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The goal of this study was to optimize the coagulation-flocculation process in wastewater generated from the paper and pulp industry using a grey relational analysis (GRA)-based Taguchi method. Process parameters included types and doses of natural coagulants and coagulant aid, and pH. To track the efficiency of the treatment process, the following responses were chosen for optimization: chemical oxygen demand (COD), total dissolved solids (TDS) and turbidity ofwastewater, alone or in combination or all together. Analysis of variance showed that the type and dose of the coagulant aid were the most significant parameters, followed by pH and the dose of the coagulant; the type of coagulant used was found to be insignificant in the coagulation-flocculation process. Optimization of process parameters to achieve lower turbidity and greater removal of COD and TDS was verified in a separate confirmatory experiment, which showed improvements in COD and TDS removal and a decrease in turbidity of 8.2, 6.35 and 26.17%, respectively, with the application of the Taguchi method and GRA. [ABSTRACT FROM AUTHOR]

This paper studies the differences and determinants of handwashing practices in India and identifies sections of the population with poor handwashing practices who are relatively more vulnerable during the COVID-19 pandemic. We have used the data from the recent National Sample Survey (NSS, 76th round) for India (2018). Bivariate and logistic regression analyses have been performed to predict the determinants of handwashing practices across states and socio-economic groups. Levels of education of the household head, Usual Monthly Per Capita Expenditure (UMPCE) of the household, access to water (other than drinking water) resources and sanitation facilities, and the availability of water with soap in and around latrines are major socio-economic and demographic factors that impact handwashing practices. Higher access to principal sources of water for drinking and other purposes, access to bathrooms and latrines with soap, and the availability of water in or around latrines increase the likelihood of handwashing among the people. Universal handwashing across different sections of the population will be effective to prevent further infection. The available data help us to identify the vulnerable sections of the population which are towards the lower end of the handwashing compliance spectrum. The policymakers can outline specific planning and strategy implementation for them. [ABSTRACT FROM AUTHOR]

The Eastern Indian Gangetic Plains are characterized by a primarily nature-dependent region blessed with an enormous supply of mineral resources. The region is witnessing a rapid transition in its demographic structure because of rapid industrialization. The region provides a classic example of an area which shows a trend reverse to that observed globally, as far as the frequency of extreme precipitation events is concerned. This paper provides a risk characterization of the entire region, based on the empirical behavior shown by data available so far, in addition to predictions based on theory of extreme values. The long-term behavior prediction is made with an aim to provide policy makers ample time and direction to develop suitable disaster prevention measures. The focus is primarily on extremely high rainfall events, their frequency, trend and estimated long-term behavior. The study corroborates the stability assumption behind the Indian monsoon, and also provides an indication of the expected long-term as well as short-term threats. This study provides a unique application of the extreme value theory to help in developing a threat map for a region whose population is known to be highly impacted by any significant deviations from a normal monsoon. [ABSTRACT FROM AUTHOR]

This article provides updated status of the arsenic affected rural habitations in India, summarizes the policy initiatives of the Ministry of Drinking Water & Sanitation (Government of India), reviews the technologies for arsenic treatment and analyses the progress made by states in tackling arsenic problems in rural habitations. It also provides a list of constraints based on experiences and recommends suggested measures to tackle arsenic problems in an holistic manner. It is expected that the paper would be useful for policy formulators in states, non-government organizations, researchers of academic and scientific institutions and programme managers working in the area of arsenic mitigation in drinking water, especially in developing countries, as it provides better insights compared to other available information in India on mitigating arsenic problems in drinking water in rural areas. [ABSTRACT FROM AUTHOR]

Snow- and glacier melt are important contributors to river discharge in high-elevated areas of the Himalayan region. Thus, it is important that the key processes controlling snow and glacier accumulation and melting, are well represented in hydrological models. In this study, the sensitivity of modelled discharge to different snowmelt parameterizations was evaluated. A distributed hydrological model that operated on a 1 × 1 km2 grid at a daily time resolution was applied to a high-elevated mountainous basin, the Upper Beas basin in Indian Himalaya, including several sub-basins with a varying degree of glacier covered areas. The snowmelt was calculated using (i) a temperature-index method, (ii) an enhanced temperature-index method including a shortwave radiation term, and (iii) an energy balance method. All model configurations showed similar performance at daily, seasonal, and annual timescales and a lower performance for the validation period than for the calibration period; a main reason being the failure to capture the observed negative trend in annual discharge in the validation period. The results suggest that model performance is more sensitive to the precipitation input, i.e. interpolation method than to the choice of snowmelt routine. The paper highlights the challenges related to the lack of high quality data sets in mountainous regions, which are those areas globally with most water resources. [ABSTRACT FROM AUTHOR]

Water reuse is recognized as a tool to increase water supply in peri-urban areas of semi-arid and arid regions of the world. However, it is an option rarely explored for rural areas in developing countries, and has not been documented extensively in the scientific literature. This paper presents results from 6 greywater reuse systems which were built with the objective to augment water supply and to provide sanitation in rural low income areas of Madhya Pradesh, India. The systems are based on reclaiming greywater from bathing for the use in toilet flushing and kitchen garden irrigation. The reuse systems were implemented based on the scientific rationale presented in the WHO (2006) guidelines. The paper presents evidence from the operation and evaluation of the greywater treatment plants under field conditions between 2005 and 2008. The paper concludes that greywater is a highly cost effective solution for water scarcity. In this study, reusing greywater resulted in a 60% increase in water availability, a reduction in open defecation and a fourfold increase in food availability. [ABSTRACT FROM AUTHOR]

Given the high level of capital investment and the history of government subsidized services, full cost pricing of water services has yet to take hold in India. As a result, it remains broadly underpriced leading to public perception that water is "free" The current tariff levels in India are too low to cover even operating costs. This paper examines the existing Indian urban water tariff models (fixed tariff, volumetric tariff, increasing block tariff etc.), their relevance and problems. It was found that none of the tariff structures could satisfy all the design objectives (cost recovery, economic efficiency, equity, affordability etc.). Also subsidies are not explicit and well targeted for poor population. There are several studies and issues that do demonstrate the opportunities for tariff increase and improved cost recovery. This paper highlights the results of such studies and brings out issues needing consideration. Improved cost recovery would lead to improved financial status of the water utilities. Also, subsidies, if designed suitably and well targeted, would serve the concerns of the economically weaker sections. Such reform process would eventually lead to socio-economic sustainability. [ABSTRACT FROM AUTHOR]

Roorkee, a sub-tropical urban town in India, has shown a rapid unplanned growth in the past. This paper presents the findings of a study of characteristics of urban soil, rainwater, and runoff emanating from different sources areas and the stormwater flows in the drains. Urban soil showed significant increase in the concentration of all constituents in comparison to the nearby rural soil. Soil metal pollution index suggested multi-element contamination. The traffic and transportation system emerged as the major source of metals and organics. Concentration of rainwater ions was observed to follow the pattern Ca2+> HCO3-> Cl-> NO3-> Na+ >Mg2+>SO42- >K+. Runoff results indicated a significant enhancement in the concentration of most measured constituents over their rainfall levels. The values of runoff coefficient varied between 0.05 and 0.58, with the high values displayed by the paved areas. Multiple regression equations were developed relating event mean concentration to various storm characteristics. The total load of all measured constituents was observed to vary considerably among the study sites, the direct runoff loads being much higher than the dry weather loads. [ABSTRACT FROM AUTHOR]

This special edition is a compilation of papers delivered orally at the workshop on regionalization of models for operational purposes in developing countries held during the joint International Association of Hydrological Sciences (IAHS) and International Association of Hydrogeologists (IAH) International Convention in Hyderabad, India during September 2009. The overall theme of the convention was 'Water: A vital resource under stress -- how can science help?' How science can help solve practical water resources management problems and regionalization of models have been recurring themes in hydrological science over the last few decades. If anything, however, the gap between scientific developments and their application in practice has widened, notably in developing countries where financial and institutional constraints continue to be difficult to overcome. While data scarcity remains a major problem, a combination of developments in models, availability of remotely sensed data and an understanding of the treatment of uncertainty implies that we can overcome many of the data deficiency issues. Unfortunately, this does not seem to be the case in practice, and effective and sustainable technology transfer remains elusive in many developing countries. [ABSTRACT FROM AUTHOR]

In India a large number of pharmaceutical industries are manufacturing drugs of complex type subsequently producing huge quantities of wastewaters. The herbal pharmaceutical industries are one of them which manufacture various herbal medicines from natural products and certain chemicals and metal combinations. During their manufacturing process a large number of toxicants enter the watercourse harming the biota of the receiving water bodies. Zooplankton organisms being at the base of the food chain if affected, will subsequently affect the fisheries potential at large, harming the interest of man. Keeping this point in view a herbal pharmaceutical manufacturing industry based at Nagpur was selected for investigation with respect to assessing its toxic effect on the freshwater crustacean Cypris spp. during short duration toxicity tests. This research paper discusses in detail the bioassay evaluation of raw, neutralized and physico-chemically treated herbal pharmaceutical effluent for arriving at a concentration safe for the Cypris spp. [ABSTRACT FROM AUTHOR]

Most coastal cities use the ocean as a site of waste disposal where pollutant loading degrades the quality of coastal waters. Presently, the west coast of Mumbai receives partially treated effluent from wastewater treatment facilities through ocean outfalls and discharges into creeks as well as wastewater/sewage from various open drains and nallahs which affect the water quality of creek and coastal water. Therefore, the objective of this paper is to simulate and assess the hydrodynamic behaviour and water quality due to impact of sewage and wastewater discharges from the west coast of Mumbai. Hydrodynamics and water quality were simulated based on present conditions and validated by using measured tide, current data and observed DO, BOD and FC. Observed and simulated results indicated non compliance to standards in Malad, Mahim creeks and the impact zones of ocean outfalls. The developed model could be used for generating various conditions of hydrodynamics and water quality considering the improvement in wastewater collection systems, treatment levels and proper disposal for proper planning and management of creeks and coastal environment. [ABSTRACT FROM AUTHOR]

The state of Punjab comprising 1.5% area of the country has been contributing 40-50% rice and 60-65% wheat to the central pool since last three decades. During last 35 years The area under foodgrains has increased from 39,200 sqkmha to 63,400 sqkm and the production of rice and wheat has increased from 0.18 to 0.32 kg/m² and 0.22 to 0.43 kg/m² respectively. This change in cropping pattern has increased irrigation water requirement tremendously and the irrigated area has increased from 71 to 95% in the state. Also the number of tube wells has increased from 0.192 to 1.165 million in the last 35 years. The excessive indiscriminate exploitation of ground water has created a declining water table situation in the state. The problem is most critical in central Punjab. The average rate of decline over the last few years has been 55cm per year. The worst affected districts are Moga, Sangrur, Nawanshahar, Ludhiana and Jalandhar. This has resulted in extra power consumption, affects the socio-economic conditions of the small farmers, destroy the ecological balance and adversely affect the sustainable agricultural production and economy of the state. Therefore, in this paper attempt has been made to analyse the problem of declining water table, possible factors responsible for this and suggest suitable strategies for arresting declining water table for sustainable agriculture in Punjab. The strategies include shift of cropping pattern, delay in paddy transplantation, precision irrigation and rainwater harvesting for artificial groundwater recharge. [ABSTRACT FROM AUTHOR]

Arsenic in groundwater is a huge problem in numerous regions of the world. Many people are exposed to high arsenic concentrations and consequently risk getting ill or even die as a result of arsenic poisoning. There are several efficient technologies for the removal of arsenic but often these methods have disadvantages, e.g. high costs for installation and/or operation, the need for chemicals or the production of arsenic contaminated filter sludge. These disadvantages can make the application difficult, especially in poor regions. Under suitable ancillary conditions the subterranean (in-situ) treatment, which is often used for iron and manganese removal from groundwater, can also be applied for the removal of arsenic and can be a cost-effective treatment technology. A field trial was carried out with a low-cost in-situ treatment plant in West Bengal/India which is described in this paper, in order to investigate whether this treatment technology is also applicable under the boundary conditions there. As for the in-situ treatment technology besides oxygen no additives are required and no arsenic contaminated filter sludge is produced this technology could be a suitable method for arsenic removal especially in poor regions. [ABSTRACT FROM AUTHOR]

This paper describes the assessment of the sustainability of a number of different sewage treatment technologies by means of a multi-criteria, participatory method for a scattered settlement of urban fringe of Surat. The special efforts have been made for the broad participation to achieve stronger democracy, better quality of the end product, and a more effective process. The mere participation of technocrats and bureaucrats certainly lead to the greater efficiency in working methods. However, the ultimate goal of sustainable developments of such technologies could not be reached in absence of democratic participation and social learning. Keeping this important aspect in view for assessment of sustainability, the detailed study was conducted in the presence of policy makers and stakeholders, academicians, technical experts, finance managers and NGO, to find out sustainability criteria and indicators for three different sewage treatment technologies: (A) Conventional Activated Sludge Process (B) Extended Aeration System, and (C) Upflow Anaerobic Sludge Blanket (UASB) Reactor followed by Aerated Lagoon and Polishing Pond. Technologies were compared according to four criteria subdivided into twenty operational indicators. Criteria and indicators were evaluated as in a weighted-scale matrix. In India, sustainability criteria used in this type of comparisons are often restricted to a limited set of environmental impacts and financial costs but in this study additional criteria were evaluated including economic, social, and technical aspects. Based on the values assigned by the panel, the Sustainability Index (SI) was calculated for each technology. According to the SI and a predefined scale, sustainability was medium for options A and B, whereas high for option C. The purpose of this study is to provide a basis for the selection of a particular technology based on a rational and democratic assessment of its contribution to sustainability in the local and global context. [ABSTRACT FROM AUTHOR]

This paper presents results of a novel application of coupling the Activated Sludge Model No. 3 (ASM3) and the Anaerobic Digestion Model No.1 (ADM1) to assess a tropical wastewater treatment plant in a developing country (Surat, India). In general, the coupled model was very capable of predicting current plant operation. The model proved to be a useful tool in investigating various scenarios for optimising treatment performance under present conditions and examination of upgrade options to meet stricter and upcoming effluent discharge criteria regarding N removal. It appears that use of plant-wide modelling of wastewater treatment plants is a promising approach towards addressing often complex interactions within the plant itself. It can also create an enabling environment for the implementations of the novel side processes for treatment of nutrient-rich, side-streams (reject water) from sludge treatment. [ABSTRACT FROM AUTHOR]

This paper suggests an approach to solve the Indian coastal water quality management problem based on waste load allocation studies and application of modelling techniques. The waste load allocation procedure suggested in this paper assists in deriving a quantitative relationship between the waste load discharged and the receiving coastal water concentrations or effects of concern as presented by water qualitystandards. The approach sequentially addresses the topics of hydrodynamics, mass transport, water quality kinetics and problems of bioaccumulation and toxicity. The water quality modelling section describesthe role of water quality modelling in WLA procedure. The paper alsodiscusses the criteria and procedures for formulation of coastal zone management plans. The second part of the paper illustrates the concept with the help of brief case studies wherein simple screening procedures and the water quality modeling techniques have been applied. The first case study describes the application of the WASP model to arrive at the level of treatment required for municipal wastewater being discharged into Mumbai coastal waters so that the designated coastal water quality criteria is not violated and the degree of treatment is optimized. The second case study deals with the study of differentoptions relating to disposal of tailings from an iron ore beneficiation plant keeping in view the impact of these tailings on marine water quality and ecology. [ABSTRACT FROM AUTHOR]

The quantity and quality of water available for irrigation is variable from place to place in India. There are regions where the farmers have no access to any surface water body, nor do they have any groundwater source yielding water of acceptable quality for irrigation. Insome of the coastal areas, neither surface water nor ground water ofacceptable quality may be available. In such areas, setting up an industry and transporting good quality surface water from long distances to the site may be useful for farmers in the adjacent areas; the treated wastewater from the industry may constitute a dependable sourcefor irrigation. This paper gives a brief account of some of these peculiar situations. Whatever the situation, it is necessary that the water used for irrigation is of an acceptable quality for the crop concerned, growing on the soil of the site. For a given crop, during itsgrowth cycle, it is essential that the concentration of the soil solution around the root zone with regard to dissolved solids and specific ions, does not exceed the tolerance limit for the crop. The tolerance limits for various crops are different, representing 8- to 10-fold variation. Soil type and meteorological parameters of the site, fora given irrigation scheduling, also govern as to what will be the maximum soil solution concentration during the growth cycle of the crop. For a given crop, given soil and prevailing climate, the quality ofirrigation water and management ultimately determine this maximum level. At a given place, the type of soil and meteorological parameterscannot be managed by human beings. The farmer can, however, exercisesome control on the quality of irrigation water by selecting an appropriate source or changing the quality by dilution and/or he can makecertain changes in the agronomic control and crop selection. In thispaper, an attempt has been made to describe a few more important irrigation water quality criteria which will be easy for the users to follow and ar [ABSTRACT FROM AUTHOR]

Concern over agricultural diffuse pollution sources in integrated water quality management has been growing recently. Such sources are likely to be even more critical in developing countries, including India, where agriculture and rural habitats are still dominant, unlike the G7 or other affluent industrialised nations. A number of special features of the Indian scene need to be considered. These include: (i) extremely varying rainfall and stream-flow patterns; (ii) still largely traditional agricultural practices with average application of fertilizers and pesticides and significant areas under dry farming or only marginal irrigation; (iii) a very large cattle population, with agriculture almost always linked with animal husbandry; (iv) a culture of living close to the river (if not in the river) with dominating instream uses of bathing, washing, cattle wading, waste disposal, etc. and large-scale floodplain farming; and (v) scant respect for rules, regulations and laws alongside an extremely weak law-enforcement machinery. The paper shows that in the non-monsoon (non-flood) periods, which may account for all but 2 months of a year, agricultural diffusepollution sources seem to have no impact on stream water quality. During these periods flows are low to minimal and pollution is dominated by the in-stream uses, sullage waters of rural communities and point discharges from urban/industrial sources, if any. Pollution due to agricultural return waters, either as wash-off or as seepage, appearsto be rare during the 8-10 fair weather months. However, surface wash-off of pollutants from agricultural sources becomes the dominant factor during flood flows, and seepage/drainage from agricultural fields/soils continues to pollute streams for a month or two after the monsoons are over. Application of chemical fertilizers and pesticides (or any other agricultural chemicals) in India is still low compared todeveloped countries, and while eutrophication due to high levels of was [ABSTRACT FROM AUTHOR]