零价铁法处理露天垃圾倾倒场渗滤液的研究

实验表明,采用零价铁法工艺,利用金工下脚铁屑处理露天垃圾倾倒场垃圾渗滤液,可在有效消除渗滤液中难降解有机污染物和毒害重金属的同时,提高其可生化性,减少CODcr、色度、氨氮、总磷等污染物的含量,降低其进一步净化处理的负荷。经正交试验优化得实验条件下适宜的处理条件是pH值4.0,反应时间10h,铁屑投加量120g。处理效果为总磷去除率98.0%、色度降低率96.0%、COD去除率71.3%、氨氮去除率为14.4%。

山西省大同市智家堡公园设计

智家堡公园项目于2008年启动,2009年5月开始建设,同年9月底基本建成。项目位于山西省大同市老城区南部,用地边界南为规划青年路,北为开元东街,东起御河南路,西至规划支路。西南角为已建中水水厂,东南角为立交桥。公园总体设计范围为30hm2。建设前为垃圾倾倒场。垃圾存量40余万方。公园设计概算为7 451万,竣工决算为7 417万。

本月聚焦

中国已成世界最大的电子垃圾倾倒场中国环境与发展国际合作委员会最近发布了《中国经济发展的外部环境影响——国际法分析》报告。该报告中指出,中国电子垃圾集散处理地有广东贵屿镇、龙塘镇、大沥镇、浙江台州地区、河北黄骅市、湖南、江西等地,尤以广东和浙江最为集中。

“渣土围城”成城市痛点

据《中国建筑垃圾资源化产业发展报告（2014年度）》统计,近几年中国每年建筑垃圾的排放总量为15.5亿吨~24亿吨之间,占城市垃圾的比例约为40%。城市面貌改变如此之快,鲜有人关心这些渣土如何消失,最后又去向哪里。而多数城市渣土受纳场的建设,远远跟不上渣土产生的速度,同时又面临多头管理、监管缺失、再利用率低的困境。最终,＂渣土围城＂隐疾,成为很多城市的一个痛点。深圳之＂围＂按当地媒体的报道,深圳的余泥渣土排放难问题,是在2001年之后才出现的。在此之前,

Impulse force reductions and their effects on WBV exposures in high impact shovel loading operations

When shovels load the dump trucks with over 100-ton passes under gravity dumping conditions, they will create a large impact force on the dump truck body which generates high frequency shock waves which expose the operators to whole body vibrations （WBV）. The main cause of such truck vibrations is the large impact force due to the gravity dumping of large tonnage passes. Therefore a rigorous mathematical model has been developed for the impact force containing all the necessary factors upon which it depends. Latter, a thorough analysis shows that percentage reduction of 7.19%, 9.40%, 13.27%, 14.8%, 17.30% and 18.13% can he achieved by reducing the dumping distance to 6.33 m, 6.0 m, 5.5 m, 5.33 m, 5.0 m and 4.9 m, respectively, as compared to when the dumping distance was 7.33 m. Even more reduction in the magnitude of impact force can he observed if the shovel pass gets divided into more than two sub-passes. Therefore, these models can he used to figure out the number of sub-passes into which a single ore pass can he divided and/or the extent to which the dumping distance can he reduced which would reduce the impact force significantly enough to obtain safer yet economic operations.

《品德与生活》教学方法谈

一、调查访问法如教学《脏乱的害处》时,我让学生自己去看看生活中有哪些脏乱现象,哪里被污染了。孩子们通过观察、询问,了解到我们这个小城的护城河污染严重,河水乌黑难闻,不见鱼儿的身影,两岸成了垃圾倾倒场,臭味能飘几千米。针对学生调查得来的情况。