共查询到20条相似文献,搜索用时 187 毫秒
1.
2.
3.
以城市硬底化为主导的城市人工生态系统极大地改变了城市地表界质,弱化了自然生态系统的功能,导致了城市热岛效应、城市水害、环境污染等诸多问题出现并不断加剧。文章提出"城市水窗"的概念,并探讨了其涵义、类型和作用,提出了在城市生态系统中如何通过"城市水窗"的建设强化城市人工生态系统中土壤圈等自然生态系统的功能建议。 相似文献
4.
城市生态环境的好坏直接影响城市经济可否可持续发展,研究城市生态环境建设经济评价指标体系对城市经济的持续发展具有重要的指导意义。本文分析了城市生态环境问题产生及国内外城市生态环境建设的现状,提出了盐城市城市生态环境建设经济评价指标体系的构建过程,为盐城市城市的生态环境建设最佳方案的选择提供科学依据。 相似文献
5.
6.
城市森林是城市生态系统的重要组成部分,是城市可持续发展的基础和保障。城市森林为城市生态系统提供了多方面的服务功能。本文着重阐述了城市森林改善城市小气候、净化大气和污水、涵养水源、维持大气碳氧平衡等生态服务功能并讨论其在提高城市环境质量中的作用。 相似文献
7.
随着我国经济社会的不断发展,城市垃圾的处理和管理逐渐成为了制约我国城市和环境持续健康发展的一大难题。因此,需对城市垃圾进行合理和高效的处理,加强管理体系的建设,使城市环境得到有效的保护,加快现代化城市的建设步伐。本文论述了我国城市垃圾的处理现状及技术,分析了我国城市垃圾处理及管理中所存在的问题,提出了相应的对策建议,并且探讨了城市垃圾的新型处理技术。 相似文献
8.
9.
10.
本文概述了生态城市的理念以及生态城市对于城市垃圾处理的基本要求,综述了目前遵循生态城市理念所采取的城市垃圾资源化处理的技术路径。以北京怀柔文化生态城为例,进行了城市垃圾资源化技术集成研究,提出区域垃圾资源化的基本项技术和推荐项技术,总结区域垃圾资源化产生的效益。最后,基于生态城市理念提出了针对城市垃圾资源化处理的一些建议。 相似文献
11.
Dezhen Chen Zhenzhen Guan Guangyu Liu Gongming Zhou Tong Zhu 《Frontiers of Environmental Science & Engineering in China》2010,4(2):235-243
Aged municipal solid wastes (MSW) excavated from landfills and dumpsites were characterized to analyze their fraction composition,
moisture content, and lower heat value (LHV). The necessity and feasibility of recycling combustibles from aged MSW to improve
the incineration of fresh MSW were investigated. The results showed that combustibles in aged MSW were easily separated from
other components and than LHV of the separated combustibles are higher than 11000 kJ/kg. The fresh MSW are of high moisture
contents with average LHV below 6500 kJ/kg, making their stable combustion difficult to maintain in MSW incinerators. For
both fresh MSW and aged MSW, plastics are the main contributor to their LHV. To improve incineration of fresh MSW that are
characterized with low LHV, combustibles separated from aged MSW were made into refuse derived fuel (RDF) pellets and were
then added to fresh MSW by 2% wt.–5% wt. LHV variation and air supply resistance change of the MSW layer on the incinerator
grate caused by the addition of RDF was checked, and no significant changes were found. No obvious difference was observed
for the ‘burn-out time’ between RDF pellets and fresh MSW either. RDF made from aged MSW combustibles is found to be a promising
auxiliary fuel to improve the incineration of fresh MSW, and aged MSW from old landfill cells and dumpsites can be finally
disposed of jointly with fresh MSW by recycling combustible from the former to be coincinerated with the latter in the incineration
plants. 相似文献
12.
近年来,以城市固废为原料制备生物炭为其资源化利用开辟了新思路,但在制备方式、影响因素及主要应用领域仍缺乏有效阐述。介绍了生物炭的制备方式,系统分析了城市固废原料、生产工艺对生物炭产率和性质等影响;在此基础上,概述了生物炭在垃圾填埋场治理修复(渗滤液处理、垃圾填埋场覆盖、可渗透反应墙材料)和土壤改良(理化性质、营养环境)的应用现状。结果表明:1) 热解和水热碳化是城市固废制备生物炭的常用方式,其形成的生物炭具有较大的比表面积、孔隙率及更丰富的组分,对污染物质(如I-、Cu2+等)具有较强的吸附能力;2) 城市固废自身特性及生产工艺都会对所得生物炭的性质产生影响;3) 以特定城市固废生产的生物炭可用于垃圾填埋场修复和土壤改良,对填埋场造成的土壤、大气、地下水污染均具有良好的处理效果,也能充分提高土壤养分的有效性。该成果可为基于城市固废的生物炭生产及环境治理修复相关研究提供参考。 相似文献
13.
The increase in MSW (Municipal Solid Waste) recycling may attribute to two factors: one is diffusion effect through households' adoption of MSW recycling (an innovative service offered and provided by the government); the other is organizational learning effect due to the reformation of MSW management system (the MSW recycling service provider). The diffusion effect takes place across households through the exchange of information while learning effect occurs through employee's accumulated experience in MSW recycling and the consequent innovation in associated with institutional change within the service provider. In this paper, we develop three models, including (1) the diffusion effect model, (2) the organizational learning effect model, and (3) the interaction model to explain the performance of MSW recycling. Using Taiwan's recyclable waste collected, we show that (1) the diffusion effect and learning effect have significantly impacts on MSW recycling, (2) environmental policy has a significant impact on environmental diffusion and organizational learning, and leads to the accelerating performance of MSW recycling, (3) the interaction of diffusion and organizational learning have a positive impact on MSW recycling performance. 相似文献
14.
随着人口持续增长和居民生活水平提高,垃圾产生量日益增加。城市生活垃圾良好分类有利于提高垃圾处置效果,减轻环境压力,改善环境生态。本文通过对泸州市生活垃圾分类现况调查,从年龄阶段、学历和月收入三个方面分析影响生活垃圾分类的原因,找出了提高居民垃圾分类意识是当前应解决的主要问题,提出了针对各类居民的主要宣传媒介,为西部中小城市垃圾分类收集提供建议。 相似文献
15.
16.
对我国城市固体废物(MSW)清运量、无害化处理量、卫生填埋量和场所、焚烧量和堆肥量的变化进行了趋势分析、相关性分析以及时空分布分析;并且对联合国气候变化框架公约(UNFCCC)官方网站公布的《京都议定书》中附件1国家温室气体的排放数据进行了统计分析. 结果表明:我国城市固体废物清运量和卫生填埋量很大并逐年增加;城市固体废物卫生填埋处理厌氧消化产生的温室气体随着填埋量以及标准卫生填埋场所的变化而变化;从发达国家各领域的温室气体排放情况来看,废物领域的减排潜力很大,尤其是城市固体废物卫生填埋处理,这对我国开展城市固体废物卫生填埋处理温室气体减排有一定启示. 相似文献
17.
介绍了徐州市生活垃圾的处理现状;对生活垃圾中常见成分比例和垃圾热值进行了测定.应用MATLAB7.0软件,以影响城市生活垃圾产生量的主要因素(人口数量、人均可支配收入、燃气化率、源头减量及资源化利用率)作为输入,来建立预测城市垃圾产量的BP神经网络模型,发现当隐含层的节点数为8时,网络收敛速度较快,预测偏差最小,于是确定预测模型的结构为4-8-1,应用该模型对徐州市生活垃圾产量进行了预测.最后,以所得数据为基础,并结合当地实际情况,提出了徐州市垃圾综合处置和资源化的若干措施. 相似文献
18.
城市生活垃圾低污染气化熔融系统研究 总被引:7,自引:0,他引:7
为彻底消除城市生活垃圾焚烧过程中的二次污染,对流化床气化与旋风燃烧熔融系统进行了研究.我国典型城市生活垃圾流化床气化试验表明,最佳气化温度为600℃左右;对垃圾焚烧飞灰进行熔融特性试验表明,垃圾焚烧飞灰在1 300℃左右、垃圾掺煤焚烧飞灰在1 400℃左右时,能顺利熔融,二分解率99.99%以上,重金属有效固化.结合我国实际,提出了2种气化熔融系统方案:①基于垃圾综合处理的筛上物气化熔融技术方案;②原生垃圾+辅助燃料气化熔融技术方案;并进行相应的热力性能分析,研究表明2种方案都能较好满足气化熔融要求. 相似文献
19.
Xiao Gang Ni Mingjiang Chi Yong Jin Yuqi Zhang Jiaquan Miao Qi Cen Kefa 《Frontiers of Environmental Science & Engineering in China》2007,1(4):498-503
In order to eliminate secondary pollution caused by municipal solid waste (MSW) incineration, a MSW gasification and melting
process is proposed. The process is expected to reduce the emission of pollutants, especially heavy-metals and dioxins. In
this paper, the combustible components of MSW and simulated MSW were gasified in a lab-scale fluidized bed at 400°C–700°C
when the excess air ratio (ER) was between 0.2 and 0.8. The experimental results indicated that the MSW could be gasified
effectively in a fluidized bed at approximately 600°C–700°C when excess air ratio was 0.2–0.4. The melting characteristics
of two typical fly ash samples from MSW incinerators were investigated. The results indicated that fly ash of pure MSW incineration
could be melted at approximately 1,300°C and that of MSW and coal co-combustion could be melted at approximately 1,400°C.
When temperature was over 1,100°C, more than 99.9% of the dioxins could be decomposed and most of the heavy-metals could be
solidified in the slag. Based on the above experiments, two feasible MSW gasification and melting processes were proposed
for low calorific value MSW: (1) sieved MSW gasification and melting system, which was based on an idea of multi-recycle;
(2) gasification and melting scheme of MSW adding coal as assistant fuel.
__________
Translated from Environmental Science, 2006, 27(1): 69–73 [译自: 环境科学] 相似文献