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1.
催化湿式氧化农药废水及催化剂的研究 总被引:8,自引:0,他引:8
通过浸渍法制备了4种氧化物为主活性组分的负载固定型催化剂,用于过氧化氢催化湿式氧化(CWHPO)处理有机农药废水。用实验确定了催化湿式氧化的条件,不同催化剂处理效果的比较表明,四元组合MnO2-CuO-CeO2-CoO催化剂性能较好,当反应在常温常压下,维持pH=7~9,反应时间为40min时,COD的去除率大于80%,色度去除率大于90%。 相似文献
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利用催化湿式氧化法对一高含硫废水的处理效果进行了系统的研究。筛选出适合处理该种废水的WH型合金催化剂 ,并在此催化剂上考察了反应温度、压力、空速以及气水比 (体积 )等工艺条件对废水处理效果的影响 ,同时考察了废水在催化湿式氧化反应处理前后可生化性的变化。在 2 6 5℃、7.0MPa、空速 =1.0h- 1 、气 H2 O(体积 ) =2 0 0条件下 ,废水COD去除率可达到 77.1%。经过催化湿式氧化处理后 ,废水的BOD5 CODCr值显著提高 ,其值由 0 .0 16提高至 0 .6 4 ,可生化性良好 相似文献
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采用浸渍法制备Cu负载型活性炭催化剂,运用该催化剂催化湿式氧化(CWPO)处理转运站垃圾渗滤液,以出水COD去除率为指标检测催化剂活性和稳定性。实验考察焙烧温度、焙烧时间、浸渍浓度3个因素对催化活性的影响,并对催化剂进行XRD和BET表征。结果表明:当焙烧温度为400 ℃,焙烧时间2 h,浸渍浓度0.4 mol·L-1时,催化效率最高,渗滤液COD去除率为89.9%。紫外光谱和三维荧光光谱的结果表明,用所制备的Cu负载型活性炭催化湿式氧化垃圾渗滤液,可以较好地除去垃圾渗滤液中的难降解有机物。催化剂的重复利用实验表明该催化剂稳定性良好。 相似文献
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以陶瓷-活性炭球为载体制备载Ru催化剂,用于催化湿式氧化(CWAO)法处理酚醛树脂废水,考察了陶瓷-活性炭球载体、Ru负载量和陶瓷球宏孔孔径等对催化剂的催化活性和稳定性的影响。实验结果表明,催化剂催化活性的顺序为:Ru/KC-120>Ru/KC-80>Ru/KC-60>KC-120>无催化剂。在200℃,氧气分压为1.5 MPa等条件下,催化湿式氧化酚醛树脂废水,3% Ru/KC-120催化剂表现良好的催化活性与稳定性,在120 min内,COD和苯酚去除率分别达到91%和96%。 相似文献
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催化湿式氧化处理高含硫废水的研究 总被引:10,自引:0,他引:10
利用催化湿式氧化法对一高含硫废水的处理效果进行了系统的研究。筛选出适合处理该种废水的WH型合金催化剂,并在此催化剂上考察了反应温度、压力、空速以及气水比(体积)等工艺条件对废水处理效果的影响,同时考察了废水在催化湿式氧化反应处理前后可生化性的变化。在265℃、7.0MPa、空速=1.0h^-1、气/H2O(体积)=200条件下,废水COD去除率可达到77.1%。经过催化湿式氧化处理后,废水的BOD5/CODcr值显著提高,其值由0.016提高至0.64,可生化性良好。 相似文献
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Cu-C是一种优化制备的负载型催化剂,实验中以其催化湿式氧化处理高浓度LAS废水。本实验用浸渍法和附着沉淀法制备该催化剂,并考察了反应时间、反应温度、溶液浓度、催化剂的投加量以及不同的制备方法等对催化剂性能的影响,以水样COD和LAS的去除率来评价催化剂的活性。实验结果表明,该方法制备的催化剂具有很好的处理高浓度LAS废水的能力;当反应温度为50℃,反应时间为120 min,催化剂的投加量为2 g时,催化剂的催化效果最好,COD去除率为79.76%,LAS去除率为88.28%。并且,当活性炭与催化剂的振荡吸附时间超过20 min时,活性炭的吸附对废水中LAS的去除基本上无影响。 相似文献
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湿式双氧水氧化处理染料中间体H-酸钠盐溶液的研究 总被引:8,自引:1,他引:7
在0.5 L压力反应器内,对染料中间体H-酸钠盐溶液进行湿式双氧水氧化(WPO)及湿式双氧水催化氧化(CWPO)降解处理.分别考察反应时间、双氧水用量、温度、进水pH值和催化剂等对反应过程与对象污染物降解的影响规律.结果表明,WPO能在温和的条件下降解难于生物降解的有机物,在温度为110℃、压力为0.5 MPa、双氧水用量为理论需用量、进水pH=5的条件下,处理含10 g/L H-酸钠盐的H-酸盐溶液的COD和色度去除率分别为62.0%和98.7%;采用非均相Cu/Ni复合催化剂,在同样操作条件下,CWPO对同一废水的COD和色度去除率分别可达到92.0%和99.9%.表明催化剂的存在大大提高了WPO的氧化效果. 相似文献
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催化湿式氧化法处理吡虫啉农药废水的优化工艺条件 总被引:11,自引:1,他引:11
采用催化湿式氧化技术在2 L高压反应釜中处理吡虫啉农药废水,分别以复合金属氧化物Cu/Mn、Cu/Ce、Ce/Mn及Ce/Ag为催化剂来考察对废水COD去除率的影响.发现Cu/Ce、Ce/Mn、Cu/Mn催化剂有较高的催化活性;Ce/Mn催化剂最稳定;Ce/Ag催化剂的Ag溶出量很大.选用性能良好的Ce/Mn催化剂,考察了反应温度、反应压力和废水的初始pH对催化湿式氧化效果的影响.结果表明,催化剂的加入可使COD去除率提高37%左右,同时处理后废水的BOD5/COD从0.19提高到0.65以上;当反应温度为150~230 ℃时,处理效率随温度升高明显增加;总压4.8 MPa、氧分压1.2~2.4 MPa时,适当增加氧分压亦能提高氧化效率;废水初始pH对氧化效果影响不大,但对催化剂的稳定性有影响.优化工艺条件最终为:催化剂为Ce/Mn;温度190 ℃;氧分压1.6 MPa;进水pH为6.21;反应时间120 min. 相似文献
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Jaana Koistinen Sirpa Herve Raija Paukku Mirja Lahtiperä Jaakko Paasivirta 《Chemosphere》1997,34(12):2553-2569
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. 相似文献
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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. 相似文献
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G T Brooks 《Journal of environmental science and health. Part. B》2013,48(5):619-621
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. 相似文献
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Organochlorine compounds in a three-step terrestrial food chain 总被引:1,自引:0,他引:1
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. 相似文献
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Ralph A. Chapman Carol Harris 《Journal of environmental science and health. Part. B》2013,48(4-5):397-407
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. 相似文献
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Torben Nielsen Anders Feilberg Mona-Lise Binderup 《Environmental science and pollution research international》1999,6(3):133-137
The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen.
In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in
1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for
buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was
caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced
many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH,
while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to
be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator,
was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with
a depletion of benzo(a)pyrene. 相似文献
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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. 相似文献
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Andreia Garcês Isabel Pires Paula Rodrigues 《Journal of environmental science and health. Part. B》2020,55(1):75-89
AbstractIn the last decades, the use and misuse of pesticides in the agriculture have increased, having a severe impact on ecosystems and their fauna. Although the various effects of pesticides on biodiversity have been already documented in several studies, to our knowledge no consistent overview of the impact of pesticides in vertebrates, both terrestrial and aquatic, is available. In this review, we try to present a concise compilation of the teratogenic effects of pesticides on the different classes of vertebrates – mammals, birds, reptiles, amphibians and fish. 相似文献
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P.R. Fresquez J.D. Huchton M.A. Mullen L. Naranjo Jr. 《Journal of environmental science and health. Part. B》2013,48(5):611-622
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, 240Pu, 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. 相似文献
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Jennifer C. Anhalt Thomas B. Moorman William C. Koskinen 《Journal of environmental science and health. Part. B》2013,48(3):207-213
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. 相似文献