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Improvement of MSBR Process for Treatment of Sand-laden Sewage
Yu Hao,
Tao Rujun,
Guo Qinxin
Issue:
Volume 4, Issue 4, December 2018
Pages:
91-96
Received:
15 May 2018
Accepted:
21 June 2018
Published:
27 November 2018
DOI:
10.11648/j.ajwse.20180404.11
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Abstract: The influent of a sewage treatment plant was mainly composed of domestic sewage. Modified Sequencing Batch Reactor (MSBR) process was adopted, in order for the design effluent quality to meet the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918 - 2002). High Sand content in the influent caused operational problems such as poor aeration in sequencing batch tank, high sediment content and siphon effect in the effluent of MSBR. The problems were solved by analyzing the reasons and taking improvement measures, thus ensuring the effluent quality to meet the discharge standard.
Abstract: The influent of a sewage treatment plant was mainly composed of domestic sewage. Modified Sequencing Batch Reactor (MSBR) process was adopted, in order for the design effluent quality to meet the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918 - 2002). High Sand content in t...
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Analysis and Treatment of Typical Problems of GIS Circuit Breaker
Bing Shen,
Shaobin Jiang,
Zhangxiu Li,
Guozheng Li
Issue:
Volume 4, Issue 4, December 2018
Pages:
97-100
Received:
14 August 2018
Accepted:
29 August 2018
Published:
27 November 2018
DOI:
10.11648/j.ajwse.20180404.12
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Abstract: With the development and progress of society, the demand for electric energy is increasing day by day. The number of hydropower stations has increased dramatically. In the large-scale hydropower stations and substations currently under construction, GIS high-voltage switch stations have gradually replaced traditional high-voltage switch stations due to their advantages of arc extinguishing and insulation performance, low floor space and high reliability. The GIS breaker body and the operating mechanism of the GIS breaker, or other components of the GIS switch station, are subject to various reasons such as design, manufacture, installation, commissioning, operation and maintenance. Frequently, the GIS breaker leaks, the circuit breaker refuses to move, the operating mechanism cannot store energy normally, and the closing time is not easy to measure. These phenomena pose a serious threat to the safe and stable operation of the power system. Such typical phenomena of GIS circuit breakers deserve our consideration of inquiry, analysis and summary. Find the root cause of the failure and propose the most effective improvement. This paper proposes and solves several typical faults during the installation, commissioning, operation and maintenance of GIS circuit breakers. Provide reference for the fault analysis and processing of GIS circuit breakers in the future.
Abstract: With the development and progress of society, the demand for electric energy is increasing day by day. The number of hydropower stations has increased dramatically. In the large-scale hydropower stations and substations currently under construction, GIS high-voltage switch stations have gradually replaced traditional high-voltage switch stations du...
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Research and Application on Seepage Detection and Repair of Anti-Seepage System for Earth-Rockfill Dam with Asphalt Concrete Core
Wei Min,
Zhou Heqing,
Cui Dongdong
Issue:
Volume 4, Issue 4, December 2018
Pages:
101-106
Received:
21 August 2018
Accepted:
1 November 2018
Published:
29 November 2018
DOI:
10.11648/j.ajwse.20180404.13
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Abstract: The asphalt concrete core wall has been widely used in various kinds of high dams because of its good performance of anti-seepage, deformation and rapid construction speed. In recent years, the leakage phenomena of some asphalt concrete core dams begin to occur, endangering dam safety. To determine the leakage status, location and access of the bituminous concrete core, drilling holes are arranged in the upper and lower reaches of the bituminous concrete core wall. With water as the medium, underwater sonar, color TV observation in hole, consecutive test of tracer, water level analysis in the dam body and physical detection and other methods were used for detection. Then the leakage state of asphalt concrete core wall of dam body is comprehensively analyzed and determined according to a variety of test results. At the same time, aiming at the problems existing in the direct repair of asphalt concrete core wall in the dam body, repairing project of concrete seepage cut-off wall, controlling grouting repair scheme, as well as its key control factors, construction process and technical parameter indexes were studied. Through the application of multiple engineering examples, the treatment effect was remarkable, which can provide a reference for the treatment of similar engineering problem.
Abstract: The asphalt concrete core wall has been widely used in various kinds of high dams because of its good performance of anti-seepage, deformation and rapid construction speed. In recent years, the leakage phenomena of some asphalt concrete core dams begin to occur, endangering dam safety. To determine the leakage status, location and access of the bit...
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Modelling the Impacts of Land Use Change on Stream Flow in the Kimwarer Catchment Using SWAT
Daniel Kimutai Kiplagat,
Julius Kipkemboi Kollongei,
Clement Kiprotich Kiptum
Issue:
Volume 4, Issue 4, December 2018
Pages:
107-116
Received:
26 October 2018
Accepted:
21 November 2018
Published:
3 January 2019
DOI:
10.11648/j.ajwse.20180404.14
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Abstract: The Kimwarer River basin covers 138.2 km2. It has experienced ecosystem degradation due to extensive farming that has impacted on water yield. This study was undertaken to assess the impacts of land use changes on river flow using SWAT, a mathematical model that has the potential to predict the impact of land management practices on water at catchment scale. Current and historic flow data were collected for model calibration and validation. The model was then used to simulate stream flow for different land use and land cover scenarios by varying the extend of forest cover and agriculture. The model was successfully calibrated and validated for stream flow, and proved capable of predicting flow with R2 and NSE values of 0.79 and 0.31 respectively. During validation, the model predicted flows with R2 and NSE values of 0.70 and 0.50 respectively. For scenario analysis to determine the effect of land use change on stream flow, it was observed that runoff decreased with increase in forest cover, while base-flow increased. Introduction of terraces as a management operation on agricultural land reduced runoff by 46%. It is evident from the study that the current trend of land use change affects stream flow.
Abstract: The Kimwarer River basin covers 138.2 km2. It has experienced ecosystem degradation due to extensive farming that has impacted on water yield. This study was undertaken to assess the impacts of land use changes on river flow using SWAT, a mathematical model that has the potential to predict the impact of land management practices on water at catchm...
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Estimation of Potential Evapotranspiration by Different Methods in Handan Eastern Plain, China
Issue:
Volume 4, Issue 4, December 2018
Pages:
117-123
Received:
28 November 2018
Accepted:
25 December 2018
Published:
18 January 2019
DOI:
10.11648/j.ajwse.20180404.15
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Abstract: Potential evapotranspiration estimation is the foundation of water resources assessment. Based on the daily meteorological data during 2000-2005 of Linzhang Meteorological Station in Handan Eastern Plain, temperature-based Hargreaves method, radiation-based Priestley-Taylor method, and FAO Penman-Monteith method with comprehensive consideration of aerodynamics were used to estimate potential evapotranspiration. Correlations between monthly potential evapotranspiration and water surface evaporation were conducted. The results indicated that potential evapotranspiration calculated by Hargreaves method was the largest, while the potential evapotranspiration calculated by Priestley-Taylor method was the smallest. The seasonal potential evapotranspiration values for the three methods were summer > spring > autumn > winter. The correlation between potential evapotranspiration calculated by the FAO Penman-Monteith method and water surface evaporation during the same period was best (r=0.991). In contrast, Penman-Monteith method is more suitable for estimating the potential evapotranspiration in Handan Eastern Plain.
Abstract: Potential evapotranspiration estimation is the foundation of water resources assessment. Based on the daily meteorological data during 2000-2005 of Linzhang Meteorological Station in Handan Eastern Plain, temperature-based Hargreaves method, radiation-based Priestley-Taylor method, and FAO Penman-Monteith method with comprehensive consideration of ...
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