微生物絮凝剂与聚合氯化铝复配处理涂料废水的响应面优化

采用响应面分析法对聚合氯化铝(PAC)与污泥生产的微生物絮凝剂复配处理涂料废水的过程进行了优化,设定的响应值为COD和色度去除率。实验分别拟合了关于COD去除率和色度去除率的二次模型,根据响应值的分布情况,确定涂料废水的最佳絮凝条件为微生物絮凝剂浓度47 mg/L,PAC浓度39 mg/L,pH为8.2,CaCl2浓度0.38 g/L,搅拌速度210 r/min。最佳絮凝条件下,微生物絮凝剂对涂料废水中COD和色度的去除率分别达到77.6%和68.9%。     

复合菌群的构建及其所产微生物絮凝剂的动力学研究

由2株产低效絮凝剂产生菌构建出产高效絮凝剂的复合菌群--复合1.实验表明,复合1能在啤酒废水培养基中生长良好,并产生絮凝活性为96.8%的MBF.该MBF中含多糖和蛋白质等有机高分子物质.它能有效去除靛蓝印染废水中的COD和色度,两者的最大去除率分别为79.2%和87.6%.考察了该MBF在优化工艺条件下对靛蓝印染废水的絮凝过程,并得出了其去除COD和脱色的经验动力学方程.     

PS高级氧化-离子沉淀-V型砂滤组合工艺深度处理AO7染料废水应用研究

采用Fe2+活化PS高级氧化-离子沉淀-V型砂滤组合工艺对模拟印染废水进行深度处理。以AO7为模型污染物,模拟COD约100 mg/L的废水,考察了PS、Fe SO4投加量和摩尔比对COD去除率、体系剩余SO2-4浓度和SS去除率的影响。结果表明,该组合工艺能有效处理AO7废水,当PS∶Fe2+∶AO7摩尔比为30∶15∶2时,COD去除率可达最大的80.6%,处理成本5元/m3;当PS∶Fe2+∶AO7摩尔比为30∶15∶4时,COD去除率可达77.6%,SO2-4去除率高达60.6%,出水SO2-4浓度124.4 mg/L,处理成本2.7元/m3;当PS∶Fe2+∶AO7摩尔比为30∶20∶8时,COD去除率可达64.7%,SO2-4去除率达42.4%,出水SO2-4浓度110.5 mg/L,SS10 mg/L,处理成本为最低的1.5元/m3。组合工艺中高级氧化塔为COD去除的关键环节;离子沉淀池可以有效去除反应过程中产生的SO2-4。     

新型铁镁复合絮凝剂的制备及其处理印染废水的实验研究

制备了新型铁镁复合絮凝剂(PFMS)并应用于印染废水处理,考察了投药量、溶液pH、沉降时间等因素对絮凝效果的影响;同时,与其他常规市售絮凝剂进行了对比实验.结果表明,PFMS能有效去除污染物,在最佳投药量时,COD和色度去除率可分别达到69%和86%;PFMS处理印染废水的絮凝效果好于常规市售絮凝剂;在低投药量下,PF...     

Ti4+复合聚合硫酸铁絮凝剂的制备表征及絮凝性能

以FeSO4·7H2O为原料,NaClO3氧化法制备出聚合硫酸铁,并用Ti4+与其复合得到复合絮凝剂。运用XRD及FTIR对絮凝剂结构进行了表征,并通过处理油田废水含油量和浊度考察了絮凝剂的絮凝性能。结果表明,Ti4+与聚合硫酸铁复合以后,样品分子量增大,结晶性变差,晶粒变小,无定形结构所占比例增大。Ti4+与聚合硫酸铁不是简单的混合,而是发生了一定的相互作用,并且生成了Ti—O—Fe键。通过正交实验优化出的制备条件为:n(Ti4+)/n(Fe3+)=0.05;合成温度为65℃;搅拌时间为1 h。复合后的产物对油田废水的处理效果优于复合前,且在pH值为7,投加量(以铁计)为20 mg/L时絮凝性能最好,其油去除率与浊度去除率分别为89.8%和98.3%。     

合成聚硅酸硼镁硫酸铁的正交实验研究

研究了用硅酸钠、硼砂、硫酸镁和硫酸铁为原料，制备聚硅酸硼镁硫酸铁（PSBMFS）混凝剂的方法及合成条件。通过正交实验，考查了硅酸活化pH值、缩聚反应时间和陈化时间等合成条件；同时考察了B/Si摩尔比、Mg/Si摩尔比和Fe/Si摩尔比等影响因素。结果表明：PSBMFS具有良好的混凝性能和脱色效果，能有效去除印染废水中的色度和COD，2种污染因子的去除率分别可达95.9%和67.9%。     

响应面法优化Fenton处理难降解反渗透垃圾浓缩渗滤液

采用了基于中心复合设计(CCD)的响应面分析方法(RSM)研究了Fenton试剂处理难降解反渗透垃圾浓缩渗滤液过程中初始pH、FeSO4.7H2O用量、[H2O2]/[Fe2+]摩尔比3个因素对浓缩液中COD去除率的影响。由Design Ex-pert 7.1软件设计分析实验数据,得到了一个二次响应曲面模型,模型具有较高的回归率(R2=0.9699),与实验结果吻合程度较高。该模型显示COD的去除率与3个因素之间不是简单的单调函数关系,它们彼此之间存在一个最佳数值而使去除率达到最高。H2O2与Fe2+之间具有很强的相互增效作用,COD的去除由氧化作用和混凝作用共同完成。在最佳pH值为3.75,FeSO4.7H2O投加量为17.91 mmol/L、[H2O2]/[Fe2+]摩尔比为1.36的反应条件下,COD去除率能达到最高值(72.25%)。     

混凝+芬顿法对中晚期垃圾渗滤液色度去除

垃圾渗滤液经一般生化处理后色度很大。对混凝和芬顿法结合深度处理垃圾渗滤液对色度去除进行了研究。混凝段通过中心复合设计(简称CCD)和响应面方法(简称RSM)分析了混凝的色度去除率的响应特征,建立了实际因素的最终方程模型:Y(色度去除率,%)=-553.40+73.74A+229.06B+0.38AB-34.16A2-22.67B2,(Y、A、B分别代表色度去除率、投加量和pH)并对絮凝条件进行优化,得到混凝反应的最佳优化条件:投加量1.11 g/L,pH 5.06,及在此条件下的去除率67.2%。在芬顿段,将芬顿反应对水中亲水性有机物相对含量(UV254)与对色度的去除特征相结合进行了研究,证明色度的去除跟该类有机物的去除有关,色度去除率最优值条件选择为H2O2/COD=1.0,Fe2+/H2O2=0.35∶1,而初始pH=2.5时对色度的去除达到99%以上。整个工艺出水可达到达标排放标(GB16889-2008)。     

MAP沉淀法去除渗滤液中低浓度氨氮

考察了pH值、搅拌时间、Mg∶N和N∶P摩尔比对鸟粪石化学沉淀法(MAP)去除垃圾渗滤液中低浓度氨氮的影响,使用Design Expert 7.1.3进行3水平4因素响应曲面中心复合设计优化实验,并通过二次多项式拟合和参数优化,得到:当pH为10,搅拌时间为30 min,Mg∶N摩尔比为1.41,N∶P摩尔比为1.34时,氨氮去除率(Y1)可以达到最大值71.2%,体系中的残留PO34--P浓度(Y2)趋近于零,达到我国《生活垃圾填埋场污染控制标准排放标准》的排放标准。此外,X射线衍射图谱的分析表明大部分沉淀物质为磷酸铵镁。     

基于响应面法优化MAP法处理垃圾渗滤液工艺的研究

利用单因素实验以及响应面法(response surface methodology,RSM),对磷酸铵镁法(magnesium ammonium phosphate,MAP)去除垃圾渗滤液氨氮的影响因素进行了分析和探讨。考察了pH值为8.0～11.0、n(Mg)∶n(N)摩尔比为0.8～1.6、n(P)∶n(N)摩尔比为0.8～1.3条件下,分析氨氮去除率的变化,用Design-Expert软件处理实验数据,得到了二次响应曲面模型以及优化的水平值。基于经济和操作简便性的考虑,pH值由优化水平的8.3调整为9.5,n(Mg)∶n(N)、n(P)∶n(N)摩尔比取优化水平分别为1.40、1.19,氨氮去除率平均值为92.2%,虽然该条件比最佳条件下的氨氮去除率降低了2个百分点,但从操作的难易程度以及经济性方面,体现了其优势。通过X衍射与电镜扫描分析沉淀物质的成分与晶形,表明大部分沉淀物质为磷酸铵镁。     

Use of diffuse reflectance spectrometry in spot test reactions for quantitative determination of cations in water

Diffuse reflectance spectroscopy can be successfully used for the quantitative determination of small amounts of pollutants like metals. The remission function was found to be linearly proportional to the concentration, when we applied the Kubelka–Munk equation. The color reactions of Cu(II), Co(II), and Ni(II) with dithiooxamide, were realised on filter paper. Reaction between Fe(III) and ammonium thiocyanate was realized on filter paper and gelatine matrix. All measurements were accomplished with a laboratory-constructed reflectometer. We have obtained a calibration curve by plotting the optical density of reflectance A_R vs log of the mol l⁻¹ concentration. Limits of detection at the 10⁻⁴ M level were estimated for all the compounds. Linear dynamic range extend over one order of magnitude and shows the potential of device for the quantitative analysis of environmental pollutants.     

Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of ΣPFAS were estimated to be ∼6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea.     

Polychlorinated dibenzo-p-dioxins and related compounds: the blood levels of young Japanese women.

We investigated PCDDs and related compounds in the blood of young Japanese women, approximately 20 years of age, who had not yet had children, and discussed how the TEQ level of PCDDs and related compounds in their blood may affect the next generation. Means of total TEQ levels were 0.063 pg/g for whole blood basis and 21 pg/g for lipid basis. TEQ of PCDDs, PCDFs and coplanar PCBs accounted for about 43, 34 and 23% of the total TEQ in the whole blood basis, respectively. In the lipid basis, their values were about 44, 34 and 22%, respectively. Previously, we investigated PCDDs and related compounds levels in mother's breast milk, lymphocyte subpopulation and thyroid function of their children, and found negative correlations between the TEQ level of PCDDs and related compounds and CD4+/CD8+, and/or the TEQ level of PCDDs and related compounds and the T₄ level in 36 mothers and children. Of these cases, the average age was approximately 28 years. PCDDs and related compounds may be related to immunopathy, such as atopic dermatitis. The effects of PCDDs and related compounds on babies of young Japanese women are important and must be further evaluated.     

Effect of vegetation in pilot-scale horizontal subsurface flow constructed wetlands treating sulphate rich groundwater contaminated with a low and high chlorinated hydrocarbon

In order to characterize the effect of vegetation on performance of constructed wetlands (CWs) treating low and high chlorinated hydrocarbon, two pilot-scale horizontal subsurface flow (HSSF) CWs (planted with Phragmites australis and unplanted) treating sulphate rich groundwater contaminated with MCB (monochlorobenzene, as a low chlorinated hydrocarbon), (about 10 mg L⁻¹), and PCE (perchloroethylene, as a high chlorinated hydrocarbon), (about 2 mg L⁻¹), were examined. With mean MCB inflow load of 299 mg m⁻² d⁻¹, the removal rate was 58 and 208 mg m⁻² d⁻¹ in the unplanted and planted wetland, respectively, after 4 m from the inlet. PCE was almost completely removed in both wetlands with mean inflow load of 49 mg m⁻² d⁻¹. However, toxic metabolites cis-1,2-DCE (dichloroethene) and VC (vinyl chloride) accumulated in the unplanted wetland; up to 70% and 25% of PCE was dechlorinated to cis-1,2-DCE and VC after 4 m from the inlet, respectively. Because of high sulphate concentration (around 850 mg L⁻¹) in the groundwater, the plant derived organic carbon caused sulphide formation (up to 15 mg L⁻¹) in the planted wetland, which impaired the MCB removal but not statistically significant. The results showed significant enhancement of vegetation on the removal of the low chlorinated hydrocarbon MCB, which is probably due to the fact that aerobic MCB degraders are benefited from the oxygen released by plant roots. Vegetation also stimulated completely dechlorination of PCE due to plant derived organic carbon, which is potentially to provide electron donor for dechlorination process. The plant derived organic carbon also stimulated dissimilatory sulphate reduction, which subsequently have negative effect on MCB removal.     

BAT and BEP as instruments for reducing emissions of unintentionally produced POPs and development of guidelines under the stockholm convention

The 6th Intergovernmental Negotiating Committee (INC 6), under the Stockholm Convention on POPs, gave an expert group the mandate to develop guidelines for the application and implementation of best available techniques (BAT) and best environmental practices (BEP) for the prevention and reduction of unintentionally produced and emitted POPs, including polychlorinated dibenzodioxins/-furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB). Measures to reduce or eliminate the release of these POPs to the environment can be found in Article 5 of the Convention. BAT and BEP are already being applied as emission reduction instruments in a number of industrialised countries and are elements of other major international treaties, e.g. the UN ECE Protocol on POPs and the Marine Convention's OSPAR and HELCOM, and of the EU Directive for Integrated Pollution Prevention and Control (IPPC Directive). Existing concepts are presented and compared with the requirements of the Stockholm Convention. Consequences, perspectives and questions for the future intersessional work of the above-mentioned Expert Group are discussed.     

Natural attenuation of trichloroethene and its degradation products at a lake-shore site

Subsurface contamination by trichloroethene (TCE) was detected at a Michigan National Priorities List (NPL) site in 1982. The TCE plume resulted from the disposal of spent solvent and other chemicals at an industrial facility located in the eastern shore of Lake Michigan. TCE degradation products of three dichloroethene (DCE) isomers, vinyl chloride (VC) and ethene were present. The plume was depleted of oxygen and methanogenic at certain depths. Transects of the plume were sampled by slotted auger borings the year after the TCE plume was first discovered. Water samples were also taken from lake sediments to a depth of 12 m about 100 m offshore. Later samples were taken along the shoreline of the lake with a hand-driven probe. Later in 1998 water was taken from sediments about 3-m from the shoreline. The average concentration of each chemical and net apparent base coefficient between appropriate pairs of transects between the lower site and lakeshore were calculated. Loss rates were then calculated from an analytical solution of the two-dimensional advective-dispersive-reactive transport equation. Net apparent rate coefficients and a set of coupled reaction rate equations were used to extract the apparent loss coefficients. This study showed the field evidence for natural attenuation of TCE.     

Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal

Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean.     

Using a Set of Strategic Indicator Systems as a Decision-making Support Implement for Establishing a Recycling-oriented Society - A Taiwanese Case Study (16 pp)

Background Scope and Aims. To realize the vision of sustainable development (SD) originating from the ‘only one earth’ philosophy, and to integrate the conceptions of ecology and sustainability into the planning and decision-making criteria of urban growth management, the establishment of a recycling-oriented society (ROS) is essential. However, before the above intention can be achieved, it is indispensable to develop a system of strategic indicators for supporting a radical reformation of the urban development plan. Therefore, this study, based on the conception of the new urban development pattern ROS, attempted to carefully choose a sample city in Taiwan for launching a preliminary case study, and furthermore designed and proposed a concise and strategy-oriented assessment indicator system termed ROSAIS. ROSAIS, on the one hand, can act as a compass for understanding resource using efficiency and recycling status during city development and, on the other hand, can serve as an implement supporting decision-making for ROS construction.Methods According to the definition and spirit of ROS, the structure of ROSAIS should clearly represent the relationship between resources and environment in human activities. The eco-efficiency indicator system (EEIS) and environmental symbiosis indicator system (ESIS) can be considered two key sub-indicator systems, and are the necessary components of ROSAIS. EEIS chooses the dominant production sectors in urban economic activities to calculate their eco-efficiency (EE). Separately, for obtaining a consensus regarding the framework of ESIS, the questionnaire approaches and expert consultation, together with the research experience and foundation of current relevant studies and indicator systems, are applied when crucial resource and environmental issues and respective indicators are selected.Results and Discussion The calculation results of EEIS in this case study indicated that among the three dominant production activities (agricultural, fishery, and animal husbandry sector) the fishery sector has the highest EE, which indicates that the fishery activities and resources significantly influence the sustainability of the economic-environmental system of the sample city. Furthermore, according to a consensus achieved in ESIS, local green spaces, resource recovery, energy consumption pattern change, freshwater conservation and greenhouse effect abatement were considered as the five crucial issues influencing how the case study city can develop into an ES-city. The rate of local green spaces, resource recycling, freshwater conservation and the rate of reduction of nonrenewable energy use as well as carbon dioxide (CO2) emissions were used to evaluate the above five issues.Conclusion This case study is unparalleled in Taiwan. Even in Japan, where ROS legislation has been implemented, this kind of study remains in the preliminary stages. Furthermore, when communicating the indicator results, it is essential to provide the context and countermeasures of the crucial issues that are faced. The two sub-indicator systems proposed in this case study could comply completely with the above-mentioned requirements. For example, the EEIS provides information for achieving a balance between environmental burden and economic benefits among dominant production sectors; the ESIS provides information for setting strategies for overcoming the crucial issues faced. Recommendation and Outlook This study recommends that urban planers should consider the construction of the corresponding strategic indicator system to be indispensable, and makes further use of the indicator results related to the environmental education of residents for identifying and promoting participation with ROS, and turning them into implements for supporting urban SD decision-making. Furthermore, a successful indicator system depends on data availability and quality. This study recommends that urban planers should pay considerable attention to constructing relevant data collection channels, databases and the data quality.     

Emissions from soil fumigation in two raised bed production systems tarped with low permeability films

Raised beds are used to produce some high-value annual fruit and vegetable crops such as strawberry in California (CA) and tomato in Florida (FL), USA. Pre-plant soil fumigation is an important tool to control soil-borne pests in the raised beds. However, fumigant emissions have detrimental environmental consequences. Field trials were conducted to evaluate emissions of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) in two different production systems with raised beds covered by different tarps. In the CA trial, InLine (60.8% 1,3-D and 33.3% CP) was drip-applied at 340 kg ha⁻¹ to 5 cm deep in the beds (30 cm high and 107 cm wide) tarped with polyethylene (PE) or virtually impermeable film (VIF). In the FL trial, carbonated Telone C35 (63.4% 1,3-D and 34.7% CP) was shank-applied at 151 kg ha⁻¹ to 20 cm deep in the beds (22 cm high and 76 cm wide) tarped with totally impermeable film (TIF). Emissions from tarped beds relative to furrows were contrary between the two trials. For the CA trial, the emission was 47% of applied 1,3-D and 27% of applied CP from PE tarped beds and 31% of applied 1,3-D and 15% of applied CP from VIF tarped beds, while that from uncovered furrows was <0.4% for both chemicals in both fields. In the FL trial, only 0.1% 1,3-D was emitted from the TIF tarped beds, but 27% was measured from the uncovered furrows. Factors contributing to the differences in emissions were chiefly raised-bed configuration, tarp permeability, fumigant application method, soil properties, soil water content, and fumigant carbonation. The results indicate that strategies for emission reduction must consider the differences in agronomic production systems. Modifying raised bed configuration and fumigant application technique in coarse textured soils with TIF tarping can maximize fumigation efficiency and emission reduction.     

Assessment of Organochlorine Pesticide Residues in Water,Sediment, and Fish of the Songhua River,China

This study examined residual concentrations and associated ecological risks of the organochlorine pesticides (OCPs) hexa- chlorocyclohexane (HCH) and dichloro-diphenyl-trichloroethane (DDT) in water, sediment, and fish of the Songhua River in Zhaoyuan County, China. In June 2012, 10 water, 10 sediment, and 20 fish samples were collected. Residual concentrations of ΣHCH and ΣDDT ranged from 10.0–35.59 ng L^?1 (mean 28.03 ± 11.66 ng L^?1) and 5.12–39.66 ng L^?1 (mean 32.36 ± 11.58 ng L^?1) for water. Residual concentrations of ΣHCH and ΣDDT ranged from 0.52–3.00 ng g^?1 (mean 2.04 ± 0.73 ng g^?1) and 0.34–3.41 ng g^?1 (mean 2.38 ± 0.92 ng g^?1) for sediment. The ratios of α-HCH/γ-HCH were close to 1 at the majority of sampling points, indicating considerable new pollution from the use of lindane. The ratios of p,p′-DDE + p,p′-DDD/ΣDDT were less than 0.5, indicating recent inputs from DDT impurities in dicofol. All HCH and DDT isomers except for p,p′-DDD were detected in fish tissue samples, but the associated ecological risks were estimated to be below levels of concern. The study revealed a historical usage of OCPs in the Zhaoyuan section of the Songhua River and new OCP from the use of lindane and dicofol.