Total,dissolved, and bioavailable metals at Lake Texoma marinas

Dissolved metals in water and total metals in sediments were measured at marina areas in Lake Texoma during June 1999 to October 2001, and October 2001, respectively. The metals most often found in the highest concentrations in marina water were Na and Ca, followed by Mg and K. Elevated Cu levels detected in lake water appeared to be associated with Cu based anti-fouling paint used on boats. Metal concentrations in sediment were much higher than in water. The relative order of the concentration in sediment was Ca > Al > Fe > K > Mg > Na. Elevated Cu level at specific locations appeared to be associated with local anthropogenic sources of boat repair activities. There were positive relationships between several metal elements in water and sediment. Metals in 16 sediments from lake marinas were extracted with a weak electrolyte solution [0.1 M Ca(NO3)2] to predict the bioavailability of metals. Among the five heavy metals studied (As, Cd, Cr, Cu and Zn), Cu was the most bioavailable in Lake Texoma marinas.     

Escherichia coli and total coliforms in water and sediments at lake marinas

Escherichia coli, a fecal coliform, and total coliforms were monitored between September 1999 and October 2001 in five marinas at Lake Texoma, located on the Oklahoma and Texas border. The general trend was that densities of E. coli were lower in the summer season due to the lower loading of fecal material into Lake Texoma and the ecological conditions of the lake, such as more vigorous grazing by protozoa and less viability of E. coli at an elevated temperature. The densities of total coliforms greatly increased in the summer. E. coli levels increased with depth, and the bottom water samples had higher densities of E. coli mainly due to their association with particles. There was a direct relationship between amount of gasoline sold, which was related to recreational boating activity, and the resuspension of E. coli. This indicated that recreational boating activity in lake marinas may have resuspended bottom sediments with bound E. coli, and the presence of E. coli in marinas was not an indication of recent fecal contamination. E. coli were detected in the largest densities at the boat dock points, followed by the gasoline filling station, and marina entrance. In addition, enumeration of bacteria in bottom sediment showed that the densities of E. coli and total coliforms in sediment were much higher compared to those in lake water.     

BOD生物传感器的研制与应用

介绍了ＢＯＤ生物传感器的原理、研制过程以及实际测定。该仪器测定ＢＯＤ的周期为３０ｍｉｎ，有较高的精密度和准确度，与稀释法有良好的相关性，可以及时信息反馈，特别适用于污水处理过程中的控制分析以及ＢＯＤ的快速测定。     

Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China

To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m~3, was the most severe. NO~3-was always higher than SO_4~(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4~(2-)was faster than that of NOXto NO_3~-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols.     

宜昌市山水林田湖生态保护与修复研究

在对宜昌生态环境现状调查和问题剖析的基础上,研究了宜昌市山水林田湖生态保护与修复的总体思路、目标指标、分区策略和重点领域。研究结果表明:宜昌市山水林田湖生态保护与修复应按照长江三峡库区生态保育片、西南武陵山-清江流域生态屏障片、东部支流沮漳河流域生态恢复片及中部长江沿线生态修复片四大片区系统实施流域水环境治理与保护、矿山环境治理与恢复、土地整治与土壤改良、生态系统与生物多样性保护四大类项目,形成关键技术整体解决方案。     

废水中微量Cr^6＋测定中的试样前处理

采用离子交换树脂预处理工业废水方法测定微量Ｃｒ＾６＋，排除了Ｃｒ＾３＋、Ｆｅ＾３＋、Ｈｇ＾２＋等阳离子干扰，减除水中浊度、色度、免去冗长预处理手续，使原方法简便易行，回收率达９０％以上。     

河口水中矿物油分析的研究

紫外分光光度法在河口水中矿物油测定中，存在着标准油品的选择、水样萃取的乳化处理及河口水样测定方法选择等问题。提出了解决存在问题的可行方法，进一步完善测定方法。     

一项引人注目的气候变化应对措施 --刍议碳处理技术的开发和应用

综合归纳了当前各种二氧化碳的减排技术,介绍了国际上碳处理技术的最新进展,提出碳处理技术是一项不容忽视的气候变化应对措施,应引起我国政府和科学界、工业界的高度重视.     

APPLICATION OF TABU SEARCH TO GROUND WATER PARAMETER ZONATION1

ABSTRACT: The spatial distribution of hydrogeologic parameter is an important issue in ground water simulation. One of the methods is to divide an area into several zones such that parameters are assumed to be constant within zone. The purpose of this study is to apply Tabu Search (TS) to find the best zonation of parameters that can result in the best ground water simulation. The initial zonation can be determined as the Thiessen method, and then zonation is optimized by T.S. The mean square error between simulated and observed hydraulic heads was used as the objective function. A designed confined aquifer with known zonation was used as an example to test the proposed method. Results indicated that Tabu Search can locate the optimal zonation successfully and avoid being trapped by local optimal zonations. Besides this, four other arbitrary initial zonations can be directed to the optimal zonation by TS, which proves the robustness of the proposed method. The method proposed in this study is feasible and expected to work well in the field problems with sufficient sampling of concerned parameters.