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反应沉淀一体式矩形环流反应器处理城市污水的影响因素研究 总被引:1,自引:0,他引:1
通过中试研究了不同溶解氧浓度、有机负荷、HRT条件下,反应沉淀一体式矩形环流反应器(RPIR)对深圳市南山污水处理厂低C/N城市污水的处理效果。结果表明,在控制溶解氧浓度为1 mg/L、COD容积负荷小于2.5 kg/m3.d、NH4+-N容积负荷不超过0.2 kg/(m3.d)、HRT为4 h时,COD平均去除率可达90%,NH4+-N平均去除率超过80%。RPIR在处理该城市污水过程中具有良好的抗冲击负荷能力,污染物去除效率高,运行稳定。 相似文献
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摇动床生物膜反应器和活性污泥法组合技术处理高浓度有机废水的研究 总被引:2,自引:1,他引:1
利用摇动床生物膜反应器(简称摇动床)技术具有的容积负荷高与污泥产量低的优点,在普通活性污泥池的前部填充高性能丙烯酸树脂纤维(Biofringe)填料,研究了摇动床和活性污泥法组合技术处理高浓度有机废水的有效性。结果表明,该组合技术具有很强的有机物去除能力,当进水COD平均质量浓度由1500mg/L上升到2514mg/L时,出水COD的平均去除率基本保持在96%以上;整个运行阶段的出水COD浓度均满足《污水综合排放标准》(GB8978—1996)的二级标准;当进水NH4+-N浓度增加时,NH4+-N的去除率由99.7%降低到76.5%,但是在试验运行的整个阶段,摇动床和活性污泥法组合技术系统都表现出较强的硝化能力;活性污泥池中最高的混合液悬浮固体(MLSS)质量浓度为10625mg/L,最高MLSS约为普通活性污泥法的4倍;运行结束后的污泥产率为0.186,污泥产率仅为普通活性污泥法的50%左右。 相似文献
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采用添加阿科蔓生态基的曝气氧化塘对长春市新凯河污染河水进行了中试实验。研究结果表明,氧化塘中COD、NH+4-N和TP的去除率随季节变化较大,高温溶解氧不足时,曝气能明显提高污染物去除率。低温时,低强度曝气有利于温度的传递,延长氧化塘的运行时间。溶解氧大于2 mg/L时,夏季时COD去除率最高达到40.89%,NH+4-N去除率最高达到57.11%,秋季时TP去除率最高达到34.65%。COD、NH+4-N和TP的平均出水浓度分别达到37.92、4.02和0.56mg/L,基本满足地表水Ⅴ类水质要求。 相似文献
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《环境工程学报》2016,(9)
开发出一种两段进水生物膜法好氧/好氧/缺氧-膜生物反应器(OOA-MBR)强化生物脱氮工艺,以模拟生活污水为研究对象,重点考察了流量分配比、曝气方式和水力负荷等因素对系统运行效果的影响,并对工艺控制参数进行了优化。实验结果表明,在系统HRT 4.8 h,流量分配比为1∶1,后置MBR池曝气方式采取Air-on 4 min/Air-off 6 min模式,进水COD(380±20)mg·L-1、NH+4-N(35±5)mg·L-1、TN(35±5)mg·L-1时,出水COD、NH+4-N和TN去除率分别达到93.9%、91.8%和77.7%,出水水质满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准。 相似文献
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研发了一种基于射流曝气的管式反应设备,考察了负荷和DO对反应器处理效能的影响。实验结果表明,在温度为15℃、DO 6.0 mg/L、有机负荷为1.0 kg COD/(m3.d)、氮负荷为0.30 kg TN/(m3.d)、HRT为8 h的条件下,管式反应器可使生活污水的COD、NH4+-N及TN分别从335 mg/L、105 mg/L及110 mg/L降至43 mg/L、14 mg/L及18 mg/L,去除率分别为87%、86%和83%。DO对反应器脱氮效能影响显著,DO为6 mg/L时,能构建出同步硝化反硝化系统,NH4+-N和TN的去除率分别为96.6%和86.7%。 相似文献
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MBBR处理猪场废水厌氧消化液的研究 总被引:5,自引:0,他引:5
采用移动床生物膜反应器(MBBR)处理猪场废水厌氧消化液,考察了水力停留时间(HRT),进水COD和NH3-N浓度对反应器处理效果的影响.结果表明,在温度为20~30℃,填料填充比为50%,进水COD和NH3-N浓度分别为1016 mg/L和496 mg/L条件下,当HRT为12.5 h时,COD和NH3-N去除率可分别达到62%和77%,猪场废水厌氧消化液中可生物降解性有机物基本得到去除,当HRT增至23.8 h时,COD和NH3-N去除率分别为64%和86%,出水COD和NH3-N浓度分别为368 mg/L和70 ms/L,均达到了<畜禽养殖业污染物排放标准>(GB18596-2001)的要求. 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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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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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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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 D.H. Kraig M.A. Mullen L. Naranjo Jr. 《Journal of environmental science and health. Part. B》2013,48(5):885-899
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. 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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Wilkins K Nielsen KF Din SU 《Environmental science and pollution research international》2003,10(3):162-166
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. 相似文献
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Blunt RE Walsh KA Ashton DK Viant MR Chipman JK 《Environmental science and pollution research international》2007,14(5):293-296
A Natural Environment Research Council (NERC) funded Knowledge Transfer (KT) workshop was held in the United Kingdom (UK)
to identify the needs and opportunities in the application of molecular biology and ‘omics’ techniques to environmental monitoring
and risk assessment. Attendees highlighted a lack of effective communication between end-users and researchers as well as
difficulties with data interpretation as reasons behind the slow uptake of molecular biology and omics techniques. A number
of promising areas in which new techniques could be implemented at a practical level in the very near future were identified,
thereby raising the profile of these recent technologies and providing vital proof of concept work. Molecular taxonomy, bacterial
source tracking and pre-screening of chemicals for potential toxicities were all viewed as areas in which omics and molecular
techniques could have immediate value, with the aim of reducing cost, increasing efficiency and providing more comprehensive
data of improved quality. 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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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