电镀废水处理站DTCR辅助氢氧化物沉淀工艺改造

某废水处理站改造前采用传统氢氧化物沉淀工艺处理高浓度含铬、氰镉电镀废水,运行不稳定,出水不能达标排放。工艺改造后增加了高分子重金属捕集沉淀剂DTCR辅助去除重金属,在含铬废水DTCR投加量为50 mg/L、含氰镉废水DTCR投加量为10 mg/L条件下,出水总铬、镉分别稳定在0.5 mg/L、0.2 mg/L以下,远低于《电镀污染物排放标准》(GB 21900—2008)限值。     

重金属废水生物处理技术

主要从生物法去除废水中重金属的原理,重金属废水生物处理技术,及重金属废水生物处理的影响因素等方面,综述了国内外有关重金属废水生物处理技术的研究成果,并介绍了重金属废水生物处理的工程应用,提出关于重金属废水生物处理的研究方向。     

利用核裂变廢物去除廢水中的重金屬

去除废水中的镉、铬、锌等金属离子,一般采用还原而后沉淀或析出的方法。还原法有利用直流电的电化学法、离子交换法、药品沉淀分离法等。为了提供简单而便宜的重金属去除法,可利用核裂变产物放出的β射线还原废水中     

利用沸石去除电镀废水中重金属离子的试验研究

天然沸石经过适当改性后用于去除电镀废水中重金属离子的试验结果表明:沸石具有较好的离子交换性能,可同时去除电镀废水中的Zn,Cr,Ni等重金属离子,以确保电镀废水达标排放。采用沸石进行电镀废水处理时,其最佳过流速度为4～5m/h,此时,Zn,Cr,Ni的有效去除率分别达到80%,60%,40%以上,工作周期可长达12h以上。     

提高人工湿地重金属净化效果的关键技术研究进展

人工湿地因具有建设成本低、运营管理简单、净化效果好等优点,被广泛应用于重金属污废水的去除。综述了国内外对人工湿地在重金属污染控制方面的研究进展,针对人工湿地对部分重金属污染物去除效率偏低的问题,论述了从改良填料、优选植物、组合工艺等方面来强化人工湿地对重金属的净化效果,分析了优化人工湿地关键技术的优缺点,并对今后人工湿地的研究与应用提出了展望,对该技术的进一步深入研究具有积极意义。     

水生植物去除重金属机制及生理响应研究综述

重金属是水环境中的典型污染物,存在着潜在的生态风险。利用水生植物去除重金属的处理方法具有高效、环保、经济等特点,成为当前研究的热点领域。阐述了植物对重金属的去除机制主要有植物吸收、根际微生物活动、植物根系微环境作用及植物富集,综述了植物在重金属胁迫下发生的生理响应,包括植物生长、细胞结构、酶活性等方面的生理变化。并讨论分析了pH、温度、底泥性质等对水生植物去除重金属过程的影响。同时,提出了植物去除重金属及响应机理方面还需深入研究的几个问题。     

用电凝聚法从水中去除重金属离子

用可溶性电极电解处理电镀车间废水(即电凝聚法)是有前途的处理方法之一。本文讨论电凝聚法去除废水中重金属离子的研究成果。电解时,铁一水系统进行下列电化学反     

沸石用于含铬废水处理初步研究

利用沸石作为吸附剂,通过改变沸石用量、pH值、C_r~(6+)初始浓度、吸附时间等多个因素以确定沸石处理含C_r~(6+)废水的最佳工艺条件,对含C_r~(6+)重金属废水进行吸附处理。结果表明,投加量3.0 g/100 m L,振荡时间60 min,去除效果最佳。相同条件下,使用硫酸亚铁改性后的人造沸石比未改性的天然沸石去除率高出13.64%。利用沸石这种廉价的物质,在提高对含C_r~(6+)废水去除效率的同时也降低了运行成本,达到以废治废的目的。     

新型污水处理剂PFS问世

山东省泰安市泰山区岱东环保去污剂厂新近开发出一种新型污水处理剂——聚合硫酸铁（PFS）水处理剂,其COD去除率在80％左右,远远高于聚合氯化铝净水剂,脱色率在85％以上,对微生物、悬浮物、重金属的去除率效果显著。液体PFS中含有大量聚合阳离子,对污水中的菌类、泡沫及臭味去除效果明显,水解均匀,聚合反应快,沉淀迅速,全部处理时间仅需     

3种微藻在龟鳖养殖废水中的生长与脱氮除磷特性

选取小球藻(Chlorella sp.)、栅藻(Scenedesmus sp.)和螺旋藻(Spirulina sp.)为试验藻种,分别接种于经沉淀池初步处理后排放的龟鳖养殖废水(取自无为县某养殖场,简称WW废水)和无任何处理直接排放的龟鳖养殖废水(取自大杨镇某养殖场,简称DY废水),考察3种微藻生长特性和对废水中氮磷的去除效果,比较其对龟鳖养殖废水的净化能力。结果表明:所选的3种微藻在两种废水中生长特性不同,DY废水中3种微藻细胞密度与生物量均大于其在WW废水中的相应指标,DY废水中小球藻、栅藻和螺旋藻的最大生物量分别为0.26 g/L、0.28 g/L和0.20 g/L。不同微藻对废水中氮磷去除效果各不相同,栅藻去除TN效果最好,最大去除率为93.65%,小球藻去除TP效果最好,最大去除率为99.46%,螺旋藻去除NH+4-N效果最好,最大去除率为98.79%。     

硅酸盐细菌处理含重金属污水的试验与分析

结合试验分析并肯定了硅酸盐细菌在重金属污水,特别是在重金属离子含量不太高的垃圾渗滤液处理中的应用潜力,同时阐述了硅酸盐细菌去除重金属离子的三种可能的作用机理:代谢过程中分泌的草酸、柠檬酸、酒石酸和氨基酸等多种有络合官能团的有机酸,可与重金属离子形成络合物,从而减轻或消除重金属对微生物的毒害作用;可分泌大量粘稠的胞外多聚物——荚膜多糖,对重金属离子有絮凝作用;菌体细胞表面和胞外物质对某些重金属离子有吸附作用。     

改性膨润土处理重金属离子废水的研究进展

重金属离子对人体有害,在废水中很难处理,利用廉价吸附剂有效处理重金属离子,既经济又环保。膨润土价廉易得,比表面积大,吸附性好,是一种天然的矿物质吸附剂。文章总结了膨润土吸附重金属离子的机理,并分析了改性膨润土在吸附重金属离子方面的研究进展及存在问题,并提出了解决办法。     

电浮选法净化含高浓度Cu2+和Zn2+的废水研究

以自制的间歇式电浮选柱为反应容器,采用电浮选方法对含高浓度Zn^2+和Cu^2+混合离子废水进行了净化试验研究,浮选过程中考察了pH值、电流密度、初步浮选时间、离子强度4个主要因素对浮选效率的影响。试验选用混合离子的整体去除效率为评价指标,优化了电浮选方法净化含混合重金属Zn^2+和Cu^2+的实验条件,得到了较好的浮选条件。该方法操作简单,处理效果较理想,对实际利用电浮选法处理重金属离子废水工程具有一定的参考价值。     

Study on risk management of heavy metals for reuse of biosolids.

The behaviour of heavy metals was investigated at 22 wastewater treatment plants (WWTPs). In addition, the survey of heavy metal balance was conducted in detail at one WWTP. For the measurement, 22 types of heavy metals were selected from the chemical materials of pollutant release and transfer register (PRTR). There were some heavy metals, which were detected not in wastewater but in dewatered sludge. By means of the detailed survey at one WWTP, 60 to 80% of some heavy metals, such as B, Mn, Co, Ni and Mo, were discharged with treated water. According to the results of PRTR, Zn, B and Mn accounted for a large part of the discharge into the water course. To estimate the behaviour of heavy metals in the environment, leaching tests were applied to the products made of biosolids. During a series of leaching tests for building materials, it was observed that the concentration of heavy metals was very small, but the ratio of increase keeps a constant value. Therefore, it was considered that the acid extractable contents of heavy metal would be important.     

包头市地下水重金属污染分布特征及来源分析

为了查明包头市地下水质量与污染状况,在包头市采集地下水样品33组、地表水样品4组,对其重金属Cr、Cd、Hg、Pb和As等指标进行了测试分析。据此,运用水化学、环境地球化学、环境质量评价和污染评价等理论和方法,分析了该区地下水重金属含量分布、污染程度及来源。结果表明,包头市四区地下水均受到不同程度重金属的污染,其中东河区地下水重金属元素检出、超标点均为最多,污染程度最大;5种重金属元素检出率由高到低依次为Pb>As>Cd>Cr6+,按污染程度由高到低依次为Pb>Cr6+>As>Cd。通过对涉重企业废水排放资料、土壤重金属和地表水(污水)测试结果分析可得,工业废水排放是地下水重金属污染主要物质来源。相关性分析结果表明地下水中Cd与Pb存在显著相关性,二者可能具有同源性。     

Isolation and screening of heavy metal resistant bacteria from wastewater: a study of heavy metal co-resistance and antibiotics resistance

The uncontrolled discharges of wastes containing a large quantity of heavy metal create huge economical and healthcare burdens particularly for people living near that area. However, the bioremediation of metal pollutants from wastewater using metal-resistant bacteria is a very important aspect of environmental biotechnology. In this study, 13 heavy metal resistant bacteria were isolated from the wastewater of wadi El Harrach in the east of Algiers and characterized. These include zinc-, lead-, chromium- and cadmium-resistant bacteria. The metal-resistant isolates characterized include both Gram-negative (77%) and Gram-positive (23%) bacteria. The Minimum Inhibitory Concentration (MIC) of wastewater isolates against the four heavy metals was determined in solid media and ranged from 100 to 1,500 μg/ml. All the isolates showed co-resistance to other heavy metals and antibiotic resistance of which 15% were resistant to one antibiotic and 85% were multi- and bi-antibiotics resistant. The zinc-resistant species Micrococcus luteus was the much more heavy metal resistant. The results of toxicity tests on Vibrio fischeri showed that the DI(50) (5 min) as low as 0.1 carried away luminescence inhibition greater than 50%.     

植物对重金属的抗性机理及其植物修复研究进展

重金属是一类重要的环境污染物，过量的重金属会对植物产生毒害，但某些植物可形成特定的抗性机制，以适应环境的变化。对过量重金属对植物的毒害作用以及植物对重金属抗性的机理进行了综述，并阐述了植物修复重金属污染的方式及其研究领域。     

Surfactant enhanced remediation of cadmium contaminated soils

An investigation involving the addition of surfactant to remediate cadmium-contaminated soils was perfoemed to determine the optimal surfactant enhanced remediation system. Anionic (sodium dodecyl sulfate, SOS), nonionic (Triton X-100, TX100) and cationic (cetyltrimethylammonium bromide, CTAB) surfactants were used to elucidate the extraction efficiency of surfactant. EDTA and diphenylthiocarbazone (DPC) were also added to enhance the extraction efficiencies of surfactants. Moreover, the pH effect was examined to determine the optimal surfactant systems. The addition of anionic and nonionic surfactants can enhance the desorption rates of cadmium, lead and zinc, whereas the addition of cationic surfactant decreased the desorption efficiency of heavy metals. The desorption efficiency was found to increase linearly with the increasing surfactant concentration below critical micelle concentration (CMC) and remained relatively constant above the CMC. Moreover, the addition of EDTA can significantly enhance the desorption efficiency of heavy metals. Cationic surfactant was shown to be a more effective surfactant than nonionic and anionic surfactants in extracting heavy metals under acidic environment. The desorption efficiency of heavy metal in the surfactant/EDTA mixture system was in the order of Cd > Pb> Zn. However, the addition of DPC lowered the heavy metal removals by 2 to 4 times. Also, increasing pH value can decrease the extraction capabilities of nonionic and anionic surfactants. The results of this study demonstrate that surfactant in combination with complexing agents can be effectively used as chemical amendments to flush cadmium-contaminated soil by proper selection of type and concentration of surfactant and complexing agent at different pH values.     

两种絮凝工艺去除污水中金属元素的对比试验

分别采用化学生物絮凝与化学絮凝两种工艺处理同一低浓度城市污水,对比分析污水中金属元素的去除效果。试验结果表明,在相同加药量的条件下,化学生物絮凝工艺在增加絮凝产物中铝元素含量的同时,对部分有害重金属的控制也优于化学絮凝工艺。但该工艺在处理高浓度污水时,处理效果会受重金属浓度的制约。