EDDS强化Fe0-Al0体系降解废水中4-氯酚的性能和机理

采用乙二胺二琥珀酸（EDDS）强化Fe⁰-Al⁰体系还原水溶液中的O₂产生H₂O₂和·OH等活性氧（ROS）的绿色高级氧化工艺,以4-氯酚（4-CP）模拟废水为研究对象,考察了溶液的初始pH值、铁铝的质量比、EDDS投加量和4-CP的初始浓度等因素对4-CP降解的影响.采用电子自旋共振（ESR）法、苯甲酸捕捉法以及4-CP的降解产物等证实了ROS的产生及4-CP的降解机制.结果表明：EDDS强化Fe⁰-Al⁰/O₂体系对4-CP的去除率随溶液初始pH的升高而降低,但在pH=2.5～9范围内,始终具有较好的4-CP去除率;随Fe⁰：Al⁰质量比增加4-CP的去除率先增大后减小,最佳质量比为4：1;随EDDS投加量和4-CP初始浓度增加,4-CP的去除率增大;EDDS可使体系的高级氧化能力提高9倍,在初始pH=2.5、Fe⁰=8g/L、Al⁰=2g/L、EDDS=1.5mmol/L条件下,反应3h后100mg/L 4-CP的去除率和脱氯率均达到近100%..     

MW-Fe0/H2O2体系预处理垃圾渗滤液浓缩液有机物

为探究MW-Fe⁰/H₂O₂类芬顿反应对渗滤液浓缩液的效能与机理,探讨了废水初始pH值、Fe⁰投加量、H₂O₂投加量、MW功率和反应时间等影响因素对有机物去除效果,通过类比实验对MW-Fe⁰/H₂O₂体系处理渗滤液浓缩液中MW辐射的反应机理进行研究,并采用了SEM和XRD技术对反应前后的Fe⁰物相变化及催化机理进行了探究.结果表明,在初始pH值为3.0,Fe⁰投加量0.5g/L,H₂O₂投加量20mL/L,MW功率400W,反应时间14min时,其COD、UV₂₅₄以及色度（CN）的去除率分别为58.70%、85.69%和88.30%.类芬顿类比实验说明MW-Fe⁰/H₂O₂体系处理后具有较高的有机物去除率和可生化性;紫外-可见光谱表明,Fenton和MW-Fe⁰/H₂O₂类芬顿反应均能使废水中有机物的芳香性程度、分子量和缩合度大幅度降低,但MW-Fe⁰/H₂O₂类芬顿反应优于其他反应过程;三维荧光光谱显示,MW-Fe⁰/H₂O₂类芬顿反应能使渗滤液浓缩液中荧光峰峰位蓝移,说明废水的腐殖质缩合度减小,且分子量大幅降低.与此同时,Fe⁰在反应过程中,表面由光滑变得粗糙且被腐蚀为Fe₃O₄和FeOOH等物质.MW-Fe⁰/H₂O₂类芬顿反应的主要机理为芬顿反应及铁氧化物-H₂O₂非均相芬顿反应的高级氧化作用、铁基胶体对有机物的吸附沉淀,而MW的热效应和非热效应加速了以上作用的进行,从而能对渗滤液浓缩液中有机污染物进行快速去除.     

大气降尘中铅、锌、铜、铁的原子吸收光谱法测定

研究了大气降尘中铅、锌、铜、铁等金属元素的原子吸收光谱测定方法,用氢氟酸消解法对降尘进行预处理,并对方法的精密度、准确度进行了检验,结果较为满意.该法简便、快速、灵敏.     

磁流体处理印染废水初探

探讨了Fe3O4磁流体在不同条件下对降低印染废水的COD和色度两个方面的影响，实验表明，当pH=11，十二烷基叔胺的量是亚铁量的0．16倍时，COD降低最多，脱色效果最好，且磁场强度在160mT左右时，磁流体沉降最快。     

Metal Concentrations in Pore Water of the Lusatian Lignite Mining Sediments and Internal Metal Distribution in Juncus bulbosus

The aim of this study was to determine a suite of four metals (Fe, Mn, Zn, Cu) in the sediment, porewater and a pioneer plant (Juncus bulbosus) of Lusatian lignite mining lakes in eastern Germany. An attempt was made to understand the factors which affect element concentrations in the above- and below-ground biomass of Juncus bulbosus in an extreme environment. Water samples, sediments, porewater and plant material collected from two different mining lakes dominated by Juncus bulbosus species were analyzed for their elemental content. Additionally, scanning electron microscopy (SEM) and an energy-dispersive X-ray (EDX) detector were used to follow the internal metal distribution in the roots of Juncus plant. Results showed that sediment and porewater element concentrations in the lakes decreased in the order Fe > Mn > Zn and Cu. All the four elements were higher in the roots than in above-ground tissues, suggesting that iron plaque induced on roots under anaerobic conditions served as a metal reservoir, but not as an ultimate mechanism to control metal concentrations in the above-ground tissues. SEM and EDX analyses revealed that the rhizodermis, exodermis and endodermis cells regulate the traffic of transition metals and therefore avoid excess levels that are toxic to the plant in acidic mining-impacted lake sediments.     

云贵高原湖泊沉积物一水界面铁、锰、硫体系的研究进展

通过对云贵高原湖泊沉积物一水界面铁、锰、硫体系的研究 ,揭示了湖泊铁、锰循环受氧化还原边界层、沉积物一水界面等多重界面的控制 ;湖水中硫酸盐的浓度制约着其扩散的物理过程 ,进而影响着硫酸盐还原作用 ;硫酸盐还原对铁、锰循环产生亚扩散层屏蔽效应 ;铁、锰循环伴随有微量金属元素的沉积后再迁移现象 ;沉积物一水界面为认识湖泊污染问题、有效地解决湖泊铁、锰的季节性污染等提供了科学依据。     

泸沽湖氧化还原边界层的季节性迁移及其对水质的影响

通过对云南泸沽湖孔隙水和沉积物垂直剖面Ｍｎ，Ｆｅ及其它氧化还原参数季节性变化规律的研究，建立了湖泊氧化还原边界层的季节性迁移模式，同时定量评估了重金属界面扩散作用对上覆湖水水质的季节性影响。结果表明，孔隙水和沉积物Ｍｎ，Ｆｅ浓度均呈明显的峰形分布，Ｍｎ，Ｆｅ峰的位置和形状以及其它氧化还原参数都表现出季节性变化的特点；     

水稻耐亚铁的水培鉴定指标研究

通过水培试验，研究Ｆｅ（２＋）胁迫下的水稻品种生物性状和主要生理生态特性，明确Ｆｄ（２＋）１２０ｍｇ／ｋｇ为鉴别水稻品种耐性差异的适宜亚铁浓度．并提出可将苗高、根系生长量、根系氧化力、干物质产量作为水稻品种耐亚铁的鉴定指标．     

Effect of humic acids on the Fenton degradation of phenol

We show that the degradation of phenol by Fe(III) and hydrogen peroxide is faster in the presence of humic acids. This is most likely due to faster reduction of Fe(III)-humate complexes by H₂O₂/HO₂^·/O₂^–· when compared with Fe(III)-H₂O complexes. The fact that humic acids, a major class of naturally occurring compounds, favour the Fenton reaction has great relevance in the field of water and soil decontamination, where organic compounds usually have a negative effect. Furthermore, it adds insight into the self-depuration processes of natural aquifers.     

Metal contamination of riverine sediments below the Avoca mines, south east Ireland

The River Avoca is severely polluted by discharges of acid mine drainage (AMD) from the abandoned sulphur and copper mines at Avoca. The riverine sediments were studied during a low flow period to establish the degree of contamination and to identify the major processes affecting sediment metal concentrations. pH plays a major role in the regulation of zinc adsorption and desorption in sediments, showing a significant correlation (p&0.001). The zinc concentration in the sediment falls below background levels after the input of AMD. However, the metal precipitated when the pH increased downstream of a fertiliser factory (pH8.0), some 7 km below the mine. In contrast Cu and Fe significantly increased (p0.001) both in the sediment (0--30 mm depth) and the surface ochre immediately below the mixing zone. Copper removal appears to be primarily by co-precipitation. Higher sediment enrichment factors for all metals were obtained in the surface sediment layer (ochre) deposited on larger stones and in floc material collected in sediment traps, compared with the subsurface sediment. Cadmium was not recorded in any of the sediment collected at the detection limit used (0.01 g g-1). Metal deposition in the sediments was found to be spacially variable, so sub-sampling is required, although replicates show little variation. Results indicate that short term variation in metal inputs is identified by sampling the surface layer only, whereas sampling of the subsurface layer (<63 m fraction) is more suitable for identifying long-term trends in sediment quality. The implication of sediment analysis in assessing environmental impact is discussed.