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901.
902.
Manfred Fehr 《The Environmentalist》2006,26(1):21-29
Summary Present municipal waste management paradigms in Brazil do not allow for flexible approaches to solving an extremely dynamic
problem. This paper discusses the basic flaws in present thinking models of residents and municipal administrators. Fundamental
arguments presented on municipal solid waste relate to nomenclature, destinations, definitions, logistics, social dynamics,
social assistance programs, education and employment philosophies. In each case, the consequences of the stalemate are explained
in terms of the unsustainable situation of constantly growing landfills. In sequence, a proactive thinking model is presented
and explained that has the potential of drastically reducing landfill size. It is called Municipal Transit Material Processing.
The model has been tested successfully in small communities and is now available for scale-up. The landfill diversion achieved
stands at 62% of household waste in comparison with 15% theoretically possible in Brazil with selective collection models.
Although of necessity the arguments apply directly to Brazil, the basic ideas behind the reasoning may be extrapolated to
other Southern countries. The following simple example will illustrate to the reader the type of paradigm inversion the paper
proposes to convey. The classical political slogan in Brazil is “get children out of garbage dumps”. The inversion proposed
and explained is “do away with garbage dumps”. 相似文献
903.
Masaya?Koshikawa Akira?IsogaiEmail author 《Journal of Material Cycles and Waste Management》2004,6(1):64-72
Fourteen paper sludge samples were collected at seven representative pulp and paper mills in Japan, and were analyzed to obtain fundamental data on the reuse of paper sludge-incinerated ash as papermaking material. For comparison, incinerated ashes of municipal solid waste (MSW) were collected at MSW incineration plants in Tokyo, and analyzed by similar methods. Elementary and X-ray diffraction analyses revealed that the predominant elements in paper sludge samples are calcium, silicon, aluminum, and magnesium, which are derived from paper fillers, coating pigments, and coagulants used in papermaking and process effluent treatments. Similar results were also obtained for the MSW-incinerated ashes, indicating that major components in the collected MSW are paper-related materials. Incineration of paper sludge around 800°C is recommended in terms of high brightness of the incinerated ash, which has about 60% brightness. Calcium, silicon, and aluminum components in the paper sludge are fused or sintered by heating. Although paper-sludge-incinerated ashes have irregular shape and large particle size distributions, they may be used as papermaking materials after pulverization using a ball mill. The MSW-incinerated ashes have 5%–30% water-soluble fractions and low brightness, and thus incineration conditions must be changed to reuse the MSW-incinerated ash as a papermaking material.Part of this paper was presented at the 68th Research Conference of Japan Tappi, Tokyo, 2001 相似文献
904.
分置式膜-生物反应器处理生活污水及其体积负荷的确定 总被引:4,自引:1,他引:3
分置式膜-生物反应器处理生活污水的运行结果表明,在不同的污泥龄和水力停留时间下,处理效果稳定,污泥上清液中COD浓度平均为19.5m g/L,膜出水COD浓度平均为5.3m g/L. 对分置式-生物反应器的体积负荷进行推导表明,浓缩区的存在是该工艺处理能力较大的原因. 体积负荷由膜出水有机物浓度与污泥混合液有机物浓度之比α,浓缩区与反应器体积之比β和膜出水量与污泥混合液循环流量之比λ决定,即可以通过增加浓缩区体积和调整循环流量来控制分置式-生物反应器的处理能力. 相似文献
905.
Wei Wang Jianguo Jiang Xuelong Wu Shunwen Liang 《Journal of Material Cycles and Waste Management》2000,2(2):65-69
In China, controlling environmental pollution resulting from solid waste (SW) and hazardous waste (HW) has become one of the
most pressing tasks in the field of environmental engineering. It is reported that the annual generation of industrial solid
waste (ISW) in China exceeded 0.6 billion tons in the 1990s, and is increasing every year. Although ISW management has been
strengthened in recent years, about 40% of SW is put in uncontrolled landfill without appropriate treatment. According to
statistics from the national Environmental Protection Agency, the cumulative ISW uncontrolled landfill in China had reached
6.6 billion tons by the end of 1995, occupying around 55 000 hectares of land. Although some major uncontrolled landfills
were constructed, nonetheless groundwater contamination resulted from the use of low-standard liners and poor management.
Furthermore, about 20 million tons of ISW was discharged into the environment illegally, and a third of this waste was discharged
directly into water bodies, making ISW one of the greatest pollution sources for surface water and ground water. Environmental
pollution accidents resulting from SW occur about 100 times a year in China, and environmental issues frequently arise because
of ISW pollution. The practices of SW management, treatment, and disposal started relatively late in China, and for a long
time the management of SW pollution has received little attention compared with water and air pollution management. China
faces problems such as the insufficiency of management laws and regulations, insufficient investment, inadequate treatment
and disposal technology, and a lack of qualified technicians. At present, most treatment and disposal technology cannot meet
the requests for solid waste pollution control. In order to protect, restore, and improve environmental quality in China and
to realize sustainable development, the safe management and disposal of solid and hazardous wastes is a pressing challenge.
In recent years, much attention has been paid to SW management in China, and investment to develop management and treatment
technologies has increased. In 1995, the Law for Solid Waste Pollution Protection was issued, and work on solid waste treatment
and disposal began to be legally managed. SW treatment and disposal facilities have been constructed, and now operate in some
large and medium-sized cities. In particular, rapid improvements have been seen in ISW recycling, collection, and disposal
of municipal solid waste and regional HW management. All the figures in this paper are from 1995, and represent the situation
in China in that year.
Received: April 18, 2000 / Accepted: May 15, 2000 相似文献
906.
907.
908.
采用分段进水生物脱氮工艺处理生活污水.设置0.9,0.6,0.4,0.3m3/h4组曝气量,相应的好氧区溶解氧(DO)浓度约为2.8,1.7,0.8,0.5mg/L左右.结果表明,在好氧区DO为0.5mg/L左右的低氧条件下,通过对系统进行适当的控制,可以取得较好的硝化效果,氨氮去除率可达98%以上.同时,由于低曝气量下混合液从好氧区到缺氧区携带的DO量减少,并且在好氧区发生了同步硝化反硝化作用,使得TN去除效果明显优于高曝气量的情况.另外,由于工艺结构的特点,分段进水生物脱氮系统可长期在低氧条件下运行,且污泥沉降性能良好. 相似文献
909.
生活垃圾焚烧厂贮坑沥滤液的污染与可处理特性 总被引:12,自引:4,他引:8
通过对生活垃圾焚烧厂贮坑沥滤液历时6个月的常规污染物监测,分析了沥滤液中溶解性有机物(DOM)分子量分级和重金属在不同分子量DOM中的分布,以探讨沥滤液的污染与可处理特性结果表明:沥滤液有机污染程度高.沥滤液中有机物以非溶解性(约占有机物总量的23%)和分子量<4 ku的DOM(超过DOM总量的88%)为主,低碳有机酸和醇的总量占沥滤液中DOM(分子量<4 ku)的50%.沥滤液中重金属含量高,在DOM各分子量分级中,重金属主要与分子量<4 ku的DOM相关,尤其是Zn和Ni的分布占90%以上,并且重金属(除As和Hg外)的分布与有机物的分布呈显著的正相关性.根据沥滤液的性质,宜采用混凝或厌氧-好氧生物方法对其进行处理. 相似文献
910.
The European Union Landfill Directive calls on member states to reduce the amount of biodegradable municipal solid waste disposed of to landfill. In addition, national waste strategies will require the constituent parts of the United Kingdom to achieve increased household waste recycling and recovery rates. Both these measures will require the development of the infrastructure to support national high-intensity recycling and composting schemes and the construction of at least 35 new municipal waste to energy incinerators. Before plans can be developed for meeting the targets several areas relating to municipal solid waste need to be clarified. Depending on the definition of municipal solid waste, its composition and likely future growth rates the number of incinerators required could be up to 170. 相似文献