Distribution and Fate of Escherichia coli in Lake Michigan Following Contamination with Urban Stormwater and Combined Sewer Overflows

Escherichia coli distribution and persistence in nearshore Lake Michigan were assessed following heavy rains and sanitary sewer overflow (SSO) and combined sewer overflow (CSO) events over a 5-year period, including an 18-day period following 25.4 cm of rainfall in which intensive studies were conducted following multiple CSO and SSO events. E. coli levels in the Milwaukee estuary and harbor following SSO and CSO events ranged from 10⁴ to nearly 10⁵ CFU/100 mL, which were significantly higher (p ≤ 0.05) than levels following rainfall alone. Sites outside of the breakwall but within the contamination plume (e.g., within 2 km of the harbor) were an order of magnitude lower. Locations 2–5 km from the harbor ranged from below detection limits, of < 1 to 5 CFU/100 mL. E. coli levels corrected for dilution based on specific conductivity measurements were lower than what would be expected for loss due to dilution alone, suggesting a combination of die-off and dilution, were responsible for the rapid disappearance of these organisms outside of the harbor. E. coli and fecal coliforms measured concurrently demonstrated that fecal coliforms could be recovered longer than E. coli in the open waters of the lake. E. coli isolated directly from sewage treatment plant influent were found to have a marked increase in antibiotic resistance traits for ten antibiotics commonly used in the human population compared with isolates from two animal sources of fecal pollution. However, E. coli obtained from sewage impacted water (n = 2,513) and from stormwater impacted water (n = 1,465) collected the previous year when there were no sewage overflows, were found to have no significant difference (p < 0.05) in the frequency of resistance when comparing the two conditions. E. coli survival characteristics and population dynamics are most likely influenced by multiple factors in complex systems such as the watershed/estuarine/lake environments of the Great Lakes.     

石化行业污水回用途径的可行性分析

随着石化行业污水回用技术的成熟,污水回用途径成了制约污水回用的瓶颈。通过对各种回用水途径的可操作性比较,筛选出最佳途径,并通过现场试验,从技术、经济、可操作性方面论证,认为石化污水回用于工业循环冷却水场作为补充水确实可行。     

The biodegradability of two primary alcohol ethoxylate nonionic surfactants under practical conditions,and the toxicity of the biodegradation products to rainbow trout

A field trial has been performed to measure the biodegradability of two typical alcohol ethoxylate nonionic surfactants, “Dobanol” 45-7 and “Dobanol” 45-11, by dosing them to biological filters in a mixture with domestic sewage. Influent levels were 10 and 25 mg l^?1 of each surfactant and 96–98% degradation was achieved within a temperature range of 5–10°C. The surfactants had no adverse effects on the filters in terms of the usual sanitary parameters (BOD, COD, TOC and ammoniacal nitrogen). Tests on the effluents indicated no residual acute lethal toxicity to rainbow trout Salmo gairdneri).     

Disinfection of wastewaters: high-energy electron vs gamma irradiation

A study was undertaken to examine the sensitivity of a wastewater population of coliphage, total coliforms and total flora present in raw sewage and secondary effluent after irradiating with similar doses delivered by a high-energy electron beam and y -radiation. The electron beam study was conducted on a large scale at the Virginia Key Wastewater Treatment Plant, Miami, Fla. The facility is equipped with a 1.5 MeV, 50 mA electron accelerator, with a wastewater flow rate of 8 ls⁻¹. Concurrent y-radiation studies were conducted at laboratory scale using a 5000 Ci, ⁶⁰Co y -source. Three logs reduction of all three test organisms were observed at an electron beam dose of 500 krads, while at least four logs reduction were observed at the same dose utilizing the y-source.     

老挝南欧江梯级水电站二期厂房生活给水系统设计

水电站厂房生活给水系统应能够可靠、高效地为厂内工作人员提供满足要求的生活用水。老挝南欧江梯级水电站二期厂区附近均无可用的市政供水管,无法依靠市政供水系统为厂区提供生活用水。以老挝南欧江梯级水电站二期厂房生活给水系统设计为例,提出了针对远离城镇,无市政供水情况下,水电站厂房生活给水系统的设计思路、设计方案、设计的要点及难点。     

小型发生炉煤气在矿区的应用

本文从民用角度主要介绍了发生炉煤气站工艺流程，讨论了煤气站的经济性、存在问题及对策，从而确定发生炉煤气作为民用煤气的可行性。     

国内化纤市场的现状及预测

分析了１９９３年底至１９９４年１季度国内化纤价格上扬及１９９５年２季度以来价格下滑的形势，提出国内化纤工业调整的必要，并预测了今后国内化纤市场的发展趋势。     

探讨回收污水中有用的物质

重油催化裂化等的污水含汽油、硫和氨，将汽油、硫和氨回收是哈尔滨石化分公司具有发展前景的项目。     

UASB-SBR工艺处理城市生活污水的研究

研究了UASB工艺处理城市生活污水的可行性，通过UASB与SBR组合工艺的运行实验，得出在水力停留时间3h时，COD去除率为61．67％-82．32％，出水COD达到国家污水排放二级标准。在氮磷去除效果不佳的情况下，采用SBR工艺处理后，其出水COD、SS、氮、磷等指标均达到国家污水一级排放标准。     

复合微生物处理生活污水的研究

对复合微生物进行了研究,利用4种微生物群分别与活性污泥混合使用处理城市污水,考察了这几种复合微生物群在不同水力停留时间时的污水处理效果,并且用空白活性污泥作对照,进行了出水CODcr的值及其去除率的对比、分析和研究。