苦咸水脱盐的纳滤技术的研究

着重考察纳滤装置对苦咸水中Cl-、Mg2+、Ca2+的去除作用以及影响纳滤膜工作的因素。结果表明:(1)0.60MPa为纳滤膜最佳的操作压力;(2)温度对产水通量和离子去除率有很大影响,宜控制在20℃;(3)纳滤膜运行周期为12h,影响纳滤膜产水通量的主要因素是苦咸水中的部分离子结垢;(4)纳滤膜对苦咸水中的Ca2+的去除率为90%,Mg2+的去除率为78%,Cl-的去除率为44%,可见纳滤膜对不同价态离子的去除效果不同,对二价和高价离子的去除率明显高于一价离子;(5)纳滤膜的酸洗效果远好于碱洗,同时酸洗可去除膜表面的无机盐离子且不会破坏纳滤膜的产水性能。     

SPEEK涂层纳滤膜处理草甘膦废水

以聚醚砜(PES)超滤膜为基膜,采用涂层法制备磺化聚醚醚酮(SPEEK)中空纤维复合纳滤膜,研究其对草甘膦的浓缩和去除。考察了该膜在浓缩草甘膦模拟废水中的操作条件,如跨膜压力、进料浓度、进料pH和离子强度等对通量和截留率的影响。结果表明,随跨膜压力的增加,草甘膦的截留率和水通量均增加,当跨膜压力由0.3 MPa增加到0.8 MPa时,水通量由34.0 L/(m2.h)增加至98.0 L/(m2·h),截留率高于98%;增加进料浓度和离子强度,截留率和通量均减小,当进料浓度由100 mg/L增至1 000 mg/L,水通量降低12.4%,截留率降低8.4%;而pH由3.0升至11.0时,截留率增加,但通量几乎不变。当把该膜材料用于浓缩含高浓度NaCl的草甘膦母液时,发现在0.5 MPa压力和pH=11.0下,复合纳滤膜对NaCl的截留率低于20%,对草甘膦的截留率可达90%。这说明该复合纳滤膜可以把草甘膦与NaCl有效分离开来,为草甘膦的回收利用提供了基础。     

LVJ纳滤膜对磺胺二甲基嘧啶截留性能

用LVJ-NF102聚酰胺纳滤膜在LJ-2540ST卷式膜中试设备中进行纳滤截留水体中磺胺二甲基嘧啶实验,考察操作时间、操作压力、磺胺二甲基嘧啶浓度和离子强度等因素对纳滤膜截留磺胺二甲基嘧啶的影响.结果表明,LVJ纳滤膜对磺胺二甲基嘧啶的截留率100 min后基本稳定;随操作压力的增加,LVJ纳滤膜通量和对磺胺二甲基嘧啶的截留率都增大;随着溶液中磺胺二甲基嘧啶浓度的增加,LVJ纳滤膜通量下降,对磺胺二甲基嘧啶的截留率先增大后维持不变;随溶液中离子强度的增加,LVJ纳滤膜通量和对磺胺二甲基嘧啶的截留率都减小.在磺胺二甲基嘧啶浓度为28.2 mg/L、操作压力为0.4 MPa条件下,LVJ纳滤膜5 min可使溶液中磺胺二甲基嘧啶截留82.7％.     

草甘膦模拟废水的纳滤分离过程研究

为研究草甘膦纳滤分离过程的影响因素及变化规律,选用GE Osmonic的DK膜对草甘膦模拟废水进行纳滤分离过程的研究。实验表明,20℃、浓度500 mg/L、pH=2.96的草甘膦模拟废水,其截留率随跨膜压力升高而略有升高,其渗透通量随跨膜压力的升高几乎线性增加;随操作温度升高渗透通量增加,但截留率下降;渗透通量和截留率均随料液初始浓度的增加而降低;在pH值为3~5的范围内,草甘膦的截留率随pH值升高而下降,在膜的等电点附近达到最低,该pH值范围内渗透通量在膜的等电点附近较高;在pH值为5~11的范围内,草甘膦的截留率随pH值升高而升高,在该pH值范围内渗透通量随pH值升高而降低;由于屏蔽效应,草甘膦的截留率随NaCl浓度的升高而降低。     

酒石酸钾钠（PST）对纳滤处理重金属废水的强化效果

以酒石酸钾钠（PsT）为络合剂，分别选取cd、zn、As和Ph4种金属废水，探索络合纳滤工艺对金属离子去除率和膜通量的强化效果，测定纳滤膜表面接触角以表征膜通量变化规律，并研究了压力、金属浓度和溶液pH参数对络合纳滤过程的影响。结果表明，PsT对4种金属去除的强化效果存在相似规律，分别有一个最佳PsT添加浓度。随PsT浓度的增加，金属离子去除率先增大后减小，而膜通量一直增大。研究发现，纳滤膜表面接触角与膜通量呈稳定的反比例关系，与金属离子种类和PsT添加量无关。随着操作压力的增大，膜通量线性增加，去除率基本不变；金属离子浓度的增加对膜通量影响不大，金属去除率略有上升；pH在4～5之间变化时，As去除中膜通量和去除率均有所升高，而cd、zn和Ph3种溶液处理效果基本不受pH影响。     

纳滤去除水中的内分泌干扰物

采用陶氏DOW FILMTEC NF270芳香聚酰胺类复合纳滤膜处理水中内分泌干扰物——17α-乙炔雌二醇（EE2），实验中分别考察了原液浓度、操作压力、pH值、Ca²⁺浓度及腐殖酸共存等不同条件下对EE2截留效果的影响。结果表明，NF270对于去除水中的EE2具有很好的效果，截留率可达到97.6%，而且，实验发现，原液浓度对EE2的截留效果影响较小；当操作压力为0.6 MPa时，膜对EE2的截留效果最好；而随着pH值和Ca²⁺浓度的增加，膜对EE2的截留率均呈上升趋势；而当腐殖酸存在时膜对EE2的截留率有明显提高，但同时也造成膜污染加剧和膜通量下降，特别是在EE2、腐殖酸和Ca²⁺共存时，膜污染更加严重。     

酒石酸钾钠(PST)对纳滤处理重金属废水的强化效果

以酒石酸钾钠(PST)为络合剂,分别选取Cd、Zn、As和Pb 4种金属废水,探索络合纳滤工艺对金属离子去除率和膜通量的强化效果,测定纳滤膜表面接触角以表征膜通量变化规律,并研究了压力、金属浓度和溶液pH参数对络合纳滤过程的影响。结果表明,PST对4种金属去除的强化效果存在相似规律,分别有一个最佳PST添加浓度。随PST浓度的增加,金属离子去除率先增大后减小,而膜通量一直增大。研究发现,纳滤膜表面接触角与膜通量呈稳定的反比例关系,与金属离子种类和PST添加量无关。随着操作压力的增大,膜通量线性增加,去除率基本不变;金属离子浓度的增加对膜通量影响不大,金属去除率略有上升;pH在4~5之间变化时,As去除中膜通量和去除率均有所升高,而Cd、Zn和Pb 3种溶液处理效果基本不受pH影响。     

无机陶瓷纳滤膜分离高钠盐废水中的锶

本实验研究表明,仅用截留分子量为1000的无机陶瓷纳滤膜分离高钠盐模拟溶液中的锶,分离效果并不理想.为提高陶瓷纳滤膜对锶的选择分离效果,选择了分子量为3000的聚丙烯酸作为陶瓷纳滤膜分离的强化剂,重点探讨了溶液pH值、聚丙烯酸浓度、温度及离子强度对模拟溶液盐分离效果和膜通量的影响,并得到了适宜的锶钠分离条件.实验结果表明,在适宜条件下,通过聚丙烯酸强化和两级分离,陶瓷纳滤膜可大大提高模拟溶液中锶离子的选择分离效果,锶/钠的分离因子高达205.     

组合工艺去除垃圾渗滤液中的DBP和DEHP

探讨了采用实验室规模的生物处理组合工艺(上流式厌氧污泥床+曝气生物滤池+缺氧反应器+膜生物反应器,UASB+BAF+ANO+MBR)处理垃圾渗滤液过程中,邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DE-HP)两种内分泌干扰物在各工艺段的去除效率和机理。测定结果表明,对于DBP和DEHP浓度分别为164.4μg/L和215.0μg/L的原水,总出水浓度分别降至11.8μg/L和10.4μg/L,去除率分别达到92.9%和95.2%,处理效果良好。其中DBP在处理工艺中逐级降解,主要是微生物的降解作用。MBR是DEHP的主要去除工艺段,去除比例达到56.6%,膜截留效果明显。采用生物处理组合工艺可实现对垃圾渗滤液中DBP和DEHP的同时高效去除。     

无机陶瓷纳滤膜分离高钠盐废水中的锶

本实验研究表明，仅用截留分子量为1000的无机陶瓷纳滤膜分离高钠盐模拟溶液中的锶，分离效果并不理想。为提高陶瓷纳滤膜对锶的选择分离效果，选择了分子量为3000的聚丙烯酸作为陶瓷纳滤膜分离的强化剂，重点探讨了溶液pH值、聚丙烯酸浓度、温度及离子强度对模拟溶液盐分离效果和膜通量的影响，并得到了适宜的锶钠分离条件。实验结果表明，在适宜条件下，通过聚丙烯酸强化和两级分离，陶瓷纳滤膜可大大提高模拟溶液中锶离子的选择分离效果，锶／钠的分离因子高达205。     

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.     

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.     

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 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.     

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

Abstract

This paper summarizes radionuclide concentrations (³H, ⁹⁰Sr, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu, ²⁴¹Am, and ^totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y^‐1 (2.2 μSv y^‐1), deer bone = 3.8 mrem y^‐1 (38 μSv y^‐1), elk muscle = 0.12 mrem y^‐1 (1.2 μSv y^‐1), and elk bone = 1.7 mrem y^‐1 (17 μSv y^‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y^‐1 (1000 μSv y^‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.     

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.