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991.
The efficiency of a Stormwater Infiltration Basin (SIB) to remove contaminants from urban stormwater was assessed in the current investigation. The SIB, installed in an urban suburb in eastern Sydney (Australia), was monitored over seven rainfall events to assess the removal efficiency of the remedial device for total suspended solids (TSS), nutrients (TP, TKN, Nox, TN), trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn), organochlorine pesticides and faecal coliforms (FC) from stormwater. The weighted average concentration (WAC) of TSS in the stormwater effluent from the SIB was reduced by an average of 50%, whereas the WAC of Cu, Pb and Zn were also reduced by an average 68%, 93% and 52%, respectively. However, the WAC of Cr, Fe, Mn and Ni displays either similar concentrations as the stormwater influent (Cr and Mn), or substantially higher concentrations (Fe and Ni), due possibly to leaching of fine-grained zeolite clay particles in the filtration bed. The mean removal efficiency of the SIB for total phosphorus (TP) and total Kjeldahl nitrogen (TKN) was 51% and 65%, respectively. In contrast, the average WAC of oxidisable nitrogen (nitrate and nitrite nitrogen or Nox) is about 2.5 times greater in the effluent (1.34 ± 0.69 mg L–1) than in the incoming stormwater (0.62 ± 0.25 mg L–1). The WAC of total nitrogen (TN) was similar for stormwater at the in-flow and out-flow points. The SIB was very efficient in removing FC from stormwater; and the WAC of almost 70 (100 mL)–1 at inflow was reduced to <2000 cfu (100 Ml)–1 at the outflow, representing a mean removal efficiency of 96%. Due to the low concentrations of Cd, organochlorine pesticides and PAHs in the stormwater, it was not possible to assess the efficiency of the SIB in removing these contaminants. 相似文献
992.
概述了现今比较流行的"空气流域"新概念,介绍了在此概念基础上的"空气流域管理"新观念,认为它们可以作为我国城市空气质量达标战略的新起点. 相似文献
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995.
张茜 《中国环境管理干部学院学报》2004,14(1):24-25,89
采用单一成分絮凝剂和多种成分絮凝剂按不同配比多种方法对污水进行处理。对所用药剂加以筛选,优化组合。结果表明用高分子絮凝剂成本低,沉降速度快。 相似文献
996.
Jiapeng Hua Zhongmin Liang Zhongbo Yu 《Journal of the American Water Resources Association》2003,39(5):1017-1025
ABSTRACT: New formulas and procedures under the framework of the Rational Formula are presented that are applicable to flood design problems for a small basin if the geometry of the basin can be approximated as an ellipse or a rhombus. Instead of making the assumption in the traditional rational formula that the rainfall is uniformly distributed in the whole duration (Dw) of a design storm, the new method modifies that assumption as: the rainfall is uniformly distributed only in each time interval CD) of the design storm hyetograph, thus extending the rational formula applicable to the case that the rainfall duration is less than the basin concentration time (Tc). The new method can be applied to estimate the flood design peak discharge, and to generate the flood hydrograph simultaneously. The derivation of the formulas is provided in detail in this paper, and an example is also included to illustrate how to apply the new formulas to the flood design problems in small basins. 相似文献
997.
Kent W. Olson 《Journal of the American Water Resources Association》1980,16(2):294-299
ABSTRACT: The methodology underlying, and the estimates incorporated in the Corps of Engineers' economic evaluation of the Arkansas River Basin Chloride Control Project are evaluated and judged deficient in several ways. An improperly specified alternative cost analysis probably results in overestimates of the total regional demand for water, the demand for Arkansas River Water, and the cost-savings realized with the project in place. The quantitative effect of these errors is not determined. However, other adjustments are identified which are evaluated using the Corps' data. These adjustments reduce B/C from 2.64 to 0.57; principally as a result of corrections for over-estimates of cost-savings in steam-electric generation, and for use of improper discounting procedures and gross output-earnings ratios. 相似文献
998.
John W. Labadie John M. Shafer Robert Aukerman 《Journal of the American Water Resources Association》1980,16(3):477-485
ABSTRACT: There is considerable misconception about the dangers of opening to a recreating public in great need of additional open areas. A systematic procedure for identifying the factors essential to the selectio, planning, and management of reservoirs for recreation is described. A detailed case study conducted by an interdisciplinary project team is presented to demonstrate the feasibility fo maintaining storage levels in recreation-conductive high country reseroirs without unduly injuring downstram water users. The idea is to trade water with reservoirs having less recreation potential. The optimal means of doing this is found via a river basin simulation model with quasi-optimizing capability. Results of the case study show that this strategy is indeed feasible. Applicable to other areas may require analysis of tradeoffs if at least some damage to downstream users is unavoidable. 相似文献
999.
Thomas C. Brown Benjamin L. Harding William B. Lord 《Journal of the American Water Resources Association》1988,24(4):801-814
ABSTRACT: This study examined the disposition of streamflow increases that could be created by vegetation management on forest land along the upper reaches of the Colorado River. A network optimization model was used to simulate water flow, storage, consumptive use, and loss within the entire Colorado River Basin with and without the flow increases, according to various scenarios incorporating both current and future consumptive use levels as well as existing and potential institutional constraints. Results indicate that very little of the flow increases would be consumptively used at current use levels, or even at future use levels, if water allocation institutions remain unchanged. Given future use levels and economically based water allocation institutions, up to one-half of the flow increases could be consumptively used. The timing of streamflow increases, and the institutional constraints on water allocation, often limit the potential for consumptive use of flow increases. 相似文献
1000.
M. B. Bayer 《Journal of the American Water Resources Association》1974,10(2):311-317
ABSTRACT: This paper explores the use of nonlinear programming in river basin water quality modelling. Applications recently reported in the literature, along with the author's experience with nonlinear programming, are reviewed. Results obtained using nonlinear programming are compared with the results obtained by other researchers using linear and dynamic programming to solve river basin water quality optimization problems. These water quality models have objective functions with continuous first partial derivatives, several inequality and variable bound constraints, and are of the form: minizie Σj=nj=1Yj(Xj) subject to Σj=nj=1aijXjbi, i=1,2, …, m cjXjdj, j= 1,2, …, n The variable Xi is the maximum allowable ratio of the BOD (biochemical oxygen demand) of the effluent outflow to the BOD of the wastewater inflow for treatment plant j, in the range cj to dj. The aijd and bi are constants in the DO (dissolved oxygen) and BOD constraints. The resuks show, given certain assumptions about the data, that nonlinear programming is a better solution method for these problems than is either linear programming or dynamic programming. 相似文献