活性硅酸混凝剂PFASSC处理造纸废水

利用硅酸钠、硫酸铝、三氯化铁和硫酸为主要原料制备了复合型活性硅酸混凝剂ＰＦＡＳＳＣ并对造纸废水进行了处理，得到活性硅酸混凝剂ＰＦＡＳＳＣ最佳配方为：ＰＨ＝２．０（Ｆｅ＾３＋＋Ａｌ＾２）／ＳｉＯ２（摩尔比）＝１．５，Ｆｅ＾３＋／Ａｌ＾３＋（摩尔比）＝１．０，与常用混凝剂相比，ＰＦＡＳＳＣ混凝剂处理造纸废水对除浊、脱色和去除ＣＤＤＣｒ有更加优良的性能。     

絮凝—酸化法预处理腈纶纺丝生产废水的实验研究

研究采用絮凝－酸化法对腈纶纺丝废水进行预处理,考察了絮凝剂的选用及多种絮凝实验条件对实验结果的影响。结果表明,以ＰＦＳ作絮凝剂,絮凝ｐＨ６．０,ＰＦＳ 投加量为０．３ｍｌ,ＰＡＭ投加量为０．４ｍｌ时的ＣＯＤ,ＢＯＤ５和ＮＨ３－Ｎ及ＣＮ＾－去除率分别为３０％,３１％,８％及３２％。     

几种混凝剂处理煤气洗涤废水的比较

用４种常用的混凝剂Ａｌ２（ＳＯ４）３,ＰＡＣ,ＰＦＳ及ＦｅＳＯ４分别对煤气洗涤废水进行了混凝实验研究,结果表明,使用上述４种药剂对废水ＣＯＤｃｒ最高去除率分别为６３．９％,６７．４％,６１．３％和５７．４％;乳化油去除率分别为７１．６％,７５．６％,７４．８％和７０．５％,浊度去除率分别为９３．４％,９４．１％〈９５．６５和９９．１％,而从经济效益上看,４种药剂去除每ｋｇ废水中ＣＯＤｃｒ所需药剂费     

含氟废水的混凝沉淀处理

研究了ＦｅＣｌ３,Ａｌ２（ＳＯ４）３,ＰＦＣＳ和ＡＰＡＭ对含氟废水的混凝沉淀处理。结果表明：石灰乳,ＰＦＣＳ和ＡＰＡＭ对废水中的氟及ＣＯＤ具有较好的处理效果,处理后水质达到国家二级排放标准。     

新型无机高分子絮凝剂在制革废水处理中的应用研究

介绍了一种新型无机高分子絮凝剂－硅钙复合型聚合氯化铝铁（ＳＣＰＡＦＣ）在制革废水处理中的应用。结果表明，该产品对废水的浊度去除率为９９％，ＳＳ去除率为９５％，ＣＯＤ去除率为９０％，Ｃｒ＾３＋的去除率为８５％左右。最佳使用ｐＨ值为６．０￣９．０，最佳投药量为０．３５￣０．４０ｇ／Ｌ，最佳混凝时间为１５￣２０ｍｉｎ，在同样条件下各项性能均优于ＰＡＣ２倍以上。同时该絮凝剂还可用于生活饮水、生产用水及其他     

SBR法处理印染废水的研究

应用ＳＢＲ法、ＰＡＣ－ＳＢＲ法，微电解－ＳＢＲ法对印染废水进行了对比处理试验研究。试验结果表明：微电解－ＳＢＲ法处理效果优于其它两种方法，当进水ＣＯＤ＝１０００～１６００ｍｇ／Ｌ，色度＝２００～８００倍，ＢＯＤ５＝２５０～４００ｍｇ／Ｌ时．ＣＯＤ去除率在８５％左右，ＢＯＤ５去除率和脱色率均在９０％以上，出水达到排放标准。     

酸性分散染料废水的治理及综合利用研究

利用硫酸含量达１５％－４０％的酸性分散染料废水和废铁作用制得聚合硫酸铁,并用其作净水剂处理印染废水。结果表明,每ｔ酸性废水可生产１．０５ｔ浓度１６０ｇ／ＬＦｅ＾３＋的取合硫酸铁溶液,出水的酸含量降低了８３．５％。用所制得的聚合硫酸铁处理印染废水,ＣＯＤ去除率可达７０．４％－９５．４％,色度去除率可达６５．７％＿９０．５％,具有较好处理效果。     

DHDPS的细胞表达、提纯和结晶

ＤＨＤＰＳ是赖氢酸合成通路中第一步的合成酶。将中国春小麦的ＤＨＤＰＳ基因质粒移植入ＲＤＡ８中，得到ＲＤＡ８／ｐＤＢ２６菌株，本研究通过细胞培养、层析提纯和结晶条件的探索，给出了一个较好的技术路线，并为开展义衍射分析蛋白结构创造了条件，通过该研究，对中国春小麦ＤＨＤＰＳ和野种大肠杆菌的ＤＨＤＰＳ差异有了一定的了解，并且对细胞培养的ＭＭ介质处理，ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ，Ｐｈｅｎｙｌ－Ｓｅｐｈａｒｏｓｅ和ＭｏｎｏＱ层析的方法给出具体实验条仲。酶活的检测和蛋白浓度测定都是采取高灵敏度的方法。结晶的ＳＣｒｅｅｎｉｎｇ条件对于二种ＤＨＤＰＳ有很大的差异。对野种大肠杆茵的ＤＨＤＰＳ，需要表面活性剂Ｎ－ｏｃｔｙｌ－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ，ｐＨ１０．０～１０．５，对于中国春小麦一ＤＨＤＰＳ则未找到较好的表面活性剂，ｐＨ６．８～７．６。中国春小麦一ＤＨＤＰＳ晶体培养条件在以往文献中未见报导。     

光催化氧化-混凝工艺处理化工废水

探索了光催化氧化－混凝工艺处理废水的工艺条件,最佳光催化氧化处理条件为ＰＨ＝３,催化剂为铁盐,氧化剂Ｈ２Ｏ２,低压汞灯,光照时间１．５ｈ,废水温度４５℃,温凝剂选用ＰＡＣ和ＰＡＭ（混凝剂的投加量为原水ＣＯＤｃｒ：ＰＡＣ：ＰＡＭ＝７：１．５：０．０１）,混凝ＰＨ６,沉降时间０．５ｈ,在该工艺条件对ＣＯＤｃｒ为１７３－７０１４４ｍｇ／Ｌ的十二烷基苯磺酸钠废水、苯酐废水、富马酸废水、邻苯二甲酸二辛酯废水     

利福平废水的絮凝和生化处理研究

种福平生产的废水ＣＯＤ高达６万,用ＰＦＳ、Ｃ－ＰＡＭ脱稳,密集网捕式絮凝处理后,ＣＯＤ去除率达２７％,ＢＯＤ５／ＣＯＤｃｒ从０．１９上升到０．３２,絮凝前后水质和色谱分析表明,絮凝后５种有机物去除效率均在２２％以上,使生化处理成为可能,进生化池废水经稀释后,用活性污泥法处理９天后,ＣＯＤ从１．５万降至ＣＯＤ〈３００ｍｇ／Ｌ,达到治理要求。     

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.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

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.     

Sorption and predicted mobility of herbicides in Baltic soils

This study was undertaken to determine sorption coefficients of eight herbicides (alachlor, amitrole, atrazine, simazine, dicamba, imazamox, imazethapyr, and pendimethalin) to seven agricultural soils from sites throughout Lithuania. The measured sorption coefficients were used to predict the susceptibility of these herbicides to leach to groundwater. Soil-water partitioning coefficients were measured in batch equilibrium studies using radiolabeled herbicides. In most soils, sorption followed the general trend pendimethalin > alachlor > atrazine～ amitrole～ simazine > imazethapyr > imazamox > dicamba, consistent with the trends in hydrophobicity (log K_ow) except in the case of amitrole. For several herbicides, sorption coefficients and calculated retardation factors were lowest (predicted to be most susceptible to leaching) in a soil of intermediate organic carbon content and sand content. Calculated herbicide retardation factors were high for soils with high organic carbon contents. Estimated leaching times under saturated conditions, assuming no herbicide degradation and no preferential water flow, were more strongly affected by soil textural effects on predicted water flow than by herbicide sorption effects. All herbicides were predicted to be slowest to leach in soils with high clay and low sand contents, and fastest to leach in soils with high sand content and low organic matter content. Herbicide management is important to the continued increase in agricultural production and profitability in the Baltic region, and these results will be useful in identifying critical areas requiring improved management practices to reduce water contamination by pesticides.