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91.
The secondary effluent from municipal plants in Korea generally represents higher BOD with lower SS. Therefore, more soluble forms of organics and NH4-N need to be removed to improve its effluent for reuse. In this study reuse possibility of secondary effluent and CSO (combined sewer overflow) using BAF (biological aerated filter) was evaluated. The tertiary application with 1.2 h EBCT, SS, BOD and COD showed stable concentrations less than 1.3, 1.3 and 6.2 mg/L, respectively. Nitrogen could be nitrified even at 7 degrees suggesting BAF can be used for a water reuse method as well as an effective add-on facility in cold regions. However, BAF was not stable with CSO application at increased flow rates suggesting CSO must be equalised prior to application. Disinfection was necessary even during normal weather conditions. 相似文献
92.
This paper presents a preliminary study for the removal of COD and suspended solids in wastewater treatment by combining magnetic field and electrocoagulation (EC) technology. The experiments were carried out using batch apparatus and setup in the static method. Batch experiments with two monopolar iron (Fe) plate anodes and cathodes were employed as electrodes. Wastewater samples were prepared from milk powder with an initial COD of 1,140 mgL(-1) and suspended solids of 1,400 mgL(-1) and acidic conditions were employed (pH approximately 3). DC current was varied from 0.5-0.8 A and operating times were between 30 and 50 min. The results show that the effluent wastewater was very clear (turbidity approximately 9 NTU) and its quality exceeded the direct discharge standard. The suspended solids and COD removal efficiencies were as high as 30.6 and 75.5%, respectively. In addition, the experimental results also show that the electrocoagulation could neutralise the pH of wastewater. 相似文献
93.
94.
R. James Maguire Richard J. Tkacz David L. Sartor 《Journal of Great Lakes research》1985,11(3):320-327
Water and sediment samples from 29 locations in the Detroit and St. Clair rivers were analyzed for the highly toxic tri-n-butyltin (Bu3Sn+) species and for the less toxic di-n-butyltin (Bu2Sn2+) and n-butyltin (BuSn3+) species and inorganic tin. In general, locations sampled in the St. Clair River were less contaminated with butyltin species than those in the Detroit River. Inorganic tin and BuSn3+ were detected in over 90% of all subsurface water samples, while Bu2Sn2+ and Bu3Sn+ were detected in 45 and 28% of the same samples, respectively. The highest concentration ofBu3Sn+ in subsurface water, 5.9 × 10?10 mol Sn/L, was at the mouth of the Ecorse River, a tributary of the Detroit River. The three butyltin species and inorganic tin were also detected in 23–46% of all sediment samples. The highest concentrations of Bu3Sn+ in sediment were found close to the mouths of the River Rouge, another tributary of the Detroit River, and the Ecorse River, and were 6.2 × I0–7 and 1.7 × I0–7 mol Sn/kg dry weight, respectively, for the top 2 cm of sediment. 相似文献
95.
96.
Rainwater collection as a possible water source in developing countries is introduced. The major parameters in calculating the size of the tank are defined. Six methods that have been used previously to relate demand, storage, reliability and the rainfall pattern are compared to the Ottawa Model over a wide range of demands. 相似文献
97.
Don J Webber 《Economic journal (London, England)》2004,114(499):F549-F551
98.
99.
如今,全球都笼罩在经济衰退之中.如果下一个就要轮到贵公司,你该怎么办?当然你要尽力保证企业财务的稳定.但更重要的是,你还必须了解公司在衰退结束后的目标设计.如果你知道企业的发展方向和如何实现这一目标,那么衰退时期是改善公司相对战略地位的好时机. 相似文献
100.
The International Water Management Institute (IWMI) has made important changes in the thrust of its research programmesince 1995. These new thrusts include attention to the implications of increasing water scarcity at the global level; the adoption of a river basin paradigm leading to new insights into opportunities for water conservation and productivity; application of new information technologies and quantitative analytical techniques; and a stronger focus on policy, institutional issues, health and environment, and social inequities in access to water. This paper describes these changes and provides an overview of the remaining papers in this special issue of Water Resources Development. 相似文献