Application of Non-Conventional Filtration Technologies in Pollution Control

Deep bed filtration is becoming increasing important in wastewater treatment particularly in tertiary treatment as stringent water quality standards are emphasized. A detailed pilot-scale filtration study conducted with secondary effluent in a sewage treatment plant indicated that tertiary filtration with prior alum flocculation is capable of producing high quality effluent, particularly an effluent with phosphorus content of less than 0.3 mg/L (Vigneswaran and Ngo, 1994). Main problem of dual media filter has been rapid headloss development thus frequent backwash requirement. To overcome this problem two independent experimental studies were conducted: one with mobile bed filtration (MBF) and the other with combined downflow floating medium flocculator/prefilter (DFF) and coarse sand filter (CSF) system. A semi-pilot scale mobile bed filtration study conducted using oxidation pond effluent indicated that MBF with contact-flocculation arrangement was good in removing COD, T-P and turbidity with practically no headloss development. Sand of 0.6-0.84 nm dia and 50 cm depth was sufficient to reduce the COD and P from 55 mg/L and 4.5 mg/L to 15 mg/L and 0.5 mg/L respectively at a filtration rate of 7.5 m3/m2.h. Another experimental study with combined DFF-CSF system indicated that the DFF with in-line flocculation addition is a good pretreatment unit to reduce the phosphate upto 80-90%. The fact that DFF resulted in uniform filterable-flocs, it can also successfully be used as a static flocculator/prefilter unit. The introduction of DFF on top of a coarse sand filter increased the filter run time and removal efficiency (more 90-95% of NH3-N and T-P removal respectively). Most importantly, the backwashing of this system was achieved with small quantity of water at low backwash indicated that the removal efficiency was also superior with this system apart from the major advantage of low operating cost.     

五里湖淤泥现状及生态清淤

对五里湖淤泥现状进行了调查，表明影响五里湖水质的主要污染是五里湖湖底的淤泥，目前淤泥平均厚度为0.6m-0.8m，淤泥量约360万t。根据淤泥中有机质，TN和TP水平分布，有机质平均为40.37g/kg，TP平均值为2.61g/kg，TN平均值为1.19g/kg，均超过了太湖和梅梁湖底泥中有机质，TN和TP的平均值，五里湖底泥的有机污染已相当严重。指出淤泥是湖体营养盐和污染物的聚集地和储存仓库，不断向水体释放营养物质和污染物质，淤泥所产生的二次污染已成为五里湖湖水富营养化和藻类爆发的主要原因之一。提出为改善五里湖水质，应采用生态清淤治理五里湖淤泥污染，同时将生态清淤与交通，绿化和生态农业建设有机结合起来，合理利用清出的淤泥，提高生态清淤的综合效益。     

疏浚后杭州西湖富营养化评价

以综合营养状态指数(TLIc)法评价疏浚前后杭州西湖(Ⅰ~Ⅳ站)的富营养化水平,并与水体浮游动物生物量指标做相关分析。结果表明,Ⅰ站和Ⅳ站综合营养状态指数年平均值下降幅度较大,Ⅱ站和Ⅲ站TLIc年平均值下降幅度较小。疏浚促进了西湖中有机物的氧化分解,降低水体中高锰酸盐指数,抑制底泥中磷的释放。湖水TLIc值随浮游动物生物量升高而显著增大,并以轮虫生物量与TLIc值之间的正相关性最稳定。     

生物监测在航道疏浚工程环境影响评价中的应用

通过生物监测手段对长江口宝山北水道航道疏浚工程进行了生态环境影响跟踪监测和评价.结果发现,工程结束后生物优势种和多样性指数与环评同期相比基本稳定,施工期间生态指标密度和生物量有所波动.监测评价结果反映了疏浚工程的施工对长江口的生态环境影响有限,并随着工程结束周边水域环境正日益恢复.     

Dredging and contaminant exposure to tree swallows nesting on the upper Mississippi River

In 2008 and 2009, dredge material from the Mississippi River in Pool 8 south of Brownsville, Minnesota was used to construct nearby islands. Chemical analysis of sediment in 2001 and 2002 in the area to be dredged indicated detectable concentrations of organic and inorganic contaminants. Tree swallows (Tachycineta bicolor), whose diet is mainly aquatic invertebrates, were used to evaluate contaminant exposure in both the dredged and newly created habitat. Organic and inorganic contaminant data were collected from tree swallows in 2007 through 2010 at one study site near the dredging operation, a reference study site upriver from the dredging activity, one study site down river from the dredging activity, and one study site on a newly created island (2009 and 2010 only). Organic and element concentrations were at background levels in all samples. Polychlorinated biphenyl and p,p′-dichlorodiphenyldichloroethylene concentrations in tree swallow nestlings decreased at all study sites over the period 2007 to 2010 including the island study site between 2009 and 2010. Element concentrations in tree swallow livers for the non-island study sites did not show a trend among years in relation to the dredging. Selenium concentrations at the newly created island were higher and cadmium concentrations were lower in 2010 than 2009. Hatching success of eggs in successful nests was not associated with dredging activities.     

南京南湖底泥疏浚后水质演化规律调查

对疏浚后的南京南湖底泥的TP、TN和COD释放规律、补水后的水质状况以及藻类演替规律进行了调查。结果表明,上覆水中TP平均质量浓度基本不随自来水补入量的增加而发生变化,TN和COD质量浓度随自来水补入量的增加而增大;水体中的TP、TN和COD含量总体呈上升趋势;从2005年3月中旬起,出现藻类的大量繁殖,在2005年7月发生水华,藻类优势种由裸藻、隐藻和小环藻演替为裸藻、栅藻和韦斯藻,藻类总量由2005年3月的3.7×106L-1上升到2006年4月的1.5×107L-1。     

湖库污染底泥环保疏浚工程环评要点探讨

以滇池草海污染底泥疏挖及处置工程为例,分析了湖库底泥疏挖项目环境影响评价因素识别与评价重点,探讨了施工期对水域水质及周围景观影响、施工期恶臭、噪声等的环境影响评价要点,底泥堆放对地下水与土壤环境影响、堆放恶臭对环境影响的评价要点,及疏挖工程的环境效益与运营期对周围生态环境影响分析的要点。针对该类工程在疏挖、余水处理和污染底泥堆存过程中的二次污染问题,提出了切实可行的二次污染防治对策。     

滇池污染底泥环保疏浚一期工程实施后环境效益评估

通过对滇池草海污染底泥环保疏浚一期工程实施前后水质、底质及水生生物的监测和分析,评价工程实施后对改善草海水质,减轻内源负荷及对水生态恢复的环境效益。结果表明,疏浚工程直接去除了草海污染底泥层,随污染层分别去除TN、TP20 538 t和1 716 t。疏浚后草海水体透明度由0.37 m提高到0.80 m,水体中的TN和TP由疏挖前的8.91 mg/L和1.07 mg/L降低到疏挖后的8.15 mg/L和0.69 mg/L。疏浚后新生界面层促使形成新的水—沉积物的平衡,水质与底质条件改善以及水下光照条件超过沉水植物恢复的需求,是疏浚后水生态呈现恢复趋势的机理。     

Environmental Monitoring Of Remedial Dredging At The New Bedford Harbor, Ma, Superfund Site

New Bedford Harbor (NBH), MA, is a Superfund site because of high polychlorinated biphenyl (PCB) concentrations in the sediment. From April 1994 to September 1995, a remedial dredging operation (termed the “Hot Spot”) removed the most contaminated sediments (PCB concentrations greater than 4000μg/g) from the upper harbor. During remediation, a monitoring program assessed the potential environmental impacts to NBH and adjacent Buzzards Bay. The monitoring program was developed with input from federal, state, and local authorities. Site-specific decision criteria were established to assess net PCB transport, water column toxicity, and PCB bioaccumulation in blue and ribbed mussels (Mytilus edulis and Geukensia demissa, respectively). The remediation was completed without exceeding PCB net transport or acute toxicity effects specified in the decision criteria. In addition, PCB bioaccumulation in mussels during this time period was not significantly greater than pre- or post-operational measurements. The results indicated that approximately 14000 cubic yards of highly PCB contaminated sediment were permanently removed with minimal environmental effects. The lessons learned during this operation, as well as previous pilot studies at the site, will be used to make full-scale remedial efforts in NBH more efficient and environmentally protective.     

滇池宝丰湾疏浚区底泥污染程度评价及环保疏浚深度的确定

根据滇池外海主要入湖河口及重点区域底泥疏浚工程,宝丰湾疏浚区设计阶段勘察结果,采用内梅罗污染指数法及Lars Hakanson的重金属潜在生态风险指数法对疏浚区底泥进行了污染程度评价。针对底泥污染空间分布特征,确定疏浚深度,为环保施工提供依据。     

泰东河疏浚工程对通榆河水质的影响

为了解泰东河疏浚工程对通榆河水质的影响,于2012年6月8日、9月12日、12月6日,对泰东河沿线以及通榆河东台段进行调查取样,分析施工期间河体水质变化。结果表明,施工期间水质参数基本保持在Ⅱ~Ⅲ类。根据江苏省水环境监测中心盐城分中心2011年、2013年监测资料评价分析,泰东河河道疏浚后,清理了河床淤泥,提高了泰东河的行洪、抗洪以及通航能力,其水质的好转有效地改善了下游通榆河的水质,确保了饮水安全。     

Modelling of Materials Policies

This paper discusses the REAP1 model and its application for the analysis of CO₂ reduction and waste management policies for Japanese petrochemicals. The pros and cons of this modelling approach in comparison to other tools is elaborated. This is followed by a discussion of the model code and the modelling results. The results show that CO₂ policies can have significant impacts on waste flows and waste policies can have significant CO₂ benefits. As a consequence both effects must be considered in policy assessment. Pricing instruments are recommended instead of regulations because of the complex physical relations in the materials life cycle that extend beyond sector boundaries. A taxation approach is superior to a subsidy approach because rebound effects can be avoided.     

Distribution of Chlorinated Organic Pollutants in Harbor Sediments of Livorno (Italy): A Multivariate Approach to Evaluate Dredging Sediments

Dredging is a very important procedure for harbor management. InItaly the guidelines for the offshore dumping of dredged materials are issued by the Ministry of Environment. Theydescribed a few steps of dredging activities, such as thesampling strategy, but do not deal with limits or guide-valuesfor the chemical, physical and biological composition of theresulting sediments. The quality of dredged materials is mainlydependent on the presence of inorganic and organic pollutants.In particular, polychlorinated biphenyls (PCBs) and organo-chlorinated pesticides are seen as a high priority inmarine environment by international organizations because oftheir persistence, toxicity and bioaccumulation capacity.In this article the presence of some PCBs and organo-chlorinatedpesticides in sediment samples collected from the harbor ofLivorno (Northern Tyrrhenian Sea) was investigated. Theconcentration of HCHs, Aldrin, Chlordanes, DDEs, DDTs, and PCBsin 12 representative sites ranged between <1 g kg^–1and 95, 19, 32, 35, 107, and 111 g kg^–1, respectively.The application of univariate and multivariate statisticaltechniques, such as linear regression analysis and principalcomponent analysis, to the experimental data showed a differentdistribution of PCBs in the two sediment layers. On thecontrary, the vertical distribution of the other investigatedpollutants was more homogeneous and affected by randomvariability. The multivariate approach was an important tool to establish more rational criteria for the management of dredged materials.     

机动车排放细颗粒物精细化源谱构建及应用

利用真空瓶现场采样并结合单颗粒气溶胶质谱(SPAMS)技术,对主流品牌汽油车和柴油车排放细颗粒物进行组分分析和源谱构建。结果表明：汽、柴油车尾气源谱特征整体较为相似,相似度均值达到0.88,均以碳和钙为主要特征组分;部分柴油车特征源谱中硫酸盐特征较为明显,碳组分中OC特征突出;汽油车源谱特征中磷酸盐特征相对突出,且碳组分中短链元素碳占比较高。根据建立的源谱进行实际道路观测,结合风速、风向等气象要素分析,2021年2月1日—24日观测点位对应的移动源占比为33.5%,其中汽油车贡献21.0%,柴油车贡献12.5%。     

目标考核视角下的城市生态文明建设综合评价

在阐述生态文明建设内涵的基础上,从资源利用、经济发展、国土空间布局、生态环境保护和社会进步5个方面选取30项指标,运用综合指数法开展深圳市生态文明建设评价,并借助灰色系统模型GM(1,1)预测其发展趋势。研究表明,深圳市生态文明建设成果逐步凸显,除国土空间布局对生态文明建设贡献呈下降趋势外,其余4个方面对其贡献均逐步提高;地方政府生态文明建设考核压力逐步趋缓。预测显示深圳市生态文明建设得分持续小幅度增加,生态文明建设得到持续加强。当前生态文明建设重点在于优化国土空间布局,需要加强耕地保护、调整土地利用结构和控制人口密度。     

室内装饰装修材料测试舱的研制与应用

介绍了测试舱的研制意义、测试舱构造和温度控制部分,以及空气交换、循环控制,空气净化装置和温度、湿度、流速显示装置等.通过实验,对测试舱的温度控制,空气净化系统检验,空气交换、循环的检验,释放甲醛平衡点的快速判断和测试舱的比对等运行技术指标进行了论证、优化.结果表明,简易的室内装饰装修材料测试舱对主要运行参数可以自动运行与控制,运行情况满足国家标准方法的技术指标要求,与同类商品化测试舱相比,误差在2%左右.     

五氯酚标准样品的研制

五氯酚是美国ＥＰＡ公布的１２９种重点污染物名单以及我国环境优先监测污染物黑名单中的重点污染物,也是环境监测和环境科研工作中的主要对象。本文介绍了这种污染物毒理特性和液体介质标准样品的分析、研究、制备方法。     

标准样品在环境监测应用中几点问题的探讨

环境(有证)标准样品(CERM)已成为环境监测及其质量保证/质量控制(QA/QC)重要工具和常用方法,科学理解和合理使用CERM越来越重要。 文章将CERM在环境监测应用中的有关问题归结为"泛标样"倾向和对CERM特性值误区两个方面,结合典型案例,通过不确定度评定分析相关误区或偏颇,并提出选择性使用CERM、按规定条件使用CERM、全面了解掌握CERM特性值、合理运用CERM特性值范围和慎重评价CERM特性值范围内测定结果的差异等具体对策和建议。     

列车车厢内装材料VOCs释放特性研究

列车车厢内的空气质量对乘客的健康和乘坐舒适度有明显影响.密闭车厢的内装材料所释放的挥发性有机物(VOCs)是影响车厢内环境空气质量的主要污染物.为研究25G型客车车厢内空气VOCs浓度的分布机理及扩散规律,采用环境测试舱法和扫描电镜(SEM)表征,对车厢主要内装材料(座椅坐垫、PVC地板、墙板等)的VOCs释放速率进行...     

Concentration and Distribution of Persistent Organic Pollutants (POPs) in Harbour Dredging Sediments: A Pilot Study Using a Statistical Approach for a More Efficient Characterisation and Management

The Italian guidelines concerning the dumping of dredgingmaterials implies chemical, physical and microbiologicalcharacterisation of dumping sediments collected through aspecific sampling strategy.POP's such as PCB's and organochlorine pesticides, areconsidered as priority pollutants in all the InternationalConventions for the protection of the marine environment, inconsequence of their persistence, toxicity and bioaccumulation capacity.In the present article the concentrations and distribution ofPCB's and organochlorine pesticides in dredging sediments ofPiombino harbour (northern Thyrrenian sea) were investigates.The results showed high POP's concentrations in all the studiedareas. The maximum values were: 3.94 mg kg^-1 dry weight for PCB's(IUPAC Nos. 28; 52; 101, 118; 137; 153; 180; 209); 2.04 mg kg^-1 d.w.for HCH's (-, -, - and -hexachlorocyclohexane isomers); 0.28 mg kg^-1 d.w. for DD's (DDT + DDE + DDD).Subsequently, the data related to each pollutant were treatedwith statistical tests, in order to verify how well the samplingstrategy is able to represent the distribution of contaminantsin the dredging area. Finally, management strategies werederived for the studied dredging sediments.