人工湿地控制非点源污染的应用

随着点源污染的有效管理和控制，非点源污染已成为水环境污染的主要原因。人工湿地作为一种控制水环境非点源污染的有效工具，已被世界上很多国家所认可。本文首先简述了非点源污染的危害，其次对人工湿地的概念和类型进行了介绍，论述了人工湿地对非点源污染中氮、磷、重金属和农药等主要污染物的去除机理，最后对人工湿地处理系统的附属设施、水力因素、表土层以及植物收割等应用问题进行了探讨。     

整治塔里木河上、中游用水结构,恢复和重建下游绿色走廊

塔里木河下游的卡拉到罗布庄(台特马湖口)，河道长度491kin，塔河中、上游大规模水土开发，使其下游的水量不断减少。从20世纪70年代开始，大西海子水库就成了塔里木河最终归宿地，两大沙漠在绿色走廊的多处合拢。绿色走廊生态危机已越来越显露出来，遏制塔河下游生态恶化趋势刻不容缓，重新构筑绿色长城不能在延误了。笔者于2002-10月和2004—05月先后两次对塔河中、下游地区进行实地考察，在实地考察和前人研究资料的基础上，对整治塔河上、中游，恢复和重建下游绿色走廊问题进行探讨。     

稠油污水处理系统改造与絮凝剂筛选试验研究

河南油田井楼稠油联合站含油污水中的污油和悬浮物含量较高,超过150mg/L。为此,对该处理系统进行了改造,并对絮凝剂的筛选进行了试验。结果表明:无机絮凝剂与有机絮凝剂联合作用,可对污水中所含有的污油和有机物杂质的悬浮物产生很好的絮凝沉降效果。加药浓度、加药顺序及沉降时间均对絮凝沉降效果有一定的影响。改造后的污水处理系统实现了污水达标回注,降低了无效回注费用。同时还回收了污油,降低了药剂成本,产生了十分明显的经济效益,每年节约成本约500万元。     

抚顺石化公司硫磺回收装置的扩建和改造

抚顺石化分公司石油三厂原有硫磺回收装置的处理能力已经不能满足生产的需要,2002年对硫磺回收装置进行了扩建和改造。该装置采用了一段高温转化、二级催化转化的克劳斯工艺,采用揝SR敾乖?吸收工艺处理尾气。扩能改造后,新增的尾气处理能力与硫磺回收能力相配套,排放的废气符合国家现行的环保标准。该装置工艺路线合理、可靠,硫回收率高。     

铅锌矿产资源开发重金属污染风险评价

在论述环境风险评价的概念、理论和方法的基础上,通过对某典型铅锌矿山重金属污染程度、重金属毒性响应系数和生态危害系数的计算与探讨,建立了铅锌矿山重金属生态风险评价指标体系.根据所建立的指标体系,计算了每个样点的生态风险指数,结果认为该矿山总体环境质量很差,重金属污染极其严重.     

垃圾焚烧飞灰中重金属的固化/稳定化处理实验研究

研究了城市生活垃圾焚烧-电灰的特性及飞灰中重金属的特性,对利用水泥作粘结剂进行飞灰固化/稳定化处理效果开展了系统的实验研究,分析了水泥固化/稳定化飞灰的工艺特点和最佳工艺参数,并讨论了粘结剂固化飞灰机理以及重金属浸出毒性,为进一步研究城市生活垃圾焚烧飞灰的无害化处理与利用提供了有重要价值的参考依据.     

Sustainable pattern analysis of a publicly owned Material Recovery Facility in a fast-growing urban setting under uncertainty

Sustainable development goals are achievable through the installation of Material Recovery Facilities (MRFs) in certain solid waste management systems, especially those in rapidly expanding multi-district urban areas. MRFs are a cost-effective alternative when curbside recycling does not demonstrate long-term success. Previous capacity planning uses mixed integer programming optimization for the urban center of the city of San Antonio, Texas to establish that a publicly owned material recovery facility is preferable to a privatized facility. As a companion study, this analysis demonstrates that a MRF alleviates economic, political, and social pressures facing solid waste management under uncertainty. It explores the impact of uncertainty in decision alternatives in an urban environmental system. From this unique angle, waste generation, incidence of recyclables in the waste stream, routing distances, recycling participation, and other planning components are taken as intervals to expand upon previous deterministic integer-programming models. The information incorporated into the optimization objectives includes economic impacts for recycling income and cost components in waste management. The constraint set consists of mass balance, capacity limitation, recycling limitation, scale economy, conditionality, and relevant screening restrictions. Due to the fragmented data set, a grey integer programming modeling approach quantifies the consequences of inexact information as it propagates through the final solutions in the optimization process. The grey algorithm screens optimal shipping patterns and an ideal MRF location and capacity. Two case settings compare MRF selection policies where optimal solutions exemplify the value of grey programming in the context of integrated solid waste management.     

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.     

Experimental investigation of a 250-kW turbine organic Rankine cycle system for low-grade waste heat recovery

An organic Rankine cycle (ORC) is generally used for converting low-grade heat into electricity. In this study, an extensive literature survey was conducted to identify current research gaps on experimental ORC systems. Specifically, there is limited experimental data and limited details on thermal and expander efficiencies of ORC systems. In order to address these gaps, the objective of this study included developing a turbine ORC with a power output exceeding 50 kW and thermal efficiency exceeding 8% for a heat source temperature < 120°C. The experimental results indicated that the system achieved a net power output of 242.5 kW and a thermal efficiency of 8.3% (the highest value for a turbine ORC system for the heat source temperature below 120°C). Thus, the study addressed the gaps identified in the research area of ORCs.     

利用白云石石灰去除与回收污泥厌氧消化液中氮和磷

以白云石石灰为实验材料去除与回收污泥厌氧消化液中的氮磷,通过小试实验研究不同投药固液比S/L、初始pH值、反应温度、搅拌速度及反应时间对去除与回收氮磷效果的影响。实验结果表明,在最佳投药固液比S/L为300mg/L,最佳初始pH值范围为8.5~9.5,反应温度为25.0℃,搅拌速度为150 r/min,反应时间为24 h条件下,氨氮(NH+4-N)和磷(PO3-4-P)的去除率分别为37.26%和89.60%。利用X射线衍射仪(XRD)、扫描电镜(SEM)对沉淀产物进行了表征,通过分析可知沉淀产物中含有磷酸铵镁(MAP),可实现废水中氮磷经济有效的回收。