苏州市生活垃圾两种处置方法的生命周期影响评价

采用生命周期评价的方法，比较了苏州市垃圾填埋和垃圾焚烧2种处置方法对环境的影响。研究的系统范围主要包括垃圾收集、垃圾运输、垃圾填埋或焚烧以及发电等几个部分。采用收集的垃圾组分数据，利用IPCC推荐的模型等，计算了垃圾填埋和垃圾焚烧时CO₂等气体污染物的排放量。根据对垃圾渗滤液的实测数据，计算了水污染物的排放量。环境影响评价采用日本开发的AIST-LCA Ver4计算机软件进行。计算结果表明：垃圾填埋的生态币值要大得多，可见垃圾焚烧对环境的影响比垃圾填埋的影响要小。所获得的结论较为客观地反映了对环境的影响，可以作为中国城市垃圾处置决策的参考依据。     

高热值城市生活垃圾归类分流处置的能值分析

生活垃圾处理已成为限制城市化进程和城市经济发展的重大问题之一,采用垃圾归类分流处置方法可以有效地促进垃圾减量化和资源化的效果。以西安市典型高校校园生活垃圾为代表性高热值焚烧型城市生活垃圾,通过绘制能值系统图辨析卫生填埋-沼气发电、焚烧发电、生物质燃料混烧发电等3种垃圾处理系统的能值投入和产出过程。依据垃圾物理组成和热值数据分别计算了2种处理系统的能值产出率、环境负载率、能值投资率、可更新能源投入率和能值可持续指数等5项基本能值指标,并从能量利用的角度对3种生活垃圾处理方法的环境可持续性与经济竞争力进行了比较分析。能值分析结果表明,采用生活垃圾焚烧和生物质燃料混烧发电处理法在能量转化效率和环境影响方面具有显著优势,对高热值焚烧型生活垃圾采用"归类分流-集中焚烧处理"的方式有利于提高城市生活垃圾减量化处理的环境效益与经济收益。     

垃圾焚烧厂焚烧底灰的处理研究

系统地研究了常州市环境卫生综合厂垃圾焚烧车间的底灰。研究结果表明，根据中国现行的污染控制标准，该厂的底灰属于一般废物，可以以建筑垃圾的方式处理。但对底灰的分选和分类研究结果表明，底灰含有一定量的未燃烬的有机废物，也有一些可回收利用的废物。因此，底灰应该先分选后，再对无利用价值的渣土作填埋或其他处置。     

垃圾焚烧飞灰的稳定化处置与资源化利用研究进展

随着垃圾焚烧处理日益广泛的应用，垃圾焚烧飞灰的稳定化处置和资源化利用成为一个亟待解决的问题。文中对垃圾焚烧飞灰的稳定化处置和资源化利用技术分别进行了综合论述，为飞灰的无害化和资源化处理提供参考。     

本期推荐

正本期"专论"栏目刊发了罗小勇、王艳明、龚习炜、徐辉撰写的《垃圾焚烧固化稳定化飞灰填埋处置面临的问题与对策》一文。该文提出的对策与建议对开展固化飞灰安全填埋处置相关研究具有参考价值。随着我国生活垃圾终端处置由填埋逐渐转变为焚烧,飞灰产量迅速增加,其安全处置已经成为生活垃圾焚烧全过程污染控制和风     

国内最大的垃圾焚烧厂日前在上海点火投产

既能无污染处理垃圾又能用来发电的国内最大垃圾焚烧厂日前在上海点火投产。坐落在上海西郊江桥的生活垃圾焚烧厂占地 2 0 0余亩 ,政府投资额为 2 .4亿元人民币 ,一期工程生活垃圾日处理能力为 10 0 0 t,年处理垃圾可达 33万 t,其垃圾处理服务范围可覆盖上海 1/ 3的城市面积。二期工程建成后 ,将达到日处理垃圾 15 0 0 t的规模。上海生活垃圾日产生量达到万 t,而此前 7成以上都用来填埋。填埋处理既占用大量土地资源 ,环保性也不高。新点火的上海江桥生活垃圾焚烧厂采用焚烧、生化、填埋综合方式来处理垃圾。其烟气排放严格执行欧盟标准 ,废…     

中国西北典型城市西宁生活垃圾产生及回收

预测了中国西北典型城市西宁的生活垃圾清运量,同时分析了西宁的生活垃圾物料流向,从而估算西宁未来的生活垃圾产生量,为西宁生活垃圾管理规划提供依据。研究发现,西宁未来生活垃圾清运量和产生量均呈增长状态,2025、2035年西宁生活垃圾产生量分别为240.33万、334.04万t,2020—2035年的平均年增长率为3.71%。在考虑分拣率的条件下,2025、2035年西宁生活垃圾人均日产生量分别为1.72、2.21kg/(人·d)。目前,西宁生活垃圾分两级分拣回收,一级分拣率为35.11%,二级分拣率为0.18%,填埋率为64.71%。为提高资源化利用率,建议西宁加强一级分拣能力,特别是加大对纸类和塑料的回收能力;在末端处置上,建议规划考虑建设生活垃圾焚烧发电设施。     

城市生活垃圾焚烧灰渣资源化利用的研究进展

生活垃圾焚烧技术是减少垃圾体积和重量的一种非常有效的工程技术，并在国内大中城市得到推广应用。但是由于焚烧残留物的焚烧灰渣至少仍然占到原有质量的20％，如何处理处置焚烧灰渣已成为城市发展亟需解决的一个重要难题。文中对灰渣资源化利用的已有方法（生态水泥的主要原料；垃圾填埋场覆盖材料；水泥-混凝土的代替骨料；沥青的代替骨料以及飞灰作塑料橡胶的填料等）进行了总结和回顾，分析了各种资源化方法的优缺点、应用前提和研究进展，并针对资源化利用的现实问题，提出了一些规范和建议。     

控制城市垃圾焚烧二恶英产生与扩散方法

控制垃圾焚烧二恶英产生与扩散分三部分：首先，通过预处理除去原生垃圾中的聚氯乙烯塑料，从源头上控制垃圾焚烧二恶英产生的物质基础；其次，垃圾焚烧炉采用组合式循环流化床锅炉，实行垃圾先低温热解气化，然后高温燃烧垃圾热解气体的方式，同时在炉内加入添加剂实现稳定燃烧和部分脱氯，以减少二恶英在炉内生成和炉后形成量；最后，在烟气尾部采用吸附剂吸附二恶英，并与布袋除尘器配套使用，控制二恶英的尾部扩散。该工艺具有成本低、控污效率高等优点，特别适用于发展中国家的垃圾焚烧二恶英控制。     

广州市餐厨垃圾不同处置方式的经济与环境效益比较

对广州市餐厨垃圾采用填埋、焚烧、综合处理3种处置方式的经济和环境效益进行了对比分析。结果表明,对于一座日处理能力为500t的餐厨垃圾处理厂而言,如果采用制取沼气和提炼生物柴油的综合处理方式,则年处置费用约为3833万元,年运输成本约为1825万元,年总收益(主要为出售生物柴油和发电)为7093万元,年净收益可达1435万元;一座日处理能力为500t的餐厨垃圾处理厂通过综合处理提炼的生物柴油若替代普通柴油使用,则每年可减少CO2排放量达110000t,而且餐厨垃圾厌氧发酵过程中产生的CO2也能被有效回收并加以利用。总体来说,综合处理方式既实现了餐厨垃圾的资源化有效利用,也达到了低污染排放的目的,经济与环境效益均达最佳。     

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.     

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.     

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.