絮凝与生物强化组合技术处理油田含聚污水

针对河南油田采油污水,室内选择4种常用无机絮凝剂与阳离子聚丙烯酰胺(CPAM)复配,筛选出最佳的絮凝剂用量:聚合氯化铝(PAC)用量为300 mg/L,CPAM用量为10 mg/L。研究了投加HPAM降解菌对油田含聚污水中COD的去除效果,优选出2株以聚合物(HPAM)为唯一碳源的降解菌,通过分子生物学16SrDNA鉴定,XL-1和XL-2菌分别为苏云金芽孢杆菌和溶血不动杆菌。实验结果表明,在温度为30℃,pH为7.5,降解72 h的条件下,XL-1菌的B/C增大了0.11,COD去除率提高了11.03%;XL-2菌的B/C增大了0.07,COD去除率提高了6.3%。油田污水经絮凝-生物强化组合工艺处理后,出水COD平均值为77.1 mg/L,总去除率为73.2%,絮凝段和生化段工艺的COD去除率分别为54.1%和19.1%,达到《污水综合排放标准(GB/T 8978-1996)》排放标准。     

一个中药污水处理工程运行实例

江苏省某企业中药污水处理工程采用调节池+深度水解+三级接触氧化+沉淀的处理工艺,该工艺运行费用低,处理效果稳定,便于管理,操作简单,易于维护。运行过程中,进水COD为2 500～3 500 mg/L,BOD5为1 200～1 500 mg/L,其出水各项指标均达到《污水综合排放标准》(GB 8978-1996)中的一级排放标准。     

Experimental research of dyeing and printing wastewater treatment by flocculation-MBR combined technology

采用絮凝—膜生物反应器(MBR)组合工艺进行印染废水处理的试验研究.结果表明,调节pH至8.5、搅拌时间为30min时,COD和色度去除效果最佳;而单纯絮凝工艺对印染废水处理效果不理想,最佳运行条件为64 mg/L NaOH+75 mg/L饱和石灰水+0.2 mg/L聚丙烯酰胺(PAM)+3 mg/L硅酸钠+8 mg/L聚合氯化铝(PAC),COD和NH3-N平均去除率分别达到23.91％、31.17％.在上述最佳运行条件下,采用絮凝—MBR组合工艺处理印染废水,效果较显著;出水COD均值可达42.2mg/L,其平均去除率为91.62％;出水NH3-N均值可达6.26 mg/L,其平均去除率为92.43％,出水水质可达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级B标准.     

气浮-SBR-滤池工艺处理制药废水

采用气浮-SBR-滤池工艺处理制药废水.运行结果表明,该工艺处理效果稳定,耐冲击负荷能力高,不会发生污泥膨胀同题.出水COD≤100 mg/L,BOD5≤30 mg/L,SS≤70 mg/L,达到<污水综合排放标准>(GB 8978-1996)一级标准.而且该工艺运行费用较低,操作简单,易于维护.     

青岛啤酒(扬州)有限公司污水处理站改造方案

采用水解-酸化+SBR工艺处理啤酒废水,当进水浓度在800～2 500 mg/L,处理规模达到3 000 m3/d,经处理后的出水可达国家<综合污水排放标准>(8978-1996),主要污染物ρ(COD)＜100 mg/L.     

微纳米气浮技术用于炼化污水的深度处理

采用作者自行设计制作的混凝-微纳米气浮装置对炼化企业污水处理厂二沉池出水进行深度处理,考察了混凝剂投加量、工作压力、回流比和水力停留时间对气浮效果的影响,结果表明,最佳工艺参数为:混凝剂Fe Cl330 mg/L,工作压力0.2 MPa,回流比为20%,水力停留时间6 min。在此实验条件下,COD去除率为39.13%,SS去除率为51.85%,气浮出水COD60 mg/L,达到了《污水综合排放标准》(GB 8978-1996)一级B标准。     

化纤浆粕废水治理技术研究与工程应用

用试剂A、B和化纤酸性废水,采用中和酸析内电解絮凝沉淀生物氧化四步处理工艺,对某化纤厂pH为12左右,COD1.2×104mg/L,SS1.22×103mg/L,色度3000倍的棉浆粕废水进行综合处理,出水各项指标均能达到国家《污水综合排放标准》(GB89781996)中的二级标准,并大大降低了处理费。     

化学破乳絮凝与SBR二段法处理采油污水的试验研究

采用化学絮凝与 SBR生化联合的二段法工艺对采油污水进行处理 ,采油污水经第一段化学破乳絮凝后 ,CODCr去除率可达 85 %以上 ,油去除率可达 95 %以上 ;第一段处理出水再经第二段 SBR生化处理后可使出水中 CODCr≤ 60 mg/L、BOD≤ 3 0 mg/L、SS<3 0 mg/L、油 <10 mg/L,达到了油田回注水标准和含油污水的国家二级排放标准 ,可实现废水的资源化     

鱼糜加工废水治理工程实例分析

采用凝聚回收-气浮-厌氧折流板反应器(ABR)-A/O工艺处理高浓度鱼糜加工废水.工程设计处理能力为800m3/d,进水COD为8 439 mg/L,处理后出水达到<污水综合排放标准>(GB 8978-1996)一级标准.实际运行结果表明,该废水处理工艺不仅能保证出水水质,而且高效低耗,是一种切实可行的处理技术.     

前处理-水解-生物接触氧化工艺处理染料废水

介绍了前处理-水解-生物接触氧化工艺处理染料废水的工程实例.当进水COD≤8000 mg/L时,出水可达到国家<污水综合排放标准>(GB8978-1996)二级标准.     

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.