This report reviews China's water scarcity situation, assesses the policy and institutional requirements for addressing it, and recommends key areas for strengthening and reform. It is a synthesis of ...the main findings and recommendations from analytical work and case studies prepared under the World Bank Analytical and Advisory Assistance (AAA) program entitled 'Addressing China's Water Scarcity: from Analysis to Action.' These studies focus on several strategically important thematic areas for China where additional research was needed, as identified by the research team and advisory group based on a review of pressing issues. These areas are governance, water rights, pricing, ecological compensation, pollution control, and emergency response. The approach has been to evaluate Chinese and international experience to identify policy and institutional factors that have proven effective in promoting the adoption of water conservation and pollution reduction technologies. The research was based on literature reviews, qualitative and quantitative policy analyses, household surveys, field trips, and case studies to develop feasible recommendations for a plan of action based on realities on the ground.
The authors describe and analyze a nongovernmental, multi-stakeholder, consensus-based approach to river basin management in the Fraser River basin in Canada. The Fraser River drains 238,000 k
Based on the results of radioecological studies in the aquatic ecosystem of the South-Ukrainian Nuclear Power Plant region (SUNPP), the tritium content in technological reservoirs (cooling pond, ...biological pond of the cleaning station, splash pool) and adjacent surface and groundwater bodies were analyzed. It is shown that the average annual volumetric activity of tritium in the water of technological reservoirs of the SUNPP during 2014 - 2018 is kept at the level of 110 - 160 Bq/l, with a tendency to increase with an average annual rate of 12 - 13 Bq/l, which correlates with a decrease in the volume of blowdown water discharge from the cooling pond (about 8698 thousand m3 per yr). Higher levels of volumetric activity of tritium were registered in the water of technical wells - leakage markers in the technical system, which, moreover, are fed from the pools of cooling towers and spray units. The tritium content in the bioponds of the sewage system of the SUNPP decreased from more than 1000 Bq/l in the early 1990s to 100 - 130 Bq/l in 2017 - 2018, which led to a decrease in its level in the Trikratsky reservoir and should affect lowering its level in groundwater sources, which are located below the natural runoff. Taking into account the physicochemical properties of tritium and the conclusions of well-known scientists about the extremely rapid accumulation of tritium in the environment, the necessity of hydroecological monitoring of the tritium content in surface water bodies is substantiated, the water of which is used for irrigation of agricultural crops and which are hydrodynamically connected with the technological water bodies of the SUNPP, as well as sources of drinking water located downstream of the natural runoff from the technological reservoirs of the nuclear power plant.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
AbstractMicrobiologically induced deterioration (MID) of concrete sewers is a common problem that requires a considerable amount of rehabilitation investment every year. MID is the result of dilute ...sulfuric acid dissolving the cement matrix. The acid is produced by a complex series of chemical and biochemical reactions. Hydrogen sulfide (H2S) is produced by sulfur reducing bacteria (SRB) in the liquid phase, and then in time, this gas is converted by sulfur oxidizing bacteria (SOB) into sulfuric acid (H2SO4). The last conversion occurs above the liquid level under aerobic condition. The objective of this study is to present a literature review and authors’ experience on progress acquired over years in understanding causes and effects of MID of concrete in municipal sewerage systems, methods to prevent and control MID from happening, and rehabilitation of already damaged pipes and structures. Published papers were identified that directly or indirectly reported MID of concrete in sewer structures over a period from 1980–2018. The literature review and authors’ data suggest that deterioration of concrete is a complex process that involves varied surface interactions. Many empirical inputs that vary with installation and repair of various structures have been identified. The addition of liquid antimicrobial additive per standard procedure shows resistance of concrete to MID. Additionally, results show that resistance of concrete to MID increases with increase in the mixing time of the admixture. Further research is needed to study the concrete–microorganism interactions to have a better understanding of the microbiologically induced culture that leads to concrete deterioration in the sanitary sewerage systems. Additionally, there is a need to identify and develop more effective coatings, and safe antibacterial agents that can be used during construction of sewers to inhibit colonization of SOB over the exposed portion of the sewers.
A study on a pilot plant accomplishing synchronous municipal sewerage-sludge stabilization was conducted at a municipal sewerage treatment plant. Stabilization of sewerage and sludge is achieved in ...three-step process: anaerobic reactor, roughing filter and a microbial-earthworm-ecofilter. The integrated ecofilter utilizes an artificial ecosystem to degrade and stabilize the sewerage and sludge. When the hydraulic retention time(HRT) of the anaerobic reactor is 6 h, the hydraulic load(HL) of the bio-filter is 16 m3/(m2 x d), the HL of the eco-filter is 5 m3/(m2 x d), the recycle ratio of nitrified liquor is 1.5, the removal efficiency is 83%-89% for COD(Cr), 94%-96% for BOD5, 96%-98% for SS, and 76%-95% for NH3-N. The whole system realizes the zero emission of sludge, and has the characteristics of saving energy consumption and operational costs.
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