地下环境中Fe2+对硝基苯的还原衰减作用模拟研究

研究了地下环境中的Fe2+对硝基苯(NB)的还原衰减作用,模拟了Fe2+还原硝基苯的过程及不同硬度、CO32-、SO42-、NO3-、Cl-等地下水化学组成对反应的影响,目的是阐明Fe2+还原硝基苯的机制及水化学组成对反应影响的原因.结果表明,在温度为10℃、pH为6.8的条件下,Fe2+和硝基苯浓度皆对其还原衰减有影...     

Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate: Batch uptake behavior

Chromium and/or arsenate removal by Fe(II) as a function of pH, Fe(II) dosage and initial Cr(VI)/As(V) ratio were examined in batch tests. The presence of arsenate reduced the removal e ciency of chromium by Fe(II), while the presence of chromate significantly increased the removal e ciency of arsenate by Fe(II) at pH 6–8. In the absence of arsenate, chromium removal by Fe(II) increased to a maximum with increasing pH from 4 to 7 and then decreased with a further increase in pH. The increment in Fe(II) dosage resulted in an improvement in chromium removal and the improvement was more remarkable under alkaline conditions than that under acidic conditions. Chromium removal by Fe(II) was reduced to a larger extent under neutral and alkaline conditions than that under acidic conditions due to the presence of 10 mol/L arsenate. The presence of 20 mol/L arsenate slightly improved chromium removal by Fe(II) at pH 3.9–5.8, but had detrimental e ects at pH 6.7–9.8. Arsenate removal was improved significantly at pH 4–9 due to the presence of 10 mol/L chromate at Fe(II) dosages of 20–60 mol/L. Elevating the chromate concentration from 10 to 20 mol/L resulted in a further improvement in arsenate removal at pH 4.0–4.6 when Fe(II) was dosed at 30–60 mol/L.     

化学沉淀结合Fenton法预处理脱硫废液的原理与效果分析

脱硫废液因含有高浓度氰化物、硫氰化物、硫化物等有毒组分而影响焦化废水处理的生物工艺.以焦化企业产生的实际脱硫废液为研究对象,选用化学沉淀-Fenton氧化的串联方法尝试预处理及分析方法的可行性,通过单因素实验,考察了硫酸亚铁投加剂量、反应前后溶液pH值、反应时间3种条件对脱硫废液中总氰及易释放氰去除效果的影响,在优化条件下对经硫酸亚铁沉淀后的脱硫废液残液进行Fenton氧化实验.结果表明,当硫酸亚铁投加量为理论值的1.2倍,H2O2投加量为COD当量的0.3倍时,可使脱硫废液的COD去除率达到76.65%,使初始浓度分别为327.7、704.6和2087.3 mg.L-1的氰化物、硫氰化物及硫化物基本得到去除,为后续生物处理创造了有利条件.化学沉淀结合Fenton法是脱硫废液预处理效率高且实用的方法.     

利用盐酸酸洗废液制取复合亚铁絮凝剂

介绍了利用盐酸酸洗废液为原料制备复合亚铁絮凝剂的方法 ,研究了复合亚铁的除浊性能 ,考察了硅铁比、水样pH和温度对其混凝性能的影响 ,探讨了其电导性质 ,并应用于印染废水的混凝处理。结果表明 ,复合亚铁絮凝剂效果好、处理成本低 ,值得推广应用。     

利用硫酸渣生产铁精粉的新工艺研究

实验了一种新的工艺来处理硫酸渣,该方法能很好地脱除烧渣中的硫并富集其中的铁,解决了硫酸渣脱硫难的问题。经过处理后可以将其开发为有用的铁精粉作为炼铁原料或者是生产其他铁系产品,实现了废物的资源综合利用。     

阴离子对Fenton氧化降解聚乙烯醇的影响

研究了亚铁盐中NO3-、SO42-、Cl-、Br-等阴离子对Fenton氧化降解高浓度聚乙烯醇(PVA)效果的影响。实验结果表明:酸性条件下具有氧化性的阴离子NO3-或能被氧化形成具有氧化性物质的离子Cl-、Br-对Fenton氧化降解PVA有协同促进作用,且氧化性越强越容易促使PVA大分子链断裂;含NO3-、Cl-、Br-和SO42-的Fenton氧化降解PVA,COD去除率分别为70.05%、70.60%、72.40%和87.90%。采用COD去除率相差不大、产物分子量较小的硝酸亚铁、氯化亚铁、溴化亚铁中的一种作为Fenton试剂催化降解PVA较适宜。     

硫酸亚铁法与硫化钠法处理络合铜废水的对比研究

通过硫酸亚铁（FeSO4）法和硫化钠（Na2S）法处理络合铜废水的对比实验研究,探讨了FeSO4和Na2S破络机理、两种药剂的授加量、pH值、絮凝剂（PAM）的加入量对铜去除率的影响,分析两种处理方法的优缺点,以期为线路板厂络合铜废水处理提供参考。     

金属络合剂在烟气同时脱硫脱硝中的应用

液相络合法是烟气同时脱硫脱硝中广泛应用的方法之一。液相络合法常用的金属络合剂有亚铁络合剂和钴络合剂等。重点介绍了亚铁氨羧络合剂、含-SH的亚铁络合剂和六氨合钴络合剂、乙二胺合钴络合剂等同时脱硫脱硝的基本过程及常用吸收液的再生方法,指出了金属络合剂在烟气同时脱硫脱硝中应用时存在的问题及今后的发展方向。     

Impact of different benthic animals on phosphorus dynamics across the sediment-water interface

As a diagenetic progress, bioturbation influences solute exchange across the sediment-water interface (SWI). Different benthic animals have various mechanical activities in sediment, thereby they may have different effects on solute exchange across the SWI. This laboratory study examined the impacts of different benthic animals on phosphorus dynamics across the SWI. Tubificid worms and Chironomidae larvae were introduced as model organisms which, based on their mechanical activities, belong to upward-conveyors and gallery-diffusers, respectively. The microcosm simulation study was carried out with a continuous flow culture system, and all sediment, water, and worms and larvae specimens were sampled from Taihu Lake, China. To compare their bioturbation effects, the same biomass (17.1 g wet weight (ww)/m2) was adopted for worms and larvae.Worms altered no oxygen penetration depth in sediment, while larvae increased the O2 penetration depth, compared to the control treatment. Their emergence also enhanced sediment O2 uptake. The oxidation of ferrous iron in pore water produced ferric iron oxyhydroxides that adsorbed soluble reactive phosphorus (SRP) from the overlying water and pore water. Larvae built obviously oxidized tubes with about 2 mm diameter and the maximum length of 6 cm in sediment, and significantly decreased ferrous iron and SRP in the pore water compared to the control and worms treatments. Worms constructed no visually-oxidized galleries in the sediment in contrast to larvae, and they did not significantly alter SRP in the pore water relative to the control treatment. The adsorption of ferric iron oxyhydroxides to SRP caused by worms and larvae inhibited SRP release from sediment. Comparatively, worms inhibited more SRP release than larvae based on the same biomass, as they successively renewed the ferric iron oxyhydroxides rich oxidation layer through their deposition.     

重金属螯合捕集剂NBMIPA的合成及其捕集Cu2+、Zn2+性能

以间苯二甲酰氯(IPC)和巯基乙胺盐酸盐(CHC)为原料,采用一步法合成重金属螯合捕集剂N,N’-双(2-巯基乙基)—1,3-苯二甲酰胺(NBMIPA),重点研究了物质的量比(n(CHC):n(IPC))和反应温度对NBMlPA产率的影响,并研究了NBMIPA投加量和pH对Cu2+、Zn2+捕集性能的影响.结果表明:重金属螯合捕集剂NBMIPA的最佳合成工艺为n(CHC):n(IPC) =2.8、反应温度-5℃,此时NBMIPA的最高产率为78.64％;NBMIPA对Cu2+和Zn2+的捕集性能优良,NBMIPA投加量越大,捕集性能越高;NBMIPA对pH具有较宽的适应性.当NBMIPA投加量分别为45 mL和30 mL时,NBMIPA对Cu2+和Zn2+的捕集效果最佳,Cu2+的去除率达到99.33％,残余Cu2+浓度为0.46 mg·L-1,Zn2+的去除率达到97.49％,残余Zn2+浓度为1.84 mg·L-1.