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131.
The concern over ensuing freshwater scarcity has forced the developing countries to delve for alternative water resources. In this study, we examined the potential of stagnant surface water bodies (SSWBs) as alternative freshwater resources in the densely populated Chittagong metropolitan area (CMPA) of Bangladesh??where there is an acute shortage of urban freshwater supply. Water samples were collected at 1-month intervals for a period of 1 year from 12 stations distributed over the whole metropolis. Samples were analyzed for pH, water temperature (WTemp), turbidity, electrical conductivity (EC), total dissolved solids, total solids, total hardness, dissolved oxygen (DO), chloride, orthophosphates, ammonia, total coliforms (TC), and trace metal (Cd, Cr, Cu, Pb, As, and Fe) concentrations. Based on these parameters, different types of water quality indices (WQIs) were deduced. WQIs showed most of CMPA-SSWBs as good or medium quality water bodies, while none were categorized as bad. Moreover, it was observed that the minimal water quality index (WQIm), computed using five parameters: WTemp, pH, DO, EC, and turbidity, gave a reliable estimate of water quality. The WQIm gave similar results in 72% of the cases compared with other WQIs that were based on larger set of parameters. Based on our finding, we suggest the wider use WQIm in developing countries for assessing health of SSWBs, as it will minimize the analytical cost to overcome the budget constraints involved in this kind of evaluations. It was observed that except turbidity and TC content, all other quality parameters fluctuated within the limit of the World Health Organization suggested standards for drinking water. From our findings, we concluded that if the turbidity and TC content of water from SSWBs in CMPA are taken care of, they will become good candidates as alternative water resources all round the year.  相似文献   
132.
Soft subgrades’ stabilization by using various fly ashes   总被引:1,自引:0,他引:1  
This publication presents the results of research involving different types of self-cementing fly ashes (without any other activators) for the stabilization of four different types of soft subgrades from various road sites in Wisconsin, USA. The strength approaches were applied to estimate the optimum mixture design and to determine the thickness of the stabilized layer. The stabilized soil samples were prepared by mixing fly ash at different contents at varying water contents. The performance of fly ash stabilized subbase depends both on the specific source of fly ash and the engineering properties of soils. It is suggested that the performance analysis of fly ash should be based upon the laboratory tests such as index properties, compaction, unconfined compressive strength and CBR tests of a specific site. This is suggested rather than using the study of the physical properties and chemical composition of fly ash and soil. As disclosed in the literature, the strength gain due to stabilization depends mainly upon three factors; ash content, molding water content and compaction delay. The samples were subjected to unconfined compression strength and California bearing ratio (CBR) tests after 7 days curing time to develop water content–strength relationship. To evaluate the impact of compaction delay that commonly occurs in the field during construction, the sets of samples were compacted 2 h later after mixing with water. The unconfined compression strength and CBR tests were performed and used to determine the thickness of the stabilized layer in pavement design. All of these factors were taken into account throughout this research.  相似文献   
133.
This article attempts to examine the influence of some selected predictor variables on female age at first marriage in slum areas of Bangladesh. A path and multiple classification analysis (MCA) approach have been adopted. Authors thought that respondent’s educational level and the mass media such as watching television have a significant direct impact on age at marriage, while the types of family and occupational status have an indirect effect on age at marriage.  相似文献   
134.
Environmental Science and Pollution Research - Energy consumption for sustainable development has become a crucial issue in recent years. The anthropogenic effects of traditional energy sources...  相似文献   
135.
Environmental Science and Pollution Research - The daily utilization of a large amount of raw materials is causing a rapid depletion of natural resources. The growth of the human population is...  相似文献   
136.
Environmental Science and Pollution Research - Yard waste is one of the key components of municipal solid waste and can play a vital role in implementing zero-waste strategy to achieve sustainable...  相似文献   
137.
Environmental Science and Pollution Research - Surface sediments along the Southern Terengganu coast (≤7 km from the coast) were analyzed for polycyclic aromatic hydrocarbons (PAHs). The...  相似文献   
138.
Environmental Science and Pollution Research - Currently, a well-developed combination of irrigation water quality index (IWQIs) and entropy water quality index (EWQIs) for surface water appraisal...  相似文献   
139.
Environmental Science and Pollution Research - The objective of this work is to understand the fluctuating nature of wind speed characteristics on different time scales and to find the long-term...  相似文献   
140.
Environmental Science and Pollution Research - Several studies have suggested the direct relationship between skin complications, air pollution, and UV irradiation. UVB radiations cause various...  相似文献   
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