3个城市生活垃圾焚烧炉飞灰中二噁英类分析

对3个城市生活垃圾焚烧炉飞灰中二英类浓度分布的实验研究表明,飞灰中二英类异构体的浓度分布具有相类似的特征,高氯代二英类的含量明显高于低氯代二英类.飞灰中二英类的毒性贡献主要来自多氯二苯并呋喃(PCDFs).布袋除尘器前添加活性炭粉末时,飞灰的二英类浓度比没有添加活性炭时高1.8倍,而尾气中二英类浓度相应降低.     

不同植物废物对垃圾堆肥过程VSCs释放的影响

选取黄豆杆、红薯藤、菠萝蜜果核和紫檀树叶4种植物废物,分别与生活垃圾混合进行堆肥处理,考察堆肥过程中甲硫醇、甲硫醚、二甲基二硫醚3种含硫类可挥发性有机物(VSCs)释放量与植物废物性质之间的关系.结果表明,各工况下,3种VSCs释放均集中在堆肥初期(前6d),甲硫醇均为主要的恶臭贡献者.不同工况的3种VSCs释放浓度差异显著.其中,以红薯藤为堆肥配料的工况下3种VSCs累积释放浓度均最高,以黄豆杆和紫檀树叶分别为堆肥配料的工况相对较低,累积释放浓度仅为前者的16.0%~74.3%,并低于生活垃圾单独堆肥. VSCs释放水平与混合原料的易降解有机物含量呈正比,与其植物多酚的含量呈反比.     

我国塑料包装废物的产生和回收特性及管理对策

通过现场调查和资料调研,分析了塑料包装废物的流向和环境特征,总结了塑料包装废物回收的基本特点和经验教训,论述了塑料包装废物回收模式特点,深入分析了回收过程中存在的问题,并提出了加强塑料包装废物回收的管理对策. 结果表明:塑料包装是塑料制品中的重要构成部分,由于质量轻、回收体积大,不易回收,我国每年产生大量的塑料包装废物,城市生活垃圾填埋场成为塑料包装废物的主要流向和污染源. 目前我国塑料包装废物回收依托的是进城务工的个体回收者,与现阶段的国情相符合. 塑料污染问题不是短期内能解决的,必须采取长期的综合管理对策,如进行源头减量化、制定鼓励回收利用的经济政策、采取适宜的无害化处置方式等.      

Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz,Spain

Here we show that heavy metal geoaccumulation is apparent in the Tinto and Odiel estuary and, at a lower magnitude, in off-shore sediments. Values above probable effects level (PEL) are recorded for As, Cu, Hg, Pb and Zn in the Tinto and Odiel estuary, for As and Hg in the associated off-shore sediments and for As in the Guadiana River. Significant correlations were found between total organic carbon (TOC) and Cr, Cu, Ni and Zn in the Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in the Guadiana River. PCA analysis differentiated the three studied locations.     

Future solutions for the treatment and disposal of hazardous wastes in China

The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle, to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for the construction of these planned facilities is also presented.     

Enrichment of elements in industrial waste incineration bottom ashes obtained from three different types of incinerators,as studied by ICP-AES and ICP-MS

The elemental composition of the industrial waste incineration bottom ash (IWIBA) samples collected from three different types of incinerator with different kinds of wastes were compared. The major-to-ultratrace elements in the IWIBA samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). As a result, ca. 40 elements in the concentration range from milligrams per gram to submicrograms per gram could be determined with relative standard deviations of less than 5%. The IWIBA sample from petrochemical wastes contained lower concentrations of the elements, because fewer mineral constituents were contained in the input waste materials. On the contrary, the elemental concentrations in the IWIBA sample from industrial solid wastes provided the highest values for most elements, while the elemental compositions of the IWIBA sample from food wastes were similar to those of municipal solid waste incineration bottom ash. In addition, it was found from the analytical results that the levels of various heavy metals such as Cr, Mn, Fe, Ni, Cu, As, Zr, Mo, Sb, Ba, and Pb were higher in the IWIBA samples than in municipal solid waste incineration bottom ash. The enrichment factors of the elements in the IWIBA samples were estimated from the analytical results to compare the elemental distributions in incineration bottom ashes in relation to their mining influence factors, which are the indices for human use of the elements.     

Environmental monitoring of heavy metals and arsenic from Ag-Pb-Zn mining: a case study over two millennia

2000 years of mining activity at Wiesloch, Germanyleft behind a legacy of mining wastes, some of which haveextremely high contents of toxic elements like As, Cd, Tl,Sb, Pb and Zn. To evaluate their long-term impact ondifferent environmental compartments, the detailedenvironmental monitoring presented here focused on themineralogical and chemical characterization of thedifferent waste materials, consisting of dumpings with orefragments, flotation tailings and medieval metallurgicalslags. Leaching experiments with these materials, usingeluents of different compositions and pHs were carried outto assess the conditions governing the mobilization and re-fixation of these species. It was shown, that the carbonatehost rock of the mineralization, the loess blanket coveringthe area and the organically rich municipal sewage sludgesdeposited on top of the tailings, represent potentialbarriers to the dispersion of toxic elements over a muchlarger area. Moreover, particulate emissions from thesteep, unvegetated escarpments of the tailing heapsrepresent a continuous thread to the environment.     

Air pollutant emission potentials of cotton textile manufacturing industry

Cotton textile manufacturing operations cause air pollution. Air pollutants are generated by fossil fuel fired combustors due to their flues and/or a variety of chemicals in use for production. Excessive use of chemicals can be stopped or minimized by replacing them or by optimizing the production processes. Energy and water conservation are important goals in textile workplaces as well. There is substantial research and development to minimize pollution potentials of textile operations. In this paper air polluting potentials of cotton textile manufacturing operations are discussed and some quantitative examples are given for evaluating the risks to the environment. Studied impacts to environment cover direct discharges into the ambient air as well as the workplace atmosphere. Further studies are recommended for minimizing the impacts to the local and global air quality due to cotton textile production facilities.     

Fish Disease Monitoring in the Dutch Part of the North Sea in Relation to the Dumping of Waste From Titanium Dioxide Production

Gross pathologies were recorded in a total of 5942 individual common dab (Limanda limanda L.) at 5 sites in and around Dutch coastal waters, in spring, from 1986 to 1988. Two of these sites (an offshore dumping ground and an inshore site influenced by direct river discharge) received large quantities of diluted acids of titanium dioxide waste (TDW); the other three were selected as reference sites for comparison.

The main diseases recorded were epidermal hyperplasia/papilloma, lymphocystis, liver nodules (pre-neoplastic and neoplastic lesions), and infections caused by the protozoan Glugea sp. Frequencies of disease were analysed using a logit model. There was a consistently high prevalence of epidermal hyperplasia/papilloma in dab from the two sites that received TDW when compared to the other sites. However, no dear relationships were found between the prevalence of epidermal hyperplasia/papilloma and dumping-associated heavy metals or other relevant environmental and biological factors. No significant spatial trend was revealed for liver nodules, although there was a statistically significant association between the occurrence of epidermal hyperplasia/papilloma or of lymphocystis and that of liver nodules in individual fish. Prevalences of lymphocystis were usually higher at offshore sites than in inshore areas, while prevalences of Glugea showed the opposite trend.

Although at first sight the pattern of disease prevalence would appear to furnish a strong case for a cause-and-effect relationship between TDW and epidermal hyperplasia/papilloma, interpretation of the data is complicated by interference from riverine inputs, long-distance dispersion of discharged wastes, local hydrographic conditions, and possible local migration of dab. On the basis of present results, therefore, the possibility that discharges of TDW contributed to the occurrence of this disease cannot be proven or discounted.