The wetlands are the partially water-submerged environments that are highly productive, and support fauna and flora species in significant numbers that are dependent for their survival on the organic production of wetlands. Kanwar Lake is situated about 22 kilometers to the northwest of Begusarai. The Gandak River, a tributary of the Ganges, meanders across the area, creating the largest oxbow lake in Asia. It is a natural body of water that is significant on many different levels, including ecological, floral, faunal, geomorphological, and zoological. In 1989, the state government of Bihar designated Kanwar as a protected area for avian species. It has been considered a Ramsar site since 1987, but the wetland was not one of the 13 designated sites. In 1984, the lake’s area was 6,786 hectares (ha), but by 2004, it had shrunk to 6,043.825 ha. Only 2,032 hectares remained of the original lake area by 2012. Wealthy farmers and locals have rapidly colonized the lake bed. Lake biodiversity has declined as weeds have grown across the wetland. Widespread deforestation, overgrazing, unsustainable agricultural methods and over-exploitation of biomass for wood, fodder, and timber have stripped the land of its natural vegetative cover and exacerbated erosion. The research deals with the ecological study of the area and how urbanization has caused impacts on it. It focuses on how this has caused the deterioration of the lake and the measures for restoring the lake ecology, safeguarding the trend of urbanization. After analyzing the major key issues and analyzing the issues at the edge of the lake and around the Manjhaul, some of the major findings conclude that there is a need for stormwater management of the whole city, restoration of Kanwar wetland, and industrial control around the lake.

Real-time fine-scale data was collected along the Bagmati River, in Kathmandu Valley, using mobile and fixed sensor system during the winter season. The water quality parameters; pH, conductivity, total dissolved salt (TDS), salinity, oxygen reduction potential (ORP), dissolved oxygen (DO), and turbidity were measured in the space domain using a fixed sensor and mobile sensor (small rafting boat loaded with sensor) systems. The water quality parameters from the fixed sensor system revealed that the Bagmati River was comparatively less polluted upstream from Gokarna to Tilganga sites and molecular oxygen present in the water was enough to decompose organic pollutants. However, the water quality downstream from Tinkune to Balkhu sites was degraded drastically making it unfit for living organisms. Temporal variation of water quality attributes that human activity significantly enhanced pollutants which severely degraded the water quality in the daytime. The fine-scale space domain heat map data of the mobile sensor system also suggested that the water quality continuously deteriorated from Shankhamul to Sundarighat sites. The ORP value was always negative and decreased with downflow and becomes -263 mV near the Sundarighat Bridge. The mixing of tributaries and increment of solid waste and untreated sewer along the river enhanced pollutants excessively and decreased oxygen level to zero. The results attributed that decomposition of the sewer by microorganism consumed almost all oxygen which produced volatile compounds and generated malodorous odor downstream of Bagmati River.

Total suspended solids are an indicator of material constituted by sedimentable solids, suspended solids, and colloidal, whose origin is erosion, wastewater discharges, and agricultural waste. The objective of this research was to determine territorial water erosion, its relation with total suspended solids, and the water quality in the lower basin of the Usumacinta River in Tabasco. Three sampling points were established, located in the municipalities of Tenosique, Emiliano Zapata, and Jonuta, in the state of Tabasco. Water samples were collected during 12 monthly sampling campaigns in an annual cycle, and the total suspended solids were determined according to the provisions of the NMX-AA-034-SCFI-2015 standard. Water erosion was calculated based on the Universal Soil Loss Equation (USLE) and with the use of geographic information systems (GIS). The results obtained were statistically analyzed, finding that the measured maximum TSS concentrations are 130.92 mg.L-1 in Boca del Cerro, 165.28 mg.L-1 in Chabl?, and 113.91 mg.L-1 in Jonuta which are within the permissible concentrations for protection of freshwater aquatic life and agricultural irrigation according to ecological criteria of water quality (CE-CCA-001/89), in Mexico. The lower basin of the Usumacinta River has areas with extreme erosion (990 tons.ha-1yr-1), with conditions that accelerate the erosion process, such as annual rainfall between 1805 mm and 2250 mm, clay soils located on slopes greater than 16%, and agricultural soils. These events cause loss of the soil fertile layer where agriculture is developed, also giving rise to the accelerated transport of suspended solids; which negatively alter the quality of the water of the Usumacinta River.

In India, festivals like Ganesh Chaturthi, Durga Puja form an integral part of its rich and diverse cultural heritage. The ritual of idol worshipping and immersion into water bodies signifies the cycle of creation and dissolution, acknowledging the rhythm of nature that all things come from nature and go seamlessly back to it for a cycle to begin. But, in recent times the practice of immersing Plaster of Paris (POP) made idols along with other decorative material into natural water bodies has immensely raised the severe issue of water pollution and creating an uncongenial aquatic ecosystem. In this purview, a pilot project for chemical disintegration of POP idols during Ganesh festival was run in Bhopal, Madhya Pradesh, India to study the effective application of a chemical method developed by CSIR-NCL, Pune by using ammonium bicarbonate. Water samples were collected before and after idol immersion activity from the tank. The detailed chemical analysis of the aqueous phase was carried out to study the effect on various parameters and application of residues. The analytical results reveal that the method has its practical utility as both the products of the reaction can further be used in chalk making and as fertiliser with dilution. The concentration of heavy metals was found minimal and in the limits in the treated aqueous phase. This paper also supports the sustainable management of such functions rather than the use of artificial materials.

The considerable increase in the amount of nitrogen in the surface water is a major environmental problem. It has become a great matter of worry because of the multiple environmental effects including eutrophication and health risks. The El-Kebir West watershed is a coastal plain in northeastern Algeria.This study aims to determine the physicochemical quality of waters of the western WadiEl-Kebir and its main tributariesand also to evaluate the spatiotemporal variabilityof its physicochemical quality in particular of mineral nitrogen during wet and dry periods. Four sampling campaigns were realized as follows: January 2015 and February 2016 corresponding to water high season and in March and September 2016 corresponding to the low season. The water samples were obtained from the seven stations located along western Wadi El-Kebir. Temperature, pH,conductivity,dissolved oxygen,SO42-, PO43-, NO3-, NO2-and NH4+ were measured either in situ or in the laboratory.A statistical treatment employingthe PCA method (The Principal Components Analysis) was applied for all the obtained results. It has been noticed that the S2 and S3 upstream stations are very rich in ammonium (NH4+) at the low water period with average values of 15.22 mg/L and 20.41 mg/L, respectively.This study has shown the influence of seasonal variations and anthropogenic activities on the evolution of physicochemical settings, in general, and on mineral nitrogen in particular. In conclusion,the waters of Wadi El-Kebir were of an average to poor quality.

The Yongding River is the mother river of Beijing. However, due to the environmental pollution caused by the economic development, the water and coastal environment of this river has suffered from great destruction. The ecological restoration of the Yongding River is imperative. In this paper, we analysed seven basic water quality indicators in Yongding River based on Information Entropy and found that the main factors for affecting water quality were ammonia and CODMn. Then the basic water quality indicators were predicted, based on Grey System GM(1,1) model and we concluded that turbidity and conductivity would grow fastest in the next 20 years. Finally, we made some reasonable ideas and methods in Yongding River ecological restoration.

To ensure the safety of drinking water, understanding the trends of water quality in water resource and to provide a scientific basis for water quality management, a three-layer BP neural network is selected to simulate and predict six water quality indicators of the outbound of Dahuofang Reservoir. The six water quality indicators are dissolved oxygen, five days’ biochemical oxygen demand, permanganate index, ammonia nitrogen, total nitrogen and total phosphorus. Training the model with water quality data from 2005 to 2011, Levenberg-Marguardt optimization algorithm is adopted to train samples. After reaching the error requirement, simulate the model with the water quality monitoring data in 2012 and test the model accuracy. Simulation results show that the accuracy of the model prediction is higher in 2012. It is proved that this model can be used to predict water quality of the outbound mouth in Fushun section, and the model provides a theoretical basis for improving the water quality of the reservoir area and can be used to guide the actual water quality management.

The study aims to understand the distribution of groundwater quality in coastal regions from Injambakkam-Thiruvanmyiur areas, Chennai. Groundwater samples were collected from the coastal regions of Tamil Nadu. The objectives of the study are to determine the groundwater quality characteristics such as pH, alkalinity, electrical conductivity, chloride, hardness, total dissolved solids, dissolved oxygen and map the spatial distribution of groundwater quality in the study area by using open source software Quantum GIS (QGIS). The physico-chemical parameters and the quality of the water vary with space and thus mapping it with the GIS is an efficient way to draw conclusions about the study area. Inverse Distance Weighted (IDW) interpolation method was used to create various raster maps which show the spatial distribution. With the present study it is found that, most of the regions in the southern part of the study area have poor to very poor quality based on the Water Quality Index (WQI).

The objective of this study is to examine the physical, chemical and biological characteristics of swimming pool water in Mafraq city, north of Jordan and the overall quality of the used water. Three public swimming pools were selected from Mafraq city [Areef Pool (SW1), Teachers Club Pool (SW2) and Anakeel Pool (SW3)] to analyze the physical, chemical and biological properties of their water as well as determine their compliance with the Jordanian Standards for Swimming Pools Water. Sampling was carried out weekly for eight successive weeks between July and August 2019 before bathing (after disinfection) and after bathing and analysed in Al al-Bayt University and Ministry of Environment laboratories. The parameters used to evaluate the quality of water in swimming pools were temperature, pH, electrical conductivity (EC), dissolved oxygen (DO), residual chlorine (Cl2), total organic carbon (TOC), trihalomethanes (THM), major cations and anions, selected heavy metals, and total coliform bacteria, E. coli and Pseudomonas. Most of the physical and chemical parameters analysed were within the recommended limit except for pH and EC. Residual chlorine exceeded the permissible limits in SW3 before and after bathing, recording mean values of pH, EC (4.3 ± 0.25 - 4.33 ± 0.44), (2314 ± 343 - 2453 ± 460), respectively. The dissolved oxygen was less than the recommended limit. Total coliforms, E. coli and Pseudomonas counts were < 1 before and after bathing in all the samples.

The epilithic diatoms of a periurban watercourse of Casablanca city (Bouskoura stream) were studied from samples taken in 8 stations (distributed in the upstream-downstream direction) for two years (August 2015-July 2017). The recorded diatomic flora consists of 54 species corresponding to 27 genera and belonging to 5 main families: Monoraphids, Naviculaceae, Nitzschiaceae, Araphids and Surirellaceae. This flora is predominantly alkaliphile and characterizes ?-mesosaprobe to polysaprobes and eutrophic to hypereutrophic media. Responses assemblage to natural and anthropogenic disturbances were analyzed. Diatom assemblages structure analysis shows that downstream of this watercourse, where pollution is intense, the abundances of pollosensitive taxa such as Achnanthes minutissima, Cymbella affinis are low or even nulls and we are witnessing the appearance of polysaprobe forms such as Nitzschia palea, Nitzschia capitellata and Nitzschia frustulum that tolerate rich environments in organic matter or highly polluted. Spatial variation in species diversity could not highlight changes in water quality at the prospected sites; on the other hand, the change in the percentage of pollutant-tolerant taxa (PTV) revealed the full extent of the alteration due to gradual nutrient and organic matter inputs into the Bouskoura watercourse. In addition, the correlation obtained between this index and the organic pollution index (IPO) is highly significant. Principal component analysis (PCA) highlighted taxonomic differences between stations. The results obtained in this work have emphasized the importance of diatoms as a bioindicator of the health status of this periurban watercourse.