纳米铁对微生物燃料电池启动的影响

设置3组不同阳极底物的微生物燃料电池（microbial fuel cell,MFC）：无添加污泥（对照组）、含化学合成零价纳米铁的污泥（c-nZVI组）和含绿色合成零价纳米铁的污泥（g-nZVI组）,拟探究不同来源零价纳米铁（nZVI）对MFC启动的影响。3组MFC经由5个周期启动,实验结果表明,在c-nZVI组和g-nZVI组的启功阶段,高浓度的绿色合成零价纳米铁和化学合成零价纳米铁均对MFC的输出电压产生抑制作用,当MFC成功启动后,零价纳米铁对MFC的输出电压影响不明显。此外,COD去除率、SEM和电化学表征数据表明,绿色合成零价纳米铁相比于化学合成零价纳米铁在电极表面富集程度、对电极表面性质改变以及产电菌活性的抑制作用更弱。     

铁还原菌作用下含镉聚合硫酸铁絮体中铁还原与镉释放规律及其影响因素

选取Shewanella oneidensis MR-1为供试铁还原菌,旨在研究MR-1在还原含Cd聚合硫酸铁絮体过程中,絮体中Fe（Ⅲ）还原、Cd释放规律及影响因素。结果表明,扰动可促进絮体中Fe（Ⅲ）还原及Cd释放;絮体中Cd的添加使得Fe（Ⅲ）还原过程中产生的二次矿物主要物相由磁铁矿转变为针铁矿,且Cd浓度的增加导致Fe（Ⅲ）还原率逐渐降低,Cd释放率也逐渐降低;絮体中Fe浓度的逐渐增大同样使得Fe（Ⅲ）还原率逐渐降低,Cd释放率则先增大后减小;腐殖质类模型物质蒽醌-2,6-二磺酸钠的添加可提高絮体中Fe（Ⅲ）的还原率,进而促进Cd的释放。对同一体系或不同体系间的Fe（Ⅲ）还原率及Cd释放率进行线性拟合,结果发现较大的Fe（Ⅲ）还原率能够导致絮体中Cd的更多释放,从而对环境造成更大的危害。     

铁黄生产中废水处理与废渣的回收利用

介绍了氧化铁黄生产中的废水治理情况，同时其产生的废渣可回收利用。经过治理产生的环境、经济和社会效益显著。     

铁的环境地球化学综述

本文详细介绍了铁在表生地球化学环境中的存在状态,亚铁的氧化动力学,铁微生物地球化学及铁在表生带迁移转化的环境学意义,强调了铁环境地球化学研究的重要性     

铁矿石对脱除烧结废气中NOx的催化效应

向混合料中加添加剂能够在烧结过程中脱除烧结废气中的NO。实验研究了铁矿石对NO脱除反应的催化效应。在900℃下,分别以5种不同铁矿石作为填料层,用2种标准气体和压缩空气配制的混合气体模拟烧结废气。试验结果表明,铁矿石种类对铁矿石的催化能力有重要影响。D型铁矿的催化能力最强而且不会发生弱化,NO转化率接近100%;其它几种铁矿石的催化能力较差,随着反应时间的延长有明显的弱化现象,但很快即基本趋于稳定状态,NO转化率达到了60%~70%。     

氧气促进纳米零价铁除砷效果及其作用机制

为了探究氧气对纳米零价铁(nZVI)除砷的影响,考察了不同的氧含量(厌氧、低氧、中氧和高氧)条件下nZVI对As(Ⅲ)/As(V)的去除效果,并结合表征结果分析了氧气对nZVI除砷的影响机制。结果表明：氧气存在会显著促进nZVI对As(Ⅲ)/As(Ⅴ)的去除,但不同氧含量对nZVI除砷的促进程度有所不同;随着氧含量的增加,As(Ⅲ)/As(Ⅴ)的去除率呈现先增大后减小然后再增大的趋势。在初始砷浓度为50 mg·L⁻¹、nZVI投加量为200 mg·L⁻¹、O₂/nZVI摩尔比等于0.5时,砷的去除率达到最大,As(Ⅲ)和As(Ⅴ)体系中砷的去除率分别为96.27%和51.75%。固相表征结果表明：氧气对nZVI的氧化程度及除砷效果具有较大的影响,在低氧条件下,nZVI被少量氧化为无定型铁矿物进而提高除砷效果;在中氧条件下,nZVI被氧化为大量的溶解态Fe(Ⅱ)/Fe(Ⅲ),溶解态铁对砷没有去除效果,从而导致砷的去除率降低;在高氧条件下,nZVI被大量氧化,溶解态Fe(Ⅱ)/Fe(Ⅲ)进一步被氧化形成新的无定型铁矿物,可增强除砷效果。以上结果可为评估不同氧含量条件下纳米零价铁除砷效果以及人为强化纳米零价铁除砷效果提供参考。     

复合铁添加物对混合有机固废厌氧产氢的影响

将城镇污水处理厂的城市污泥与餐厨垃圾混合后,经厌氧消化处理后可产生能源气体氢气,从而达到资源化利用的目的.废铁屑是机械加工厂的固体废弃物,将其处理后可得到一种新型复合铁材料(FE/FEO).将城市污泥和餐厨垃圾预处理后按体积比1:1比例混合,分别等分放入2个反应器中,一个投加FE/FEO粉末作为为FE/FEO组,另一个...     

In situ sequential treatment of a mixed contaminant plume

Groundwater plumes often contain a mixture of contaminants that cannot easily be remediated in situ using a single technology. The purpose of this research was to evaluate an in situ treatment sequence for the control of a mixed organic plume (chlorinated ethenes and petroleum hydrocarbons) within a Funnel-and-Gate. A shallow plume located in the unconfined aquifer at Alameda Point, CA, was found to contain up to 218,000 μg/l of cis-1,2 dichloroethene (cDCE), 16,000 μg/l of vinyl chloride (VC) and <1000 μg/l of 1,1 dichloroethene (1,1 DCE), trans-1,2 dichloroethene (trans-1,2 DCE) and trichloroethene (TCE). Total benzene, toluene, ethylbenzene and xylenes (BTEX) concentrations were <10,000 μg/l. Contaminated groundwater was funneled into a gate, 3.0 m wide, 4.5 m long and 6.0 m deep (keyed into the underlying aquitard) where treatment occurred. The initial gate segment consisted of granular iron, for the reductive dechlorination of the higher chlorinated ethenes. The second segment, the biosparge zone, promoted aerobic biodegradation of petroleum hydrocarbons and any remaining lesser-chlorinated compounds, stimulated by dissolved oxygen (DO) and carbon dioxide (CO₂) additions via an in situ sparge system (CO₂ was used to neutralize the high pH produced from reactions in the iron wall). Groundwater was drawn through the gate by pumping two wells located at the sealed, downgradient, end. Over a 4-month period an estimated 1350 g of cDCE flowed into the treatment gate and the iron wall removed 1230 g, or 91% of the mass. The influent mass of VC was 572 g and the iron wall removed 535 g, corresponding to 94% mass removal. The other chlorinated ethenes had significantly lower influent masses (3 to 108 g) and the iron wall removed the majority of the mass resulting in >96% mass removal for any of the compounds. In spite of these high removal percentages, laboratory column tests indicated that at these levels of chlorinated contaminants, surface saturation of the iron grains likely contributed to lower than expected reaction rates. In the biosparge zone, mass removal of cDCE appeared to occur predominantly by biodegradation (65%) with volatilization (35%) being an important secondary process. The dominant removal process for VC was volatilization (70%) although significant biodegradation was also indicated (30%). Laboratory microcosm results confirmed the potential for aerobic biodegradation of cDCE and VC. When average influent field concentrations for cDCE and VC were 220,000 and 46,000 μg/l, respectively, the sequential treatment unit removed 99.6% of the total mass and when the influent concentrations decreased to 26,000 and 19,000 μg/l for cDCE and VC, respectively, >99.9% removal within the treatment gate was attained. BTEX compounds were found to be significantly retarded in the iron treatment zone. Although they did eventually break through the granular iron, and into the gravel transition zone, none of these compounds was detected in the biosparge zone. No noticeable interferences between the anaerobic (reductive) and aerobic parts of the system occurred during testing. The results of this experiment show that in situ treatment sequences are viable, although further work is needed to optimize performance.     

铁氧化物/活性炭对饮用水中Sb(V)的吸附性能及机理

采用液相沉积法制备了铁氧化物/活性炭复合材料(Fe₂O₃@AC),通过单因素实验和正交实验优化了材料的制备条件,使用SEM、FTIR、XRD、XPS等分析方法对材料的形貌和性质进行了表征分析,通过吸附实验探究了Fe₂O₃@AC吸附除锑的效果及影响因素,并进一步对吸附除锑的机理进行了深入探讨。结果表明：最佳制备条件为纯水:乙醇:=4:1,Fe²⁺:Fe³⁺=1:1,总铁浓度为0.594 mol·L⁻¹,制备液pH=1.88。Fe₂O₃@AC吸附除锑的能力较其他金属基材料和活性炭有明显提高,锑原水质量浓度为38 μg·L⁻¹,Fe₂O₃@AC投加量为0.08 g·L⁻¹,吸附平衡后水中锑的去除率达97%,剩余锑质量浓度为1.06 μg·L⁻¹,满足国家饮用水卫生标准要求。微观表征显示铁氧化物颗粒成功负载于活性炭上,且铁氧化物晶体的结构完好。吸附反应符合准二级动力学和Langmuir等温模型,吸附反应以单层化学吸附为主,吸附类型为液膜扩散,颗粒内扩散,质量扩散的叠加形式。吸附方式为共沉淀,及溶解态锑与固相铁氧化物形成络合物,参与反应的官能团为—OH、—COOH、—Fe—OH、—Fe—O—Fe。     

纳米零价铁与黑曲霉发酵液联用对砷锑污染土壤的淋洗修复

土壤砷 (As) 、锑 (Sb) 污染对生态环境和人体健康有着潜在的风险,采用黑曲霉发酵液 (FB) 与纳米零价铁 (nZVI) 联用淋洗修复As、Sb污染土壤。通过振荡淋洗实验,探究nZVI强化FB淋洗去除As、Sb的效果及不同条件下对As、Sb淋洗效率的影响。结果表明,制备的FB对污染土壤中As和Sb有着较好的去除效果,去除率可达84.1%和71.8%;nZVI对FB去除As、Sb有强化作用,在nZVI质量浓度为0.1 g·L⁻¹、pH为1和淋洗时间为60 min的条件下,其淋洗效果最佳,对As、Sb淋洗效率可达96.6%和95.6%,修复后的土壤达到《土壤环境质量 建设用地土壤污染风险管控标准 (试行) 》 (GB 36600-2018) 二类用地标准。nZVI-FB对土壤中As、Sb的解吸动力学符合拟二级动力学方程。nZVI-FB能够有效的提取土壤中As、Sb的铁铝氧化物结合态。本研究结果可为As、Sb复合污染土壤的淋洗修复提供参考。