炭纤维载体固定床厌氧发酵启动运行效果实验

以开发高效率、抗冲击性能强的高浓度有机废水沼气发酵技术为目的，用传统的 UASB反应器作为对照，研究了以炭纤维为生物膜载体的固定床厌氧反应器的启动运行效果。反应器进口废水 COD 为 5 000 mg/L, 水力停留时间 (HRT) 由213 h 逐步缩短为35 h，进水有机容积负荷(OLR)由0.56 kg COD/ (m³·d)提到3.45 kg COD/(m³·d)。结果表明，固定床反应器厌氧发酵的效率比对照高，出水 pH 值也比对照稳定；运行到第 50 d 时，固定床厌氧反应器和对照的 COD去除率分别由第 7 d 的36.56%和33.58%上升到87.9%和62.6%；固定床厌氧反应器的容积比产气率最高为1.16 m³/(m³·d)，累计产气量为415.59 L，而对照的容积比产气率最高值仅为0.31 m³ /(m³·d)，累计产气量为 71.66 L，前者最高容积比产气率和累计产气量分别是后者的3.74倍和5.78倍。固定床厌氧反应器的启动速度、COD 去除率和产甲烷效率显著地高于对照反应器。     

多级厌氧法处理螺旋霉素工业发酵菌渣效果的研究简

通过自主设计的多级厌氧反应器系统来考察半连续处理螺旋霉素工业发酵菌渣的效果。该系统总反应体积为44 L，由4个11 L的升流式厌氧反应罐组成，罐体间采用串联方式连接。121 d的连续运行周期分为3个阶段，各阶段的有机负荷率分别为1.27、1.82和2.73 kg COD/（m³·d）。全过程中主要监测了各级罐体的产气量和螺旋霉素的降解。结果表明，多级厌氧反应器系统启动初期会出现产气不稳定现象，经过2个月的运行之后系统达到稳定状态。在有机负荷达到2.73 kg COD/（m³·d）时，各级罐体仍能稳定运行，总产气的45%集中在1号罐。在系统启动初期，螺旋霉素不能被明显降解。运行约80 d后，整个体系达到了快速降解螺旋霉素的状态，在2.73 kg COD/（m³·d）的有机负荷率下，螺旋霉素降解率达到97%，同时可溶性COD降解率也达到了90%。     

2 种不同性能炭纤维载体的固定床厌氧反应器运行效果比较简

分别采用炭纤维（CF）和活性炭纤维（ACF）作为固定床厌氧反应器的生物膜载体，以不加任何载体的相同规格的反应器为对照，在中温（35±1）℃、连续进料条件下处理高浓度糖蜜废水，实验历时 165 d ，比较评价了2种不同性能的炭纤维作为载体的固定床厌氧反应器的运行性能。结果表明，CF 和 ACF 均是较好的微生物附着的载体材料，具有较强的处理高负荷有机废水和抵抗pH冲击的能力，能显著地提高反应器运行系统的稳定性。具有高比表面积的 ACF 较之 CF 更易于微生物固着并挂膜。对照在进水 COD超过 20 000 mg/L，相应 OLR为 8.35 kg COD/（m³·d）时，系统开始酸化。而以 CF 和 ACF 为载体的反应器能在进水 COD 高达 70 000 mg/L ，相应的 OLR 分别为 36.85 和 39.06 kg COD/（m³·d） 的高有机负荷下运行，且系统的pH更稳定。对照及以 CF 和 ACF 为载体的反应器的最高容积产气率分别为4.33、17.12和16.12 m³/（m³·d）；165 d 的累积产气量分别为5 665.4、22 675.8和26 112.8 L，后2者的产气量分别是对照产气量的 4.0 和 4.6 倍。     

含盐量与负荷对好氧颗粒中自养与异养菌的影响

研究了含盐量分别为2.5％和5％，有机负荷分别为8 kg COD/(m³·d) 和16 kg COD/(m³·d)条件下好氧颗粒污泥中自养菌和异养菌的成长情况，研究结果如下：(1)系统在高COD负荷条件下抗盐度的冲击能力要强于低负荷条件；(2)从4个反应器对COD的去除效果来看，含盐量对异养菌的影响要低于硝化自养菌；(3)在低负荷情况下，硝化自养菌为优势菌种，在一个周期内产生的NO^-₃-N要高于高负荷，而在高负荷情况下，异养菌为优势菌种。     

EGSB 反应器处理产氢发酵液简

以厌氧颗粒污泥为接种污泥，对厌氧颗粒污泥膨胀床（EGSB）反应器处理产氢发酵液的启动性能进行了研究。结果表明，在温度为（35±1）℃，水力停留时间（HRT）为6 h的条件下，逐渐提高进水COD，经过40 d连续运行，EGSB反应器启动成功。容积负荷达到14 kg COD/（m³·d）时，COD去除率约为80%，产气量为26.84 L/d，甲烷含量为57.9%。     

负荷及盐度对好氧颗粒污泥EPS的影响

研究了序批式反应器(SBR)内好氧颗粒污泥在不同有机负荷(1.6 kg COD/（m³·d）和8 kg COD/（m³·d)）和不同含盐(2.5%和5.0%)条件下胞外聚合物(EPS)的变化情况，并对EPS、比耗氧速率(SOUR)和孔隙率之间的关系作了进一步探讨。结果表明：在SBR反应器中，负荷较含盐量对好氧颗粒污泥EPS变化的影响要显著，且EPS糖成分和SOUR之间、EPS蛋白成分和孔隙率之间均呈负相关。另外，高负荷条件下的系统稳定性要优于低负荷。     

厌氧颗粒污泥膨胀床（EGSB）处理生活污水试验研究

采用厌氧颗粒污泥膨胀床（EGSB）反应器在常温下处理小区生活污水，接种颗粒污泥。试验结果表明：当进水COD 411～560 mg/L，反应器容积负荷可达到3 kg COD/(m³·d)，水力停留时间4 h，上升流速8 m/h，COD去除率可达到85%以上，出水COD为67～88 mg/L。并对EGSB反应器的结构及运行控制参数进行了优化，使其适宜于在常温下处理生活污水及其他低浓度有机废水。     

中试螺旋式自循环厌氧反应器处理安乃近制药废水的稳定性能简

以制药废水实验了50 m³螺旋式厌氧反应器（SPAC反应器）的稳定性。采用Augmented Dickey-Fuller（ADF）单位根检验表明，螺旋式反应器具有良好的启动和运行稳定性。负荷冲击实验显示，SPAC反应器具有较好的耐浓度冲击能力和耐水力冲击能力，所能耐受的最大浓度冲击强度大于60 000 （mg·h）/L（进水浓度提升2倍），所能耐受的最大水力冲击强度为300（m³·h）/d（进水流量提升50%）。SPAC反应器还具备受扰恢复能力。在反应液pH低于5.74，出水浓度、COD去除率和容积COD去除速率（VRR）分别为3 500 mg/L、22.30%和2.52 kg/（m³·d）的工况下，经过30 d恢复，出水浓度、COD去除率和VRR的恢复程度达到80%~90%。     

耐酸厌氧消化污泥处理餐厨垃圾简

采用耐酸驯化的厌氧消化污泥处理餐厨垃圾，在酸性条件下（pH=4.5），对实验装置容积负荷从1.0 kg VS/（m³·d）分9次逐级增加到5.0 kg VS/（m³·d）的过程进行了跟踪监测，并较深入地研究了驯化污泥代谢活性和处理效果。实验结果表明，pH 4.5的耐酸厌氧消化污泥，最佳投加负荷约为4.5 kg VS/（m³·d），此负荷下容积产气率，CH₄含量平均值均达最大，分别为1.68 m³/（m³·d），75.0%。耐酸厌氧消化装置持续增料运行46 d，产甲烷菌仍能保持较高的活性，其COD去除率范围为40.4%~75.0%，仍能保持pH 7.2时处理效果的65.0%~91.8%，表明在低pH、低碱度下实现稳定的产甲烷过程是可行的。     

DIC厌氧反应器在医药废水处理中的应用

以微电解和催化氧化技术作为预处理，采用双循环厌氧反应器、生物接触氧化以及曝气生物滤池工艺，处理吡啶类医药废水，出水各项指标均达到了国家排放标准《污水综合排放标准》（GB8978-1996）的一级标准。其中双循环厌氧反应器，处理经预处理后的医药废水时，容积负荷可达8.6 kg COD/(m³·d)，COD去除效率可达83.8%。     

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.     

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.     

The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes

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.     

Teratological effects of pesticides in vertebrates: a review

Abstract

In 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.     

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.     

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.     

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.     

Knowledge transfer initiative between molecular biologists and environmental researchers and regulators

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.