电镀废水中重金属处理方法

介绍了电镀废水中重金属处理的3种方法:中和沉淀法、硫化物沉淀法及螯合物沉淀法。讨论了中和沉淀法和硫化物沉淀法的优点及存在的问题,并给出了解决方法。螯合物沉淀法有待进一步研究。     

高盐工业废水中重金属物质分析方法研究

煤化工企业生产排放的废水中含有多种重金属离子,对重金属离子的有效去除十分必要。对通过无机物沉淀法、捕集剂沉淀法与络合纳滤法三种实验方法进行比较分析,最终确定捕集剂法为最优工艺方法。将30mg/L的5#捕集剂加入pH=9的溶液中,反应10min后再分别加入1mg/L的PAC和PAM,沉淀10min,重金属物质总的去除率可达99.6%以上,充分说明其具有良好的使用价值。     

一种新型深度除汞工艺

采用硫化物沉淀法以及辅助吸附法对含汞废水进行除汞处理。废水除汞装置为硫化汞沉淀法,主要采用间歇操作,根据水中的汞含量将硫化物按一定比例加入,反应后产生硫化汞沉淀,经絮凝沉降后过滤分离后,所得粗滤液经活性炭深度吸附处理后回用。本工艺中经吸附后的污水中汞含量小于0.003 mg/L,达到污水排放标准,所得达标污水可经进一步处理后循环利用。     

一种以磷矿石为原料生产工业级磷酸的方法

本发明涉及一种以磷矿石为原料生产工业级磷酸的方法，属磷的化合物技术领域。它是将磷矿石破碎、球磨并过筛，再经稀磷酸和浓硫酸分解后过滤，滤液泵入密封的工程塑料反应器中，在搅拌下通入硫化氢使其与各种金属离子充分反应；经过滤除去各种金属硫化物沉淀；滤液泵入另一个带搅拌的反应器中，在搅拌下加入硅酸钠和磷酸钙，反应后经过滤；滤液经活性炭脱色后再过滤；     

含汞废水深度处理的研究

介绍了"硫化物沉淀法+金属还原法+沸石分子筛吸附法"处理天伟化工有限公司含汞废水的方法.采用"中和池+三级反应罐(三级絮凝沉淀)+过滤+还原床+沸石分子筛吸附床"工艺,将废水中汞的质量浓度降至0.003 mg/L以下.     

化学沉淀法处理乙烯裂解废碱液中的硫化物

采用化学沉淀方法处理乙烯裂解废碱液中的硫化物,寻求到了一种较合适的沉淀剂CuO,并考察了影响沉淀效果的各种因素。结果表明：在沉淀反应温度20℃,反应时间30min,CuO：S=1．5：1(摩尔比)等条件下,S^2-的去除率可达到96．78％,CODCr的去除率达到73．83％。沉淀剂CuO再生后可以循环使用,满足处理要求。     

废水中硫化物含量的测定

废水中硫化物在酸性条件下游离成硫化氢气体，被吸收液吸收，生成硫化物沉淀。用碘量法测定硫化物含量。     

抚顺洗涤剂化工厂废水处理工程设计

洗涤剂化工厂废水中含有大量的石油类、固体悬浮物(SS)、硫化物、酚及BOD、COD等有机污染物．采用隔油、涡凹气浮(CAF)、接触氧化、混凝沉淀、过滤、活性炭吸附等工艺处理后,出水达到循环水回用及生活杂用水水质标准。     

方形截面纤维表面气溶胶粒子多机理过滤性能数值分析

采用数值方法求解绕方形截面纤维流场,考虑粒子布朗扩散、拦截效应和惯性碰撞捕集机理的联合作用,用布朗动力学方法研究方形截面纤维的过滤性能,考察了纤维迎风角(θ)、填充率(C)和过滤风速(u?)对捕集效率、质量因子及粒子沉积分布的影响。结果表明,小粒子的扩散捕集或大粒子的惯性捕集在方形纤维表面的粒子沉积行为均表现出显著的局部沉积特征,且与粒子捕集机理和迎风角有关。方形纤维质量因子的分析结果表明,在高填充率下,方形纤维的过滤压降虽高于圆截面纤维,但具有较高的捕集效率,综合过滤性能仍明显优于圆截面纤维,但在低填充率下,方形纤维综合过滤性能劣于圆截面纤维。     

谈车用柴油机尾气排放的陶瓷滤材

陶瓷滤材具有的优良性能,使得其在空气净化、高温烟气过滤、金属液过滤、尤其柴油机尾气微粒捕集等方面得到了广泛的应用。针对车用柴油机的尾气排放治理已是当务之急,分析了柴油机排放颗粒的控制技术和柴油机尾气微粒捕集的净化技术受到关注,论述了柴油机排气微粒捕集过滤和扩散的机理,介绍了多孔陶瓷过滤元件的结构、性能特点及柴油机微粒过滤器的滤材性能特点,指出了柴油机微粒过滤器的发展趋势。     

纳米硫化铁在环境保护中的应用研究进展

总结了近二十年来纳米硫化铁在环境中的应用报道,综述了纳米硫化铁的合成方法、污染物去除效果和机理以及溶液组分对材料本身和污染物去除的影响。介绍了纳米硫化铁目前在环境中主要用于重金属离子去除(如镉、汞、铀、锝等)、氯代有机物的脱氯和难降解有机物的高级氧化等过程,其对污染物的去除机理主要包括吸附、(共)沉淀、还原、催化氧化。指出虽然纳米硫化铁在污染物处理方面取得了良好的效果,但是依然存在问题,如溶液中共存的阴阳离子和腐植酸会对材料的团聚、腐蚀以及污染物的吸附行为和处理效果产生不同的影响。提出目前国内外对于纳米硫化铁材料自身性能研究尚未深入,材料在反应过程中及实际环境中的迁移、转化及其对污染物去除的影响值得深入。     

磷化渣废液除锌制备高纯度磷酸三钠

为了实现磷化渣碱溶后所得废液的综合利用,采用中和沉淀法和硫化钠沉淀法去除磷化渣废液中的杂质锌,对中和沉淀法和硫化钠沉淀法的工艺条件进行优化,并由此设计磷化渣废液除锌制备高纯度磷酸三钠的生产工艺。对于中和沉淀法,在反应体系pH=8.85,反应时间为10 min时,Zn2+去除率可达97.96%;对于硫化钠沉淀法,在反应体系pH=6.85,硫化钠投加量与Zn2+的摩尔比为1:1,反应时间为10 min时,Zn2+去除率可达99.80%。相比于中和沉淀法除锌制备磷酸三钠工艺,硫化钠沉淀法除锌制备磷酸三钠工艺具有更高的磷酸三钠纯度,为98.85%,固相产品中Zn2+含量更低,仅为0.0004%,符合化工行业分析纯标准。该工艺大幅度地回收了磷化渣废液中的PO43-离子和Na+离子,为实现磷化渣综合利用的工业化提供新思路。     

Precipitation dynamics of zinc sulfide multiscale agglomerates

Homogeneous precipitation of zinc sulfide from thioacetamide decomposition in presence of zinc sulfate in acid solution results in the formation of four‐scale agglomerates. We present here experimental results relative to the monitoring of several physicochemical (pH, electrical conductivity, concentration in sulfide ions, turbidity) and morphological (agglomerate shape and size) parameters throughout the precipitation process. From these parameters essential characteristics of the precipitation process can be determined, especially the supersaturation level and the precipitated product mass. From this information and with the help of microphotographs of samples withdrawn at different stages of the precipitation, it is possible to formulate a new mechanism of zinc sulfide precipitation. In particular, the nature of the different agglomeration scales is elucidated as well their succession in time. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

利用反硝化技术解决油田水处理系统中硫化物问题的技术实践

为了解决油田水处理系统中硫化物给生产带来的实际问题,从微生物学角度开发了能够有效除硫控菌(SRB)的反硝化抑制剂.现场试验结果表明,抑制剂投加量为85 mg/L时,能够将油系统沉降罐中硫化物降至未检出水平,沉降罐的除油率提高32.7%,解决了现场沉降罐沉降效率差、废水系统来水水质恶化等实际问题;滤前投加抑制剂能够提高过...     

Development of a Precipitation Based Separation Scheme for Selective Removal and Recovery of Heavy Metals from Cadmium Rich Electroplating Industry Effluents

Abstract

The treatment of electroplating wastes is a serious worldwide problem, because of their high content of many different heavy metals. Chemical precipitation based treatment methods could be an important alternative for fractional selective separation of heavy metals if they are systematically developed by sequencing of pH, adjusting the added portions of precipitating agents, and selecting the optimum time period before removing the precipitate from the solution. In this study, for selective removal and recovery of Cd from real electroplating bath wastewater (containing high amounts of Cd, medium amounts of Zn, Cu, Fe and small amounts of Ni, Co, Mn), a precipitation based separation scheme was developed. The scheme comprised of three consecutive steps: 1) Acid treatment with nitric acid (HNO₃). Cyano‐metal complexes were decomposed in acidification step and complete removal of iron was achieved. 2) Alkali precipitation by sodium hydroxide (NaOH). Large portion of Cd was recovered as pure Cd(OH)₂. 3) As a polishing step sulfide precipitation by sodium sulfide (Na₂S) was applied. pH was the critical parameter in sulfide precipitation. Addition of sodium sulfide in alkali pH range led to cadmium precipitation whereas copper was totally precipitated in acidic pH range. The sulfide precipitation step may be replaced by more environmentally friendly steps (e.g. polymer enhanced ultrafiltration) until the heavy metal concentrations were reduced down to suitable discharge limits.     

硫化钠沉淀法从含铑溶液中富集铑工艺研究

用硫化钠作沉淀剂,从含铑强酸性水溶液中沉淀富集铑金属。通过实验确定了影响铑沉淀率的诸多因素,如沉淀剂加入量、沉淀温度、沉淀剂硫化钠加料速度、陈化时间及搅拌速度等。结果表明,当沉淀剂硫化钠与铑的物质的量比为10、沉淀温度为100 ℃、硫化钠加入速度为5 mL/min、陈化时间为1 h、搅拌速度为600 r/min时,铑沉淀率达到最大,铑沉淀率最高为99%以上。富集后溶液铑含量低于1 mg/kg,铑富集效果明显。     

改性活性炭纤维脱除COS的研究

本研究采用的催化剂为活性炭纤维,采用了Co~(2+)、Ni~(2+)、Fe~(3+)、Cu~(2+)等多种金属离子通过浸渍法改性活性炭纤维的性能,对COS进行深度脱除。本实验采用固定床反应器,分别通过改性离子的种类、含量、原料气的伴生组分、反应气氛、反应相对湿度和温度的不同催化剂的脱硫性能。结果表明:改性后的催化剂在脱硫性能上有了明显的提高,并根据实验结果推测了过渡金属离子在活性炭纤维上脱除COS的反应机理。     

从工厂回收废料硫化镍制备镍盐

研究了以从工厂含镍废液中回收的硫化镍为原料,试验从酸浸出,除杂净化和沉镍等方面制取镍盐的工艺过程和最佳条件。由本工艺可以生产出高含量镍的镍盐,其品位符合国家或企业标准,废镍的回收率达91％以上。     

Theoretical modeling of thermal stress imposed by selective permeation membranes reinforced with graphene oxide

The main purpose of the present work is to study the thermal stress imposed by selective permeation hydrogel‐filled nonwoven membranes (SPHM) in various environmental conditions, including cold, moderate and hot, in view of high and low wearer activity levels. In addition, graphene oxide (GO) has been used in the matrix structure of SPHM to reduce thermal stress. Hence, a mathematical model is proposed to study one‐dimensional heat transfer through SPHM reinforced with GO. Heat transfer equation was solved using the differential quadrature method and the resulting model was verified by experiments using a dynamic heat transfer simulation apparatus. It was observed that SPHM causes a significant thermal stress, especially in hot environments, and high activity level due to the low thermal conductivity of hydrogels. The results also showed that an increase in the GO content from 0.1% up to 0.5% leads to an increase in thermal conductivity up to 85% of blank SPHM without GO. Therefore, SPHM reinforced with GO is a promising candidate for protective clothing, especially in hot environments. Also, the mathematical model can be useful in predicting thermal stress for designing SPHM‐based PCs in various environmental conditions and activity levels. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44752.