改性油页岩灰渣对水中镉离子的吸附性能

采用酸碱化改性方法对油页岩灰渣进行改性,确定最佳酸碱化方案,并研究了环境因素对改性油页岩灰渣吸附镉离子的影响。实验研究结果表明,油页岩灰渣经50%的HNO3和20%的NaOH处理时,对镉离子的吸附能力最强。在吸附温度为30℃,初始溶液pH为6～7条件下,0.6 g的改性油页岩灰渣对50 mg/L Cd2+溶液50 mL,吸附150 min时,其吸附率达到86%以上。在实验条件下,改性油页岩灰渣对Cd2+的吸附符合Langmuir和Freundlich等温吸附方程,相关系数分别为0.9626和0.9944,其对Cd2+的理论饱和吸附量达到7.91 mg/g。改性油页岩灰渣对Cd2+的吸附主要归因于离子交换和表面吸附作用。     

SDS改性沸石吸附结晶紫简

以表面活性剂十二烷基硫酸钠（SDS）对沸石进行改性,改性后的沸石对结晶紫溶液进行吸附,以紫外可见分光光度计分析最佳吸附条件。实验结果表明,在30℃,SDS改性沸石投入量为0.25 g;吸附平衡时间为1 h;pH为8的条件下,对含50 mg/L结晶紫染料的去除率可达到92.6%,吸附量达到4.63 mg/g。SDS改性沸石吸附结晶紫的等温吸附曲线与Henry型和Freundlich型均拟合较好。热力学参数计算结果表明,吸附符合自发吸热过程。     

沸石改性及其去除水中氨氮的实验研究

通过实验研究了沸石改性条件及其对水中氨氮吸附去除的影响。结果表明,加热改性与无机酸改性不能显著提高沸石对氨氮的吸附量。利用NaOH改性的最佳浓度为1 mol/L,此条件下对氨氮吸附量可提高到650.68 mg/kg,为天然沸石的2.82倍。利用无机盐改性时,对氨氮吸附效果最好的是NaCl改性沸石,其次为KCl改性沸石与CaCl₂改性沸石。随着NaCl溶液浓度和改性时间的增加,改性沸石对氨氮的吸附量显著增加,可达天然沸石的3～4倍;在NaCl浓度为150 g/L与改性时间为18 h条件下,改性沸石对氨氮吸附量可达887.35 mg/kg,为天然沸石的3.84倍。     

胺化麻黄废渣生物吸附剂对水中阳离子染料的吸附

以麻黄废渣为原料,采用环氧氯丙烷和二乙烯三胺对其进行化学改性,得到麻黄废渣的改性产物。将其应用到中性红和亚甲基蓝2种染料模拟废水的吸附实验,并研究了p H值、吸附剂用量、吸附时间等因素对吸附的影响。结果表明,在p H值为5.5,吸附温度为25℃的条件下,用4 g/L的胺化麻黄废渣生物吸附剂吸附初始浓度为1 000 mg/L的中性红溶液0.5 h,去除率为99.89%;用10 g/L的胺化麻黄废渣生物吸附剂吸附初始浓度为500 mg/L的亚甲基蓝溶液1 h,去除率为99.38%。改性吸附剂对中性红和亚甲基蓝的吸附可以用准二级动力学方程描述,吸附等温线符合Langmuir和Freundlich模型,根据Langmuir方程,25℃时胺化麻黄废渣生物吸附剂对中性红和亚甲基蓝的最大吸附量分别为362.3 mg/g和152.7 mg/g。实验结果显示,胺化麻黄废渣生物吸附剂是一种吸附性能优异的吸附剂,用于处理染料废水有较好的应用前景。     

阳离子表面活性剂改性油茶果壳对水溶液中甲基橙的吸附

以阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)对油茶果壳进行改性,制备CTAB-油茶果壳(CTABCOS)吸附材料,并采用批实验法对其对水溶液中甲基橙的吸附去除进行了研究。考察了溶液p H、吸附剂用量和离子强度等对水溶液中甲基橙的吸附影响,并研究了体系的吸附动力学和吸附热力学特征。结果表明,向100 m L浓度为50 mg/L的甲基橙溶液中加入0.40 g CTAB-COS,在最佳实验条件下,CTAB-COS对甲基橙的去除率可达96.66%。溶液离子强度增大,甲基橙去除率降低。CTAB-COS对甲基橙的吸附行为符合拟二级动力学模型,吸附等温线可用Langmuir模型进行较好拟合,在20℃时最大吸附量为18.31 mg/g。吸附热力学结果表明,吸附过程为可自发进行的放热过程。再生性实验结果表明,再生6次后,CTAB-COS对甲基橙的吸附去除率仍可达到80%。该改性油茶果壳可应用于阴离子型染料废水的吸附法处理。     

环糊精改性沸石制备方法及对对-硝基苯酚吸附性能的影响

在碱性条件下,β-环糊精与2,3-环氧丙基三甲基氯化铵合成了阳离子化的β-环糊精(CCD),并用于改性沸石获得环糊精改性沸石(CDMZ).研究了CCD合成条件对CDMZ吸附对.硝基苯酚性能的影响.结果表明,在2,3-环氧丙基三甲基氯化铵与β-环糊精的配比为7:1,溶液pH=13的合成条件下,合成的CCD改性沸石所得CDMZ对对-硝基苯酚的吸附能力最佳.同时研究了沸石改性前的活化处理,CCD改性沸石的初始浓度和改性时间对CDMZ吸附对-硝基苯酚性能的影响.实验表明,改性前用NaCl溶液活化沸石有助于CDMZ吸附性能的改善;当CCD改性沸石的初始浓度和改性时间分别为15 g/L(以β-环糊精计)和8 h时,所得CDMZ对对-硝基苯酚(120 mg/L)的吸附能力可达263.7μg/g.     

微波强化有机改性膨润土对磷的吸附特性研究

利用十六烷基三甲基溴化铵(CTMAB)在微波辐射条件下对浙江临安膨润土进行改性,制得有机改性膨润土,利用其含磷模拟废水进行处理,考察了不同的工艺条件如有机改性剂用量、微波辐射强度、辐照时间、吸附时间、改性膨润土投加量、pH值对废水中磷去除效果的影响。结果表明:在有机改性剂用量为3 mmol/g,微波辐照强度为96 W/g,微波辐照时间8 min为最佳制备条件。改性膨润土用量为12 mg/L,反应时间为15 min,溶液pH为7及常温条件下,改性膨润土对浓度为50 mg/L的含磷废水去除率达到97.3%,吸附符合Freundlich吸附等温方程。     

改性糠醛渣吸附脱硫废水中钙离子

石灰石-石膏法烟气脱硫技术中石灰石利用率低导致钙流失严重,为实现脱硫废水中Ca2+的资源化利用,进行糠醛渣改性和Ca2+的吸附特性研究。实验结果表明,利用H3PO4改性后的糠醛渣对脱硫废水中Ca2+具有较高的吸附率;在振荡的前30 min吸附率上升极快,至90 min时基本达到平衡吸附量;对Ca2+浓度对吸附率影响研究结果表明,平衡吸附量与平衡浓度关系符合Langmuir等温吸附方程;在初始Ca2+浓度为300 mg/L的溶液中加入3 g吸附剂,温度30℃条件下振荡90 min,平衡吸附量为8.41 mg/g。     

香蕉皮改性吸附剂对氨氮吸附特性

利用Na OH对香蕉皮进行改性,制备改性吸附剂,研究吸附时间、温度、p H等3个因素对其氨氮吸附性能的影响。实验结果表明,Na OH改性提高了该吸附剂对氨氮的吸附能力,在较广温度范围内,该改性吸附剂保持着较高的吸附效率,在吸附氨氮过程中氨氮去除率随着p H值增大呈上升趋势,水质呈中性和碱性时,改性吸附剂表现出较高的吸附效率。相同氨氮初始浓度条件下,在吸附剂投加量增加,氨氮去除率升高,在氨氮浓度为6 mg/L时,可达到96.78%。在20℃温度条件下,饱和吸附量理论值达到9.478 7 mg/g。改性香蕉皮吸附剂对氨氮的吸附符合伪二阶吸附动力模型,氨氮饱和吸附数据符合Langmuir和Freundlich等温吸附模型。     

SDS改性沸石吸附结晶紫

以表面活性剂十二烷基硫酸钠（SDS）对沸石进行改性,改性后的沸石对结晶紫溶液进行吸附,以紫外可见分光光度计分析最佳吸附条件。实验结果表明,在30℃,SDS改性沸石投入量为0．25g;吸附平衡时间为1h;pH为8的条件下,对含50mg／L结晶紫染料的去除率可达到92．6％,吸附量达到4．63mg／g。SDS改性沸石吸附结晶紫的等温吸附曲线与Henry型和Freundlich型均拟合较好。热力学参数计算结果表明,吸附符合自发吸热过程。     

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.