以磷酸钙盐形式从污水厂回收磷研究

磷是一种不可再生的资源,也是造成水体富营养化的关键因素,为此在北京某污水厂进行了从厌氧段末端上清液中以磷酸钙盐形式回收磷的试验.考察了pH、温度、反应时间等参数的影响,建议采用曝气和投加碱液相结合的方法调节pH值至9.3～9.5,此时磷回收率可达80%左右.     

论生物入侵与园林植物引种

诠释了生物入侵的概念，认为生物入侵的形成，是以外来生物为基础，以其“恶性”繁殖为特点和以危及本地动植物的生存为结果的系统化过程，对形成城市园林生物入侵的种类进行了归类，提出了园林植物引种，造成生物入侵的原因和防治对策。     

秦山核电二期工程地基动态参数测试和地基动态模型

秦山核电二期工程是我国重点建设的大型核电项目。参照国内外的核安全规程,用先进的仪器设备,在该工程场地上进行了全面、系统的地基动态参数测试。这次测试的内容、规模和难度在我国是前所未有的,主要包括用孔内剪切锤激振、爆炸激振和电火花激振等激振方法,进行了四组跨孔测试和二十个钻孔的系统声波测井。最后,根据对测试结果的分析提出了地基岩体的动态模型。本文主要介绍了这次测试工作的测试方案、技术方法和测试成果。     

Elimination of beta-blockers in sewage treatment plants

beta-Blockers are used to treat high blood pressure as well as patients recovering from heart attacks. In several studies, they were detected in surface water, thus indicating incomplete degradability of these substances in sewage treatment plants (STPs). In this study, we determined the sorption coefficients (K(D)) and degradation rates of the four beta-blockers sotalol, atenolol, metoprolol and propranolol in sludge from an STP operating with municipal wastewater. The sorption coefficients (K(D), standard deviations in brackets) were determined as 0.04(+/-0.035), 0.04(+/-0.033), 0.00(+/-0.023) and 0.32(+/-0.058) Lg(-1)(COD), and the pseudo-first-order degradation rate constants were estimated to be 0.29(+/-0.02), 0.69(+/-0.05), 0.58(+/-0.05) and 0.39(+/-0.07) Ld(-1)g(-1)(COD) for sotalol, atenolol, metoprolol and propranolol, respectively. These values translate into a typical elimination in STPs (sludge concentrations of 4g(COD)L(-1) and a hydraulic retention time of 6h) of 25%, 37%, 44% and 50% for sotalol, propranolol, metoprolol and atenolol, respectively. These results are also confirmed by measurements in two municipal STPs for atenolol, sotalol and propranolol. The estimated eliminations are slightly too high for metoprolol.     

Bacterial population changes in hospital effluent treatment plant in central India

Hospital effluent with its high content of multidrug resistant (MDR) enterobacteria and the presence of enteric pathogens could pose a grave problem for the community. It was planned at our tertiary care hospital in central India to study the population changes at various steps of effluent treatment plant (ETP) like collection, aeration, clarification, liquid sludge, dried sludge, high-pressure filter and treated wastewater. The study included viable bacterial counts, coliform counts, staphylococcal, enterococcal, Pseudomonas and multiple drug resistant (MDR) gram negative bacterial counts in the different stages of ETP. In order to study the distribution of bacteria as free floating in liquid and adherent to suspended particles, enumeration of the bacteria in the filterate and the sediment was also carried out. The effluent input showed 55% of the 8.6 x 10(6)/ml bacteria as coliforms and E. coli which was a typical of fecal flora. The prevalence of MDR coliforms was 0.26%. The substantial reduction (> 3log) was seen for the effluent coming from the clarifier. The bulk of the bacteria in the hospital effluent remains firmly adhered to solid particles; aeration and clarification removes bulk of the bacteria by physical processes like flocculation. The treated liquid effluent still contains sizeable loads of MDR bacteria and inactivation by procedure such as chlorination is required. The bacteria get concentrated in sludge and a greater concentration of chlorine is required for decontamination.     

Experimental study and modelling of Cr (VI) removal from wastewater using Lemna minor

The removal of Cr(VI) from wastewater by Lemna minor was studied both at laboratory and pilot scale. Laboratory tests were conducted under different conditions of initial Cr(VI) concentration (0.5 and 2.0 mg/l) and temperature (285 and 291 K). Batch experiments were carried out during 16 days in which the chromium concentrations, both in the biomass and in wastewater were measured. Data were used to characterize the biouptake capacity of the biomass; results showed that it increases with the temperature and when the initial Cr concentration decreases. The biouptake process could be fitted by an equation, with a correlation coefficient of 0.98. The removal process was assessed using the data of the variation of chromium concentration in the wastewater with respect to time; this allowed obtaining constant parameters which were applied in a mathematical model for the assessment of duckweed systems in a pilot scale plant.     

居住小区的自然生态设计

结合现代生态学的发展，介绍了几种有关居住小区自然生态系统的设计方法，探讨了景观水系的设计和雨水的收集、利用，以将生态学原理应用到居住区设计中，创造人与自然和谐的环境。     

LPG储灌厂改为天然气储配站的探讨

结合石家庄市LPG储灌厂改为天然气门站及储配站的工程,从原LPG储灌厂的地理位置、改造后现有设施的可利用性、改造后是否影响城市LPG供应、球罐改造利用的可行性及可操作性等方面论述了LPG储灌厂改造为天然气门站及储配站的可行性,阐述了改造方案.     

广州抽水蓄能电站地下厂房位移预报研究

本文针对广州抽水蓄能电站大型地下厂房(主厂房与主变室)围岩变形的位移预报与施工监控问题,研究了计算模型的建立,计算参数的选择,位移预报原理,位移量测系统和施工监控准则,根据得出的主要计算结果分析了洞室围岩的稳定性,结合工程实践全面系统地建立了位移预报的理论和方法。这类方法对其他同类硬岩地下工程的设计有参考价值。然而由于这类研究方法尚不多见,因此在应用于其他工程的时候,其量测系统的设置和一些数据的取值还需继续研究与完善。     

污水处理厂投资项目特许经营期中的水价调整

以贵阳小河污水处理厂特许经营期间水价调整合同条款及实际操作为例,对污水处理厂投资项目中的风险及其规避方式进行了分析,探讨了污水处理厂投资项目如何通过水价调整来达到政府、企业双赢的若干问题.