新物化法深度处理焦化废水

采用絮凝/吸附新物化法工艺对焦化废水进行深度处理.选用了新型复合高效絮凝剂(PFASSB),结合粉煤灰作为吸附剂,考察了絮凝剂用量、pH对絮凝效果的影响以及粉煤灰用量、pH、吸附时间、生石灰用量对吸附效果的影响.结果表明:(1)PFASSB最佳用量为10 mg/L,絮凝效果优于其他常用絮凝剂,适合处理焦化废水,处理前可以不用调节pH;(2)粉煤灰廉价易得、最佳用量为150 g/L,吸附饱和后的粉煤灰的处置可以考虑资源化再利用;(3)新物化法深度处理后的出水COD、NH3-N分别为70.21、19.37 mg/L,分别达到了<污水综合排放标准>(GB 8978-1996)的一级标准和二级标准.     

壳聚糖/海藻酸钠复合絮凝剂的吸附性能

采用壳聚糖和海藻酸钠制备新型复合絮凝剂,通过正交实验考察复合絮凝剂投加量、搅拌时间、絮凝温度及pH值等因素对曙红染料废水吸附效果的影响,并采用红外光谱对产品进行表征。结果表明:最佳吸附条件为复合絮凝剂投加量0.30 g,pH值为5.00,搅拌时间为2.0 h,絮凝温度25℃时,脱色率可达97.52%。复合絮凝剂对曙红溶液的吸附等温曲线遵循Freundlich吸附等温式和Langmuir等温吸附式。     

铁镍改性膨润土对废水中有机污染物的吸附性能研究

以钠基膨润土为原料,制备了铁镍无机改性土和铁镍有机复合改性土,并应用于造纸废水的处理,探讨了改性土用量、废水pH值、搅拌时间等因素对COD去除率的影响,通过正交实验对实验条件进行了优化.结果表明:铁镍有机复合改性土和铁镍元机改性土对废水的处理效果明显好于原土;膨润土的用量、废水的pH对COD的去除率影响较大;对于铁镍无机改性土,吸附剂用量为12g/L,溶液pH=2,吸附时间为10 min时,对废水中COD的去除率为54.06%;对于铁镍有机复合改性土,吸附剂用量为14g/L,溶液pH=3,吸附时间为20 min时,对废水中COD的去除率为70.10%.     

铁镍改性膨润土对废水中有机污染物的吸附性能研究

以钠基膨润土为原料,制备了铁镍无机改性土和铁镍有机复合改性土,并应用于造纸废水的处理,探讨了改性土用量、废水pH值、搅拌时间等因素对COD去除率的影响,通过正交实验对实验条件进行了优化.结果表明：铁镍有机复合改性土和铁镍元机改性土对废水的处理效果明显好于原土;膨润土的用量、废水的pH对COD的去除率影响较大;对于铁镍无机改性土,吸附剂用量为12g/L,溶液pH=2,吸附时间为10 min时,对废水中COD的去除率为54.06%;对于铁镍有机复合改性土,吸附剂用量为14g/L,溶液pH=3,吸附时间为20 min时,对废水中COD的去除率为70.10%.     

壳聚糖衍生物的合成及其絮凝性能的研究

对从虾蟹壳中制备的壳聚糖进行改性，分别制得壳聚糖衍生物——壳聚糖季铵盐和羧甲基壳聚糖，用于味精废水的絮凝实验。实验结果表明，壳聚糖、壳聚糖季铵盐和羧甲基壳聚糖作为絮凝剂处理味精废水均有较好的效果，以壳聚糖季铵盐的效果最好，其pH值适用范围宽、絮体沉降快，是一种具有良好反应活性的高分子絮凝剂。     

改性壳聚糖复合凹凸棒土絮凝油漆废水

将壳聚糖、阳离子淀粉和二甲基二烯丙基氯化铵(DMDAAC)进行三元接枝共聚,制备了三元接枝改性壳聚糖(CTS-DMDAAC-CS),通过红外光谱和扫描电镜对其结构进行了表征。并且将三元接枝改性壳聚糖与凹凸棒土进行优化复配,对油漆废水进行了絮凝实验,得出了当pH=12,沉降时间为20 min,复合絮凝剂投加量为0.2 g,三元接枝共聚物∶凹凸棒土=1∶10时,该复合絮凝剂对油漆去除率最佳能够达到89.3%,并且絮凝效果好,是一种新型绿色环保的有机-无机复合絮凝剂。     

粉煤灰对焦化废水总铬去除的影响

以1 mg/L模拟焦化废水为研究对象,采用高锰酸钾氧化-二苯基碳酰二肼分光光度法测定焦化废水中总铬,研究不同条件下粉煤灰对总铬去除率的影响.结果表明:(1)粉煤灰粒径、粉煤灰用量、搅拌时间、pH对总铬去除率都有一定的影响.最佳条件:粉煤灰粒径为150μm,粉煤灰用量为4.00 g/L,搅拌时间为40 min,pH为3.在最佳条件下,总铬去除率可达98.82%.(2)在粉煤灰处理模拟焦化废水的最佳条件下,粉煤灰处理实际焦化废水的总铬去除率达90.00%.(3)粉煤灰处理焦化废水,可以以废治废,而且处理效果好、处理费用低、原料获取方便,在实践中具有可操作性.     

接枝共聚木质素絮凝处理电镀废水中的重金属离子

对含有低浓度重金属离子的电镀废水进行处理研究,采用木质素磺酸盐与丙烯酰胺接枝共聚合成了一种木质素接枝共聚物,应用正交实验确定最佳操作条件,并通过红外光谱对其结构进行了表征.用这种改性木质素磺酸盐处理电镀废水,当其用量为90 mg/L,pH值控制在4～7,絮凝时间为2 h,在室温的条件下,可使电镀废水中的Cu2 、Zn2 、Pb2 和Ni2 去除率分别达到93%、90%、96%和90%以上.     

化学絮凝法处理制浆废水的研究

本试验较系统地研究了红、白松去皮废材硫酸盐法制浆,洗浆废水化学絮凝特征、工艺技术条件、絮凝效果以及化学污泥浓缩、脱水技术。实验室试验及中间扩大试验表明,洗浆废水化学絮凝处理,能有效地去除废水中有色物质(去除率约为80—90％)、细小纤维等悬浮物质(去除率为90％以上)以及耗氧物质(COD_(cr)去除率为50—70％)。处理过程中,絮凝剂添加量及废水pH值是主要控制参数。最适宜的添加量随废水污染负荷而异,可通过试验求得。对于COD_(cr)=700毫克/升洗浆废水,硫酸铝用量以300—400ppm为宜;处理前最好将pH值调节至6.0—7.0;反应时间及环境温度对絮凝效果亦有一定影响。反应时间由3分钟增加至18分钟,絮凝效果略有改善;温度由20℃降至2～3℃,对絮凝效果只有少量影响;化学污泥的浓缩、脱水问题是制浆废水絮凝处理的关键。研究表明,稀污泥采用国产(比如江苏丹阳、吉林辽源)非离子型聚丙烯酰胺(分子量为300—500万)改性产品,用量3—5ppm(对处理稀污泥计),能十分明显地改善污泥的沉降性能和过滤性能,其效果与日本三洋化成Sanfloc系列产品可比。絮凝处理药剂总费用约为0.08元/吨废水。化学污泥的处理及回收,正在进行研究。     

生物絮凝法处理洗毛废水的研究

从活性污泥中筛选适宜洗毛废水的生物絮凝剂，并用筛选的生物絮凝进行洗毛废水生物絮凝实验。实验结果表明，当300 mL废水中生物絮凝剂投加量为5 mL、温度为20℃左右、pH值为9、反应时间45 min，搅拌采用先快速搅拌5 min后慢速搅拌40 min的条件下絮凝效果最好，对COD和SS去除率可达80％以上。     

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.     

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.     

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 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.     

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.