加压生物接触氧化法处理增塑剂生产废水试验研究

主要介绍了采用加压生物接触氧化法处理增塑剂废水。在停留时间为２２ｈ，压力为０．４ＭＰａ，水中溶解氧保持５ｍｇ／Ｌ左右时，进水ＣＯＤＣＲ为１１７００ｍｇ／Ｌ，ＢＯＤ５为６８７３ｍｇ／Ｌ，出水ＣＯＤＣｒ去除率为８９％，ＢＯＤ５去除率为９６％。为增塑剂废水治理工程设计提供了重要参数。     

SBR法处理医药有机废水工艺研究

医药有机废水中ＣＯＤｃＲ２０００－３０００ＭＧ／ｌ，ｂｏｄ５３００－５００ＭＧ／ｌ，ｐＨ为４－５左右，采用ＳＢＲ法处理后，ＣＯＤｃｒ去除率大于８５％，ＢＯＤ５去除率大于９０％，ｐＨ６－９。为废水后续处理达标奠定了良好的基础。     

兼氧接触工艺处理造纸中段废水中间试验的研究

采用中试规律的兼氧接触工艺处理造纸中段废水，当处理水量为４．８ｍ＾３／ｄ，水力停留时间３～４ｈ，气水比３：１，进水ＰＨ８～９．５，平均ＣＯＤ浓度为１６４１．６ｍｇ／ｌ，ＢＯＤ５５１６．１ｍｇ／ｌ，ＳＳ６８８．４ｍｇ／ｌ的条件下，处理后出水ｐＨ７．５左右，平均ＣＯＤ浓度为１０５９．８ｍｇ／ｌ，去除率３４．９％，ＢＯＤ５２４６．５ｍｇ／ｌ，去除率５２．１％，ＳＳ１６１．９ｍｇ／ｌ，去除率为７７．１％。     

厌氧—好氧法处理渗滤液与城市污水混合废水的可行性

彩厌氧－好氧工艺对不同浓度的垃圾填埋场渗滤液与城市污水在不同混合比（ＶＳＨ：ＶＣＨ）时的处理效果及可行性进行了研究,厌氧段采用新型ＡＢＲ反应器并将控制在水解酸化阶段。研究表明,当原渗滤液ＣＯＤ〈５５００ｍｇ／Ｌ时,ＶＳＨ：ＶＣＨ达４：６是可行的,其稳定运行时的ＣＯＤ和ＢＯＤ５去除率可分别达８８．９％和９６．８％当原渗滤液ＣＯＤ≥６５００～８８００ｍｇ／Ｌ时,须将ＶＳＨ：ＶＣＨ控制在２．８以内。     

养猪场废水处理工艺研究

采用接触氧化－水解－两段接触氧化－混凝工艺处理高浓度养殖废水,通过试验得到最佳工艺参数,在最佳试验条件下,进水ＣＯＤｃｒ小于５０００ｍｇ／Ｌ,经处理后出水ＣＯＤｃｒ平均去地９７％,ＢＯＤ５去除率大于９８％,氨氮去除率大于９６％,各项主要指标可达污水综合排放标准一级标准。     

利福平废水的絮凝和生化处理研究

种福平生产的废水ＣＯＤ高达６万,用ＰＦＳ、Ｃ－ＰＡＭ脱稳,密集网捕式絮凝处理后,ＣＯＤ去除率达２７％,ＢＯＤ５／ＣＯＤｃｒ从０．１９上升到０．３２,絮凝前后水质和色谱分析表明,絮凝后５种有机物去除效率均在２２％以上,使生化处理成为可能,进生化池废水经稀释后,用活性污泥法处理９天后,ＣＯＤ从１．５万降至ＣＯＤ〈３００ｍｇ／Ｌ,达到治理要求。     

驯化活性污泥处理明胶有机废水的实验

利用驯化活性污泥对组分复杂的明胶有机废水进行有机物降解实验。结果表明,明胶废水的ＢＯＤ５／ＣＯＤｃｒ比值为０．４４－０．４６,ＣＯＤｃｒ进水浓度在１０００－１２００ｍｇ／Ｌ人,ＣＯＤｃｒ和ＢＯＤ５去除率分别达８１％－８３％和８６％－９１％。     

SBR法处理化学药物制剂废水

采用 ＳＨＲ法处理化学药物制剂废水． 调节 ｐＨ至７．５,进水 ＣＯＤｃｒ ２２４～１５３０ ｍｍ／Ｌ,曝气１０ ｈ, ＣＯＤｃｒ容积负荷达２．５８ｋｇ／ｍ~３·ｄ,ＣＯＤｃｒ的去除率高达９４．２％,处理后出水ＣＯＤｃｒ＜１００ｍｇ／Ｌ,达到综合排放标准（ＧＢ８９７－９６）一级标准。ＣＯＤｃｒ容积负荷至３．８４ ｋｇ／ｍ~３·ｄ, ＣＯＤｃｒ去除率仍＞８５．９％。     

水解酸化——好氧工艺处理混合化工废水

对某化工开发区混合化工废水进行预处理,物化出水采用厌氧水解－－好氧活性污泥法坦 步处理。研究了水力停留时间、有机负荷、容积负荷对处理效率的影响。结果表明,当上流工厌氧滤池进水ＣＯＤ浓度为７００－９００ｍｇ／Ｌ,经水解酸化－－好氧处理后出水ＣＯＤ去除率达６０％以上,色度、ＳＳ、ＢＯＤ去除率分别为８５％以上,５０￣６０％、９５％左右。经混凝沉淀、Ｆｅｎｔｏｎ试剂进一步处理,ＣＯＤ、色度可下降为１２４ｍ     

接触氧化——混凝沉淀法处理染色废水

进行了生物接触氧化法处理牛仔布染色废水的设计与工程试运转。结果表明，当废水ＣＯＤＣＲ平均浓度为５４６ｍｇ／Ｌ色度为４４８倍时，处理ＣＯＤＣＲ去除率为６８％，色度去除率８６％，出水基本能达到设计要求。     

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)