拾荒者:边缘化的回收终端

背着一个麻袋,或是骑着一辆挂着蛇皮袋的自行车,整日穿行在城市的街头巷尾,收购各种有用生活废品,或是在各式各样的垃圾桶里搜寻各种有用的垃圾.他们,被人们称为“收破烂的”,也叫“拾荒者”。     

高浓度苯酚在石墨电极上电解特性的研究

研制了数据在线采集记录系统对高浓度苯酚在石墨电极上电解过程的循环伏安行为进行了研究。采用连续循环伏安法考察了体系电解的特点,并考察了支持电解质、扫描速率、苯酚的浓度对反应体系的影响。结果表明:峰电流密度与扫描速率的平方根及苯酚浓度呈线性递增关系,支持电解质的添加量在苯酚电解过程存在最佳值,多次扫描过程中峰电流密度有下降趋势。实验推断电解效率下降是由于电极表面被聚合物污染导致,这一现象对电解处理有机物种的系统控制过程具有重要意义。     

·OH的形成机理及在水处理中的应用

以产生大量·OH为特点的高级氧化水处理技术已逐渐成为各国水处理技术研究的热点。在讨论·OH氧化能力的同时 ,重点讨论了Fenton法、纳米光催化氧化法、电化学催化降解法以及超声降解法·OH的形成机理 ,介绍了它们在水处理中的工业化应用及进展情况 ,展望了今后在该领域中多种氧化降解方法协同作用的发展方向     

危险废物处理处置技术评价方法研究

在对不同危险废物处理处置技术评价方法适用性进行分析的基础上,对危险废物处理处置技术评价方法进行了系统研究.结果发现专家评价法和环境技术评价(EnTA)法以定性评价为主,简单易行,应用范围广泛;生命周期评价(LCA)法以定量为主,但由于数据采集困难,目前在应用上还面临很多困难;层次分析(AHP)法把定性与定量评价融合得比较好,对于解决危险废物处理处置技术的选择问题行之有效.     

略谈清洁生产战略在医院废物处理中的指导意义

清洁生产战略作为环境管理的一项手段 ,是实现可持续发展战略的一项重要举措。医院废物作为一种危险废物 ,在其处理处置过程中 ,也应引入清洁生产思想 ,这对于有效利用资源和能源 ,减轻环境压力 ,都具有重要意义。     

城市固体废物好氧生物反应器填埋方式的实验研究

MSW（城市固体废物）生物反应器型填埋是一种较新颖的方法.在系统分析现有填埋方法优缺点的基础上,对其加以改进,将强制通风好氧和渗滤液循环2种方式有机地结合在一起,构建了MSW好氧生物反应器.考察了NH3、CH4、CO2、pH和温度等因素,并监测分析了渗滤液中的COD、BOD5、Zn^2＋、NH4^＋和NO3^-等指标,旨在研究其中垃圾的降解及渗滤液中COD、BOD5、Zn^2＋、NH4^＋和NO3^-的去除情况,探讨该生物反应器对垃圾和渗滤液相关参数的作用机理.结果表明,该反应器对渗滤液中COD、BOD5、NO3^-的去除率分别达到96.34%、94.58%和99.9%,对其中的Zn^2＋也有较好的脱除效果.     

Physical versus chemical effects on bacterial and bromide transport as determined from on site sediment column pulse experiments

Twenty-eight bacterial and Br transport experiments were performed in the field to determine the effects of physical and chemical heterogeneity of the aquifer sediment. The experiments were performed using groundwater from two field locations to examine the effects of groundwater chemistry on transport. Groundwater was extracted from multilevel samplers and pumped through 7-cm-long columns of intact sediment or repacked sieved and coated or uncoated sediment from the underlying aquifer. Two bacterial strains, Comamonas sp. DA001 and Paenibacillus polymyxa FER-02, were injected along with Br into the influent end of columns to examine the effect of cell morphology and cell surface properties on bacterial transport. The effects of column sediment grain size and mineral coatings coupled with groundwater geochemistry were also investigated. Significant irreversible attachment of DA001 was observed in the Fe oxyhydroxide-coated columns, but only in the suboxic groundwater where the concentrations of dissolved organic carbon (DOC) were ca. 1 ppm. In the oxic groundwater where DOC was ca. 8 ppm, little attachment of DA001 to the Fe oxyhydroxide-coated columns was observed. This indicates that DOC can significantly reduce bacterial attachment due electrostatic interactions. The larger and more negatively charged FER-02 displayed increasing attachment with decreasing grain size regardless of DOC concentration, and modeling of FER-02 attachment revealed that the presence of Fe and Al coatings on the sediment also promoted attachment. Finally, the presence of Al coatings and Al containing minerals appeared to significantly retard the Br tracer regardless of the concentration of DOC. These findings suggest that DOC in shallow oxic groundwater aquifers can significantly enhance the transport of bacteria by reducing attachment to Fe, Mn and Al oxyhydroxides. This effect appears to be profound for weakly and strongly charged hydrophilic bacteria and may contribute to differences in observations between laboratory experiments versus field-scale investigations particularly if the groundwater pH remains subneutral and Fe oxyhydroxide phases exist. These observation validate the novel approach taken in the experiments outlined here of performing laboratory-scale experiments on site to facilitate the use of fresh groundwater and thus be more representative of in situ groundwater conditions.     

Seasonal variation in the composition and concentration of butyltin compounds in marine fish of Taiwan

For the first time, strong evidence is presented to demonstrate that the accumulations of butyltin compounds (BTs) exhibit seasonal variations with respect to their compositions and concentrations in marine fishes. Measurements were made on the benthic ponyfish Leiogenathus splendens and lizardfish Trachinocephalus myops inhabiting the west coast of Taiwan. In the whole body samples of the ponyfish, BT concentrations ranged from 236 to 2501 ng/g wet wt, with those in winter considerably higher than in the other seasons (p < 0.05 ). In a similar vein, proportions of mono- (MBT), di- (DBT) and tributyltin (TBT) differed significantly (p < 0.001) depending upon the season, with TBT (75 and 50%) dominant in winter and spring and DBT (37 and 57%) and MBT (42 and 24%) dominant in summer and autumn, respectively. In the lizardfish, the concentrations of BTs were one to two orders of magnitude higher in the liver than in the muscle, i.e. 3058-11,473 vs. 36-159 ng/g wet wt, respectively. Concentrations of MBT, DBT and TBT in the muscle ranged, respectively, from 5 to 14, 8 to 35 and 23 to 110 ng/g wet wt, with the major compound being TBT (57-69%) in all seasons. However, in the liver, DBT concentrations, ranging from 992 to 7797 ng/g wet wt, differed seasonally with a descending order of autumn>summer>spring (p < 0.05). Meanwhile, TBT (41%) was predominant in spring, whereas DBT (50 and 68%) was most heavily concentrated in summer and autumn (p < 0.001). Seasonally mediated physiological changes, such as dilution due to growth and metabolic compensation, may play important roles in forming different BT accumulation patterns among seasons and organisms.     

Biological solids reduction using the Cannibal process.

A laboratory study of the Cannibal process was undertaken to determine if the Cannibal system would generate less sludge compared with a conventional activated sludge system. Side-by-side sequencing batch reactors were operated--one using the Cannibal configuration and the other as conventional activated sludge. It was found that the Cannibal process generated 60% less solids than the conventional activated sludge system, without any negative effect on the effluent quality or the settling characteristics of the activated sludge. The oxygen uptake rate for the centrate from the Cannibal bioreactor showed that readily biodegradable organic matter was released from the recycled biomass in the Cannibal bioreactor. It is proposed that the mechanism for reduced solids from the Cannibal system is that, in the Cannibal bioreactor, iron is reduced, releasing iron-bound organic material into solution. When the Cannibal biomass is recirculated back to the aeration basin, the released organic material is rapidly degraded.     

水体中卤乙酸（HAAs）的产生、测定方法与控制途径

对饮用水中普遍存在的消毒副产物形式HAAs的产生、测定方法以及控制途径进行了阐述。并对影响HAAs生成的主要因素投氯量、溴的影响以及卤乙酸副产物（HAAFP）含量等进行了分析。生物活性炭技术是一种非常有效的控制HAAs含量和减少HAAFP含量的方法，对于保障饮用水安全性具有重要意义。