离子交换纤维对金属氰络合物吸附性能的研究

采用强碱性离子交换纤维对含氰废水中主要离子铜氰络合物、锌氰络合物的吸附性能进行了研究.实验结果表明:含氰废水的pH在8～11范围内,纤维材料对金属氰络合物具有良好的吸附性能;纤维对铜氰络合物、锌氰络合物的吸附速率很快,4 min左右就可达吸附平衡;温度对铜氰络合物、锌氰络合物吸附影响不大,纤维的这些吸附特点对工业应用非常有利.     

铜、锌氰配合物在离子交换纤维上的扩散、吸附机理

运用Boyd液膜扩散公式和范山鹰等提出的扩散模型,考察了碱性溶液中铜、锌氰配合物在离子交换纤维上的扩散行为;通过分析吸附前后纤维上官能团的位置变化以及解吸前后纤维上元素含量的变化,研究铜、锌氰配合物在纤维上的吸附机理。实验结果表明,离子交换纤维对铜、锌配合物的吸附在反应初期,以液膜扩散为主控制步骤,反应后期,以空隙扩散为主控制步骤。并运用离子交换纤维在水溶液中具有类似胶体型物质的双电层结构解释了不同控制阶段吸附速率不同的原因,虽然各阶段吸附速率有所不同,但纤维对铜、锌氰配合物的吸附均为离子交换机制。     

ClO2对医院高浓度含氰废水处理的试验研究

以医院排放的高浓度含氰废水为研究对象，采用“硫酸亚铁 曝气”初级化学处理和ClO2二级深度氧化处理相结合的处理模式，不仅使含氰废水实现无毒化处理，而且使高浓度含氰废水实现资源化回收利用。试验表明，处理后的废水中CN^-浓度达到国家排放标准GB8978-1996中的一级标准，为医院高浓度含氰废水的治理提供了一种新的方法。     

混凝-化学沉淀法处理含氰废水的实验研究

采用“分步混凝-化学沉淀”法处理苯乙腈生产过程中排放的高浓度含氰废水，对混凝剂种类、用量、pH、搅拌速率等因素对总氰去除效果的影响进行了探讨，找到了此方法处理含亚铁氰化物废水的最佳工艺条件。在最佳工艺条件下处理废水，出水无色透明，总氰降到1mg／L以下。该方法工艺简单，运行费用低，处理效果好，是一种具有推广价值的新方法。     

ClO2对医院高浓度含氰废水处理的试验研究

以医院排放的高浓度含氰废水为研究对象,采用"硫酸亚铁+曝气"初级化学处理和ClO2二级深度氧化处理相结合的处理模式,不仅使含氰废水实现无毒化处理,而且使高浓度含氰废水实现资源化回收利用.试验表明,处理后的废水中CN-浓度达到国家排放标准GB8978-1996中的一级标准,为医院高浓度含氰废水的治理提供了一种新的方法.     

亚铁蓝法处理含氰废水的工程应用

文中综述了氰化物的危害和含氰废水的来源以及目前处理含氰废水的方法。以工程实例重点介绍亚铁蓝法处理此废水的应用。亚铁蓝法除氰可分二级进行,第一级在中性条件总氰去除率达到80%以上,第二级直接在一级出水加碱调pH至8～9沉淀即可,通过二级处理总氰去除率达到95%左右。     

混凝-化学沉淀法处理含氰废水的实验研究

采用“分步混凝 化学沉淀”法处理苯乙腈生产过程中排放的高浓度含氰废水 ,对混凝剂种类、用量、pH、搅拌速率等因素对总氰去除效果的影响进行了探讨 ,找到了此方法处理含亚铁氰化物废水的最佳工艺条件。在最佳工艺条件下处理废水 ,出水无色透明 ,总氰降到 1mg/L以下。该方法工艺简单 ,运行费用低 ,处理效果好 ,是一种具有推广价值的新方法     

环境污染与防治 网络版论文摘要

臭氧氧化技术在高浓度定影废水处理中的实验研究；酸化-电解循环法处理浸金含氰废水；向日葵对Cu、Pb单一及复合污染的积累效应；微波聚合磷硫酸铁净化模拟含铅废水研究；大米草在中国的分布现状与防除利用。     

O3／UV氧化法处理电镀含氰废水的试验研究

试验研究了臭氧／紫外光(O3／UV)处理电镀含氰废水的各种操作条件，O3通入量、溶液pH值等因素对除氰效果的影响，结果表明，O3与UV相结合对去除氰化物具有协同效应，该法对氰化物的去除率可达99．9％。     

EDTA对氨基磷酸树脂去除水中Cu(Ⅱ)性能的影响

乙二胺四乙酸(EDTA)是一种强络合剂,在化学镀铜工艺中广泛使用,并导致镀铜废水中含有一定量的EDTA。氨基磷酸树脂(APAR)吸附法被广泛应用于含铜工业废水治理。为优化该方法,研究不同EDTA/Cu(摩尔比)、pH、钠离子、钙离子浓度下EDTA对APAR去除铜离子性能的影响。溶液中EDTA浓度增加导致APAR去除Cu(Ⅱ)能力下降;pH=5时,EDTA对APAR除Cu(Ⅱ)性能的影响较小;EDTA对树脂除铜性能的削弱不受溶液中离子强度变化或Ca2+存在的影响。红外光谱分析表明,有一部分EDTA-Cu络合物被吸附到树脂内部。     

Microbial degradation of metal complexed cyanides and thiocyanate from mining wastewaters

A microbiological examination of the soil from a cyanide wastewater storage basin was carried out. The storage basin contained water from the cyanidation process of gold extraction, and it was composed principally of simple cyanide, metal complexed cyanide, mainly cuprocyanide, ferro-ferricyanides and thiocyanate. Pseudomonas species were the principal bacteria identified in the soil. Using the storage basin soil as a seed sludge, its potential for the biodegradation of all the cyanide complexes in the mining wastewater was studied in the laboratory, using batch, fed-batch and continuous processes. The ammonia and sulphate produced were quantified. The presence of intermediate products was suspected. In the continuous process, total degradation of all cyanide was observed at a dilution rate of 0.066 day(-1).     

活性炭纤维及其在水处理中的应用

介绍了活性炭纤维材料的发展历史、类别、结构性能、制备过程。活性炭纤维比普通活性炭性能优越，吸附量大，机械强度高，吸附、脱附速度快，正逐渐地被用于废水处理和饮用水的净化。其具体方法有常用的吸附法、电解法，以及尚在起步阶段的生物活性炭纤维法。     

活性炭-臭氧体系处理含氰废水的作用机理

针对活性炭催化臭氧化降解低质量浓度含氰废水体系,研究了活性炭吸附、催化作用在催化臭氧化体系中的作用,提出了吸附-催化臭氧化协同作用机理。在活性炭-臭氧体系中,活性炭吸附CN-的能力很弱,活性炭在反应体系中主要起了吸附、催化臭氧的作用。活性炭-臭氧体系降解CN-的过程是臭氧直接氧化、活性炭吸附臭氧与活性炭催化臭氧产生.OH自由基间接氧化三者共同作用的结果。     

强化活性炭处理工艺去除焦化厂生化出水中的氰化物

以某焦化厂生化出水为研究对象,考寨了金属负载活性炭(简称负载炭)和Fenton氧化预处理等强化活性炭工艺对总氰化物(TCN)的去除效果.在TCN批式实验中,对负载炭的金属离子种类和固定方式进行了考察,同时研究了接触时间、DO对游离氰(KCN配水)、络合氰(K3Fe(CN)6配水)及焦化厂生化出水中TCN的去除效果.结果表明,负载金属离子可以有效提高活性炭对TCN的去除量,KI固定后的载铜活性炭对TCN的去除更有效.吸附作用在活性炭去除TCN过程中起着主要作用,同时TCN在活性炭表面也发生缓慢的催化氧化反应.在穿透实验中,采用了小型炭柱穿透和微型快速穿透实验方法,得到的TCN穿透曲线基本相同.含不同比例原煤炭和负载炭的小型炭柱处理经Fenton氧化预处理的焦化厂生化出水时,在18 d的启动阶段后形成生物活性炭柱,其出水能长期达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)规定的要求.载铜话性炭可以提高活性炭工艺对TCN的去除能力,确保处理全程(57 d)出水的TCN达标.     

选矿废水的回用处理研究与实践

铅锌矿泡沫浮选废水含有大量Pb2 + 离子和有机硫化物 ,经过混凝沉淀和活性炭吸附 ,去除其中的悬浮物、重金属离子和部分COD、降低其起泡性 ,然后回用生产。回用实践证明 ,选矿废水经过上述工艺处理后 ,其浮选选别指标与洁净水基本一致     

Heavy metal retention and partitioning in a large-scale soil-aquifer treatment (SAT) system used for wastewater reclamation

Soil aquifer treatment (SAT) of wastewater relies on extensive biogeochemical processes in the soil and aquifer to achieve large-scale and economic reclamation of municipal effluents. Removal of trace metals from the wastewater is a prime objective in the operation, but the long-term sustainability of the adsorptive filtration capacity of the soils is an open question. Solid/solution partitioning (measured by the distribution coefficient, K(d)) and solid/solid partitioning (measured by selective sequential dissolution, SSD) of heavy metals were measured in soils sampled from active recharge basins in a wastewater reclamation plant and were compared to the adjacent pristine dune. K(d) values for the adsorption of Cu, Ni and Zn, measured in short-term adsorption experiments positively and significantly correlated with solution pH. Quantitative estimation of Cu, Ni and Zn adsorption on multi-sorbents indicated that surface adsorption and precipitation on Fe oxides and/or carbonate may be the major mechanisms of metal retention in these soils. SSD analyses of metal partitioning in soils exposed to approximately 20yr of effluent recharge showed that all solid-phase components, including the most stable 'residual' component, competed for and retained added Cu and Zn. Copper preferentially partitioned into the oxide component (32.0% of the soil-accumulated metal) while Zn preferentially partitioned into the carbonate component (51.6% of the soil-accumulated metal).     

Biosorption of copper(II) from aqueous solutions by pre-treated biomass of marine algae Padina sp

Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high uptake capacities for a number of heavy metal ions. In this paper, the adsorption properties of a pre-treated biomass of marine algae Padina sp. for copper(II) were investigated. Equilibrium isotherms and kinetics were obtained from batch adsorption experiments. The biosorption capacities were solution pH dependent and the maximum capacity obtained was 0.80 mmol/g at a solution pH of about 5. The biosorption kinetics was found to be fast, with 90% of adsorption within 15 min and equilibrium reached at 30 min. The effects of light metal ions on copper(II) uptake were studied and the presence of light metal ions did not affect copper(II) uptake significantly. Fixed-bed breakthrough curves for copper(II) removal were also obtained. This study demonstrated that the pre-treated biomass of Padina sp. could be used as an effective biosorbent for the treatment of copper(II) containing wastewater streams.     

The occurrence of cyanide formation in six full-scale publicly owned treatment works.

This paper presents results from an intensive monitoring program implemented at six full-scale publicly owned treatment works (POTWs) to investigate the fate and formation of cyanide in wastewater treatment processes, with a focus on chlorination and dechlorination processes. A review of historical monitoring data for cyanide species in these POTWs was also conducted. This POTW monitoring program provided a database for the investigation of cyanide formation in wastewater secondary treatment. Data from participating POTWs showed evidence of cyanide formation in this 1-year monitoring effort, although the cyanide formation pattern varied significantly from one plant to another and among seasons. Generally, the chlorination of thiocyanate (SCN-) seems to be the most important mechanism for the formation of cyanide in wastewater treatment processes, especially in chlorination and dechlorination. This hypothesis is supported by the findings of a related laboratory study of mechanisms of cyanide formation in POTWs. It is recommended that POTWs monitor SCN in influent and secondary effluent to identify its presence and adjust chlorine dose appropriately.     

Insights to false positive total cyanide measurements in wastewater plant effluents.

Many publicly owned treatment works in North America are exceeding permitted limits for total cyanide in their wastewater treatment effluents. A recently introduced rapid, segmented, flow-injection analysis procedure using UV digestion and amperometric detection of the membrane-separated cyanide was used to investigate the various scenarios by which elevated cyanide levels might be present in wastewater treatment plant effluent. A number of significant interferences can produce false positive bias during sample analysis with the traditional acid distillation technique, but are minimized or absent with the new analytical method. However, increased levels of cyanide were found in some chlorinated wastewaters compared to the levels before chlorination, suggesting a fast reaction mechanism associated with the disinfectant and some precursor in the wastewater. In particular, the contact of chlorine with nitrite in the presence of a carbon precursor appears to contribute to cyanide formation during wastewater treatment and sample handling. This paper explores the scenarios under which cyanide can form during wastewater treatment as well as those in which a false bias for total cyanide can be obtained during sample processing and provides guidance for appropriate sample handling, screening, and processing to ensure valid analytical results.