管式膜连续微滤装置处理回用城市污水的中试研究

就管式膜连续微滤装置对城市污水处理厂二沉池出水处理回用的可行性进行了中试研究，结果表明。该装置在运行压力为0．12-0．15MPa，反冲洗间隔为18min时，吨水能耗仅为0．45kWh。此时对COD、浊度有较高的去除率。分别为75．71％和94．49％，对氨氮也有一定的去除效果，去除率为40．26％；处理后出水COD、氨氮、浊度均明显优于《生活杂用水水质标准》(CJ25．1-89)中的相关规定。该装置成本低、操作简单，用于污水回用具有较高技术经济可行性。     

一体式膜生物反应器处理生活污水的中试研究

采用中试规模(1.8 m3/d)的缺氧-好氧膜生物反应器(A/O MBR)对城市污水处理回用进行了试验研究.试验结果表明,该工艺处理效果优良,系统对COD、氨氮、浊度、总氮、总磷去除率较高,COD、氨氮出水浓度分别为7～39 mg/L、0～1.31 mg/L.出水水质优于城市杂用水水质标准(GB/T18920-2002).     

一体式膜生物反应器处理生活污水的中试研究

采用中试规模（1.8m^3／d）的缺氧-好氧膜生物反应器（A／OMBR）对城市污水处理回用进行了试验研究。试验结果表明，该工艺处理效果优良，系统对COD、氨氮、浊度、总氮、总磷去除率较高，COD、氨氮出水浓度分别为7～39 mg/L、0～1.31mg／L。出水水质优于城市杂用水水质标准（GB／T18920-2002）。     

新型聚合铝硅混凝剂处理洗浴废水的试验研究

针对常规铝盐、铁盐去除洗浴废水中阴离子洗涤剂 (LAS)效果不理想的状况 ,采用高碱化度钙型聚合铝硅混凝剂 (CPASC)进行了试验研究 ,同时与聚合氯化铝 (PAC)作了比较。结果表明 ,该混凝剂对洗浴废水中COD、LAS、SS及浊度都有较高的去除率 ,特别对LAS、COD的去除率分别比PAC高 10 %和 8%以上。当投加量为 6 0mg/L时 ,出水各项指标均达到生活杂用水水质标准 (GJ2 5 .1 89)。     

电吸附对水中盐类、氨氮、COD的去除效果分析

电吸附技术作为高效、环境友好型的除盐、除氨氮技术，可应用与水的深度处理领域内。为了使污水回用达到工业用水的水质标准，对电吸附去除水中盐类、氨氮、COD的效果进行分析，结果表明，电吸附设备处理不同氨氮浓度的废水，对中低浓度的氨氮去除效果稳定，当进水氨氮浓度低于20 mg/L时，处理后出水氨氮浓度低于5 mg/L，COD浓度小于25 mg/L，达到回用标准；随着进水盐浓度的增大电吸附处理效果逐渐变差，在电导率低于2 500 μS/cm时除盐率在75%左右，氨氮去除率达到70%左右，COD去除率达到60%左右。经电吸附处理后的低氨氮浓度废水，TDS、氨氮浓度均可达到工业回用水标准。     

砂滤/超滤回用处理校园景观水

在连续式65d运行过程中,采用砂滤/超滤回用处理校园景观水,对校园景观水中高锰酸盐指数、氨氮和浊度的去除效果进行了研究。结果表明:(1)生物滤池对高锰酸盐指数去除率为1.5%～37.0%,平均去除率为18.7%;超滤膜对高锰酸盐指数去除率为40.5%～93.7%,平均去除率为67.5%。(2)生物滤池对氨氮去除率为1.0%～77.6%。(3)砂滤/超滤工艺对浊度的去除率为24.6%～100.0%。(4)生物滤池内生物相以菌胶团和后生动物为主,利用后生动物对有机颗粒等的吞噬,使系统具有良好反堵塞自我调节作用。(5)利用10%(质量分数)NaOH对膜清洗效果要优于10%(质量分数)HCl。     

二氧化氯泡沫分离法处理水合肼类废液

采用二氧化氯泡沫分离装置,研究了二氧化氯泡沫分离法对水合肼类废液的处理效果.通过实验重点考察了废水pH值、二氧化氯投加量和反应时间等参数对废水处理效果的影响.在最佳反应条件(即pH值为10,每升废水中二氧化氯的投加量为5 mg/1 000 COD、反应时间为3 h)下进行反应,原废液(COD值为30 000～35 000 mg/L,氨氮总量为2 500～2 700 mg/L)经处理后COD去除率达到99%,氨氮去除率达到96%以上.     

组合填料生物滤池处理锦纶废水二级出水的性能研究

为解决纺织行业水回用问题,采用陶粒和活性炭组合填料生物滤池对锦纶废水二级生物处理出水进行了深度净化,并考察了气水比和水力负荷对曝气生物滤池处理效果的影响.研究结果表明,曝气生物滤池处理效果良好,平均出水COD、NH4 -N和TN分别为32 mg/L、1.5 mg/L和8.1 mg/L.随着气水比的增加,COD和NH4 -N平均去除率相应提高,TN平均去除率先增大后降低,当气水比为2∶1时,COD、NH4 -N和TN平均去除率分别为48.30%、84.24%和42.18%;随着水力负荷的增加,COD、NH4 -N和TN平均去除率均降低,当水力负荷为0.39 m3/m2·h时,COD、NH4 -N和TN平均去除率分别为48.33%、84.81%和42.54%.     

微气泡曝气O3／H2O2处理RO浓水的效能及影响因素

采用O3／H2O2高级氧化工艺处理炼油厂反渗透（RO）浓水，用溶气泵加压溶气并产生微气泡强化传质，确定装置运行条件，考察气体中臭氧浓度、O3／H2O2初始摩尔比、pH和温度对O3／H2O2处理RO浓水效果的影响，并对RO浓水处理效能进行研究。结果表明，随着气体中臭氧浓度的增加，COD的去除率基本呈线性增加；加入适当量H，0，能提高臭氧氧化RO浓水的效果，O3／H2O2初始摩尔比在0～0．8范围内，COD的去除率先增加后下降，O3／H2O2初始摩尔比为O．5时COD去除率最大；pH从6．84增加到9．01，COD去除率逐渐增大，pH为10．03时COD去除率反而降低；在14～28℃范围内，温度低时，升高温度COD去除率增加较大，温度较高时，升高温度对COD去除率的影响较小。为考察该工艺的稳定性，在H：0：／0，初始摩尔比为O．5、溶液pH为8～9、臭氧浓度为80～100mg／L、温度为10-28℃条件下，对COD为90～140mg／L的RO浓水氧化处理4～10h，出水COD维持在39．9～49．9mg／L，达到《城镇污水处理厂污染物排放标准（GB18918—2002）》中的一级A标准；去除1gCOD消耗031．4～3．3g，消耗0，与H，02的总氧量为2．2～4．4g。     

Fenton氧化-前置反硝化缺氧好氧池(A/O)处理荧光增白剂废水中试研究

采用Fenton氧化-前置反硝化缺氧好氧池(A/O)对荧光增白剂废水IC出水进行中试实验研究。实验表明,在Fe2+投加量为0.003 mol/L,进水pH值为3,[H2O2]/[Fe2+]为4∶1,反应时间为2 h的条件下,Fenton氧化法对COD的去除率可以达到46%以上,出水BOD5/COD的值由0.26提高到0.58。氧化后废水进入前置反硝化生物脱氮系统进行生化处理,该系统采用间歇式进水,水力停留时间为2 d,实验结果表明,A/O系统对COD、氨氮和总氮的去除率分别达41%、90%以上和86%。该组合工艺对COD的总去除率可达到67%,出水氨氮在20 mg/L以下,总氮在37 mg/L以下。     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes

The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen. In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in 1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH, while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator, was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with a depletion of benzo(a)pyrene.     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

Teratological effects of pesticides in vertebrates: a review

Abstract

In the last decades, the use and misuse of pesticides in the agriculture have increased, having a severe impact on ecosystems and their fauna. Although the various effects of pesticides on biodiversity have been already documented in several studies, to our knowledge no consistent overview of the impact of pesticides in vertebrates, both terrestrial and aquatic, is available. In this review, we try to present a concise compilation of the teratogenic effects of pesticides on the different classes of vertebrates – mammals, birds, reptiles, amphibians and fish.     

Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos national laboratory and the doses to humans from the consumption of muscle and bone

Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for ³H, ⁹⁰Sr, ¹³⁷Cs, ^totU, ²³⁸Pu, ^239,240Pu, and ²⁴¹Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of ⁹⁰Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g^‐1 [126E‐02 Bq kg^‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g^‐1 [518E‐02 Bq kg^‐1]). The differences in ⁹⁰Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y^‐1 (1.0 ± 1.0 μSv y^‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y^‐1 (1000 μSv y^‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

Knowledge transfer initiative between molecular biologists and environmental researchers and regulators

A Natural Environment Research Council (NERC) funded Knowledge Transfer (KT) workshop was held in the United Kingdom (UK) to identify the needs and opportunities in the application of molecular biology and ‘omics’ techniques to environmental monitoring and risk assessment. Attendees highlighted a lack of effective communication between end-users and researchers as well as difficulties with data interpretation as reasons behind the slow uptake of molecular biology and omics techniques. A number of promising areas in which new techniques could be implemented at a practical level in the very near future were identified, thereby raising the profile of these recent technologies and providing vital proof of concept work. Molecular taxonomy, bacterial source tracking and pre-screening of chemicals for potential toxicities were all viewed as areas in which omics and molecular techniques could have immediate value, with the aim of reducing cost, increasing efficiency and providing more comprehensive data of improved quality.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.