改良混凝反应器强化混凝效果的研究

通过设置水平隔板强化水力扩散作用,提高了普通混凝反应器的混凝效果;比较了改良与普通混凝反应器对某污水厂二级生化出水的处理效果:在相同的pH值、速度梯度、混合及絮凝时间、沉降时间以及相同的混凝剂种类及剂量下,改良混凝反应器对CODCr、总磷(TP)及浊度的去处效果都优于传统的混凝反应器;当达到相同的CODCr,TP和浊度的去除率时,聚合氯化铝(PAC)投加量分别可以降低25%～50%,20%～30%,20%左右,因此可以大大降低成本。可见改良后的反应器通过改善水力条件、增强传质作用,强化了原水和混凝药剂的混合作用,改善了混凝处理效果,提高了各污染物的去处率,给污水厂及再生水厂混凝沉淀工艺的改造提供了借鉴。     

Walking routes to school in new urban and suburban neighborhoods: An environmental walkability analysis of blocks and routes

We assessed environmental and perceptual correlates of walking and walkability for fifth graders from three communities attending two schools: A new urban/LEED-ND pilot community, mixed, and standard suburban community. Irvine-Minnesota Inventory (IMI) walkability audits showed that new urban blocks provided more traffic safety, pleasurability, crime safety, density, and diversity. New urban routes offered greater traffic safety, accessibility, pleasurability, crime safety, and diversity, but suburban routes had greater housing density, net of controls (parental education, rooms in the home, home ownership, parent preference for child to walk to school). Parents and children perceived new urban routes to be more walkable and children walked more when they lived on more walkable routes. The suburban hierarchical street design exposed children to varied traffic safety conditions by funneling their walks from cul-de-sacs to arterials. The new urban routes to a centrally located school passed by pleasant open spaces, suggesting how community organization can create better walking conditions.     

雄安新区富硒土地资源分布特征及开发利用评价

采集雄安新区表层土壤样品（0~20cm）、大宗农作物（小麦籽实）及根系土样品,利用GIS空间分析、相关分析等方法对土壤硒含量分布、富集特征及影响因素进行分析,基于生态位适宜性评价理论模型开展富硒土地资源开发利用适宜性评价.结果表明：新区表层富硒土地16993hm²,土壤中硒赋存形态以强有机结合态为主,其次为残渣态和腐殖酸结合态,三者占土壤硒总量的87%以上,生物可利用态硒含量所占比例相对较小（水溶态硒占比4.44%、离子交换态硒占比3.43%）.小麦籽实样品富硒率28.45%,籽实中硒含量与根系土壤中硒含量具有显著相关性（r=0.77,P<0.01）.土壤硒富集主要受第四纪沉积地貌环境的影响,此外灌溉水、化肥和大气干湿沉降（燃煤降尘）等外源输入也影响贫化富集.土壤硒含量与沉积地貌环境“标志性”土壤指标Al₂O₃、Fe₂O₃、MgO和K₂O含量,土壤有机碳（Corg.）、阳离子交换量（CEC）、黏粒和粉粒含量等具有显著正相关关系,与SiO₂、Na₂O含量和土壤砂粒含量等具有显著负相关关系（P<0.01）.基于生态位评价理论模型,新区富硒土地资源开发利用适宜性评价结果表明：高适宜区（Ⅰ级）和中适宜区（Ⅱ级）主要位于新区西北容城县南张镇和小里镇、安新县寨里乡和老河头镇等地,土地面积为14397.35hm²,占新区规划总面积的8.13%.     

基于DPSIR模型的环境友好型社会评价指标体系构建

为评价区域环境友好型社会建设程度,采用DPSIR概念模型,构建起包涵5大类因子指标的评价体系。此体系评价重点在于社会子系统发展对社会所造成的资源、环境、生态压力,居民生活环境状态的改变和在社会结构与居民生活的影响,以及所导致的各项政策响应。并以沈阳市浑南新区为例,选取了包括科技技术贡献率、生态用地比例、公众对生活环境满意度在内的44项指标,构建起针对浑南新区的评价指标体系,可对浑南新区的环境友好型社会建设以及管理决策起到辅助支撑作用。     

我国环境技术验证评价制度建设探析

在概述国外环境技术验证制度快速发展的背景下,论述了我国建设环境技术验证评价制度的目的、意义和条件,提出了建设环境技术验证评价制度应采取的对策措施。     

高盐废水处理研究新发展

高盐废水处理比较困难.传统的物化、生化法处理高盐废水可以达到一定的效果,但都存在着不可避免的弊端。因此,笔者在过去几年国内外高盐废水处理研究的基础上,介绍近阶段高盐废水处理的新方法,总结经验。     

关于在丹东市新城区建设环境空气自动监测点位的阐述

根据丹东市环境空气自动监测点位现状,结合环境空气质量监测规范及创建环境保护模范城的要求。考虑在新城区建设环境空气自动监测点位。这样可以保证丹东市各行政区环境空气监测点位分布的均匀性,反映新城区主要功能区和主要空气污染源的污染状况及变化趋势。     

Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.     

Novel microbial fuel cell design to operate with different wastewaters simultaneously

A novel single cathode chamber and multiple anode chamber microbial fuel cell design(MAC-MFC)was developed by incorporating multiple anode chambers into a single unit and its performance was checked.During 60 days of operation,performance of MAC-MFC was assessed and compared with standard single anode/cathode chamber microbial fuel cell(SC-MFC).The tests showed that MAC-MFC generated stable and higher power outputs compared with SC-MFC and each anode chamber contributed efficiently.Further,MAC-MFCs were incorporated with different wastewaters in different anode chambers and their behavior in MFC performance was observed.MAC-MFC efficiently treated multiple wastewaters simultaneously at low cost and small space,which claims its candidature for future possible scale-up applications.     

Benefits and risks associated with consumption of Great Lakes fish containing omega-3 fatty acids and polychlorinated biphenyls (PCBs)

正Introduction Assessment of environmental health effects arising from exposure to multiple substances is often very challenging.This is particularly true when humans are exposed to a mixture that contains both beneficial and harmful substances.A good example relates to the risk and benefits of fish consumption.