IDENTIFICATION OF DISSOLVED-CONSTITUENT SOURCES IN MINE-SITE GROUND WATER USING BATCH MIXING1

ABSTRACT: Batch-mixing experiments were used to help identify lithologic and mineralogic sources of increased concentrations of dissolved solids in water affected by surface coal mining in northwestern Colorado. Ten overburden core samples were analyzed for mineral composition and mixed with distilled water for 90 days until mineral-water equilibrium was reached. Between one day and 90 days after initial contact, specific conductance in the sample mixtures had a median increase of 306 percent. Dissolved-solids concentrations ranged from 200 to 8,700 mg/L in water samples extracted from the mixtures after 90 days. Mass. balance simulations were conducted using the geochemical models BALANCE and WATEQF to quantify mineral-water interactions occurring in five selected sample mixtures and in water collected from a spring at a reclaimed mine site. The spring water is affected by mineral-water interactions occurring in all of the lithologic units comprising the overburden. Results of the simulations indicate that oxidation of pyrite, dissolution of dolomite, gypsum, and epsomite, and cation-exchange reactions are the primary mineral-water interactions occurring in the overburden. Three lithologic units in the overburden (a coal, a sandstone, and a shale) probably contribute most of the dissolved solids to the spring water. Water sample extracts from mixtures using core from these three units accounted for 85 percent of the total dissolved solids in the 10 sample extracts. Other lithologic units in the overburden probably contribute smaller quantities of dissolved solids to the spring water.     

POLLUTANT LOADS IN URBAN STORMWATER: REVIEW OF METHODS FOR PLANNING-LEVEL ESTIMATES1

ABSTRACT: A review of methods for planning-level estimates of pollutant loads in urban stormwater focuses on transfer of charac. teristic runoff quality data to unmonitored sites, runoff monitoring, and simulation models. Load estimation by transfer of runoff quality data is the least expensive, but the accuracy of estimates is unknown. Runoff monitoring methods provide best estimates of existing loads, but cannot be used to predict load changes resulting from runoff controls, or other changes of the urban system. Simulation models require extensive calibration for reliable application. Models with optional formulations of pollutant build up, washoff, and transport can be better calibrated and the selection of options should be based on a statistical analysis of calibration data. Calibrated simulation models can be used for evaluation of control alternatives.     

CONCEPTUAL DESIGN PROCEDURE FOR HYDRAULIC DESTRATIFICATION SYSTEMS IN SMALL PONDS,LAKES, OR RESERVOIRS FOR WATER QUALITY IMPROVEMENT1

ABSTRACT: Forced artificial mixing of temperature-stratified ponds, or small lakes or reservoirs, by liquid jets can enhance water quality and can also be energy efficient. Based on previous studies of jet mixing mechanics of stratified water bodies, a conceptual design approach is presented. The main “operational” and “system” design parameters are considered in the proposed method. Using minimization of a total cost estimate as a criterion, an iterative method for the selection of the number and size of the jets is developed and illustrated.     

建设项目环境影响的医学评价方法研究

作者在对中国我人民解放军第４７医院病建项目所产生的大气环境影响进行了医学秤价和影响，并在预测的基础上，建立了完整的环境医学影响廉政价方法，由于该评价方法完全尊循了国内现行大气环境影响评价的基本要求和程序，因此，它在今后的环境影响医学评价中净有广泛的应用。     

非时序加权灰色关联分析在环境质量综合评价中的应用

本文根据灰色关联分析的基本性质，提出一种环境质量综合评价的新方法。该方法用待评价样本各指标值组成参考数列，环境质量分级标准值组成被比较数列，通过计算参考数列与被比较数列的关联度，按最优关联识别原则综合评价环境质量等级。用４个实例与其它方法进行了对比，取得满意的效果。     

MFAM模型在河流水质污染模拟及预测中的应用

文中以时间序列分析为基础，介绍了均值生成函数这一崭新概念，并且经成份因子提取分析推导建立了模拟序列的数字模型（简记为MFAM），经对黄河下游花园口断面的1988-1989年实测水质污染指标溶解氧（DO），氨氧，化学耗氧量（COD），五日生化需氧量（BOD5）等序列模拟，结果表明MFAM模型能较好地模拟河流水质污染指标的变化趋势，拟合平均误差只有5.2-6.4%，MFAM模型应用于预测1990-1991年水质污染指标变化，结果表明预测精度达85%以上，文中最后得出结论：MFAM模型应用于河流污染模拟和预测，是完全可行且十分方便。     

植物油燃料研究概述

本文介绍了植物油作燃料的研究历史以及试验研究状况，表明植物油作为柴油的替代品是最易实现的方案。但植物油燃料还需进一步试验研究才能使其实用化，其技术储备具有深远的现实意义。本文还通过对燃料油植物栽培问题的探讨，认为“农林复合经营”是生产植物燃料油的重要途径。     

ANALYSIS OF WIND- AND SHIP-INDUCED SEDIMENT RESUSPENSION IN DULUTH-SUPERIOR HARBOR1

ABSTRACT: Suspended solids and ammonium concentration profiles measured at five locations in Duluth-Superior Harbor during July-October 1985 were analyzed to quantify wind and ship effects on sediment resuspension and resulting harbor water quality. Wind components from the SE quadrant correlated strongly with depth-averaged suspended solids concentrations that were unaffected by ship passage or thermal stratification. Winds from that quadrant have the largest fetch in the harbor. The highest correlation (r²= 0.93) was with the 6-hour average of the ESE wind velocity component. Multiple linear regression analysis of data from post-ship passage concentration profiles yielded numerical estimates of settling velocities of 0.08 to 0.25 cm s^?1, typical of ship-resuspended sediments, and vertical eddy diffusivities of 4 to 13 cm² s¹. The results suggest that ambient vertical eddy diffusivities in the harbor are less than 4 cm² s^?1 in the absence of ship passages and with winds less than 5 m s^?1 (10 knots).     

ATRAZINE IN SPRING RUNOFF AS RELATED TO ENVIRONMENTAL SETTING EBRASKA, 19921

ABSTRACT: A synoptic sampling of five surface-water sites in central Nebraska was conducted by the U.S. Geological Survey as part of its National Water-Quality Assessment Program during storm runoff in May 1992 to relate transport, yields, and concentrations of atrazine to environmental setting. Atrazine was the most extensively applied pesticide in the study unit. Atrazine transport was related to the size of contributing drainage area, quantity of atrazine applied, amount of precipitation, and volume of stream-flow. Estimated yields and mean concentrations of atrazine were related to the percentage of cropland in a drainage area. The largest estimated yields and mean concentrations of atrazine in surface water were associated from drainage areas with the highest percentage of cropland, and the smallest was associated with the smallest amount of cropland. Atrazine concentrations increased as streamflow increased but decreased at or near the time of peak streamflows, perhaps due to dilution. Atrazine concentrations then increased and remained elevated far into the stream recession. Atrazine is a regulated contaminant in finished public-water supplies. Large concentrations of atrazine could affect the management of public-water supplies because atrazine remains in solution in contrast to many other pesticides that are more easily removed.