混凝沉淀-SBR-活性炭过滤处理垃圾渗滤液

采用沉淀-SBR-活性炭过滤复合工艺对城市垃圾渗滤液进行处理,确定混凝、SBR和活性炭过滤的最隹参数.结果表明,当进水COD为2500mg/L、氨氮在900mg/L的条件下,经该系统处理后,出水COD均在300mg/L以下,氨氮在20mg/L以下,COD去除率达90%以上,氨氮去除率达98%以上,达到较好的去除有机物和去氨效果.     

催化氧化/两级生物滤池在有机胺废水深度处理工程中的应用

采用催化氧化/两级生物滤池组合工艺,以生化处理后的有机胺废水为研究对象,重点考察该组合工艺对有机胺废水COD和氨氮的去除效果.结果表明,采用催化氧化预处理工艺,能有效降低废水中的抑制性物质,提高废水的BOD5/COD;末端采用两级串联生物滤池处理该废水,能有效降低废水中的COD和氨氮.当进水COD在700～900 mg/L、氨氮在250～370 mg/L时,出水水质能够达到当地环境保护的要求(COD≤300mg/L、氨氮≤35 mg/L);同时说明该工艺能够应用于高浓度有机胺废水的深度处理,为有机胺废水的达标处理提供了一条有效的途径.     

混凝沉淀-SBR-活性炭过滤处理垃圾渗滤液

采用沉淀-SBR-活性炭过滤复合工艺对城市垃圾渗滤液进行处理，确定混凝、SBR和活性炭过滤的最隹参数。结果表明，当进水COD为2500mg／L、氨氮在900mg／L的条件下，经该系统处理后，出水COD均在300mg／L以下，氨氮在20mg／L以下，COD去除率达90％以上，氨氮去除率达98％以上，达到较好的去除有机物和去氨效果。     

褐煤活性炭吸附处理焦化废水

研究褐煤活性炭吸附处理焦化废水的性能,为褐煤活性炭用于废水处理提供理论依据和技术指导。以河南某气化厂的焦化废水为吸附原水,进行褐煤活性炭对酚吸附性能的静态和动态实验。静态实验表明,褐煤活性炭对酚的吸附性能符合弗兰德里希（Freundlich）吸附方程式。在室温条件下,对于150 mL焦化废水,当活性炭的用量为10 g,吸附反应时间为1 h,酚的去除率可达92%以上。动态实验研究表明,当进水酚浓度为3 800 mg/L,吸附1.5 h,活性炭的吸附容量可达21.38 mg/g。水处理的实验研究表明,利用褐煤制备的活性炭,对焦化废水具有良好的处理效果。     

新型活性炭固定化产品的制备及其处理焦化废水的特性

为解决优势菌种工程应用,研究不同固定化方法、载体和结构的固定化产品对焦化废水的降解特性。用活性炭粉末吸附菌种后,与聚乙烯醇和海藻酸钠混合制备了新型固定化球;用聚乙烯醇和海藻酸钠包埋吸附菌种的活性炭纤维毡,与立体弹性塑料填料连用,制备出3种不同形状的活性炭纤维膜片固定化产品复合填料。将游离菌和制备的4种活性炭固定化产品投入A/A/O工艺系统平行实验,考察处理焦化废水的效果。结果表明,活性炭纤维膜片固定化产品复合填料对焦化废水的降解能力优于其他固定化产品:缺氧池出水硝酸盐氮和亚硝酸盐氮浓度分别稳定在1.96 mg/L和0.49 mg/L,未产生氮的累积现象,COD去除率可达到60.92%。好氧池COD和氨氮降解效率分别为78.83%和85.52%,苯酚、氰化物降解效率均为97%以上。     

强化活性炭吸附技术深度处理焦化废水的可行性研究

采用混凝沉淀、活性炭吸附以及混凝沉淀 活性炭吸附工艺对焦化厂生化出水进行深度处理.单独混凝沉淀或活性炭吸附均可以将水样中COD降到100 mg/L以下,达到国家污水一级排放标准和冷却用水建议标准.活性炭根据不同的材质和进水而表现出不同的吸附性能,对于焦化厂生化出水,煤质炭Ⅰ和果壳炭均表现出良好的吸附效果,并使出水COD＜100 mg/L,但处理成本较高.混凝沉淀 活性炭吸附工艺充分发挥适合去除大分子污染物的混凝沉淀与适宜去除小分子污染物的活性炭吸附技术两者的协同增效作用,吸附单元采用廉价的煤质炭,使出水水质达到个别生产或生活用水回用标准,并且降低深度处理成本.研究结果表明,混凝沉淀 活性炭吸附作为焦化厂生化出水回用工艺是经济可行的.     

水解酸化—多级厌氧—两级串联A/O处理阿奇霉素废水效果研究

阿奇霉素废水具有高COD、高氨氮、高抗生素残留等特点,为提高废水处理工艺的降解效率和稳定性,采用水解酸化—多级厌氧—两级串联A/O工艺对其进行处理。结果表明:当进水平均COD为8 753mg/L时,出水平均COD为377mg/L,COD去除率达到95.69%,多级厌氧段的平均容积产气率为0.136 m3/(m3·d);当进水平均氨氮为324 mg/L时,出水平均氨氮为31mg/L,氨氮去除率达到90.43%;当进水阿奇霉素为63.1mg/L时,出水阿奇霉素为4.5mg/L,阿奇霉素降解率为92.87%。系统稳定运行后,微型动物在一级O池内以豆形虫、草履虫为主,在二级O池内以红斑瓢体虫、表壳虫为主。     

铁炭微电解深度处理焦化废水的研究

采用曝气铁炭微电解工艺对焦化废水进行了深度处理.结果表明,在活性炭、铁屑和NaCl投加量分别为10 g/L、30 g/L和200 mg/L的条件下反应240 min,出水COD去除率在30%～40%;酸性条件可以进一步提高COD去除率;微电解可以去除原生化出水中的难降解有机物,出水物质的分子量主要集中于2000 Da以下,以脂类和烃类化合物为主;出水的可生化性有了大幅度提高,BOD5/COD由0.08增加到0.53.实验结果表明,铁炭微电解是深度处理焦化废水的一种有效工艺.     

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。     

异相Fenton试剂催化氧化-混凝沉淀深度处理焦化废水

针对焦化废水二级生化处理出水COD、色度和浊度无法达标的问题,实验研究了异相Fenton试剂催化氧化法和混凝沉淀法以及二者联合深度处理焦化废水的效果,分别探讨了H2O2、FeOOH投加量、初始pH,混凝剂投加量及种类对COD去除的影响,确定了最佳运行条件,采用GC-MS分析了联合工艺对废水中有机物的去除规律。异相Fenton试剂催化氧化静态实验研究表明,当H2O2(10%)投加量为2 mL/300 mL,FeOOH投加量为3 g/L,初始pH为4~6之间,处理效果最佳;混凝沉淀实验中最佳的混凝剂为聚丙烯酰胺阳离子,最佳投加量为8 mg/L。异相Fenton试剂催化氧化-混凝沉淀联合工艺深度处理焦化废水,出水COD基本在90 mg/L左右,浊度为0.8NTU左右,色度为40度以下,满足国家污水综合排放二级标准(GB8978-1996)。GC-MS分析显示,联合工艺能有效减少废水中有机物的种类和浓度,并将废水中长链大分子化合物和杂环化合物分解为短链的小分子化合物,构成联合工艺出水COD的主要是小分子有机物,尤其是卤代烷烃含量较高。     

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.     

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.     

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.     

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.     

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of ³H, ¹³⁷Cs, ⁹⁰Sr, ^totU, ²³⁸Pu, ^{239, 240}Pu, and²⁴¹ Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of ³H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.     

Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils

Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg^?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg^?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of ¹⁴C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative ¹⁴CO₂ was less than 1.5% of applied ¹⁴C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.     

Biochemical interaction of six op delayed neurotoxicants with several neurotargets

Abstract

Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with ³H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia.