微絮凝-微滤用于印染废水回用反渗透预处理的试验研究

采用微絮凝过滤-微滤作为反渗透的预处理工艺,用于印染废水二级生化出水回用深度处理.试验考察了预处理效果、工艺参数和反渗透系统运行情况,分析了膜污染的类型及特点.试验结果表明,微絮凝过滤-微滤作为反渗透的预处理工艺,系统运行稳定,相对于超滤-反渗透的"双膜法"工艺,投资和运行费用相对较低,有推广应用价值.     

超声强化电絮凝处理洗车废水的试验研究

针对洗车行业对水资源的浪费及污染现状,采用超声强化电絮凝处理洗车废水.考察了电流密度、初始pH、极板间距、处理时间等因素对洗车废水处理效果的影响,并讨论了超声强化电絮凝机制.结果表明,超声强化电絮凝处理洗车废水的最佳条件是电流密度1,500 mA/cm2、初始pH无需调节、极板间距为1.5cm、处理20 min,COD与浊度去除率分别为68.77％、96.89％,出水达到《城市污水再生利用城市杂用水水质》(GB/T 18920-2002)要求.可见,超声能改变电絮凝反应动力学过程,强化电絮凝去除污染物效果.     

光助Fenton氧化、化学絮凝法联合处理R盐废水的研究

采用光助Fenton氧化、化学絮凝法联合处理生物难降解的R盐废水,考察了不同反应条件对处理效果的影响.试验结果表明,光助Fenton氧化、化学絮凝法联合处理废水,两者之间存在协同作用,可以提高处理效果,降低处理成本.在最佳试验条件下,R盐废水经光助Fenton氧化、化学絮凝法联合处理后,COD去除率可达90%以上.     

光助Fenton氧化、化学絮凝法联合处理R盐废水的研究

采用光助Fenton氧化、化学絮凝法联合处理生物难降解的R盐废水,考察了不同反应条件对处理效果的影响。试验结果表明,光助Fenton氧化、化学絮凝法联合处理废水,两者之间存在协同作用,可以提高处理效果,降低处理成本。在最佳试验条件下,R盐废水经光助Fenton氧化、化学絮凝法联合处理后,COD去除率可达90%以上。     

电絮凝处理三次采油废水

采用电絮凝技术对含PAM的三次采油废水进行处理,研究了不同极板、pH、电流密度、极板间距、搅拌速度、反应时间以及极性交换周期对大庆三次采油废水处理效果的影响。通过处理效果和成本分析,铝作为极板时处理效果要优于铁板,最佳实验条件下COD去除率达到了94.6%。同时对三次采油废水的主要性质和电絮凝处理三次采油废水的作用机理进行了分析,发现COD主要通过絮凝沉降作用去除,而电化学氧化作用和气浮作用对COD的去除效果并不显著。与普通化学混凝法相比,电絮凝处理三次采油废水在处理效果和成本方面有着独特的优势。     

超滤/反渗透双膜技术深度处理印染废水

由于印染废水具有高盐度,可生化性差,使常规方法难于处理完全.采用超滤和反渗透双膜技术处理实际印染废水,考察了不同超滤膜对废水的预处理性能,研究了BW30和CPA2两种反渗透膜在不同操作条件下对印染废水的处理效果,并分析了相关膜通量下降的原因.结果表明,超滤能有效地去除废水浊度和大分子有机物,为反渗透提供良好的进水水质.两种反渗透膜的产水化学需氧量(COD)均小于10 mg/L,电导率小于80/μS/cm,其对有机物和盐的去除率分别可达99%和93%以上,显示该产水能回用于大部分印染工序.BW30膜产水水质稍好于CPA2,但通量低于CPA2.     

物理-化学法处理桑皮脱胶废水的研究

桑皮纤维是一种资源可再生纤维素纤维,但在脱胶制取桑皮纤维过程中产生大量的废水,污染环境,限制了桑皮纤维的开发利用.采用调节pH值、絮凝、Fenton试剂催化氧化、活性炭吸附等物理-化学综合处理法处理桑皮脱胶废水,研究结果表明,通过物理化学法处理桑皮脱胶废水,COD总去除率达到97%以上,色度降到5倍.此方法处理效果明显、操作简单.     

不同来源高浓度有机废水的集中处理

按照水质情况,将多种来源于不同工业生产过程中的高浓度有机废水划分为高悬浮固体乳化液废水、难生化高浓度有机废水、高悬浮固体不含油有机废水、含铬有机废水和杂质含量较少的乳化液废水5类,分别采用酸化破乳/Fen-ton氧化/混凝/絮凝、Fenton氧化/混凝/絮凝、混凝/絮凝、还原/混凝/絮凝、震动膜过滤技术作为生化预处理技术,并通过小试和中试验证了各技术的效果。实验结果表明,按照上述分类结果,采用不同预处理技术可以得到良好的效果,废水水质明显改善,满足继续生化处理的基本条件。各预处理生产装置处理效果稳定,同时生化系统已经稳定运行120天以上,COD去除率超过90%,出水经过低剂量的Fenton试剂处理后可达到《污水排入城镇下水道水质标准》(CJ343-2012)。     

电絮凝法处理石油裂化催化剂废水

针对石油裂化催化剂废水高盐高浊、水质水量变化大的特点,采用电絮凝工艺对其进行处理,并对初始p H、极板间距、电流密度及电解时间等工艺条件进行了优化。结果表明,电絮凝法对石油裂化催化剂废水有较好的除浊效果,在最优工艺参数(初始p H=8,极板间距为1.5 cm,电流密度为25 m A/cm2,电解时间为40 min)条件下,电絮凝对废水浊度和SS的去除率分别在97%和95%以上,出水浊度和SS分别低于5 NTU和15 mg/L;电絮凝过程平均电耗为0.723(k W·h)/m3,铝阳极平均损耗为0.1497 kg/m3,主要成本为铝阳极损耗。电絮凝法适于石油裂化催化剂废水的处理,可操作性强,应用前景良好。     

絮凝-微纳气泡法处理采油废水

对采自胜利油田的采油废水,分别进行了聚硅硫酸铁(PFSS)絮凝法、微纳气泡法和絮凝-微纳气泡联合法处理,考察了处理过程对采油废水水质和所配制聚合物(部分水解聚丙烯酰胺)溶液粘度的影响。结果表明,均可有效降低废水的矿化度、油含量和悬浮物含量,明显提高用其配制的聚合物溶液的粘度;联合处理效果明显高于单独采用絮凝或微纳气泡处理的效果。所处理后的废水可有望代替淡水用于油田现场配制聚合物驱油体系,在消除油田污水环境污染的同时,可节约淡水资源。     

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.     

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.     

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.     

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.     

土壤中砷的化学平衡

本文比较详细地综述了砷的化学特性,环境背景值及来源和循环,土壤中砷的三大化学平衡即沉淀溶解平衡,氧化还原平衡,吸附解吸平衡,以及微生物对砷的转化。     

Elemental uptake by edible herbs and lettuce (Latuca sativa)

The total concentration of toxic elements (aluminum, cadmium, chromium and lead) and selected macro and micro elements (iron, manganese, copper and zinc) are reported in six leafy edible vegetation species, namely lettuce, spinach, cabbage, chards and green and red types of Amaranth herbs. Although spinach and chards had greater than 125 mv of iron, both the amaranthus herbs recorded > than 320 μ g g^{? 1} dry weight. In both the spinach and chard species, the Mn and Zn levels were appreciable recording > 225 μ g g^{? 1} and 150 μ g g^{? 1} dry weight, respectively. Aluminum concentrations were (in μ g g^{? 1} dry weight) lettuce (10), cabbage (11), spinach (167), chards (65), amaranthus green (293) and amaranthus red (233). All the micro and macro elements and the toxic elements (Ni, Cr, Cd and Pb) elements analyzed, were below the recommended maximum permitted levels (RMI) in vegetables. Further the elemental uptake and distribution of the nine elements, at three growth stages of the lettuce plant grown on soil bed under controlled conditions are detailed. In the soil, except for iron (16%), greater than 33% of the other cations were in exchangeable form. Generally in the lettuce plant, roots retained much of the iron (> 224 μ g g^{? 1}) and aluminum (> 360 μ g g^{? 1}), while leaves had less than 200 μ g g^{? 1} of iron and 165 μ g g^{? 1} of Al. Although the concentrations of elements marginally decreased with growth, the lettuce leaves had significant amounts of Mn (30 μ g g^{? 1}), Zn (50 μ g g^{? 1}) and Cu (3.6 μ g g^{? 1}). Some presence of lead in leaves (2.0 μ g g^{? 1}) was noticed, but all the toxic and other elements analyzed were well below the RMI values for the vegetables.     

The dissipation of nonlyphenol in stream and pond water under simulated field conditions

Abstract

The dissipation of 1.0 ppm nonylphenol in stream and pond water, incubated in flasks at 16°C under simulated field conditions up to 44 days indicated that the half‐life was 2.5 days if the flasks were open, and 16 days if they were closed. A transformed product was detected in the closed flasks.

Translocation of nonylphenol in water occurred when treated water samples were incubated in the presence of sediment. After 10 days, nonylphenol was detected only in the sediment, but not in water (detection limit = 10 ppb). About 80% of the nonylphenol was degraded in 71 days, but no degradation occurred if the water and the sediment were autoclaved prior to incubation.