对废旧物资回收业的管理政策分析

如何从源头做到城市生活垃圾减量化、资源化和无害化，实现物资回收再利用，获得物资回收在经济和环境效益的和谐统一，一直是理论界和现实生活中一个长期争论的问题。从政策管理的角度出发，尝试找到一个实现个人利益和政府管理角色和谐统一的方法，以期能通过政策管理，利用经济手段，从源头实现城市生活垃圾的减量化、资源化和无害化。     

农药杀虫单的稻田流失规律研究

通过测坑、人工降雨等手段，对水溶性农药杀虫单的稻田消解动态、渗漏流失和径流流失等进行了研究。结果表明，(1)无水稻时，杀虫单在稻田水中消解的半衰期为0．76d；分蘖初期，杀虫单在稻田水中降解的半衰期为1．02d；平均为0．89d。(2)杀虫单的渗漏流失量在用药后8d内可达总用药量的7％—10％，平均为8．48％。(3)极端情况下，用药当天如果遇暴雨(50mm雨量)，杀虫单的径流流失量将达到用药量的30％左右。杀虫单的渗漏损失不可避免，故其流失控制应从径流损失着手，尽量避免在可能有暴雨的当天或雨前1—2d用药。     

废水处理的新趋势与新技术

介绍了我国水污染方面的情况、水污染治理的常用技术及基本工艺流程、水治理技术发展的新趋势和几种水处理的新技术。对这些新技术的基本原理、研究方向与前景作了阐述。     

超声波处理石化厂剩余活性污泥

采用超声波处理石化污水处理厂的剩余活性污泥。介绍了超声波对污泥的作用机理，初步研究了超声波处理污泥的影响因素。大功率超声波可以降解生物污泥，释放出其中的有机物。小功率超声波能够改善污泥的膨胀特性、提高污泥沉淀特性和脱水能力、降低污泥的含水率，达到减量的目的。经超声波处理并简单过滤的污泥滤液，COD达到4200mg／L左右，污泥含水率由94％降至85％左右。     

草地畜牧业雪灾脆弱性评价 --以内蒙古牧区为例

从综合减灾和区域可持续发展的角度，建立了雪灾脆弱性评价指标体系及评价模型，并从雪灾区域孕灾环境敏感性以及区域畜牧业承灾体对雪灾的适应性两方面，对内蒙古雪灾脆弱性进行了评价。研究结果表明：内蒙古牧区雪灾脆弱性存在若明显的地域差异，中西部牧区比东部牧区脆弱性大，北部牧区比南部牧区脆弱性大，并且近10年来脆弱性提高的旗县明显增多，草地季节性干旱、北方干旱化以及草场超载过牧、退化加剧是畜牧业雪灾脆弱性呈增加趋势的直接原因。     

视屏作业人员慢性肌肉骨骼损伤的调查研究

２３２名微机操作人员的慢性肌肉骨骼损伤表现为肩、颈、下背的酸痛和肩疲劳，与对照组比差异显著。手、腕及上肢的慢性损伤虽较对照组高，但无统计学意义。这与他们的击键次数相对较少（每日１００００次左右），但需长期间保持低头及向前弯腰的坐位姿势及工作台面太高等因素有关     

品读婺源

知道婺源,不仅仅因为这里是南宋理学大师朱熹的故里,中国铁路建设鼻祖詹天佑的桑梓；不仅仅因为这里的蓝天白云、粉墙黛瓦、小桥流水,是     

Status and fuzzy comprehensive assessment of combined heavy metal and organo-chlorine pesticide pollution in the Taihu Lake region of China

The status of combined heavy metal and organo-chlorine pesticide (OCPs; i.e. HCH and DDT) pollution was investigated and the soil environmental quality of the Taihu Lake watershed, one of the most developed regions in China, was evaluated using a fuzzy comprehensive assessment. Statistical analyses showed the presence of combined pollution in the soil. At many sampling sites, heavy metal concentrations were above corresponding background values, indicating the effects of extraneous pollutants. It has been over 20 years since China banned the use of OCPs, but they can still be found in soil samples of this region. HCH levels at all investigated sites were below the Chinese Environmental Quality Standard for Soils. Fuzzy comprehensive assessment showed that the overall soil quality in this region could be categorized as class I. Nevertheless, the high coefficients of variation for levels of DDT, Cd and Hg indicated the existence of some point-source pollution. Continuous monitoring and further studies of the region are recommended to prevent pollution of farmland from these sources.     

基于IFS-动态加权的地下综合体深基坑施工风险评价

为控制地下综合体深基坑施工风险,提出了一种基于直觉模糊集(IFS)-动态加权的风险评价方法.从地质条件、建筑环境、岩土设计、施工方案和偶然风险5个方面分析地下综合体深基坑施工风险因素,构建了综合风险评价指标体系.采取施工风险5级划分方法,利用IFS理论确定指标风险;以偏大型正态加权函数确定指标权重,得到系统综合风险.以西安市某地下综合体深基坑施工实际为背景,进行方法应用.结果表明,该西安市地下综合体深基坑施工系统风险等级为显著风险.其中,指标"邻近建筑""地下管网"的风险等级为高度风险,"道路交通""基坑边坡稳定性""降排水实施"为显著风险,对此提出了相应的安全措施.     

Research on the experiment of the enhancement removal of fine sand by hydrocyclone in sewage treatment plant

The content of fine sand (< 200 μm) in primary sludge is relatively high in Chongqing sewage treatment plant owing to the part of rainwater will be mixed with sand and discharged into the municipal pipe network. Due to the insufficient separation of the sand, different obstacles to subsequent treatment processes may increase equipment wear, reduce effective volume of the tank, or shorten the cleaning cycle. There is a common use of grit chamber for the separation. Nevertheless, the use of hydrocyclone shows an outstanding performance in cost effectiveness and ease operation. The primary sludge in a sewage plant in Chongqing was monitored, and the average concentration of total suspend solids (TSS), total sand content, and volatile suspended solid (VSS) were 40.25 g/L, 17.51 g/L, and 13.41 g/L, respectively. The size of sand in the sludge was small, and the sand below 30 μm accounted for about 70% of the total sand. It formed flocs with organic matter and was removed in subsequent process units. While the size between 30–200 μm, called fine sand, was the main separation object, accounted for about 28.5%. According to XRF and XRD analysis, the sludge composition was mainly composed of quartz (SiO₂), plagioclase (Na(AlSi₃O₈)), and calcite (CaCO₃), which were similar to the main mineral composition of surface sediments and mountain rocks in the main urban area of Chongqing. A single-factor experiment on two types (FX100 and FX50) of hydrocylones was conducted to determine their abilities concerning the separation of fine sand and enrichment of organic matters from primary sludge. FX100 and FX50 showed best performance in the case of P = 0.17 Mpa, underflow diameter (Du) = 18 mm and P = 0.20 Mpa, Du = 6 mm, respectively. The removal efficiency of fine sand by hydrocyclone FX50 was 71.39%. While, it had poor performance on organic matter enrichment and the removal efficiency of which was 17.38%. By contrast, the removal rate by FX100 reached 61.89% for fine sand and only 6.89% for organic matters detached. The superimposition effect did not appear in the serial experiments on hydrocylone FX100 and FX50, but the power is 3.5 times of that of single-stage hydrocylone FX100. Comprehensive consideration of the processing capacity per unit time and operating power, the hydrocylone FX100 was more suitable for actual operation.