城市富营养化湖泊立体修复系统研究

提出对城市富营养化湖泊进行全方位、多途径的综合治理思路——富营养化湖泊立体修复系统。详细介绍了富营养化湖泊立体修复系统的含义、组成部分及实施步骤。通过实践表明该思路在理论上是合理、可行的。具有投资少、回报大、效果好、不产生二次污染、能带来社会、经济效益等优点,是一种值得推行的城市富营养化湖泊治理思路。治理城市富营养化湖泊是一个长期的过程,需要政府的支持和全民的参与。对城市富营养化湖泊的治理,使得湖泊逐渐恢复生态活力,实现城市湖泊区人与自然的协调发展。同时,引入各方面（地产、环保、能源、园林、旅游）资金的城市湖泊修复建设也为环保企业及产业的发展提供了新的途径。     

Ca2+添加对微生物矿化固结Cd2+的影响

微生物诱导碳酸盐沉淀（MICP）可将游离的重金属离子转化为稳定的矿化物,在修复土壤重金属污染方面具有广阔的应用前景.本研究从铜陵矿区周边土壤中筛选得到1株产脲酶且耐镉矿化菌株CZW-1,16S rDNA鉴定为芽孢杆菌（Bacillus sp.）,并将其利用于添加外源Ca²⁺的矿化固结Cd²⁺实验中.通过扫描电镜（SEM）、傅立叶红外光谱（FT-IR）以及X射线衍射（XRD）对矿化产物进行表征和分析.结果表明,添加一定浓度的Ca²⁺可促进细菌的生长,其最佳浓度为20 mmol·L^-1.且Ca²⁺的添加可提高细菌的最小抑制浓度和促进脲酶活性,提高对Cd²⁺的矿化率,加钙前后的矿化率由68.93%提高到75.95%.通过对矿化物的定性分析,可知加钙前后的矿物沉淀由单一CdCO₃变为CdCO₃和CaCO₃的复合沉淀,其表面也由严密紧实变成填满了小颗粒CdCO₃的多孔状.     

强化的零价铁PRB技术对PCBs污染地下水的修复

本实验强化了零价铁可渗透反应墙（Permeable Reactive Barrier,PRB）技术,分别用还原铁粉、还原铁粉＋锌粉、还原铁粉＋活性炭为主要的反应介质,以Arcolor1242为靶污染物,对强化的零价铁PRB技术治理多氯联苯污染的地下水的可行性和有效性进行了模拟研究。实验结果表明：在温度10℃,有效孔隙率为61%~67%,水的渗透速度为0.7~0.8 m.d-1的条件下,3个反应柱稳定期对PCBs的去除率分别达到94%、85%、79%,pH值从6.87升高到8.78、10.2、7.93;氧化还原电位从-48.6 mV降到-135、-107、-86.4 mV;出水铁离子的平均质量浓度为0.241、0.129和0.201 mg.L-1,脱氯率平均值为49.6%、72.6%、58.6%。综合考虑处理效果与成本,用零价铁PRB技术治理PCBs污染的地下水是可行的。     

Soil washing of As-contaminated stream sediments in the vicinity of an abandoned mine in Korea

A soil washing process was applied to remediate arsenic (As)-contaminated stream sediments around an abandoned mine in Goro, Korea. Laboratory scale soil washing experiments for As-contaminated stream sediments were performed under various washing conditions in order to maximize As removal efficiency. Stream sediments were taken from two sites (S1 and S5) along the main stream connected to an abandoned mine. Stream sediments at the two sites were divided into two groups (≥0.35 and <0.35 mm in diameter), giving four types of sediments, which were thereupon used for soil washing experiments. The results of soil washing experiments involving various pH conditions suggested that As removal efficiency is very high in both strongly acidic and basic solutions (pH 1 and 13), regardless of sediment type. Removal efficiencies for fine sediments from S1 and S5 were >95% after 1 h of washing with 0.2 M citric acid (C₆H₈O₇). When using 0.2 M citric acid mixed with 0.1 M potassium phosphate (KH₂PO₄), the As removal efficiency increased to 100%. When recycled washing solution was applied, As removal efficiency was maintained at a level greater than 70%, even after eight recycling events. This suggests that the recycling of washing solution could be successfully applied as a means of decreasing the cost of the washing process. Results from the experiments suggest that soil washing is a potentially useful process for the remediation of As-contaminated stream sediments around abandoned mines.     

原电池驱动污染高岭土中镉的电动力学迁移

以铁屑和活性炭构建的原电池研究不同电极间距下高岭土中的镉在原电池电场下的电动力学迁移. 随着反应时间的延长, 电压和电流均逐渐减小. 反应后, 高岭土的pH值从阳极到阴极逐渐增加. 高岭土中镉含量从阳极向阴极逐渐增加, 镉的去除率随电极间距的增加而降低, 高岭土的pH值愈低镉的迁移效果愈明显. 10cm的电极间距高岭土中镉的去除率达77. 9%, 在50cm的电极间距下镉的迁移作用很小. 表明利用铁炭原电池产生的电场可以驱动污染高岭土中镉的电动力学迁移.     

化学氧化修复对农田土壤和菠菜中多环芳烃含量和组成的影响

采用盆栽实验,研究了过硫酸钠（Na₂S₂O₈）和过氧化氢（H₂O₂）两种氧化剂分别与纳米Fe粉和硫酸亚铁（FeSO₄）两种活化剂结合,以及加入腐殖酸（HA）,对多环芳烃（PAHs）的去除,分析了对土壤和菠菜中溶剂可提取态PAHs以及土壤中不同结合态PAHs含量和组成的影响,并分析了波菜中PAHs的毒性当量浓度（BaP_eq）.结果表明,经过7周修复,对于土壤中溶剂可提取态PAHs,氧化剂剂量为0.2 g·kg^-1时,H₂O₂的氧化效果优于Na₂S₂O₈;活化剂剂量为0.448 g·kg^-1时,纳米Fe粉的活化效果优于FeSO₄;加入2 g·kg^-1HA后PAHs含量有所降低,去除率升高.H₂O₂、纳米Fe粉和HA联合处理后土壤和菠菜中溶剂可提取态PAHs含量均最低,其在土壤中的去除率和菠菜中的减少率均最高,其中土壤中溶剂可提取态PAHs的去除率为36.8%,在菠菜地上部和地下部的减少率分别为45.3%、36.4%.土壤去除率和菠菜减少率中,2环和3环的PAHs高于4环、5环和6环.对于结合态PAHs,经过H₂O₂、纳米Fe粉和HA联合处理后土壤中不同结合态PAHs平均去除率最高,达44.5%.化学处理后,各处理对菠菜的生物量没有影响.H₂O₂、纳米Fe粉和HA联合处理后,菠菜地上部总BaP_eq最低.     

Migration behavior and in-situ bioremediation of chlorinated hydrocarbon solvent in vadose zone: a review北大核心CSCD

It is of great significance for in-situ bioremediation to clarify the migration behavior and biodegradation laws of chlorinated hydrocarbon solvents (CHS) in the vadose zone. We systematically summarized the phase distribution of CHS, the interaction between different phases, and the migration characteristics and clarified the evolution rules of CHS under different phases in the polluted vadose zone. CHS exists in the vadose zone as the NAPL, dissolved phase, adsorbed phase, gas phase, and other phases, where there are three decay evolution stages: early, middle, and late stages. Phase change and diffusion matrix size are important indicators at different stages; at the same time, gas, solid, liquid and NAPL phase CHS have a variety of interactive relationships in the vadose zone. Subsequently, the characteristics of the three main biological metabolic pathways of CHS in the vadose zone–aerobic co-metabolism, direct oxidation and anaerobic reduction, and dechlorination–and their influencing factors were summarized. Generally speaking, the anaerobic dechlorination capacity decreases with a decrease in the number of chlorine atoms, whereas the aerobic degradation capacity increases with a decrease in the number of chlorine atoms. The current status of in-situ remediation of CHS in the vadose zone was summarized using biostimulation and bioaugmentation methods, indicating that adding nutrient substances and injecting anaerobic dechlorination strains of Dehalococcoides are effective means of remediation. Simultaneously, the factors influencing the biodegradation of CHS in the vadose zone were elaborated to acquire a systematic insight into the significance of redox characteristics (oxygen) on the degradation of CHS. Finally, research on the biodegradation of CHS in the vadose zone is prospected, and it is necessary to carry out research on the interactive relationship between different phases of CHS, the data monitoring of CHS, the structure of the functional bacterial community, and research and development of active strains to provide theoretical guidance for the in-situ remediation of CHS in the vadose zone. © 2022 Science Press. All rights reserved.     

复配农药污染土壤的微生物修复研究进展

随着农药使用量的急剧增加以及农药种类的发展,农药在土壤中的残留累积情况越来越严重,引起了社会广泛的关注,但以往对农药污染的研究主要集中在农药单体上,而复配农药作为现今的使用热点,没有得到足够的重视。本文以现有复配农药在土壤环境中的研究情况为基础,针对目前应用较多的除草剂、杀虫剂、杀菌剂之间的复配情况进行分析,以典型复配农药在土壤环境中的降解情况及环境行为为研究对象,介绍复配农药在土壤环境修复中的研究进展,为农药污染处理方面提供参考。     

不同类型固化材料对Cu污染水稻土的修复效果差异

通过室内实验,比较有机肥、钙镁磷肥、海泡石和石灰石等4种固化剂对铜污染土壤的pH和铜赋存形态的影响,从而筛选出最优的固化剂及其添加量.实验结果表明,添加钙镁磷肥、有机肥与石灰石均能显著提高土壤pH值,提高幅度依次为石灰石> 钙镁磷肥> 有机肥,海泡石对土壤pH值几乎无影响.依据作物生长最适pH值,石灰石和钙镁磷肥的添加量分别控制在4 g·kg-1、8 g·kg-1以下为宜;钙镁磷肥、有机肥和石灰石对土壤中Cu赋存形态的影响均表现出可交换态比例下降,有机结合态比例升高;3种固化剂的固化效果为:4 g·kg-1石灰石> 8 g·kg-1钙镁磷肥≈8 g·kg-1有机肥,而海泡石的固化效果较差,不宜用于改良该Cu污染的土壤.