Road and site characteristics that influence road salt distribution and damage to roadside aspen trees

During the summer of 1972 extensive necrosis of aspen (Populus tremuloides Michx.) leaves appeared on the downhill side of a road paved in August 1971 to improve access to the Santa Fe Ski Basin, Santa Fe County, New Mexico. A Forest Service investigation showed that chloride concentrations in leaf tissue were significantly correlated with leaf damage. Our study of soil chloride distribution as influenced by physiographic and road features shows a statistically significant relationship between these features and damage to road side aspen.     

Identification of odorous gases originating from refuse waste

The complex mixture of gaseous compounds emitted from refuse wastes was scrubbed through an activated carbon column until odor breakthrough occurred. Refuse air samples were collected at the influent and effluent ports of the column for analysis on a gas chromatograph-mass spectrometer system. Sampling techniques involved the concentration of gaseous volatiles on Tenax GC adsorption tubes prior to thermal desorption onto a capillary fused-silica column for compound separation. Separated compounds were scanned by a quadrapole mass selective detector and compounds were matched against a library of mass spectra and available gas standards. Results indicated that the typical odorous gases emitted from refuse waste consisted mainly of carboxylic acids and some S compounds. Sensory tests revealed that a sweetish odor was associated with the carboxylic acids which eluted from the carbon column first.     

Residues of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the Spring River,Missouri

Contamination of the Spring River in southwest Missouri by 2,3,7,8-tetrachlorodibenzo-p -dioxin (TCDD) is believed to result from several well-defined point source waste disposal sites. Analyses of 31 fish samples and samples of crayfish, mussels, other aquatic invertebrates, and sediments collected in 1981-1983 demonstrated a rapid decline in TCDD levels in biota both upstream and downstream of the area of contamination and are believed to indicate a continuing, long term input of TCDD into the river. Mean concentrations of TCDD 0.5 km downstream from the area of contamination were 38 parts per trillion (pptr) in whole fish and 20 pptr in fish fillet; mean concentrations beyond 14 km downstream were below 4 pptr in both whole fish and fillets. Caged mussels (65 day exposure) did not accumulate TCDD (detection limit, 10 pptr). High fish consumption by local sportsmen may indicate maximum permissible concentrations of less than 5 pptr. in fish fillets.     

Plastics waste handling practices in solid waste management

In order to see the impact of plastics on the overall solid waste picture, the sources and nature of wastes generated by that industry will be defined. At one end of the spectrum are industrial wastes resulting from plastics formation and from packaging and transfer. Fabrication follows and then the intermediate markets. Finally, there is the consumer. Each step generates a waste stream. The options for disposal or recycle are discussed for each waste source and the economics included are reviewed. The fate of plastics in the environment has been of concern to some, principally because plastics generally do not disappear very fast. Activity in this sector will be discussed. Engineering and other technical input for all waste handling follows economic reality and higher scrap values are resulting in new market potentials for waste plastics. The emergence of energy as a key decision point in environmental concern has highlighted the energy value of waste plastics as fuel. Current activity in this area will be discussed. An increased legislative role in solid waste management is needed. Some of the currently considered legislative practices that help and that hurt the industry's ability to assist in managing the solid waste problem will be reviewed.     

典型山区农村环境现状调查与保护对策

如何在发展山区农村经济的同时保护好当地生态环境是当前广大学者和民众关注的热点问题之一.通过设计调查问卷对粤北山区和平县热水镇的环境状况和公民环境意识进行了入户调查.调查结果表明,该镇经济水平较低,暂无工业污染;固体废弃物污染不显著,但生活垃圾乱倒、乱堆现象相当普遍;能源利用方式原始,清洁能源利用率不高;化肥、农药等过量施用现象比较严重,造成的污染不容忽视.依据调查结果建议:找准切入点,加快启动农村污水处理、垃圾处理、改水改厕等环保基础设施建设,大力推进生态农业和特色村的建设,推广清洁能源的使用,加强农村环保教育,建立农村环保监测与预警体系.     

基于关系与结构嵌入的农户农业废弃物绿色处置行为分析

如何在推进农业经济快速发展的同时又兼顾环境保护,构筑人与自然"生命共同体",已是中国推进乡村振兴战略不可回避的重要问题。区别于既有研究,运用倾向得分匹配方法(propensity score matching)克服样本选择性偏差引起的内生性,探讨了社会学"强嵌入"因素中的关系嵌入和结构嵌入对农户农业用资材废弃物绿色处置行为的影响。结果发现,结构嵌入对农户农业用资材废弃物绿色处置行为具有显著的正向促进作用,关系嵌入的作用并不明显;而家庭劳动力数量、兼业、家庭耕地面积以及农业收入比例等"零嵌入"因素是影响关系嵌入与结构嵌入的关键。基于此,该文认为,应通过建立农民利益诉求表达渠道与责任监督机制,鼓励农户加强与种养殖大户交流与沟通,营造良好的社会环保氛围等方式改善农户农业用资材废弃物绿色处置行为,以推进农业产业绿色转型。     

Effect of municipal landfill leachate on mercury movement through soils

The effect of solution composition on the movement of Hg ions through soils was studied. Three solutions spiked with HgC1₂ were passed through four different soils. The solutions were 0.25 mM Na₂ EDTA, simulated sanitary landfill effluent, and deionized water. The Hg ions were found to be more mobile in the effluent from the simulated landfill than in the other solutions. The formation of mercurous ions and the presence of organic matter seem to be the major contributing factors for Hg; movement through soils in simulated landfill effluent.     

Adsorption of cadmium to kaolinite in the presence of organic material

Kaolinite was equilibrated with Cd and with varying amounts of the individual compounds: EDTA, NTA, alginic acid, and humic acid. In experiments in which the Cd and kaolinite concentrations were held constant, and the ligand concentration allowed to vary, conditions under which ligand enhanced and inhibited Cd association with the solid phase were noted. Further experiments at constant Cd: ligand confirmed that, for alginic acid and humic acid, enhancement of uptake occurred, while EDTA diminished uptake. These results were compared with the adsorption of ligand by clay in the absence of organic, and it is suggested that the enhancement of uptake is due to the formation of an adsorbed organic layer on the clay serving as a solid phase ligand.     

Some perspectives on the paper industry's use of waste paper

The paper industry has traditionally sought fibrous resources from trees, wood residues and waste paper. Emphasis is shifting back to waste paper after 30 yr of relative decline in recycling. Management of fiber resources by major timber holding companies is being expanded to include waste paper. In the next decade the structure of the paper industry will reflect a residuals based process technology relating to both city and forest. Recovery of waste paper can be feasible with source separation or dry separation technology. The outlook for recycling more old newspapers, old corrugated containers and mixed papers from office buildings is very good. Waste paper use in the U.S.A. will double between 1972 and 1985 from 13 million tons to 26 million tons. In addition, a world fiber supply shortage will stimulate further recovery and export of waste fibers. The energy content of paper is about 7500 Btu lb^?1, not much below that of Wyoming coal. Recovery of the energy content of paper is an integral part of current efforts to convert mixed wastes to fuel or steam. By 1990 about 50 % of the waste paper generated will be usefully recovered - about 30 % will be recycled, or exported and 20 % will be burned for its energy content.     

Evaluating and utilizing biokinetic constants in activated sludge

Stoichiometric equations developed from biokinetic equations are presented for evaluating and utilizing biokinetic constants in the design and operation of the activated sludge process. Using biokinetic constants developed from non-nitrifying conditions or total system biokinetic constants rather than individual true biokinetic constants for the heterotrophic and autotrophic reactions will lead to incorrect estimates of the daily waste sludge production.     

Managing industrial wastes excluded from the sewer

The 4 different disposal techniques that are used in California for industrial waste disposal are discussed. These are: Treatment (usually chemical) followed by solar evaporation of the liquid from ponds; Incineration; Biodegradation; and Land disposal - usually burial or injection into soil or solid waste (garbage).     

Effect on life style from governmental and free enterprise cooperation

The cooperation between government and free enterprise in solid waste management affects our life style by way of promoting our bodily and mental well-being through the proper management of solid wastes generated by us, and by advancing our material welfare through resource recovery. Private enterprise provides the service and government sees to it that the service is efficient, sanitary, environmentally acceptable, and reasonable, much as with a public utility. This cooperation, peculiar to solid waste management, owes its historical origin to a combination of governmental neglect and the nature of solid wastes. Cooperation between government and private enterprise in resource recovery is essential. Private enterprise provides the technology and the marketing of the recovered resources. Government motivates the public to perform the tasks needed for the recovery through education and by the use of incentives and disincentives. Use of the recovered resource is encouraged by way of specification and subsidy. The advantageous effect on our life style coming from the judicious reuse of resources in our wastes is obvious. The price will be in the form of a bit of inconvenience on our part, and perhaps a lessening in the variety of products - undoubtedly no greater than that already brought about by inflation and the decline in competition in business.     

东江源沿江村镇生活垃圾物理特性分析

东江系广东及香港的饮用水源地,其源区包括江西省赣州市的寻乌、安远和定南3县。本研究在东江源区选取了3个典型村庄,调查农村生活垃圾的产生量及物理特性。调查发现:东江源区农村生活垃圾主要以厨余类垃圾为主,可达60%以上;其次是灰土类垃圾,可达12%以上,其他组分一般在10%以下。县级村人均垃圾产生量一般在0.2~0.47 kg·d-1,平均0.36 kg·d-1;镇级村人均垃圾产生量在0.18~0.35 kg·d-1,平均0.29kg·d-1;普通村人均垃圾产生量在0.07~0.33kg·d-1,平均0.17kg·d-1。混合生活垃圾含水率与厨余类垃圾所占的比例呈显著线性相关(R2=0.626,P=0.019)。混合垃圾平均热值在2 329 kJ·kg-1,不适合直接进行焚烧处理。     

Mobility of chlorofluorocarbons in deposits of shredder wastes from plastic and metal utilizing industries

Chlorofluorocarbons (CFCs) are used as propellants in spray cans, as refrigerants and as blowing agents for plastic foams, which are finally dumped together with solid wastes in landfills. We found shredder waste from plastic and metal utilizing industry to be highly contaminated with F12 (CF₂Cl₂) and less with F11 (CFCl₃). By means of model calculations with one dimensional diffusion models, we were able to estimate the amount and rate of outgassing of CFCs. The models were validated with measured vertical gas concentration profiles. From our results we conclude that deposition of shredder wastes containing CFCs results in a quick loss of these substances to the atmosphere with halflifes of ～ 2 d. In order to reduce CFC emission from landfills, contaminated wastes should be covered with compacted adsorbing layers (e.g., sewage sludge) immediately after their deposition.     

Species diversity and water quality in Galveston bay,Texas

The relationships between species diversity of phytoplankton, zooplankton, nekton and benthos samples and the water quality of Galveston Bay, Texas were quantitatively compared. Two water quality parameters (i.e., percent waste water or the toxicity of the water at a given sampling station) were found to be inversely correlated with species diversity. A computerized dispersion model was used to calculate percent waste water. Toxicity was measured by subjecting a blue-green alga (Coccochloris elebans) to water samples and by utilizing growth depression as the toxicity criterion. Waters from the Houston Ship Channel and the Trinity River were found to be significantly toxic and the dispersion model was again used to determine the distribution of toxicity to each bay area. Evidence that toxicity was dispersed with input waters was experimentally verified. Those areas receiving the greatest amounts of toxic effluent exhibited the lowest mean annual diversities. Predictive equations were generated, indicating that diversity at any point in the bay can be computed from Houston Ship Channel diversity and the dispersion model. Computations were also accomplished whereby dilution and/or treatment of waste inflows could be estimated to achieve a desired and/or acceptable diversity level in the bay.     

秦巴山区农户茶叶种植废弃物亲环境处理行为研究

茶叶是"绿水青山"的内生性产业,如何处理茶叶种植所产生的废弃物是保护秦巴山区"绿水青山"需解决的重要问题之一。基于意识-情景-行为模型,运用层次回归和分组回归分析了环境意识、情境因素对茶农废弃物亲环境处理行为的影响机理,研究发现:第一,环境态度、情感与责任对包装物回收影响显著,环境态度与情感存在交互效应。第二,环境态度、情感、责任与知识对修剪枝叶还田影响显著,环境责任与知识存在交互效应。第三,实施成本对环境情感-包装物回收、环境知识-修剪枝叶还田有调节效应,社会规范对环境态度、责任-包装物回收有调节效应,描述性社会规范对环境情感-修剪枝叶还田有调节效应。为此,应通过"情理合一"、政府倡导并建立回收点推动农户包装物回收行为,通过强化环境责任、增加环境知识、营造氛围促使农户实施修剪枝叶还田,以推进秦巴山区茶叶种植废弃物处理的绿色转型     

自然村生产生活废弃物循环利用模式及其评价研究

农业农村生产生活废弃物循环利用是实现农村人居环境治理、提高资源利用效率的重要途径,对美丽乡村建设具有重要意义。该文以自然村为研究对象,采用层次分析法和模糊评价法相结合的方法,统筹考虑生产生活废弃物循环利用,构建了自然村生产生活循环技术模式评价指标体系,确定各项指标的权重,建立评价方法。以河北邢台市山区某村为例,针对其生产生活废弃物产生特点,构建生产生活废弃物循环利用体系,该村农业废弃物以果木剪枝、生活垃圾、生活污水、人畜粪尿等为主,通过构建以果木剪枝热解+炭基有机肥还田为纽带的循环利用模式,辅以污水处理利用技术,实现了废弃物能源化和就地肥料化利用。通过对该自然村循环利用模式进行实地评价验证,结果表明该自然村生产生活循环技术模式评分结果为优。该文为中国村镇废弃物循环利用技术模式选择、农村人居环境改善和农业绿色发展提供参考和借鉴。     

A comparison of the particulate matter catch from EPA and modified ASME-ASTM sampling trains

The control efficiency, concentration of particulate matter and emission rate of particulate matter were determined from a municipal incinerator equipped with an electrostatic precipitator. An EPA and a modified ASME-ASTM particulate matter sampling train were used concurrently at precipitator inlet and outlet sampling ports to confirm the manufacturer's guarantee of collection efficiency and to determine compliance with local emission regulations. A comparison of the weight of particulate matter collected during 22 test runs with each type of sampling train indicated that an out-of-stack filter in the current arrangement of the ASME-ASTM train results in a particulate matter catch which is comparable to that from the front portion of the EPA train. A statistical Mest performed on the particulate matter catch from both sampling trains indicates no significance in the difference of the mean catch values of both the front portion and the combined front and back portions of the sampling trains. Doubt is cast upon previous assertions that differences in the particulate matter caught by the two sampling trains are caused by the condensation of sulfur oxides and organic vapors within the back half of the EPA train. Rather, it appears that there is a loss of particulate matter from the Alundum thimble of the ASME-ASTM train that can be caught by a fiber glass out-of-stack filter.     

Influence of labelled food type on the accumulation and retention of 60Co by a freshwater fish,Cyprinus carpio L.

The study was carried out on 3 groups of 10 fish, each fed on a different natural labelled food. The preys selected were a crustacean (Gammarus pulex), a midge larvae (Chironomus sp.) and the soft tissues from a snail (Lymnaea stagnalis), which are usually consumed by carp in the natural environment. The contaminated food consumption by the fish resulted in a ⁶⁰Co maximum transfer factor ranging from 1.2 × 10^?2 to 5.1 × 10^?2 depending on the food type. These values, and the contamination kinetics indicate that the biomagnification of the radionuclides cannot occur, even over the long term. ⁶⁰Co depuration from fish was also influenced by the contaminated food type, previously ingested. The lower elimination rate correspond to the higher value of the transfer factor (Gammarus pulex) and inversely (Lymnaea stagnalis).     

Microbial degradation of polyurethane foams and isocyanate based polyureas in different media

To assess the possibilities of the liberation of toxic aromatic amines under different conditions of disposal, the degradation of different¹⁴C-labelled polyurethane foams was investigated in the leachate of a refuse tip, in composted municipal waste and in an agricultural soil. With unlabelled foam cubes experiments were run under the environmental conditions of a refuse tip. The degradation of¹⁴C-labelled polyureas was studied in different agricultural soils. In the laboratory tests the criteria of degradation were the liberation of aromatic amines and the production of¹⁴CO₂. The degradation in the refuse tip was estimated on the basis of weight loss. From the results it can be assumed that the polyether based polyurethane foams are largely resistant to microbial as well as chemical attack under all practical conditions of disposal. Polyester based polyurethane foams are susceptible to chemical hydrolysis favored by extreme environmental conditions such as high temperature and/or low or high pH values. Under these circumstances an accumulation of aromatic amines can occur if their further microbial degradation is impeded by the lack of suitable conditions for the growth of microorganisms. No indication of any degradation of the isocyanate based polyureas was found.