Mine-drainage treatment wetland as habitat for herptofaunal wildlife

Land reclamation techniques that incorporate habitat features for herptofaunal wildlife have received little attention. We assessed the suitability of a wetland, constructed for the treatment of mine-water drainage, for supporting herptofaunal wildlife from 1988 through 1990 using diurnal and nocturnal surveys. Natural wetlands within the surrounding watershed were also monitored for comparison. The treatment wetland supported the greatest abundance and species richness of herptofauna among the sites surveyed. Abundance was a function of the frog density, particularly green frogs (Rana clamitans) and pickerel frogs (R. palustris), while species richness was due to the number of snake species found. The rich mix of snake species present at the treatment wetland was believed due to a combination of an abundant frog prey base and an amply supply of den sites in rock debris left behind from earlier surface-mining activities. Nocturnal surveys of breeding male frogs demonstrated highest breeding activity at the treatment wetland, particularly for spring peepers (Hyla crucifer). Whole-body assays of green frog and bullfrog (R. catesbeiana) tissues showed no differences among sites in uptake of iron, aluminum, and zinc; managanese levels in samples from the treatment wetland were significantly lower than those from natural wetlands. These results suggest that wetlands established for water quality improvement can provide habitat for reptiles and amphibians, with the species composition dependent on the construction design, the proximity to source populations, and the degree of acidity and heavy-metal concentrations in drainage waters.     

POTENTIALS FOR REUSE OF WASTEWATER IN NORTH CENTRAL TEXAS1

ABSTRACT There are several possible ways in which wastewater from municipalities may be reclaimed and reused so as to minimize the need for imported water in North Central Texas. The rationale for reuse is enhanced by the fact that new water quality requirements in the Trinity River system will necessitate a very high degree of treatment at municipal sewage plants, just for discharge to surface streams. The largest potential market for municipal effluent is the steam-electric power industry. Within the next decade the generating capacity for electric power in North Central Texas will have to be more than doubled to meet increasing demand. Adequate supplies of condenser cooling water for such expansion will be difficult to obtain and assure. New large power stations might advantageously be located adjacent to municipal wastewater treatment plants, to utilize effluent as make-up water for cooling towers. Experience elsewhere has shown that well-treated wastewater can be used for cooling tower make-up with a minimum of trouble, with a considerable saving in overall cost, and with conservation of pristine water for other uses.     

Public policy for the use of reclaimed water

This article documents the general need to reuse water reclaimed from sewage effluents for beneficial purposes and then considers in detail which specific uses will be most beneficial. The analysis begins by describing five levels of wastewater treatment: primary, secondary, tertiary, advanced, and advanced plus complete treatment. Next, five major uses for reclaimed water are identified: groundwater recharge, industrial use, irrigation, recreational lakes, and direct municipal reuse. Subcategories of reuse falling under each of the five major reuse categories are also identified and discussed. The analysis then proceeds to review significant literature available on health and environmental effects, treatment and distribution costs, and public opinion concerns in relation to each of the five major uses and their related subcategories. The paper concludes with a cumulative numerical analysis of the disbenefits associated with each specific type of reuse summed over the health effects, environmental effects, treatment costs, distribution costs, and public opinion concerns. Uses of reclaimed water for industrial purposes and for irrigation of fodder and fiber crops are found to be most beneficial by the analysis here employed, and use for aquifer recharge and direct municipal reuse are found to be least beneficial.     

回收与降解聚驱采出水的工艺探讨

含聚污水的处理是困扰石油行业的难题之一。基于聚驱采出水的特点,围绕聚合物的回收利用和降解理论及技术,探讨国内外含聚污水处理技术的研究与应用现状,对比分析现有处理技术存在的问题及适应性,提出采用化学混凝、气浮和水质改性等技术来回收利用PAM(聚丙烯酰胺)的新思路,打破了降解PAM的传统思维,同时分析含聚污水处理与利用技术的可行性与应用前景,有望实现含聚污水的循环利用。     

崇明岛东部不同年代围垦区土壤有机质组成变化研究

在崇明岛东部不同年代围垦区选择4个典型部位的钻孔样品,应用热裂解气相色谱质谱联用技术(Py-GC-MS),取得土壤有机质热裂解产物的类型与相对含量,从分子层面探究埋藏盐沼土壤有机质组成特征,研究土壤有机质稳定性随时间的变化规律.结果表明,自西向东4个钻孔的样品(CM2、CM4、CM5、CM6)中,分别检测到53、80、...     

RATIONAL INDUSTRIAL WATER REUSE RATIOS1

ABSTRACT: This work begins by defining rational water use, and then discusses important factors that most strongly influence it. A general model is then developed to enable factories to quantify the ratio of rational industrial water reuse based on the least cost method. The model is established to minimize the cost of water with reference to gross water use and three subsystems ‐ the intake, reuse, and discharge of industrial water. Discharge cost is determined using data from a 1997 survey of 38 factories, and reuse costs are ranked and expressed by a step function. The model is verified using data from a typical semiconductor factory in northern Taiwan's Hsinchu Science Based Industrial Park, whose effective rational water reuse ratio is about 38 percent. A sensitivity analysis shows that improving water reuse technology is the most important factor in determining the rational water reuse ratio, and the price of water is the second most important. When water costs over NT$30 (New Taiwan Dollar, US$1 = NT$34) per cubic meter, increasing reuse becomes significant. The model provides a step towards the scientific management of industrial water.     

运用LCA方法分析污水再生处理的成本效益

运用生命周期评价(LCA)方法,以西安市北石桥污水净化中心的污水处理与再生利用全过程为例进行环境影响评价,通过清单分析、当量计算和权重分析等一系列分析过程,计算出污水处理过程的投入成本及污水再生处理前后对环境的影响,得出污水在经过处理后,能够很大程度上减小其对环境的影响,从而产生环境正效益。该研究明确了污水处理在环境保护中的重要地位,同时对优化污水处理与再生利用工艺过程具有重要的参考价值和指导意义。     

不同深度处理工艺去除污水处理厂出水中氮磷的比较研究

城市污水厂出水直接进入天然水体、或经过深度处理后回用于灌溉、补充景观水体和回灌地下水,均需要进行安全性评价.针对北京市北小河污水处理厂出水经过深度处理后回用于奥运公园的安全性,比较了不同深度处理工艺对营养盐(氮、磷)总量和不同形态的去除效果.研究表明,二级处理本身对氮磷的去除效果十分有限,回用水需经过深度处理.在所研究的生物活性炭吸附、微滤、超滤、反渗透以及上述技术的组合工艺中,使用超滤和反渗透联用的工艺路线对脱氮除磷的效果较为理想,其他工艺对去除氮磷的效果十分有限.     

城市污水中的生物毒性及其臭氧削减效果研究

分别利用酵母双杂交和umu试验对5个城市9个污水处理厂进出水中生物遗传毒性和视黄酸受体(BAR)结合活性进行了调查.并考察了臭氧氧化对这两种生物效应的去除效果.结果表明,城市污水中存在不同程度的生物遗传毒性和视黄酸受体(RAR)结合活性,通过生物处理可以大幅削减污水中的RAR结合活性和生物遗传毒性,但污水厂出水中仍然普遍具有遗传毒性,部分残留RAR结合活性.5～10mg·L-1的臭氧可以有效削减二级出水中残留的BAR结合活性和遗传毒性,是一种有效的提高水质安全性的污水深度处理技术.     

矿山强酸性多金属污染土壤修复及麻疯树植物复垦条件研究

采用温室盆栽实验,研究了在不同剂量(质量分数分别为0、0.10%、0.25%、0.5%和1.0%)石灰石改良条件下,大宝山矿强酸性多金属不同污染程度土壤中麻疯树的生长状况和吸收金属特征,并探讨了麻疯树在酸性土壤中生长的抑制因素和石灰石改良适宜剂量.研究表明,在低污染酸性土壤中,Cu和Pb的高活性可能是抑制麻疯树生长的主要因素;而在高污染酸性土壤中,Cd、Cu、Zn等金属的高活性及由强酸引起的Al毒也可能是抑制麻疯树生长的主要因素;石灰石通过提高土壤pH值和降低多金属的生物有效态含量,促进了麻疯树在低污和高污土壤中的生长,其最佳剂量分别为0.25%和0.5%;石灰石可以不同程度地降低麻疯树地上部和地下舔的Cd、Cu、Pb、Zn和Al含量,同时随石灰石用量的增加,其金属含量基本呈降低趋势;麻疯树地下部金属含量高于地上部,且石灰石对麻疯树地下部金属(除Cd外)含量降低幅度较地上部大.因此,种植麻疯树与石灰石改良是联合修复大宝山矿酸性多金属污染土壤的有效措施之一.