Monitoring of abandoned quarries by remote sensing and in situ surveying

In Italy quarrying causes relevant environmental damages and alterations to the land and the ecosystems. Despite the present Italian legislation requiring the restoration of the sites after exploitation, most of the quarries, both the abandoned and the still operational ones, are not restored.The objective of this work is to indicate a monitoring methodology in order to survey the present state of the quarry sites and their evolution in time, which are the basic data needed to implement an adequate land reclamation project.Such methodology has been applied to several abandoned limestone quarries in the Latina province (close to Rome), characterised by a typical Mediterranean vegetation, but it can be applied to any other kind of litology and vegetation.The land monitoring has been realised both by using remote sensing techniques, supported by a Geographic Information System of the studied area, and by in situ surveying. The in situ surveying was able to assess the capability of the remote sensing model to describe the state of each site.     

Source separation recycling schemes: A survey

Municipal waste arisings continued to increase during the 1970s in all the industrialized economies. Currently, in the midst of a severe international economic recession, the continuing escalation in the costs of waste disposal poses significant problems for municipal authorities. With the data constraints firmly in mind, this paper estimates the secondary materials supply potential of the municipal waste stream. The calculations suggest that a significant supply potential remains to be utilized despite ‘respectable’ overall recycling rates in most industrial economies. Resource recovery options can be divided into ‘low technology’ source separation schemes and ‘high technology’ mechanical separation schemes. The authors concentrate on the former option and appraise (on the basis of social cost-benefit analysis) a number of schemes that have operated in both Europe and North America.     

石河子垦区农业生态环境

对垦区农业环境影响较突出的水污染状况，土壤次生盐渍化及土地沙化等环境问题进行研究分析，认为：垦区农业环境生态保护要兼顾垦区内外，绿洲内制约农业经济发展的重要问题仍然是水资源合理利用和土壤沙漠化问题，城市生态要严格控制工业废水的排放。     

探讨垃圾填埋场开采回用工程

介绍了垃圾填埋场开采回用的目的、稳定化条件和开采工艺,并结合盐田垃圾场清场处置工程实例,探讨了开采工艺中斜面分层作业和垃圾造堆工艺,得出结论:斜面分层作业和垃圾造堆,可以大大降低垃圾的密度,提高松散度,更有利于保障开挖作业安全。     

再生水用于景观水体的氮磷水质标准确定

污水再生利用是解决水资源短缺问题的重要措施,其中再生水回用于景观水体是主要途径之一.而防止水华爆发则是再生水景观利用的首要任务,控制再生水中的氮磷是防止水华爆发的根本措施.目前已有的景观水体水质标准中,氮磷浓度限值要求不统一,缺乏科学依据.因此再生水处理过程中氮磷控制标准执行易出现矛盾,不利于保障再生水景观利用的水质安全.再生水景观利用的氮磷控制标准,应在藻类最大生长潜力研究的基础上,通过藻类生长的Logistic模型和Monod模型、景观水体氮磷浓度模型按拟合,并结合水体自净能力和水质保障措施等综合因素加以确定.以栅藻(Scenedesmus sp)为例,通过Logistic模型和Monod模型拟合景观水体水华控制氮磷浓度限值的确定方法.     

海湾围垦工程作用下的动力沉积响应

通过采用平面二维有限元数学模型模拟计算乐清湾边滩围垦前后的潮流变化分布 ,在此基础上 ,预测围垦工程建设后导致泥沙冲淤变化。据此说明海湾围垦工程作用下的动力沉积响应。结果表明 ,海湾围垦工程对流场及泥沙冲淤的影响局限于工程区临近水域。在围区两侧 ,工程前后流速减小 ,使水流挟沙力降低 ,导致泥沙局部淤积 ;在围堤的转角外侧 ,将存在流速略有增大的区域 ,而在此的海床冲刷状况并不明显     

味精生产废水综合治理及资源化

本文提出采用化学絮凝、沉降方法除去味精发酵醪液菌体,清液采用浓缩—连续等电点法提取谷氨酸。采用新工艺后,菌体可回收作蛋白饲料,谷氨酸提取率由现在的75%—78%提高至85%,废水量减少一半以上,采用蒸发浓缩处理,回收作有机复合肥,根本解决了味精废水污染环境的问题。      

我国铁矿区土地复垦存在的问题及对策研究

铁矿开采过程中严重地破坏土地,改变了矿区的生态环境。铁矿区土地复垦是恢复矿区生态环境的主要措施。本文对铁矿区土地复垦的现状、存在的问题进行了探讨,并对铁矿区土地复垦提出一些建议。     

沈阳市赵家沟垃圾填埋场稳定化与场地回用评价

对沈阳市一个关闭2年左右的垃圾卫生填埋场的稳定化状态进行了研究。对填埋场达到稳定化状态的时间进行预测以及不同时期的稳定化程度进行评价,并提出了填埋土地的再利用方案。