胺基树脂的合成及对水中重金属离子的吸附特征

研究了使用氯甲基化聚苯乙烯交联微球为前驱体与二乙烯三胺经回流反应合成胺基树脂及其对水中Cd2+和Ni2+的吸附特征。结果表明,胺基官能团成功地嫁接到树脂表面,胺基含量为5.6 mmol/g。胺基树脂对Cd2+和Ni2+的吸附等温线表明,温度的升高有利于吸附,且吸附等温线都符合Langmuir模型。pH值对吸附的影响较大,最佳吸附pH值范围为4~6。2种金属离子在胺基树脂上的吸附都符合准二级动力学方程。     

MnO2负载树脂的制备及对As(Ⅴ)的去除效果

制备了大孔和DH302 2种MnO2的负载树脂.并用SEM、EDS手段表征了负载树脂,实验了负载MnO2后树脂对As(Ⅴ)的去除效果.结果表明:负载树脂对As(Ⅴ)的去除效果比原树脂有很大提高;吸附As(Ⅴ)后的2种负载树脂,均能较好地解吸并可重新用于对As(Ⅴ)的吸附实验.     

大孔非极性树脂处理TAIC生产废水

TAIC(三烯丙基异氰脲酸酯)作为过氧化物交联或自由基反应交联的助交联剂被广泛使用.由于TAIC性质稳定,难以降解,常规的物化方法对TAIC废水处理效果普遍较差.为了寻找一种新的废水处理工艺,本研究采用了大孔吸附树脂处理TAIC生产废水,并考察了流速、pH、反应时间对处理效果的影响以及反应动力学过程.结果表明,影响该工艺的因素主次关系为:流速＞反应时间＞pH;在最佳进水条件pH为5,流速为4 BV/h,反应时间为120 min时,COD的去除率达到62％以上,TAIC的去除率达到80％以上.反应动力学分析表明,大孔非极性树脂处理TAIC生产废水的过程基本符合二级动力学规律.     

木质素离子交换树脂对重金属离子的吸附效能

以木质素磺酸钙为反应单体,采用溶液聚合法制备了木质素离子交换树脂,对其进行了SEM电镜表征及吸附性能研究。结果表明:制备的木质素离子交换树脂依靠其表面可电离的磺酸基、羟基和羧基等多种交换基团实现对重金属离子的选择性吸附;当反应温度为25℃时,其对Cd~(2+)具有很好的吸附效果,吸附量可达到92.15 mg·g-1;在相同的实验条件下,树脂对Cu~(2+)、Cd~(2+)和Ni~(2+)的吸附效能为Cd~(2+)Ni~(2+)Cu~(2+);SEM电镜扫描结果显示:木质素离子交换树脂表面光滑致密,无明显的物理结构孔,属于凝胶型离子交换树脂。     

乙二胺基棉纤维脱硫剂的制备研究

通过氯化和胺化两步反应合成了乙二胺基棉纤维（AEAC）,并用于模拟烟气中SO₂的吸附研究。试验比较研究了不同种类的氯代试剂、胺化反应稀释剂和溶胀试剂对乙二胺基棉纤维制备和脱硫性能的影响。结果表明：乙二胺基棉纤维能有效吸附烟气中SO₂,饱和吸附容量可达120 mg/g干纤维;以N,N-二甲基甲酰胺(DMF)作为溶胀试剂,三氯氧磷(POCl₃)作为氯代试剂,并以正丁醇为胺化反应稀释剂可以大大改善乙二胺基棉纤维脱硫吸附剂的合成效果;样品含氮量和饱和硫容之间存在很好的正相关关系。     

以废塑料为基材的大孔型离子交换树脂的制备、表征和吸附性能

以废旧电视机外壳(WTVS)为原料,通过磺化反应和溶胀-渗透方法来制备大孔型离子交换树脂(SMD001),并将其作为CO_2吸附材料的载体,采用N_2吸附-脱附、傅里叶变换红外光谱(FT-IR)、热重分析(TGA)、扫描电镜(SEM)、压汞法等手段对大孔型离子交换树脂(SM-D001)进行表征。考察了不同正庚烷的量、不同乙醇/水质量比和不同致孔时间下制备的SM-D001对CO_2吸附能力的影响。结果表明,当致孔剂正庚烷的量为25 g,乙醇/水质量比为90∶10,致孔时间为5 h时,制备的离子交换树脂对CO_2的平衡吸附量达到1.87mmol·g~(-1)。以SM-D001为载体,五乙烯六胺(PEHA)为改性剂,采用配位法制备的固态胺吸附剂对CO_2的吸附能力达到3.61 mmol·g~(-1),并对其进行吸附动力学研究。上述研究结果为进一步证明固态胺吸附剂对CO_2吸附过程是物理吸附和化学吸附共同作用的结论提供参考。     

复合功能超高交联树脂吸附邻苯二酚的热力学研究

研究了胺基修饰的复合功能超高交联树脂对水溶液中邻苯二酚的静态吸附热力学特征。结果表明，在超高交联树脂上引入适量的胺基，可明显提高树脂的吸附容量。该类树脂对邻苯二酚的吸附为自发的放热过程，属于物理吸附过程。     

NKA-Ⅱ型树脂对邻氯苯甲酸的吸附研究

研究了NKA—Ⅱ型大孔吸附树脂对邻氯苯甲酸的吸附行为,考察了吸附时间、流速、温度等因素对树脂吸附一脱附的影响。结果表明,NKA-Ⅱ型大孔吸附树脂对邻氯苯甲酸有较好的吸附一脱附性能,符合Langmuir吸附模型。在最优工艺条件下,水样经固定床吸附处理后,邻氯苯甲酸浓度从2000mg／L降至30mg／L,COD从3000mg／L降至50mg／L以下。该技术为邻氯苯甲酸废水的治理和资源化提供了实用依据。     

聚乙烯吡啶树脂对间苯三酚的吸附性能

通过悬浮聚合的方法,合成了一种聚乙烯吡啶树脂(WH-06)。以大孔弱碱树脂D301和超高交联树脂NDA150作为参照,研究了WH-06树脂对间苯三酚的吸附性能,探讨了溶液的p H及无机盐对树脂吸附间苯三酚的影响。结果表明,WH-06树脂对间苯三酚的吸附等温线都同时满足Langmuir和Freundlich等温吸附方程,且间苯三酚在WH-06树脂上的吸附是一放热过程,能够自发进行,无机盐对WH-06吸附间苯三酚几乎无影响。     

带长链烷基季铵盐杀菌活性官能团树脂的合成

以强酸型阳离子交换树脂作载体 ,合成磺酰氯树脂后固载乙二胺并胺基叔胺化 ,最后加卤代烷合成带长链烷基季铵盐杀菌活性官能团树脂 ,确定了合成路线中的各步反应条件。对异养菌的杀菌性能测定结果表明 ,合成的杀菌树脂的杀菌率在测定条件下都达到了 90 %以上 ,有望用于工业和民用水的杀菌消毒     

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.     

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.     

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.     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

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.     

Phytoextraction of lead-contaminated soil using vetivergrass (<Emphasis Type="Italic">Vetiveria zizanioides</Emphasis> L.), cogongrass (<Emphasis Type="Italic">Imperata cylindrica</Emphasis> L.) and carabaograss (<Emphasis Type="Italic">Paspalum conjugatum</Emphasis> L.)

Background, Aims and Scope The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation. Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were: (1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass species as potential phytoremediators in terms of Pb accumulation by plants. Methods The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg⁻¹ (37.5 kg ha⁻¹) and 150 mg kg⁻¹ (75 kg ha⁻¹) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments using an atomic absorption spectrophotometer. This study was laid out following a 3 × 2 factorial experiment in a completely randomized design. Results On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85–39.39 Mg ha⁻¹). Carabaograss had the lowest herbage mass production of 4.12 Mg ha⁻¹ and 5.72 Mg ha⁻¹ from soils added with 75 and 150 mg Pb kg⁻¹, respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 ± 2.81 mg kg⁻¹). This was followed by cogongrass (2.34 ± 0.52 mg kg⁻¹) and carabaograss with a mean Pb level of 0.49 ± 0.56 mg kg⁻¹. Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150 mg kg⁻¹) to the soil. Discussion Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency of plants as phytoremediators could be correlated with the plants’ total biomass. This implies that the higher the biomass, the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most metal removal from the soil. Conclusions The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil. It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction on sites contaminated with high levels of heavy metals; particularly Pb. Recommendations and Perspectives High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters, battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and public parks. ESS-Submission Editor: Dr. Willie Peijnenburg (wjgm.peijnenburg@rivm.nl)