PRB强化垂直流人工湿地系统处理煤矿废水

针对常规人工湿地系统处理高浊含氮磷的有机煤矿废水不佳的问题,采用PRB与人工湿地耦合的方法,进行砂箱模拟实验研究。实验结果表明,由无烟煤、钢渣及沸石构建的PRB强化垂直流人工湿地系统对NH4+-N、PO34--P、Mn2+、COD、SS的去除率分别达到88.84%、96.08%、98.98%、85.78%和94.00%,与常规人工湿地相比,具有处理效率高、水力负荷大、占地面积小等特点,更便于运行管理。     

铁屑耦合生物麦饭石的PRB系统修复含铬酸根与硝酸根地下水

针对污染地下水中铬酸根和硝酸根迁移速度快,可渗透反应墙(PRB)常规活性材料修复效果差等问题,以铁屑、麦饭石和硫酸盐还原菌(SRB)为活性材料,构建4组耦合PRB动态柱修复地下水中Cr(Ⅵ)和NO-3-N。结果表明,4#(铁屑、麦饭石和SRB)柱修复效果较1#(麦饭石)、2#(铁屑、麦饭石)和3#(麦饭石和SRB)柱好,且稳定,对Cr(Ⅵ)和NO-3-N平均去除率分别是97.7%和97.34%,可见,以铁屑、麦饭石和硫酸盐还原菌为活性材料的耦合PRB系统修复地下水中Cr(Ⅵ)和NO-3-N具有有效性与可行性。     

可渗透反应墙原位修复垃圾渗滤液污染地下水

实验模拟地下环境,以垃圾渗滤液污染地下水为研究对象,分别采用沸石、无烟煤、陶粒、活性炭、炉渣、粉煤灰和零价铁作为填充材料,设计了7种地下可渗透反应器(PRB)。分2个阶段对PRB技术治理污染地下水可行性和有效性进行实验模拟研究,还研究了填充材料配比对PRB修复效率影响,分阶段调整复合填充材料配比,观察反应器产生的不同处理效果。考察了7种反应器内pH、EC和DO的变化情况及对污染物去除效果影响,分析了污染物去除机理;找出了反应器存在的某些不足之处。实验结果显示,2个阶段反应器对COD去除率都较高,分别为82.36%～88.11%和89.45%～93.65%。     

运用GC-MS联用技术对垃圾渗滤液中有机污染物成分的分析

通过测定垃圾填埋场渗滤液的色度、BOD5、CODCr、TOC、NH3-N、NO-2-N、NO-3-N、TKN、TP、总硬度等指标来分析渗滤液的水质特性.利用GC-MS联用技术对渗滤液中有机污染物的组分进行了鉴定,共检测出主要有机污染物63种.     

“生态沟渠+人工湿地”系统处理农田退水中噻虫嗪

研究了不同水力停留时间(HRT)和农药污染负荷(PPL)下,"生态沟渠+水平流人工湿地"和"生态沟渠+垂直流人工湿地"系统对农田退水中常规污染物和噻虫嗪的去除效果。结果表明,"生态沟渠+垂直流人工湿地"系统对COD、NH+4-N、NO-3-N、TN、TP及噻虫嗪的去除率均优于"生态沟渠+水平流人工湿地"系统,分别为76%、97%、92%、95%、88%和40%(HRT=2 d),其中噻虫嗪在沟渠段的去除率为17%,在垂直流人工湿地段的去除率为23%。延长HRT、降低PPL均有利于噻虫嗪在组合系统中的去除。对垂直流人工湿地各基质层出水噻虫嗪浓度检测结果表明,运行前期,噻虫嗪在空心砖层去除率最高(8%),主要是由于空心砖对于噻虫嗪的吸附优于沸石和钢渣,随着系统运行,土壤+细沸石层和粗沸石层的去除效率增加,植物吸收与微生物降解作用逐渐占据主导地位。微生物群落结构分析结果显示,生态沟渠段β-变形菌纲和厌氧绳菌纲丰度分别为11%和10%。垂直流人工湿地自上而下芽孢杆菌逐渐增多成为优势菌,β-变形菌和厌氧绳菌逐渐减少。厌氧、好氧交替环境有利于常规污染物和噻虫嗪的去除。     

PRB修复渗滤液污染地下水的实验研究

可渗透反应墙（PRB）原位修复地下水污染技术，具有经济、高效等特点。采用PRB技术治理渗滤液污染的地下水，反应介质的选择和介质配比是一个关键问题。因此，以渗滤液污染地下水为研究对象，分别用零价铁粉、活性炭、沸石和陶粒4种混合介质，设计了5个PRB反应器，分别为A、B、C、D和E，对PRB修复渗滤液污染地下水的可行性和有效性进行了试验研究。设计的反应器充分考虑了反应器的渗透性能。实验结果表明：混合介质反应器A、B、C、D和E对CODcr，的平均去除率分别达到了79．6％、75．6％、77．0％、78、9％和79．9％；对NH4^＋的平均去除率分别为87．3％、82．1％、92．1％、98．8％和88．5％。验证了PRB技术处理垃圾渗滤液对处理地下水污染的可行性。     

组合骨料型百喜草植生混凝土去除氮磷

以6组90 d龄期的组合骨料型百喜草植生混凝土盆栽为研究对象,用配制溶液静态培养的方法,选择氨氮(NH3-N)、总氮(TN)和总磷(TP)为主要指标,考查沸石与钢渣、沸石与浮石两种组合骨料型的植生混凝土对污染物的去除效果。结果表明,各组NH3-N 1 d、7 d的去除率分别为13.0%~16.9%和45.7%~56.7%,1 d去除率约占7 d的30%。各组TN 1 d、7 d的去除率分别为9.0%~14.1%和25.6%~39.2%,1 d去除率约占7 d的30%。各组TP 1 d、7 d的去除率分别为22.0%~33.3%和57.3%~89.3%,1 d去除率约占7 d的40%。NO-3-N、NO-2-N含量很低,NO-3-N浓度基本在0.50 mg/L以下,NO-2-N浓度变化范围在0.10 mg/L以下。综合NH3-N、TN和TP去除效果,沸石与浮石按1∶1~1∶3混合的百喜草植生混凝土具有良好的脱氮除磷效果。     

不同填料潮汐流人工湿地处理SBR尾水的对比

通过构建室内潮汐流沸石-石灰石混合填料和沸石填料人工湿地装置,探讨了不同基质人工湿地对SBR尾水中污染物的去除效果。结果表明,沸石对NH_4~+-N的吸附能力强,且潮汐间歇运行方式使系统一直保持高效的去除NH_4~+-N的能力,石灰石中Ca、Mg含量高,对P有较好的吸附。潮汐流沸石-石灰石混合填料、沸石填料人工湿地对NH_4~+-N的去除率分别为99.8%、96.7%,对TP的去除率分别为59.6%、24.9%。石灰石呈中性偏碱性,有利于水中硝化菌、反硝化菌和某些异养菌群的生长。潮汐流沸石-石灰石混合填料、沸石填料人工湿地对TN的去除率分别为43.0%、28.0%,对COD的去除率分别为43.4%、36.7%。沸石-石灰石混合填料人工湿地上层基质中微生物量最高,达到20.45 nmol·g-1填料(相当于E.coli大小的细胞2.0×109个)。2组系统中微生物量具有较明显的分层现象,且上层高于下层,这与污染物随水流推流方向的浓度变化一致。     

渗滤液污染地下氧化还原环境与污染物衰减研究

通过土柱实验研究垃圾渗滤液污染地下氧化还原环境的分带现象与污染物的衰减规律.实验结果表明:垃圾渗滤液污染晕中出现了3个顺序氧化还原带,依次为铁还原带、硝酸盐还原带和氧还原带,各带标志性物质Fe3 、NO-2和O2的最高质量浓度分别为14.81、1.41、5.8 mg/L;COD与NH 4-N在监测区间内呈现出相似的衰减规律,随距离的增加浓度降低,随时间的推移浓度升高,COD初期最高去除率达76.8%,后期降到50.0%;NH 4-N初期最高去除率达98.1%,后期降到90.2%.     

PRB技术同步去除地下水中硝酸盐和镉

为评估可渗透反应墙(PRB)技术同步去除复合污染地下水中硝酸盐和重金属的可行性,选取蛭石、活性炭、固定化微生物为PRB反应介质,采用批实验和柱实验在不同填装方式及不同水力停留时间等条件下,考察PRB技术对硝酸盐和Cd~(2+)的同步去除效果。结果表明:PRB介质为蛭石或活性炭与固定化微生物组合型填料时,Cd~(2+)对PRB去除复合污染水体中的硝酸盐影响甚微,可实现高效的同步去除;当进水NO_3-N浓度为50 mg·L-1、Cd~(2+)浓度为10 mg·L-1时,活性炭与固定化微生物的组合型反应介质对NO_3-N和Cd~(2+)去除率分别可达93.13%和95.80%,蛭石与固定化微生物的组合型反应介质对NO_3-N和Cd~(2+)去除率分别可达92.70%和99.50%,经处理后的水质可达到地下水Ⅲ级质量标准(GB/T14848-2017)。以蛭石+固定化微生物、活性炭+固定化微生物作为反应介质的PRB技术可以实现NO_3-N和Cd~(2+)的同步去除,该技术可应用于处理硝酸盐和重金属复合污染地下水。     

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.     

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.