A comparative assessment of the status of Surajkund and Rani Pond,Aurangabad, Bihar,India using overall Index of Pollution and Water Quality Index

The Water Quality Index is one of the most effective tools to communicate information on the quality of water to the people. An attempt was made to assess the annual and seasonal status of Surajkund and Rani Pond, Aurangabad, Bihar, India using the overall Index of Pollution and Water Quality Index from November 2017 to October 2019. The values of eleven parameters namely water temperature, pH, electrical conductivity, dissolved oxygen, biochemical oxygen demand, total alkalinity, hardness, total dissolved solids, chloride, nitrate and fluoride were calculated following standard methodology. A statistically significant difference was found among these parameters. The values were compared with the standard to determine the overall Index of Pollution and Water Quality Index. Results indicated that electrical conductivity, total alkalinity and total dissolved solid were higher than prescribed limits. The values 1.5–3.50 of the overall Index of Pollution estimated that the average status of water of Surajkund was acceptable (C2) but Rani Pond and Surajkund during the summer season were slightly polluted (C3). The values 74.18–233.89 of the Water Quality Index inferred that the average status of water of Surajkund and Rani Pond was slightly polluted (C3). However, on a seasonal basis, the water quality of Surajkund was acceptable (C2) but Rani Pond was slightly polluted (C3) to polluted (C4). The results revealed anthropogenic activity and entry of untreated sewage in these water bodies. The water quality felt the necessity to adopt proper management policy and conservation efforts to these water bodies.     

Physico-chemical and Water Quality Index analysis of the Okhuaihe River,Edo State,Nigeria

The water quality of the Okhuaihe River, Edo State, Nigeria was investigated from February to June 2016 to determine its suitability for drinking and other domestic purposes. Water samples collected from three stations were tested for fifteen physico-chemical parameters using standard analytical procedures. Biochemical oxygen demand and sodium were significantly different across the three stations. Except for calcium and iron, all other parameters were within the permissible limits recommended by the Nigerian Standard for Drinking Water Quality (NSDWQ) and World Health Organization (WHO). Water Quality Index (WQI) values ranged from 9.17 to 10.40, indicating excellent water quality. Although the quality of the water from the Okhuaihe River is suitable for drinking and domestic usage, regular monitoring of human activities along the water front and control of effluents discharged into the river is recommended to sustain and improve water quality.     

Use of Macrophytes in Assessing the Ecological Status of Small River (by the Example of the Okhta River,St. Petersburg)

Hydrochemical and hydrobiological characteristics have been studied at 13 sites in the Okhta River within the precincts of St. Petersburg in 2010. The Water Pollution Index (WPI), calculated according to hydrochemical parameters, characterizes the river water quality as “very polluted” to “extremely polluted.” According to the Pantle–Buck–Sláde?ek Saprobity Index, obtained on the basis of macrozoobenthos characteristics, polysaprobic and α-mesosaprobic zones can be distinguished in the watercourse. The species richness of river macrophytes is low (18 species). The Macrophyte Water Quality Index makes it possible to assess water quality in the range from “polluted” to “very polluted” water. Macrophyte trophic indexes MTR, IBMR and TIM indicate a high trophy level in the watercourse sites. Based on the analysis of hydrochemical materials and the data on macrozoobenthos and macrophytes, the general tendency is similar: deterioration of water quality downstream. Macrophyte characteristics reflect changes in hydrochemical parameters downstream the river course. А strong correlation (r =–0.76) is found between the Macrophyte Water Quality Index and WPI. The possibility of using the data on macrophytes in small rivers for assessing water quality is demonstrated.     

Water quality assessment of the Siluko River,southern Nigeria

The water quality of the Siluko River, Edo State, Nigeria was investigated from March to August 2015 to determine its suitability for drinking and usage for domestic purposes. Water samples collected from three stations were tested for thirteen physico-chemical parameters using standard analytical procedures. Temperature, phosphate and chloride were significantly different across the three stations. All other parameters, with the exception of turbidity, dissolved oxygen and phosphate, were within the permissible limits recommended by the Nigerian Standard for Drinking Water Quality (NSDWQ) and World Health Organization (WHO). Water Quality Index (WQI) values ranged from 11.24 to 16.15, indicating excellent water quality. While the quality of the water from the Siluko River is suitable for drinking and domestic usage, to prevent future deterioration of the water, it is recommended that the regulating authorities monitor effluents discharged into the river from human activities.     

An ecosystem-based approach to evaluate the ecological quality of Mediterranean undersea caves

A theoretical model of structure and functioning was constructed for the Mediterranean undersea cave ecosystem. This model integrates almost all representative components of the cave ecosystem and gives an idea of their faunal compositions, characteristics and related interactions.This model constitutes the basis of the Ecosystem-Based Quality Index (EBQI) of the European Union's Marine Strategy Framework Directive, which aims at evaluating the ecological quality of an ecosystem. It is based on four crucial complementary elements: (i) each component was weighted in accordance with its importance in determining the structure and functioning of the cave ecosystem; (ii) a suite of relevant parameters were defined to assess the ecological state of each component of the cave ecosystem; (iii) these parameters were aggregated into one relevant index, the Cave EBQI (CavEBQI), to summarize the quality evaluation for each cave site; (iv) each value of ecological state is accompanied by a Confidence Index as a measure of its reliability.The CavEBQI was used on 22 Mediterranean undersea caves of France and Italy. Disparities of ecological quality were found among caves but most of them ranged from moderate to high ecological quality. For some caves, no conclusion can be drawn when our method predicts a poor reliability of the evaluation of their ecological quality.This ecosystem-based evaluation of the quality of undersea caves seems to be a powerful tool, with the advantage of being based on almost all its components, rather than just on a few species. It is accompanied by a measure of its reliability, hence it provides a reliable idea of the ecological state of the entire ecosystem at each cave site. Monitoring the ecological state of caves and the effects of disturbances over large geographic and temporal scales is made possible with CavEBQI. Applying the same method to other ecosystems, can provide an integrated view of a marine region, which is essential when addressing questions about protection, conservation and restoration.     

Ecosystem engineering moving away from just-so stories

The concept of ecosystem engineering has been proposed recently to account for key processes between organisms and their environment which are not directly trophic or competitive, and which result in the modification, maintenance and/or creation of habitats. Since the initial reporting of the idea, little work has been undertaken to apply the proposed concept to potential ecosystem engineers in the marine environment. Biological and ecological data for the burrowing ghost shrimp Callianassa filholi (Decapoda: Thalassinidea) allowed for a formal assessment of this species as an ecosystem engineer, in direct accordance with published criteria. Despite a low population density and the short durability of its burrow structures, Callianassa filholi affected a number of resource flows by its large lifetime per capita activity. Ecosystem effects were evident in significant changes in macrofauna community composition over small spatial and temporal scales. Seasonal variation in the effects of ghost shrimp activity were associated with changes in seagrass (Zostera novazelandica) biomass, which revealed the probability of interactions between antagonistic ecosystem engineers. The formal assessment of Callianassa filholi provides the opportunity to aid discussion pertaining to the development of the ecosystem engineering concept.     

Invasive ecosystem engineers and biotic indices: Giving a wrong impression of water quality improvement?

Benthic component of an ecosystem is considered in ecological status assessment of the key European Directives. Most of the metrics proposed for the benthic quality assessment are biodiversity based. Their robustness and applicability are widely discussed in many recent studies. However an impact of invasive alien species on biotic indices and environmental quality assessments has been largely overlooked by researchers so far. In the current study we assessed Benthic Quality Index (BQI) in a coastal ecosystem, highly affected by the invasive zebra mussel Dreissena polymorpha. Zebra mussel is able of modifying benthic habitats and enhancing local biodiversity. In the analyzed ecosystem it affected benthic species richness, abundance and community structure. As a result the calculated BQI values were significantly higher in the presence of zebra mussel with evident outliers in samples with particularly high zebra mussel abundances. Therefore we found that BQI determined in our study was artificially elevated providing false signal of the ecological status improvement. Based on the results presented, we suggested data correction framework that has been tested on the current dataset and proved to be effective minimizing zebra mussel impact on BQI assessment. Our experience could be applied for other coastal ecosystems invaded by the zebra mussel or any other aquatic invasive species with resembling biological traits and bioinvasion impacts.     

Assessment of water quality and health risks for toxic trace elements in urban Phewa and remote Gosainkunda lakes,Nepal

The concentration of 13 metals (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, and Hg) and their associated health risk assessment was performed for two Himalayan lakes, urban Phewa and remote Gosainkunda, from Nepal. Water Quality Index (WQI), Metal Index (MI), Hazard Quotient (HQ), Hazard Index, and Cancer Risk were calculated in order to evaluate the water quality of these lakes. Correlation analysis revealed that Mn and Fe were derived from natural geological weathering processes and Pb, V, Cr, Co, Ni, Cu, Zn, and Cd might have originated from anthropogenic sources. The results revealed that WQI of the remote lake fell into excellent water quality and urban lake fell into poor water quality, which is also supported by the MI calculation. Moreover, the HQ of Mn in urban lake showed values greater than unity suggesting its health risk to the local inhabitants. The cancer index values indicated “high” risk due to Cr, whereas Cd possesses “very low” cancer risk on local population residing nearby areas. This study provides the useful database and suggests for the regular assessment and policy formulation for safeguarding the natural water bodies in the region.     

普者黑岩溶湖泊湿地湖滨带景观格局演变对水质的影响

湖滨带作为湖泊与陆地之间的过渡带,是健康湖泊生态系统的重要组成部分。湖滨带景观格局的演变会对湿地水质产生重要影响,因此探究影响岩溶湿地水质变化的湖滨带关键景观因子,对深入了解景观格局对岩溶湿地水质的影响过程与机制具有重要意义。选择普者黑岩溶湖泊湿地为研究对象,以2005、2007、2009、2011年共4年的Landsat遥感影像及水质监测数据为基础,通过划定湖泊湿地湖滨带缓冲区域,运用秩相关分析和冗余分析研究湖滨带景观格局对普者黑岩溶湖泊湿地水质的影响。结果表明,湖滨带不同缓冲区内景观结构类型比例差异较大;枯水期水质与土地利用类型和景观格局指数的影响大于丰水期;景观格局在不同缓冲区尺度对岩溶湿地的水质具有不同的效应;随着监测点缓冲距离的增加,个别景观指数可较好的揭示湖滨带景观格局演变对岩溶湿地水质的影响,其中,蔓延度指数(CONTAG)、斑块结合度指数(COHSION)、均匀度指数(SHEI)对水质参数的影响较大,边界密度(ED)、聚集度(AI)对水质参数的影响随缓冲距离的增加逐渐减弱,其他景观指数对水质影响差异并不明显,最大斑块指数(LPI)在缓冲距离≤300m的区域内与水质的关系较密切,面积加权平均斑块分维数(AWMPFD)与水质参数有显著负相关性,多样性指数(SHDI)对水质的影响具有不确定性;另外,大部分水质参数与土地利用面积比例有较好的相关性,且湿地面积比例是表征岩溶湖泊湿地水环境质量的主要指标。     

The Water Impact Index: a simplified single-indicator approach for water footprinting

Purpose

Along with climate change-related issues, improved water management is recognized as one of the major challenges to sustainability. However, there are still no commonly accepted methods for measuring sustainability of water uses, resulting in a recent proliferation of water footprint methodologies. The Water Impact Index presented in this paper aims to integrate the issues of volume, scarcity and quality into a single indicator to assess the reduction of available water for the environment induced by freshwater uses for human activities.

Methods

The Water Impact Index follows life cycle thinking principles. For each unit process, a volumetric water balance is performed; water flows crossing the boundaries between the techno-sphere and environment are multiplied by a water quality index and a water scarcity index. The methodology is illustrated on the current municipal wastewater management system of Milan (Italy). The Water Impact Index is combined with carbon footprint to introduce multi-impact thinking to decision makers. The Water Impact Index is further compared to results obtained using a set of three life cycle impact indicators related to water, from the ReCiPe life cycle impact assessment (LCIA) methodology.

Results and discussion

Onsite water use is the main contribution to the Water Impact Index for both wastewater management schemes. The release of better quality water is the main driver in favour of the scenario including a wastewater treatment plant, while the energy and chemicals consumed for the treatment increase the indirect water footprint and carbon footprint. Results obtained with the three midpoint indicators depict similar tendencies to the Water Impact Index.

Conclusions

This paper presents a simplified single-indicator approach for water footprinting, integrating volume, scarcity and quality issues, representing an initial step toward a better understanding and assessment of the environmental impacts of human activities on water resources. The wastewater treatment plant reduces the Water Impact Index of the wastewater management system. These results are consistent with the profile of the three midpoint indicators related to water from ReCiPe.     

Addressing water quality in water footprinting: current status,methods and limitations

Purpose

In contrast to water consumption, water pollution has gained less attention in water footprinting so far. Unlike water scarcity impact assessment, on which a consensus has recently been achieved, there is no agreement on how to address water quality deterioration in water footprinting. This paper provides an overview of existing water footprint methods to calculate impacts associated with water pollution and discusses their strengths and limitations using an illustrative example.

Methods

The methods are described and applied to a case study for the wastewater generated in textile processing. The results for two scenarios with different water quality parameters are evaluated against each other and the water scarcity footprint (WSF). Finally, methodological aspects, strengths and limitations of each method are analysed and discussed and recommendations for the methods application are provided.

Results and discussion

Two general impact assessment approaches exist to address water quality in water footprinting: the Water Degradation Footprint (WDF) calculates the impacts associated with the propagation of released pollutants in the environment and their uptake by the population and ecosystem, while the Water Availability Footprint (WAF) quantifies the impacts related to the water deprivation, when polluted water cannot be used. Overall, seven methods to consider water quality in water footprinting were identified, which rely upon one or a combination of WDF, WAF and WSF. Methodological scopes significantly vary regarding the inventory requirements and provided results (a single-score or several impact categories). The case study demonstrated that the methods provide conflicting results concerning which scenario is less harmful with regard to the water pollution.

Conclusions

This paper provides a review of the water pollution assessment methods in water footprinting and analyses their modelling choices and resulting effects on the WF. With regard to the identified inconsistencies, we reveal the urgent need for a guidance for the methods application to provide robust results and allow a consistent evaluation of the water quality in water footprinting.

     

Assessment of water quality in Iran’s Anzali Wetland,using qualitative indices from 1985, 2007, and 2014

In the present study, the water quality of the Anzali Wetland, located southwest of the Caspian Sea in Iran, was compared for the years 1985, 2007, and 2014, using a weighted arithmetic mean function (National Sanitation Foundation Water Quality Index: NSFWQI_a), a weighted geometric mean function (NSFWQI_m), and the Oregon Water Quality Index (OWQI). To that end, nine water quality parameters [pH, turbidity (TURB), temperature (T), dissolved oxygen (DO), nitrate (NO₃), total solids (TS), phosphate (PO₄), biological oxygen demand (BOD₅), and fecal coliforms (FC)] were analyzed at eight selected stations. According to the proposed classification for water quality indices (higher value (0–100), better water quality), the Wetland water quality was classified as the mean values of the three indices for the three sampled years, as follows: NSFWQI_a (13.72, 12.81, 12.07); NSFWQI_m (63.049, 52.388, 49.108); and OWQI (26.867, 14.477, 15.53). The values of NSFWQI_a, NSFWQI_m, and OWQI for the western stations were better than for the other stations in the region over the 29-year span of investigation; however, the remainders of the stations’ values were very poor. Because wastewaters discharged from industrial and agricultural areas are more concentrated in the eastern part of the Anzali Wetland, the eastern stations of the Wetland showed lower water quality compared to the central and western stations. The water of the Anzali Wetland has different quality classes according to the aggregation methods employed. It is concluded that when evaluating water quality of aquatic ecosystems, several indices should be used to obtain more comprehensive results.     

Predicting Water Quality Index (WQI) by feature selection and machine learning: A case study of An Kim Hai irrigation system

A variety of water quality indices have been used to assess the state of waterbodies all over the world. In calculating a Water Quality Index (WQI), traditional methods require the evaluation of many water quality parameters, making them costly and time-consuming. In recent years, machine learning (ML) algorithms have emerged as an effective tool to solve many environmental problems, including water quality management. In this study, we investigate the performance of the ML-based method in calculating the WQI. We apply several feature selection techniques to select the key parameters fed the ML models. Experiments are carried out to evaluate the WQI based on a dataset collected from 2007 to 2020 of An Kim Hai system, one of the most important irrigation systems in the north of Vietnam. The obtained results show that the application of selection methods allows reducing significantly the number of water quality parameters fed the ML models without losing their accuracy. In particular, by using the embedded method, we find out four important parameters, including Coliform, DO, Turbidity, and TSS, that have the greatest impact on water quality. Based on these parameters, the Random Forest model provides the best accuracy in predicting the WQI values from the An Kim Hai system with a Similarity of 0.94. The combination of feature selection and ML methods is then considered an effective alternative for calculating the WQI, leading to a desirable performance and a reduction of input parameters. This makes water quality monitoring less costly, substantial effort, and time.     

Australian water quality guidelines: a new approach for protecting ecosystem health

The Australian and New Zealand Environment and Conservation Council (ANZECC) and the Australian Water Resources Council (AWRC) have developed a National Water Quality Management Strategy which seeks to ensure that the nation's water resources are managed on a sustainable basis. An important element of this strategy are the Australian Water Quality Guidelines which focus on the protection of Australian freshwater and marine ecosystems. Here the aim is to protect biodiversity and maintain the ecological integrity of each marine and freshwater resource. Specific guidelines have been formulated in terms of key indicators of quality, with a single reference value or ranges of reference values provided for guidance. For those indicators where ranges are provided, it is the expectation that State environmental and resource management agencies will undertake local, site-specific investigations of their own systems to define the specific levels to be adopted. For the first time, specific and quantitative biological indicators have been introduced; these are species richness, species composition, primary production, and ecosystem function.As Australia progresses towards broader, more holistic, ecologically-based management of the nation's water resources, the present water quality guidelines must be extended to ecosystem or environmental guidelines, where the maintenance of adequate water quality is seen as only one (albeit important) component. Other considerations must include habitat protection, sediment quality, and stream flow maintenance. This increased emphasis on more ecologically-focused management of Australia's inland and coastal waters will present a number of challenges for the three major groups involved: the community, the managers, and the researchers. These challenges are discussed.Based on a paper presented at a Workshop on Biological Assessment of Aquatic Ecosystem Health, Sydney, 1–2 October 1992.     

Modification of expected conflicts between Drinking Water Quality Index and Irrigation Water Quality Index in water quality ranking of shared extraction wells using Multi Criteria Decision Making techniques

Groundwater resources play a crucial role in most arid/semi-arid regions such as Karaj plain, Iran. Excavation of wells and exploiting water resources of aquifers have long been known as ordinary solutions to supply water demands for drinking, agricultural and industrial purposes. In many agricultural areas such as the above-mentioned region, extraction wells have been utilized for both drinking and agricultural consumptions, while measures taken for water quality monitoring and protecting public health are seriously limited. On the other hand, most of the shared extraction wells in the region used for drinking purpose have been located near the agricultural lands and they are highly under the risk of getting polluted by Agricultural pesticides. The current paper firstly intends to demonstrate the results obtained from Drinking water Quality Index (DWQI) as well as Irrigation Water Quality Index (IWQI) and secondly determines probable conflicts that may be aroused in ranking of water wells using these two methods Subsequently, Multi Criteria Decision Making (MCDM) techniques such as Ordered Weighted Averaging (OWA), Compromise Programing (CP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) were employed to decrease effects of the conflicts. It was clarified that MCDMs, to some extent, alleviated contradictions in wells’ ranks −determined by DWQI/IWQI- and authenticated this procedure as an appropriate method for water quality ranking in agricultural societies.     

The efficient role of aquatic plant (water hyacinth) in treating domestic wastewater in continuous system

In this study, water hyacinth (Eichhornia crassipes) was used to treat domestic wastewater. Ten organic and inorganic parameters were monitored in three weeks for water purification. The six chemical, biological and physical parameters included Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammoniacal Nitrogen (NH₃-N), Total Suspended Solids (TSS), and pH were compared with the Interim National Water Quality Standards, Malaysia River classification (INWQS) and Water Quality Index (WQI). Between 38% to 96% of reduction was observed and water quality has been improved from class III and IV to class II. Analyses for Electricity Conductivity (EC), Salinity, Total Dissolved Solids (TDS) and Ammonium (NH₄) were also investigated. In all parameters, removal efficiency was in range of 13–17th day (optimum 14th day) which was higher than 3 weeks except DO. It reveals the optimum growth rate of water hyacinth has great effect on waste water purification efficiency in continuous system and nutrient removal was successfully achieved.     

Biospheric foundations of the ecosystem approach to environmental management

The ecosystem approach to environmental management inter-relates social, economic and environmental factors. Its incorporation into the Great Lakes Water Quality Agreement of 1978 changed the focus of the Agreement from water in a political context to politics in an ecosystem context. Because ecosystems are open and dependent on Biospheric processes for their continued operation, the Biosphere (global ecosystem) emerges as a globally integrating factor in ecosystem management. Influences leading to development of the ecosystem approach in the Great Lakes Basin included: a politically shared resource in jeopardy, pollution, a common drinking water source, common enemies, advances in ecosystem theory, citizen groups, international political institutions, common economic and cultural ties, and a sense of crisis. A rationale is presented for viewing nations as politically defined ecosystems.     

A modified drinking water quality index (DWQI) for assessing drinking source water quality in rural communities of Khuzestan Province,Iran

We reconsidered the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) to achieve an efficient drinking water quality index (DWQI) for assessment of drinking source water quality in rural communities of Khuzestan Province, Iran in 2009–2013. In contribution with a panel of water quality experts, the CCME WQI was mainly modified by four changes: (1 and 2) assigning weight factors for input parameters and index factors, (3) modifying excursion concept for carcinogens and bioaccumulative pollutants and (4) removing effect of unequal measurements of input parameters. The DWQI characterizes the drinking source water quality through comparing the measured values of input parameters with relevant benchmarks. The DWQI score (from 0 to 100) classifies the water quality in five categories as poor (0–54.9), marginal (55.0–69.9), fair (70.0–84.9), good (85.0–94.9) and excellent (95.0–100). Based on the DWQI, the temporal changes of the rural drinking source water quality were not significant; while the spatial variations of the water quality were considerable across the province, so the DWQI scores in the northern counties were higher than that in the southern ones. At the county level, the highest and lowest average scores of the DWQI (±standard deviation: SD) were observed in Izeh and Shadegan to be 90 ± 5 and 69 ± 10, respectively. Based on the DWQI, proportions of the drinking water sources with the excellent, good, fair, marginal and poor qualities were determined to be 6.7, 59.1, 26.2, 7.8 and 0.1%, respectively. Turbidity and Ryznar Index (RI) were introduced respectively as the health-based and esthetic parameters with the most violations (22.7 and 63.2%, respectively). The results of the case study and sensitivity analysis indicated that the DWQI is a simple, flexible, stable and reliable index and could be used as an effective tool to characterize drinking source water quality.     

An innovative approach of Drinking Water Quality Index—A case study from Southern Tamil Nadu,India

The aim of the present study is to exhaust the limitations of conventional reputed Water Quality Index (WQI) methodologies through the proposed reliable Drinking Water Quality Indexing (DWQI) system. Slight modifications were carried out in the methodology of the DWQI development which were parameter categorization, development of sub-index with regression statistics and aggregation function with Min–Max operator. Twenty-two water quality parameters were selected for quality evaluation. The proposed DWQI was compared with conventional methodologies of arithmetic DWQI and geometric DWQI and evaluated with a case study. A data set of 24 ground water samples collected from Southern Tamil Nadu, India was made to illustrate the application and feasibility of the index.The results of the case study revealed that arithmetic DWQI scores were higher than the proposed and geometric DWQI while geometric DWQI scores were lower than the proposed DWQI scores. All the indices were well correlated (r ≥ +0.98) with each other. The arithmetic DWQI exhibited significant difference (P < 0.001) with other indices but the proposed DWQI scores had insignificant variations (P = 0.40) with geometric DWQI scores. The comparison of different forms of indices showed that the proposed DWQI was the most reliable indexing system than the others which diminished the sensitivity and eclipsing problems of conventional indexing system.