基于生产者责任延伸制的废旧电池回收模式研究

为了保护环境和循环利用资源,废旧电池回收问题已经引起社会各方面的广泛关注。文章分析了我国废旧电池的回收现状,借鉴国外的经验,提出了我国废旧电池的回收模式——即生产者责任延伸制下的回收模式,运用数学模型进行比较分析,得出生产者负责回收的模式具有明显优势。     

像素法计算土地复垦方案非矢量化土地利用现状图斑面积

土地复垦方案编制过程中,需计算各地类面积,搜集的资料如果仅有非矢量化线条版土地剩用现状图,如纸版或Jpg、Tif等图像文件,统计各地类图斑块面积手工描图工作量比较大,且精确度不能满足方案需要,常常成为土地复垦方案编制效率提高的制约因素。笔者根据多年从事计算机技术及工程绘图经验,总结并实践了利用像素点法计算不规则形状图斑面积的方法,供环评、土地复垦工作者参考。     

Fate of microplastics in a coastal wastewater treatment plant: Microfibers could partially break through the integrated membrane system

• Fate of microplastics in integrated membrane system for water reuse was investigated. • Integrated membrane system has high removal efficiency (>98%) for microplastics. • Microplastics (>93%) were mainly removed through membrane bioreactor treatment. • Small scale fiber plastics (<200 μm) could break through reverse osmosis (RO) system. • The flux of microplastics maintained at 2.7 × 10¹¹ MPs/d after the RO treatment. Rare information on the fate of microplastics in the integrated membrane system (IMS) system in full-scale wastewater treatment plant was available. The fate of microplastics in IMS in a coastal reclaimed water plant was investigated. The removal rate of microplastics in the IMS system reached 93.2% after membrane bioreactor (MBR) treatment while that further increased to 98.0% after the reverse osmosis (RO) membrane process. The flux of microplastics in MBR effluent was reduced from 1.5 × 10¹³ MPs/d to 10.2 × 10¹¹ MPs/d while that of the RO treatment decreased to 2.7 × 10¹¹ MPs/d. Small scale fiber plastics (<200 μm) could break through RO system according to the size distribution analysis. The application of the IMS system in the reclaimed water plant could prevent most of the microplastics from being discharged in the coastal water. These findings suggested that the IMS system was more efficient than conventional activated sludge system (CAS) for the removal of microplastics, while the discharge of small scale fiber plastics through the IMS system should also not be neglected because small scale fiber plastics (<200 μm) could break through IMS system equipped with the RO system.     

Utilization of aluminum hydroxide waste generated in fluoride adsorption and coagulation processes for adsorptive removal of cadmium ion

Although Al-based coagulation and adsorption processes have been proved highly efficient for fluoride (F) removal, the two processes both generate large amount of Al(OH)₃ solid waste containing F (Al(OH)₃-F). This study aimed to investigate the feasibility of utilizing Al(OH)₃-F generated in Al(OH)₃ adsorption (Al(OH)₃-F_ads) and coagulation (Al(OH)₃-F_coag) for the adsorption of cadmium ion (Cd(II)). The adsorption capacity of Al(OH)₃-F_ads and Al(OH)₃-F_coag for Cd(II) was similar as that of pristine aluminum hydroxide (Al(OH)₃), being of 24.39 and 19.90 mg·g^–1, respectively. The adsorption of Cd(II) onto Al(OH)₃-F_ads and Al(OH)₃-F_coag was identified to be dominated by ion-exchange with sodium ion (Na⁺) or hydrogen ion (H⁺), surface microprecitation, and electrostatic attraction. The maximum concentration of the leached fluoride from Al(OH)₃-F_ads and Al(OH)₃-F_coag is below the Chinese Class-I IndustrialWastewater Discharge Standard for fluoride (<10 mg·L^–1). This study demonstrates that the Al(OH)₃ solid wastes generated in fluoride removal process could be potentially utilized as a adsorbent for Cd(II) removal.     

铸造旧砂再生废气治理工程实例

从工艺流程及设备、工程运行监测结果及经济指标等方面,介绍了某铸造旧砂再生废气治理工程,从实际监测结果可知:该工程运行稳定,废气中的各项污染物排放浓度均符合GB16297-1996《大气污染物综合排放标准》排放标准的要求。     

工矿区复垦土地主要污染因子分析

重点讨论了工矿区的概念、分类、土壤污染的特点及土地复垦和生态重建的主要污染因子。     

矿区土地复垦中的相关问题探讨

矿区土地复垦是实现土地可持续利用的重要环节，土地复垦中的资金落实，复垦技术利用关系到复垦工作的成败与进展快慢。     

开阔海域围填海规划的水质影响评价方法——以福建省湾外围填海为例

基于开阔海域围填海的特殊性,已有的水质影响评价定量方法较难直接应用。本文通过水动力因子分析确定污染物扩散条件,根据水质现状、围填面积和规划利用方式确定水质压力。基于上述污染物扩散条件和水质压力参数,以水质影响程度等级作为评价结果,设计了半定量评价矩阵对福建省湾外围填海规划的10个围填区进行了水质影响评价。评价结果表明:其中有1个围填区水质影响程度较大,其余围填区水质影响程度均在中等以下。此外,水质影响程度评价结果可同时为湾外围填海规划决策者提供相应的决策依据。案例应用表明:该半定量方法可以推广应用于决策型的、影响机制复杂、不确定性较强的人类活动的水质影响评价。     

东部平原矿区复垦土壤微生物群落特征及其组装过程

复垦对恢复矿区土壤生产力极为重要,但复垦土壤生产力重建的微生物学机制尚不清晰.为此,采集复垦8 a、复垦11 a、复垦14 a和复垦17 a这4个复垦时长和1个未复垦对照共75个表层土样进行16S rRNA扩增子高通量测序,分析微生物群落组成、潜在功能及其组装机制.结果表明：(1)群落丰富度随复垦时间增加而增加,且高于对照样.但群落多样性和均匀度却随复垦时间增加而降低(P<0.05);(2)复垦土壤中酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)占主导地位,且前两者相对丰度显著高于对照样(P<0.05),后两者则相反(P<0.05);(3)复垦土壤中辅酶转运与代谢、翻译、核糖体结构与生物发生等8种功能呈正向演替,随复垦时长不断增强;(4)平原矿区微生物群落生态网络模块性良好,且关键类群多属酸杆菌门和拟杆菌门.群落组装以确定性过程为主导,同质性选择贡献最大,主要受当地特殊环境操控.这些发现为改善复垦土壤生产力和生态服务提供了理论依据.     

对云南铁矿土地复垦的探讨

铁矿是一种重要的矿产资源,但铁矿的开采也带来了很多环境问题．其中对土地的破坏最为严重。矿区土地破坏主要包括挖损、塌陷、压占等,矿山的土地复垦可以节约大量的土地资源,对国民经济的发展有着重要的意义。本文对云南铁矿的土地复垦进行初步探讨．对矿山复垦提出一些建议。