活性硅酸混凝剂PFASSC处理造纸废水

利用硅酸钠、硫酸铝、三氯化铁和硫酸为主要原料制备了复合型活性硅酸混凝剂ＰＦＡＳＳＣ并对造纸废水进行了处理，得到活性硅酸混凝剂ＰＦＡＳＳＣ最佳配方为：ＰＨ＝２．０（Ｆｅ＾３＋＋Ａｌ＾２）／ＳｉＯ２（摩尔比）＝１．５，Ｆｅ＾３＋／Ａｌ＾３＋（摩尔比）＝１．０，与常用混凝剂相比，ＰＦＡＳＳＣ混凝剂处理造纸废水对除浊、脱色和去除ＣＤＤＣｒ有更加优良的性能。     

絮凝—酸化法预处理腈纶纺丝生产废水的实验研究

研究采用絮凝－酸化法对腈纶纺丝废水进行预处理,考察了絮凝剂的选用及多种絮凝实验条件对实验结果的影响。结果表明,以ＰＦＳ作絮凝剂,絮凝ｐＨ６．０,ＰＦＳ 投加量为０．３ｍｌ,ＰＡＭ投加量为０．４ｍｌ时的ＣＯＤ,ＢＯＤ５和ＮＨ３－Ｎ及ＣＮ＾－去除率分别为３０％,３１％,８％及３２％。     

几种混凝剂处理煤气洗涤废水的比较

用４种常用的混凝剂Ａｌ２（ＳＯ４）３,ＰＡＣ,ＰＦＳ及ＦｅＳＯ４分别对煤气洗涤废水进行了混凝实验研究,结果表明,使用上述４种药剂对废水ＣＯＤｃｒ最高去除率分别为６３．９％,６７．４％,６１．３％和５７．４％;乳化油去除率分别为７１．６％,７５．６％,７４．８％和７０．５％,浊度去除率分别为９３．４％,９４．１％〈９５．６５和９９．１％,而从经济效益上看,４种药剂去除每ｋｇ废水中ＣＯＤｃｒ所需药剂费     

含氟废水的混凝沉淀处理

研究了ＦｅＣｌ３,Ａｌ２（ＳＯ４）３,ＰＦＣＳ和ＡＰＡＭ对含氟废水的混凝沉淀处理。结果表明：石灰乳,ＰＦＣＳ和ＡＰＡＭ对废水中的氟及ＣＯＤ具有较好的处理效果,处理后水质达到国家二级排放标准。     

新型无机高分子絮凝剂在制革废水处理中的应用研究

介绍了一种新型无机高分子絮凝剂－硅钙复合型聚合氯化铝铁（ＳＣＰＡＦＣ）在制革废水处理中的应用。结果表明，该产品对废水的浊度去除率为９９％，ＳＳ去除率为９５％，ＣＯＤ去除率为９０％，Ｃｒ＾３＋的去除率为８５％左右。最佳使用ｐＨ值为６．０￣９．０，最佳投药量为０．３５￣０．４０ｇ／Ｌ，最佳混凝时间为１５￣２０ｍｉｎ，在同样条件下各项性能均优于ＰＡＣ２倍以上。同时该絮凝剂还可用于生活饮水、生产用水及其他     

SBR法处理印染废水的研究

应用ＳＢＲ法、ＰＡＣ－ＳＢＲ法，微电解－ＳＢＲ法对印染废水进行了对比处理试验研究。试验结果表明：微电解－ＳＢＲ法处理效果优于其它两种方法，当进水ＣＯＤ＝１０００～１６００ｍｇ／Ｌ，色度＝２００～８００倍，ＢＯＤ５＝２５０～４００ｍｇ／Ｌ时．ＣＯＤ去除率在８５％左右，ＢＯＤ５去除率和脱色率均在９０％以上，出水达到排放标准。     

酸性分散染料废水的治理及综合利用研究

利用硫酸含量达１５％－４０％的酸性分散染料废水和废铁作用制得聚合硫酸铁,并用其作净水剂处理印染废水。结果表明,每ｔ酸性废水可生产１．０５ｔ浓度１６０ｇ／ＬＦｅ＾３＋的取合硫酸铁溶液,出水的酸含量降低了８３．５％。用所制得的聚合硫酸铁处理印染废水,ＣＯＤ去除率可达７０．４％－９５．４％,色度去除率可达６５．７％＿９０．５％,具有较好处理效果。     

光催化氧化-混凝工艺处理化工废水

探索了光催化氧化－混凝工艺处理废水的工艺条件,最佳光催化氧化处理条件为ＰＨ＝３,催化剂为铁盐,氧化剂Ｈ２Ｏ２,低压汞灯,光照时间１．５ｈ,废水温度４５℃,温凝剂选用ＰＡＣ和ＰＡＭ（混凝剂的投加量为原水ＣＯＤｃｒ：ＰＡＣ：ＰＡＭ＝７：１．５：０．０１）,混凝ＰＨ６,沉降时间０．５ｈ,在该工艺条件对ＣＯＤｃｒ为１７３－７０１４４ｍｇ／Ｌ的十二烷基苯磺酸钠废水、苯酐废水、富马酸废水、邻苯二甲酸二辛酯废水     

DHDPS的细胞表达、提纯和结晶

ＤＨＤＰＳ是赖氢酸合成通路中第一步的合成酶。将中国春小麦的ＤＨＤＰＳ基因质粒移植入ＲＤＡ８中，得到ＲＤＡ８／ｐＤＢ２６菌株，本研究通过细胞培养、层析提纯和结晶条件的探索，给出了一个较好的技术路线，并为开展义衍射分析蛋白结构创造了条件，通过该研究，对中国春小麦ＤＨＤＰＳ和野种大肠杆菌的ＤＨＤＰＳ差异有了一定的了解，并且对细胞培养的ＭＭ介质处理，ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ，Ｐｈｅｎｙｌ－Ｓｅｐｈａｒｏｓｅ和ＭｏｎｏＱ层析的方法给出具体实验条仲。酶活的检测和蛋白浓度测定都是采取高灵敏度的方法。结晶的ＳＣｒｅｅｎｉｎｇ条件对于二种ＤＨＤＰＳ有很大的差异。对野种大肠杆茵的ＤＨＤＰＳ，需要表面活性剂Ｎ－ｏｃｔｙｌ－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ，ｐＨ１０．０～１０．５，对于中国春小麦一ＤＨＤＰＳ则未找到较好的表面活性剂，ｐＨ６．８～７．６。中国春小麦一ＤＨＤＰＳ晶体培养条件在以往文献中未见报导。     

杭州市大气总悬浮颗粒物中铵盐的测定与变化规律

了解杭州城区大气中ＴＳＰ铵盐成份的含量与变化，我们在朝晖（居民区）、南星桥（混合区）、和睦小学（工业区）进行了为期１年的大气监测，使用大流量采样仪，每季采样３ｄ，每天连续采样２４ｈ，然后对样品进行ＴＳＰ及其中铵成份分析测定，通过１年的监测分析与研究，初步探索了大气中ＴＳＰ铵离子浓度变化及污染程度。１实验部分１．１采样采样仪器为２Ｃ—１０００Ｇ大流量采样仪，流量１０５０Ｌ／ｍｉｎ，每季采样３ｄ，连续开机２４ｈ为一次。采样滤膜为聚氯乙烯滤膜。１．２测定方法（１）铵离子的测定：ＴＳＰ中的铵离子测定，国…     

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)