焦磷酸钾对铜污染土壤的淋洗修复

焦磷酸钾是一种对农田土壤环境友好的物质。通过批处理振荡淋洗实验研究了所配制的焦磷酸钾淋洗液对模拟污染土壤中重金属铜的淋洗特性,探讨了淋洗时间、淋洗液pH和焦磷酸钾浓度对淋洗效果的影响,并讨论了土壤中铜在焦磷酸钾淋洗液作用下的解吸动力学和淋洗前后重金属形态变化特性。结果表明,淋洗时间越长、淋洗液浓度越大,淋洗效果越好。优化实验条件,淋洗浸提24 h、淋洗液pH为7.0、n（焦磷酸钾）：n（铜）为7：1,淋洗效果较好,铜淋洗率为40.51%。焦磷酸钾淋洗的铜主要以酸提取态和可还原态为主。焦磷酸钾淋洗液对土壤铜的浸提过程符合双常数方程,说明土壤中铜在焦磷酸钾淋洗液作用下的解吸是非均相扩散过程。     

室内PM2.5浓度控制模拟分析

利用质量平衡方程建立了一次回风定风量系统室内PM2.5浓度模型,并对新风PM2.5浓度、新风量、室内污染源、过滤器效率、过滤器安装位置等因素对室内PM2.5浓度的影响进行了模拟分析。模拟结果表明：新风PM2.5浓度和室内污染源强度的变化对室内PM2.5浓度均有较大影响;新风量越大,室内PM2.5浓度受新风PM2.5浓度变化的影响越大;将过滤器分别安装在送风段、新风段和回风段,新风比为0.1时,过滤器安装在送风段效果最好,安装在新风段最差,新风比为0.8时,过滤器安装在送风段效果最好,安装在回风段最差;过滤器安装在送风段时,过滤器效率越高,室内PM2.5浓度越低,波动越小。     

氨氮废水处理技术研究进展

氨氮废水是造成水体富营养化的主要因素之一 ,本文综述了氨氮废水的几种主要处理技术 ,介绍了它们的处理原理以及适用条件 ,指出了今后研究工作中需要解决的问题和氨氮废水处理技术今后的发展方向     

堆肥中纤维素和木质素的生物降解研究现状

堆肥是垃圾处理的主要方法之一 ,厨房垃圾、园林垃圾、农村秸秆和日常生活中的废弃纤维产品均可作为堆肥原料 ,这些原料中含有一定量的纤维素和木质素 ,而纤维素和木质素在堆肥过程中较难生物降解。因此 ,国内外学者致力于研究能加速纤维素和木质素降解的高效微生物。研究发现 ,对纤维素和木质素有降解能力的微生物主要是高温放线菌和高温真菌 ,其中有独特降解机制的白腐菌在木质素降解中起着重要作用     

非均相催化湿式氧化法活性炭再生

使用浸渍法制备的CuO Al2 O3催化剂对吸附苯酚饱和的活性炭进行非均相催化湿式氧化再生研究 ,考察了反应温度、反应时间、催化剂投加量、反应氧分压、投炭量、蒸馏水量对非均相催化湿式氧化再生活性炭的影响结果 ,同时在该实验中得到非均相CuO Al2 O3催化湿式氧化再生活性炭的最佳条件。对催化剂进行了X衍射分析 ,并通过对催化剂的稳定性进行实验 ,得出该催化剂在进行催化湿式氧化再生活性炭的过程中具有较好的稳定性     

农业蔬菜废物处理方法研究进展和探讨

目前我国农业蔬菜废物污染问题正日益加重 ,蔬菜废物和其他固体废物相比具有高含水率、高营养成分和基本无毒害的特性 ,适宜于单独收集处理。本文介绍了国内外蔬菜废物处理方法的研究进展 ,包括好氧堆肥法、厌氧消化法、好氧 -厌氧联合处理法 ,并对这些方法的适用条件进行了论述。同时 ,探讨了接种微生物自然堆沤法的初步研究结果     

Analysis of photochemical pollution in summer and winter using a photochemical box model in the center of Tokyo, Japan.

In order to give an effective and rapid analysis of the photochemical pollution and information for emission control strategies, a photochemical box model (PBM) was applied to one moderate summer episode, 11 July 1996, and one typical winter episode, 3 December 1996, in the center of Tokyo, Japan. The box model gave a good prediction of the photochemical pollution with minimal investment. As expected, the peak ozone in summer is higher than in winter. The NOx concentrations in winter are higher than those in summer. In summer, NO and NO2 have one peak in the morning. In winter, NO and NO2 show two peaks during the day. Three model runs including no reactions, a zero ozone boundary condition and dark reactions were conducted to understand the photochemical processes. The effects of emission reduction on the formation of the photochemical pollution in the center of Tokyo have been studied. The results show that the reduction of NMHC emission can decrease the ozone, however, the reduction of NOx emission can increase the ozone. It can be concluded that if the NOx emission are reduced, the reduction of NMHC should be more emphasized in order to decrease the ozone concentration in the center of Tokyo, Japan, especially the reduction of the NMHC from stationary source emission.     

Chemical kinetic modeling of de novo synthesis of PCDD/F in municipal waste incinerators

A kinetic model is developed for de novo synthesis of PCDD/F from carbon in incinerator fly ash. The main mechanistic steps considered in the model are carbon gasification, PCDD/F formation, desorption and degradation. Rate equations are derived which can relate PCDD/F formation with process variables including carbon concentration of fly ash, partial pressure of oxygen, reaction temperature and time. The kinetic model has been verified using laboratory de novo synthesis data reported in the literature. When the model is applied to industrial incinerator conditions, PCDD/F formation levels of 0.1-0.5 microg/N m3 in the gas phase and 0.1-1.2 microg/g in the solid phase are calculated, and both are in good agreement with incinerator measurements.     

基于室内PM2.5控制和节能的通风策略探讨

细颗粒物（PM2.5）随空调新风进入室内,和室内产生的PM2.5粒子一起作用,导致人体暴露在室内细颗粒物环境中。为保证室内空气品质,最大限度节约空调系统运行能耗,建立了室内PM2.5浓度与CO2体积分数双组分模型,提出了适用于某会议室不同室内外PM2.5源、不同人数以及不同天气状况下的最佳通风策略,利用Simulink对炎热天气室内有无PM2.5散发源、温和天气室内有无PM2.5散发源4种工况下的不同通风方式进行仿真对比。模拟结果表明：炎热天气存在最小新风量,该值由室内人数决定,过滤送风对控制室内PM2.5浓度效果最好;温和天气存在最大新风量,且该值与过滤器效率成正比;在所研究的情况下,温和天气节能潜力比炎热天气大。     

Heavy metal (Cu,Cd, Pb,Cr) washing from river sediment using biosurfactant rhamnolipid

Heavy metal-contaminated sediments posed a serious threat to both human beings and environment. A biosurfactant, rhamnolipid, was employed as the washing agent to remove heavy metals in river sediment. Batch experiments were conducted to test the removal capability. The effects of rhamnolipid concentration, washing time, solution pH, and liquid/solid ratio were investigated. The speciation of heavy metals before and after washing in sediment was also analyzed. Heavy metal washing was favored at high concentration, long washing time, and high pH. In addition, the efficiency of washing was closely related to the original speciation of heavy metals in sediment. Rhamnolipid mainly targeted metals in exchangeable, carbonate-bound or Fe-Mn oxide-bound fractions. Overall, rhamnolipid biosurfactant as a washing agent could effectively remove heavy metals from sediment.