鼠李糖脂洗脱氯丹和灭蚁灵污染场地土壤的工艺参数

优化了鼠李糖脂洗脱氯丹、灭蚁灵污染土壤的工艺条件,为开展有机氯农药污染场地土壤洗脱修复工程实践提供科学依据和技术参数。实验结果表明,随着洗脱剂———鼠李糖脂浓度的增加,氯丹和灭蚁灵的洗脱量呈现先增加后降低的趋势;洗脱时间和液固比对洗脱效果的影响趋势与浓度相同;在0~120 r/min范围内,氯丹和灭蚁灵洗脱量随着搅拌速度的增加而增大,80、120和200 r/min的洗脱量间差异不显著;单次洗脱量随洗脱次数的增加而降低,累计洗脱量则逐渐增大。综上所述,氯丹、灭蚁灵污染场地土壤鼠李糖脂洗脱的适宜工艺参数为鼠李糖浓度10 mmol/L,搅拌速度80 r/min,固液比1∶10,洗脱时间20 min,洗脱3次。     

磁性生物炭负载Mg-Fe水滑石的制备及其吸附水中Cd（Ⅱ）和Ni（Ⅱ）的性能

合成了一种高吸附容量的磁性生物炭负载Mg-Fe水滑石复合材料（L-BC）,并用于去除水中的Cd²⁺和Ni²⁺。表征结果表明,采用浸渍联合热解法成功制备了磁性生物炭（M-BC）,水热合成法成功地将Mg-Fe水滑石负载在M-BC上。动力学研究结果表明,Cd²⁺和Ni²⁺吸附符合伪二级动力学模型,化学吸附为速率控制步骤。等温吸附研究结果表明,L-BC对Cd²⁺和Ni²⁺的吸附符合Langmuir模型,为单分子层化学吸附,最大吸附量分别为263.156 mg/g和43.291 mg/g。吸附机理主要为Mg-Fe水滑石层间CO₃^2-和表面羟基与Cd²⁺和Ni²⁺产生表面共沉淀。L-BC具有良好的吸附和重复利用性能,是一种很有前景的去除Cd²⁺和Ni²⁺的吸附材料。     

Vermicomposting as an advanced biological treatment for industrial waste from the leather industry

The leather industry (tanneries) generates high amounts of toxic wastes, including solid and liquid effluents that are rich in organic matter and mineral content. Vermicomposting was studied as an alternative method of treating the wastes from tanneries. Vermicompost was produced from the following tannery residues: tanned chips of wet-blue leather, sludge from a liquid residue treatment station, and a mixture of both. Five hundred earthworms (Eisenia fetida) were added to each barrel. During the following 135 days the following parameters were evaluated: pH, total organic carbon (TOC), organic matter (OM), cation exchange capacity (CEC), C:N ratio, and chromium content as Cr (III) and Cr (VI). The results for pH, TOC and OM contents showed decreases in their values during the composting process, whereas values for CEC and total nitrogen rose, indicating that the vermicompost reached maturity. For chromium, at 135 days, all values of Cr (VI) were below the detectable level. Therefore, the Cr (VI) content had probably been biologically transformed into Cr (III), confirming the use of this technique as an advanced biological treatment. The study reinforces the idea that vermicomposting could be introduced as an effective technology for the treatment of industrial tannery waste and the production of agricultural inputs.     

Getting caught up in the game: managing non-formal dynamics in the remediation of contaminated sediments in Oslo harbor

This study aims at describing, analyzing and evaluating the relation between management styles and process dynamics of a complex planning process confronted with unexpected dynamics. The development of an aquatic disposal site for dredged contaminated sediments in Oslo was managed by a project management style focused on timely and cost-effective implementation. Coupling the remediation project with another infrastructural project and the actual construction of the site led to unexpected dynamics in terms of resistance and controversy. Project management had difficulties in adjusting its style accordingly, resulting in even more delay and resistance. Managing complex planning projects requires a style suitable to the characteristics of the project and the capability of adjusting it to changing circumstances. The paper concludes with some explanations why it is difficult to change management styles in complex planning and implementation processes and complexity-embracing approaches to deal with this.     

我国高速公路周边土壤重金属污染现状及研究进展

以我国高速公路周边土壤重金属为研究对象，综述了我国高速公路周边土壤重金属污染特征、影响因素、来源、环境风险及其研究进展。高速公路周边土壤主要受Pb、Cd、Cr、Cu、Zn等重金属污染，主要呈现指数分布、偏态分布和两者混合分布等特点，并且受到土地利用、风向、地形、车流量等多种因素的综合影响。土壤重金属的来源除了受成土母质等自然因素影响以外，公路交通和周边工农业活动也会对其来源产生较大影响。传统的土壤重金属评价方法主要采用单因子指数法、地累积指数法、生态风险评价法等对重金属的污染等级和环境风险进行评价。未来的研究应将重金属形态分析、空间和地统计分析、重金属稳定同位素示踪和源解析模型以及预测模型等多种手段相结合，开展高速公路周边土壤重金属的污染特征、时空分布、来源及预测预警研究等，为我国高速公路沿线工农业生产布局及其土壤重金属污染防控提供科学依据和决策支撑。     

Biogenic palladium prepared by activated sludge microbes for the hexavalent chromium catalytic reduction: Impact of relative biomass

• Pd nanoparticles could be reduced and supported by activated sludge microbes. • The effect of biomass on Pd adsorption by microbes is greater than Pd reduction. • More biomass reduces Pd particle size, which is more dispersed on the cell surface. • When the biomass/Pd add to 6, the catalytic reduction rate of Cr(VI) reaches stable. Palladium, a kind of platinum group metal, owns catalytic capacity for a variety of hydrogenations. In this study, Pd nanoparticles (PdNPs) were generated through enzymatic recovery by microbes of activated sludge at various biomass/Pd, and further used for the Cr(VI) reduction. The results show that biomass had a strong adsorption capacity for Pd(II), which was 17.25 mg Pd/g sludge. The XRD and TEM-EDX results confirmed the existence of PdNPs associated with microbes (bio-Pd). The increase of biomass had little effect on the reduction rate of Pd(II), but it could cause decreasing particle size and shifting location of Pd(0) with the better dispersion degree on the cell surface. In the Cr(VI) reduction experiments, Cr(VI) was first adsorbed on bio-Pd with hydrogen and then reduced using active hydrogen as electron donor. Biomass improved the catalytic activity of PdNPs. When the biomass/Pd (w/w) ratio increased to six or higher, Cr(VI) reduction achieved maximum rate that 50 mg/L of Cr(VI) could be rapidly reduced in one minute.     

铅冶炼区土壤重金属总量和有效态含量的函数分析

采集铅冶炼企业周边3 000 m范围内220个表层土壤样品,测定了有毒有害元素铅、镉、砷和汞的总量和有效态含量,探讨了它们之间的关系。结果表明:研究区土壤受到汞、砷、铅、镉的污染依次明显严重,土壤重金属的总量和有效态含量的变异系数均大于100%,土壤镉、铅、汞、砷的生物有效性系数平均值分别为25.9%、17.2%、0.58%、0.11%。土壤铅、镉和砷的总量与其有效态含量呈显著正相关(P0.001),而汞的总量与其有效态含量的相关性不显著(P0.05)。土壤铅和镉的总量和有效态含量可以用直线函数和幂函数表达,函数反推的有效态值和对应统计值的变异系数不大于10%。     

砒霜生产化工厂危险废物处置工程设计

通过对砒霜生产化工厂原场址废渣及污染场地调查的基础上，进行了处置方案比选及技术经济比较，确定了就地安全填埋的处置方案。根据区域性危险废物集中安全填埋场的设计经验，本工程采用先进的HDPE双层防渗的安全填埋方式，并设置了雨水分流系统、渗滤液收集系统、封场处理和填埋气体导排系统，整个场区布置合理，对周围环境的影响小，投资少，取得了良好的社会效益和环境效益，并对危险废物处理处置工程设计中应注意的问题提出了建议。     

经口摄入土壤多溴联苯醚生物可给性变化及影响因素的体外消化模拟

误食土壤是污染物(如多溴联苯醚)人体(主要是儿童)暴露的重要途径,人体消化道内污染物吸收的生物可给性是针对此种暴露方式进行定量风险评估的有效途径之一.本研究采用体外消化实验模拟3种不同有机碳含量的天然土壤中典型多溴联苯醚(BDE-28、BDE-47、BDE-99和BDE-153)在胃和小肠消化液中的释放,验证部分消化释放的多溴联苯醚因消化残留固相表面的再吸附造成低估实际生物可给性,并通过不同水土比的拟合计算予以校正.结果表明,校正后的消化率普遍高于校正前;就不同土样而言,BDE-28、BDE-47、BDE-99和BDE-153在不同初始暴露浓度条件下平均提升比例范围分别为14.3%~42.3%、11.1%~32.1%、4.9%~12.3%和0.0%~7.7%.因此,未经校正的消化率会显著低估PBDEs消化道内的生物可给性,尤其是低溴代组分及PBDEs初始浓度较高或高TOC含量的土样.校正后BDE-28、BDE-47、BDE-99和BDE-153的消化率分别维持在21.9%~54.7%、18.8%~43.1%、13.4%~27.2%和9.3%~19.9%.此外,PBDEs的消化率与其辛醇-水分配系数的对数lg KOW呈显著负相关;而与土壤TOC含量及PBDEs初始暴露浓度的相关性并不显著,尤其是高溴代组分.     

石油污染土壤的生物修复技术及微生物生态效应

利用投菌法和生物刺激法对陕北子长石油污染土壤进行微生物修复研究.通过利用红外分光光度法测定不同处理方法对石油烃的去除效果确定了修复陕北石油污染土壤的最佳方案.修复过程中利用最大可能计数法(MPN)、PCR-琼脂糖电泳法、PCR-DGGE法分别测定了石油烃降解菌数目、催化基因、土壤微生物多样性对土壤微生物生态效应进行研究.结果发现石油污染土壤不同生物处理修复效果为:生物刺激(加入N、P营养物质)生物强化(投加降解菌)其他.土壤中石油烃降解率与可降解石油烃的催化基因含量之间存在正相关关系,修复过程中土壤中的石油烃和烷烃降解菌数量显著多于多环芳烃降解菌数量,投加外源降解菌SZ-1可以显著提高土壤细菌群落的多样性.研究结果有助于深入理解生物修复石油土壤过程中的微生物生态效应变化.