of the environment that is essential for human existence on earth is availability of quality water. As human activity has evolved, particularly in the industrial, household, and agricultural sectors, groundwater systems are exposed to various contaminants. Groundwater is one of the main sources of water at the University of Environment and Sustainable Development (UESD) in Ghana. However, no research has been carried out to assess the levels of microbial load and heavy metal toxicants in water transmission systems at UESD. In this current study, we investigated the levels of selected heavy metals and microbial load present in the water supply systems at UESD. Water samples were collected from four (4) different zones at the University. Atomic absorption spectroscopy (AAS) was used to analyse the levels of eleven heavy metals (Fe, Cd, Cu, Cr, Zn, Mn, Co, Hg, Pb, Ni and As), whereas correct growth media were used to estimate microbial loads. Observations for water samples were compared to the permissible limits, using one-sample t-tests. Similarly, paired t-tests and Tukey’s honestly significant difference were used to compare observations between water samples from the zones. Water quality indicators (hazard quotient (HQ) and health hazard index (HI)) were used to examine any potential health risks. In addition, water quality index (WQI) was used to predict the quality of the groundwater at UESD campus. The results showed that the levels of Fe, Cd, Cu, Cr, Zn, Mn, Co and Hg were within the permissible limits. However, the levels of Pb, Ni and As for all the sampling zones were significantly higher than the permissible limits. The results of HI and HQ for the oral ingestion pathways of the metals were within the accepted levels. The result of WQI showed that heavy metals would contaminate groundwater in wells and the natural pond on UESD campus. Total coliforms, faecal coliforms and Escherichia coli colony-forming units present in the water samples were significantly higher than the acceptable levels, indicating a possible health risk when ingested. Therefore, we recommend water recycling and regular water quality monitoring programs at the University.

Development of a Water Quality Management Model for Dry Rivers in Arid Regions: Application on Wadi Rumah, Saudi Arabia

In dry rivers, urban wastewater discharge forms a pond in the dry period, and surface runoff shapes a longer pond in the wet period. A water quality management model developed for dry rivers is applied on Wadi Rumah in Saudi Arabia. The sub-basin was delineated from 30-m × 30-m spatial resolution digital elevation model. Hydrologic loss, runoff rates, and time of concentration were determined using the soil conservation service curve number, soil conservation service unit hydrograph methods, and Kirpich formula. Hydrologic Engineering Center Hydrologic Modeling System estimated the wet weather flows for 10 low-to-medium rainfall events. A steady-state hydrodynamic model including river flows, effluent discharge, and evaporation and infiltration losses estimated the hydraulic retention time for the explicit case of ponding conditions of dry rivers. Mass balance and first-order kinetics modeled the physical (total dissolved solid and total suspended solid), chemical (biochemical oxygen demand, dissolved oxygen, chemical oxygen demand, NH3, PO4, and Cl2), and microbiological (total coliform and fecal coliform) parameters. The hydrodynamic model and biokinetic rate coefficients were calibrated with satellite images, reported literature, and field measurements. A water quality index compared the aggregated water quality against the standards for 4 intended uses. The study yields “very good” water quality for restricted and unrestricted irrigation for the dry period, “fair” for livestock drinking, and “marginal” for fishery and recreation for the dry period, while water quality remained “marginal” for all the uses in the wet period. Water quality management implies regular water quality monitoring, continuous improvement of treatment facilities, and flood plain management initiatives for the long-term sustainability of dry rivers in arid regions.

Physicochemical Characterization and Assessment of Magnitude of Pollution to Contribute to Water Sustainability

As in many countries worldwide, deterioration of quality of water in Morocco’s natural reserves continues, such that an inventory of qualities of these reserves has become necessary. Based on statistical analyses of the data collected by measuring nineteen physicochemical variables, and applying an index, the comprehensive pollution index, to those data, the quality of the waters of Lake Dayat Roumi, Morocco, were assessed. Waters of the lake are currently characterized by a salinity of 921.7 mg Cl−/L and 124.2 mg sulfates/L. The concentration of chloride exceeds the value indicated in the standard norms. This can affect the composition of the sediment, overlying water, and specific composition of biota in the lake. Status and trends of values of other parameters also indicate deterioration of water quality in this lake. Multivariate statistical analysis made it possible to differentiate four clusters of samples according to their physicochemical characteristics. These groups are due to inputs from three sources of materials: leaching of rocks from the watershed and plantations, discharge of domestic wastewater and runoff water. Samples taken from deeper parts of the lake indicate a depression of concentrations of dissolved oxygen during the hot season. The analysis results demonstrate the heterogeneous degradation of the water quality in the peripheral areas and deep parts of the lake, favored by the leaching of soils by rainwater, which, when sufficiently severe, can cause repeated mortalities of fishes. This situation requires regular water quality monitoring to develop a management plan for restoration of water quality in the lake to preserve valued ecological services.

Fish Biodiversity and Water Quality of Tropical Forest Streams Adjacent to the Western Boundary of Kinabalu Park, Sabah

Modification and degradation of habitats outside the boundaries of a national parkmay result in the park's integrity being compromised. Thus, the present study aims todocument variation in freshwater fish and water quality of tropical forest streams adjacent to the western boundary of Kinabalu Park, Sabah. Concurrently, fish samplesand environmental parameters were collected at six stations covering a total streamline length of 10 km. The three most abundant species were Tor tambra (34.4%), Barbodes sealei (19.5%), and Lobocheilos ovalis (12.4%). Tor tambra exhibited a negative allometric growth pattern (coefficient &lt; 3) and was in poor to fair condition (0.8&lt; Fulton’s condition factor &lt; 1.2). The highest fish abundance was found in downstream stations with species addition. Metrics of diversity, such as Shannon's diversityindex and the Margalef index of species richness, decreased as elevation increasedfrom 100 to 600 metres above sea level. The water quality of the forest streams isgood, classified as Class I and/or Class II by Malaysia's National Water Quality Standards, except for ammoniacal nitrogen at station 6, which was classified as Class III.Higher turbidity, orthophosphate, and ammoniacal-nitrogen values were found nearthe Podos village. In conclusion, the altitudinal gradient of fish biodiversity was observed in the forest streams near Kinabalu Park. Regular water quality monitoring ofthe downstream river is necessary, as indicated by the potential domestic impacts onthe river.Keywords: Biodiversity, Elevation, Freshwater fish, Forest stream, Kinabalu Park

Utilizing chemometric techniques to evaluate water quality spatial and temporal variation. A case study: Bahr El-Baqar drain — Egypt

This study employed factor analysis (FA)/Principal component analysis (PCA), and hierarchical cluster analysis (HCA), as chemometric techniques in Bahr El-Baqar drain, Egypt to nominate and assess the most representative parameters of the present water quality status, and to assort the sampling sites according to the similarity of the selected parameters, in summer and winter seasons. The water quality data divided the drain into two datasets (before and after El-Salam canal) according to calculated values of the means percentage difference (%) and paired t-test. FA/PCA, selected four factors as indicators of water quality, explaining the cumulative variance ranged (76.0 - 81.1)%. The HCA grouped the sampling sites before the El-Salam canal into four, and five clusters during summer, and winter, respectively while the sampling sites after the El-Salam canal were grouped into three, and four clusters during summer, and winter, respectively showing that the sampling sites are influenced by the seasonal variation. It was revealed that the major sources of variability in Bahr El-Baqar drain are foremost from an anthropogenic origin and thereafter governed by biogenic and organic activities followed by agricultural activities. Finally, this study emphasizes chemometric techniques as a powerful and useful tool to understanding the water quality spatial and temporal variations and their causes. This can support cost, effort, and time reduction, thereby reinforcing regular water quality monitoring plans and may assist in the establishment of guidelines and regulatory plans. • FA/PCA, HCA, and Pearson’s correlation were adopted as chemometric techniques. • Two datasets were created according to the means % difference and paired t-test. • 4 factors explained water quality indicators with cumulative var. (76.0 - 81.1)%. • Sources of variability are anthropogenic/biogenic, organic and agricultural. • Chemometrics evaluated water quality spatial and temporal variations powerfully.

Groundwater quality assessment using geospatial and statistical approaches over Faridabad and Gurgaon districts of National Capital Region, India

This study presents an assessment of groundwater quality over the two constituent districts (Faridabad and Gurgaon) of the National Capital Region (NCR), India, using geospatial and statistical approaches. These districts have been subjected to rapid urbanization and industrialization in recent years. The groundwater quality parameters viz., pH, electrical conductivity (EC), carbonate (CO32−), bicarbonate (HCO3−), chloride (Cl−), sulphate (SO42−), nitrate (NO3−), fluoride (F−), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), silica (SiO2), and total hardness (TH) are obtained for the year of 2017 from 28 sites over the study area. The suitability for human drinking purposes is assessed by comparing the concentration of parameters at each site with respect to their permissible limits recommended by the Bureau of Indian Standards (IS 10500: 2012). The geospatial mapping of the water quality parameters is carried out to visualize their variations, whereas their risk assessment is accomplished by the statistical approaches viz., water quality index (WQI), correlation, and principal component analysis (PCA). The number of sites exceeding the permissible limits of pH, EC, Cl−, SO42−, NO3−, F−, Ca2+, Mg2+, Na+, K+, and TH is obtained to be 7, 15, 5, 6, 8, 3, 5, 7, 18, 3, and 8, respectively. The WQI analysis revealed 10 out of the 28 sites to be unsuitable for drinking purposes. The parameters mostly exhibited positive correlations except for pH that showed a negative correlation with other parameters. The results of PCA revealed the first principal component (PC1) to explain more than 95% of the total variance, thereby significantly reducing the dimensionality. The deteriorated water quality may be mainly attributed to anthropogenic activities, i.e., reckless industrial growth, population explosion, and rapid urbanization. This study emphasizes the need for regular water quality monitoring, and the information reported will certainly help for water resources planning and management, especially over the industrial regions of NCR, India.

Seasonal Fluctuation of Escherichia coli in Nainital Lake, Uttarakhand State, India

The season has a significant impact on the presence of microorganisms in water sources. Various contaminants and bacteria are transported into water sources by heavy rains. Because of the poor microbiological condition of such water bodies, regular monitoring is required. Routine monitoring, on the other hand, considers the microbial quality of the water column.The objective of this research was to investigate the microbiological quality of Nainital Lake in Uttarakhand, using Escherichia coli as a faecal indicator organism, and examine how seasonal fluctuations (dry and rainy seasons) affected its abundance. During 2018 and 2019, samples were taken from Nainital Lake sampling sites during the summer (dry) and rainy (wet) seasons and presence of E. coli was examined using various media, IMViC and catalase tests. E. coli was discovered at all of the locations and its concentration was influenced by seasonal variations. In both years, the cfu/ml count during the rainy season was observed higher in comparison to count during the summer. The transmission of this bacteria into the water column as a result of events such as floods or human activities might harm the health of those who consume untreated lake water for recreation and other domestic reasons. As a result, community education for health care practitioners and the general public about the proper use of lake water is essential. In order to preserve human health and other aquatic life, regular water quality monitoring is also required.

Genotyping and phylogenetic analysis of free-living amoeba (Acanthamoeba and Naegleria) in treated and untreated water in the northeastern provinces of Iran

Abstract Free-living amoebae (FLA) are widely distributed protozoa in natural or man-made aquatic environments without the need for a host organism for survival. Several strains of FLA are known to be pathogenic. As of date, there is inadequate data on the geographical distribution of FLA in northeastern and northern Iran. This study aimed to investigate the prevalence and genotype distribution of Acanthamoeba and Naegleria in drinking water and surface water samples in northern and northeastern Iran. A total of 60 water samples were collected and filtered from various sources for the presence of amoebae. DNA extraction was performed, and PCR confirmed the presence of FLA. PCR products were sequenced to identify the species/genotype. Phylogenetic relationships and taxonomic status constructed using MEGA X software. The findings on growth media showed 35% (21/60) and 26% (16/60) were positive for Acanthamoeba and Naegleria, respectively, while PCR analysis also obtained similar results. All isolates of Acanthamoeba were identified as T4 genotype. Poor water quality, as well as insufficient preservation and treatment, might indicate that chlorine disinfection is ineffective in removing contamination of amoebas in treated water samples. Therefore, regular water quality monitoring is essential to control amoeba's growth, reducing the risk of human infections with FLA.

Prevalence of antibiotic resistance genes in Pangasianodon hypophthalmus and Oreochromis niloticus aquaculture production systems in Bangladesh

Antibiotic resistance genes (ARGs) constitute emerging pollutants of significant public health concern. Antibiotics applied in aquaculture may stimulate the proliferation and dissemination of ARGs. This study investigated the prevalence and diversity of ARGs in Pangasianodon hypophthalmus (formerly Pangasius) and Oreochromis niloticus (formerly Tilapia) commercial aquaculture ponds from four economically important divisions (i.e. regions) of Bangladesh using a high-throughput qPCR ARG SmartChip and further aimed to explore effects of aquaculture pond management and water quality on the observed ARG prevalence patterns. A total of 160 ARGs and 10 mobile genetic elements (MGEs) were detected across all samples (n = 33), of which 76 ARGs and MGEs were shared between all regions. Multidrug resistance genes were the most frequently encountered ARGs, followed by ARGs conferring resistance to β-lactams, aminoglycosides, tetracyclines, and macrolide-lincosamide-streptogramin B (MLSB). Research ponds managed by the Bangladesh Agricultural University had the lowest abundance and diversity of ARGs, suggesting that proper management such as regular water quality monitoring, fortnightly water exchange and use of probiotics instead of antibiotics may mitigate the dissemination of antibiotic resistance from aquaculture ponds. The Adonis test (R2 = 0.35, p < 0.001) and distance decay relationships revealed that the ARGs composition displayed a significant biogeographical pattern (i.e., separation based on geographic origin). However, this effect could possibly be due to feed type as different feed types were used in different regions. In conclusion, our results indicate that there is a vast potential for improving aquaculture pond management practices in Bangladesh to mitigate the environmental dissemination of ARGs and their subsequent transmission to humans.

MAPPING COLOURED DISSOLVED ORGANIC MATTER IN MANILA BAY USING SENTINEL-3 AND WASI

Abstract. Manila Bay is one of the most significant bodies of water in the Philippines; it has abundant natural resources that have been the source of livelihood and center of socio-economic development for centuries. However, Manila Bay is affected by multiple environmental problems and challenges. These include increased organic and nutrient loading from untreated domestic, industrial, and agricultural wastes and deterioration of marine habitats threatened by anthropogenic activities. Regular water quality monitoring is ideal in these situations, however, sampling by traditional field methods would not be enough to assess the spatial and temporal variation of water quality in Manila Bay. Gathering field data for the whole bay can also be very challenging due to its extent and logistic constraints. Remote sensing fills the need for a frequent full view of Manila Bay’s water quality. This study makes use of existing bio-optical models to estimate colored dissolved organic matter (CDOM) in Manila Bay. CDOM is the mixture of organic molecules from decayed higher plants, algae, and bacteria, and is the colored portion of the total dissolved organic matter. Sentinel-3 images with concurrent field sampling on 19 July 2021 was used to calibrate and validate the bio-optical models implemented in WASI. The parameterization output showed an R2 = 0.579 and RMSE of 1.274 m−1 from lab-measured CDOM fluorescence converted to absorption. The same parameter set was used on a different image with a concurrent water quality survey on 19 May 2021 and resulted to an R2 of 0.72 with the spectrofluorometer yellow substance concentrations.

Monitoring cyanoHABs and water quality in Laguna Lake (Philippines) with Sentinel-2 satellites during the 2020 Pacific typhoon season

Laguna Lake, the largest freshwater lake in the Philippines, is permanently subject to nutrient-driven eutrophication and pollution and experiences harmful algal blooms (cyanoHABs) periodically with serious socio-economic implications. The aim of this study is to evaluate the suitability of the Sentinel-2 imagery of the European Commission's Copernicus Earth Observation programme for lake monitoring during the 2020 Pacific typhoon season (September–November 2020). The Case-2 Regional CoastColour processor is used to atmospherically correct Level 1 data and generate water quality parameters, such as chlorophyll-a (Chl-a) and total suspended matter (TSM) at 10 m. Results show that Super Typhoon Goni and Typhoon Vamco delivered high suspended sediment loads to the reservoir at concentrations above 170 g/m3 compared to pre-storm situations (0–35 g/m3). The typhoons also affect Chl-a, with a mean concentration of 10 mg/m3 and 30 mg/m3 for pre- and post-typhoons, respectively. In addition, the normalized difference chlorophyll index (NDCI) is used in the Google Earth Engine platform for near-real time monitoring of cyanoHABs at 20 m spatial resolution. Satellite maps are key for detecting the distribution of the blooms due to the patchiness of the green algae species, which usually form scum and elongated slicks in the lake. Maximum records of bloom detection during the study period occur in the Central Bay, one of the lake sections with major aquaculture and fisheries activities. The Sentinel-2 mission improves synoptic mapping of cyanoHABs and enables trends in their extent and severity to be documented. These available methods provide an essential tool for rapid detection after extreme events and for regular water quality monitoring, which will assist and benefit the cost-effective management of Laguna Lake.

Development of Water Quality Monitoring Device Using Arduino UNO

Regular water quality monitoring of water bodies is essential to ensure it is within the allowing standard limits. The development of a simple and low-cost water quality measurement device for real time monitoring using Internet of Things (IoT) technology is presented in this study. Kolora meter is an alternative to the existing commercial monitoring devices. It was developed using the open-source platform Arduino UNO model and NodeMCU board as the microcontroller and Wi-Fi connection respectively. Two sensors such as temperature and turbidity were selected to be installed in the early stage of Kolora meter development. The physical parameters (temperature and turbidity) of water were measured and the measured data collected are able to be viewed and monitored on the mobile phone using Kolora Mobile Application via Wi-Fi connection. Therefore, this surface water quality device has potential to be applied in real time monitoring for early pollution detection and during COVID-19 pandemic spread due to limited movement.

Water Quality Assessment of Ekulu and Asata Rivers in Enugu Area, Southeastern Nigeria, Using Physico-Chemical and Bacteriological Parameters

This study was aimed at assessing the impacts of human activities on the quality of Ekulu and Asata Rivers in Enugu Area, Southeastern Nigeria. Twelve (12) water samples six (6) from Ekulu River and (six 6) from Asata River) were collected at different points along the regime of the two rivers and their physico-chemical and bacteriological characteristics/parameters determined. Results of the study indicate that the two rivers do not satisfy the Drinking Water Quality Standard of World Health Organization (WHO) and Federal Ministry of Environment (FMENV) in terms of pH/acidity (values between 4.5 and 7.0 and outside the WHO Standard of 6-5-8-5); turbidity (values between 7.88 and 294NTU units and greater than WHO standard of 5.0NTU units); iron (values between 3.10 and 7.35 mg/1 and greater than WHO standard of below 0.30mg/l; and coliform (values between 20 and 180 counts per 100ml and greater than WHO Standard of 3 counts per 100ml). Though Ekulu River is more acidic (lower pH values), more turbid (higher NTU units) and contains higher concentration of iron than Asata River. On the other hand, only Asata River do not satisfy the WHO Standards in terms of nitrate concentration (values between 8.9 and 25.9mg/l and greater than WHO Standard of 10 mg/1): and chromium (heavy metal, values between 0.189 and 0.429 mg/1 and greater than WHO Standard of 0.00lmg/1) Human activities of mining at abandoned Onyeama Coal Mine, car watch and disposal of industrial/domestic wastes are believed to be responsible for poor water quality of the two rivers in Enugu area. On the basis of Piper Diagram Classification, Ekulu River may be classified as Calcium Chloride Type, while Asata River may be classified as Mixed Water Type. Water from the two rivers, to be used for domestic and industrial purposes, should be adequately treated; and there is need to institute regular water quality monitoring programme for the two rivers. Keywords: Water Quality, Ekulu River, Asata River, Enugu Area, Assessment, Piper Diagram DOI: 10.7176/JEES/11-4-07 Publication date: April 30 th 2021

OPTMIZATION OF BIO-OPTICAL MODEL PARAMETERS FOR TURBID LAKE WATER QUALITY ESTIMATION USING LANDSAT 8 AND WASI-2D

Abstract. Laguna Lake, the Philippines’ largest freshwater lake, has always been historically, economically, and ecologically significant to the people living near it. However, as it lies at the center of urban development in Metro Manila, it suffers from water quality degradation. Water quality sampling by current field methods is not enough to assess the spatial and temporal variations of water quality in the lake. Regular water quality monitoring is advised, and remote sensing addresses the need for a synchronized and frequent observation and provides an efficient way to obtain bio-optical water quality parameters. Optimization of bio-optical models is done as local parameters change regionally and seasonally, thus requiring calibration. Field spectral measurements and in-situ water quality data taken during simultaneous satellite overpass were used to calibrate the bio-optical modelling tool WASI-2D to get estimates of chlorophyll-a concentration from the corresponding Landsat-8 images. The initial output values for chlorophyll-a concentration, which ranges from 10–40 μg/L, has an RMSE of up to 10 μg/L when compared with in situ data. Further refinements in the initial and constant parameters of the model resulted in an improved chlorophyll-a concentration retrieval from the Landsat-8 images. The outputs provided a chlorophyll-a concentration range from 5–12 μg/L, well within the usual range of measured values in the lake, with an RMSE of 2.28 μg/L compared to in situ data.

Development of Microalgae Biosensor Chip by Incorporating Microarray Oxygen Sensor for Pesticides Sensing.

A microalgae (Pseudokirchneriella subcapitata) biosensor chip for pesticide sensing has been developed by attaching the immobilized microalgae biofilm pon the microarray dye spots (size 100 μm and pitch 200 μm). The dye spots (ruthenium complex) were printed upon SO3-modified glass slides using a polydimethylsiloxane (PDMS) stamp and a microcontact printer (μCP). Emitted fluorescence intensity (FI) variance due to photosynthetic activity (O2 production) of microalgae was monitored by an inverted fluorescent microscope and inhibition of the oxygen generation rate was calculated based on the FI responses both before and after injection of pesticide sample. The calibration curves, as the inhibition of oxygen generation rate (%) due to photosynthetic activity inhibition by the pesticides, depicted that among the 6 tested pesticides, the biosensor showed good sensitivity for 4 pesticides (diuron, simetryn, simazine, and atrazine) but was insensitive for mefenacet and pendimethalin. The detection limits were 1 ppb for diuron and 10 ppb for simetryn, simazine, and atrazine. The simple and low-cost nature of sensing of the developed biosensor sensor chip has apparently created opportunities for regular water quality monitoring, where pesticides are an important concern.

Physico Chemical and Microbial Analysis of Different Sources of Water collected from Indora, Himachal Pradesh, India

Life could not be imagining without the presence of water on this earth. An ecosystem is very dependent on the quality of water. Regular water quality monitoring is very essential of a region. In the study area, no study has been yet done on the quality of drinking water and productivity level of Beas river near Arni University, Himachal Pradesh, India. The main aim of this study was to determine the water quality of three different sources of water like hand pump water, tap water, and Beas river water. For this, we have collected total twenty-six samples in the month of May 2018 and analysed for pH, TDS, EC, DO, alkalinity, phenolphthalein alkalinity, total hardness, calcium hardness, chloride, sulfate, phosphate, nitrate, carbonate, bicarbonate, E. coli, and productivity level by standard methods. The entire analysed parameters showed the lower level than the permissible guideline of the WHO except for the presence of E. coli and higher level of alkalinity. The productivity level of Beas river was indicating that trophic index belonged to the ultra-oligotrophic. From the findings, it might be concluded that hand pump water, tap water, and Beas river water was drinkable except the presence of E. coli and higher level of alkalinity in tap water and river water. However, in the case of the productivity level of Beas river was indicating the very low accumulation of dissolved nutrient salts, and a lower rate of algae growth as the productivity level belonged to the ultra-oligotrophic. Further extensive study on the water minerals and heavy metals level in all the water sources are required in this study area.

Groundwater quality assessment for domestic and agricultural purposes in Yan’an City, northwest China: implications to sustainable groundwater quality management on the Loess Plateau

Groundwater is critical for the sustainable development of the Loess Plateau, while groundwater quality is generally poor in this area due to natural factors and anthropogenic pollution. This study was carried out to investigate the suitability of groundwater for domestic and agricultural purposes in Yan’an City on the Chinese Loess Plateau and to assess its implications to sustainable groundwater management on the plateau. The index levels were compared with the threshold values established by the national and the WHO drinking water guidelines, and the suitability of groundwater for irrigation purposes was assessed using multiple agricultural water quality indicators. An entropy-weighted Technique for Order Preference by Similarity to an Ideal Solution (entropy-weighted TOPSIS) was adopted for overall groundwater quality assessment. The results indicate that the study area is characterized by saline, hard, and slightly alkaline groundwater, mainly of the HCO3–Ca·Mg type, accompanied by some minor SO4·Cl–Ca·Mg type. The dissolution of carbonates and gypsum and the leaching of soluble salts are important natural processes influencing the groundwater ion chemistry. The parameters TH, TDS, and SO42− are major indices, while Fe, Mn, F−, and NH4+ are minor contaminants affecting groundwater quality. The overall groundwater quality is generally acceptable for irrigation, and most of the water is suitable for drinking. Rainwater harvesting, water quality improvement programs, regular water quality monitoring, and multidisciplinary water research programs are suggested as measures for sustainable groundwater management on the Loess Plateau.

Assessment of the environmental health of an ecologically sensitive, semi-enclosed, basin - A water quality modelling approach

Semi-enclosed basins are environmentally dynamic and some of the most anthropogenically affected components of the coastal realm. They can reflect various environmental impacts, thus qualifying as natural laboratories to study these impacts. The Gulf of Khambhat (GoK) is such a system where analysis of in situ parameters indicated polluted conditions. The sources of various contaminants were deciphered. Though there are considerable inputs of pollutants, the assimilative capacity of the GoK holds good with high Dissolved Oxygen (DO) (6–9.3 mg/L) content as revealed in situ and in silico. High Biochemical Oxygen Demand (BOD) and marginal ammonia contamination prevail in the region. Simulations revealed that the rivers bring in a considerable amount of nitrate, organic material and phosphate into the Gulf. Considering the prevailing environmental condition, the current study posits to have regular water quality monitoring; and the carrying capacity of the Gulf should be assessed before the authorization of anthropogenic activities.