络合-超滤耦合技术处理Cd^（2＋）模拟废水的研究

研究聚丙烯酸钠PAASS与模拟废水中Cd2 络合反应动力学,结果表明:当pH为6、Cd2 浓度为10 mg·L-1和PAASS浓度为5000 mg·L-1时,络合反应符合拟一级速率方程.考察负载比对Cd2 截留系数R的影响,可得PAASS络合容量为0.033 g Cd·(g PAASS)-1.考察pH和竞争络合剂对R的影响,发现当pH从5增大到6时,R迅速增大;竞争络合剂三乙醇胺或酒石酸钠使R下降.研究络合体系超滤浓缩行为,结果表明体积浓缩因子为10时,膜通量仅下降14.6%,R值大约为1;浓缩液用于解离研究,控制解离pH为2.5,可得:当截留液镉浓度为99.6 mg·L-1时,渗透液镉浓度可达93.1 mg·L-1,对应络合物解离效率为93.5%;解离液用于超滤洗涤,当洗涤液体积为原料液体积4倍时,截留液镉浓度从洗涤前99.6 mg·L-1降低至洗涤结束时3.87 mg·L-1,镉洗脱率为96.1%,洗涤后聚电解质纯度高.     

聚季铵盐强化超滤处理铬(VI)

以聚季铵盐-22(PQ22)为络合剂,研究Cr(VI)的强化超滤行为,考察聚电解质/金属质量比、pH值及外加盐对PQ22-Cr(VI)络合体系截留系数和膜通量的影响,并研究了络合体系的浓缩、解络合和洗涤过程. 结果表明,当聚电解质/金属质量比为80及pH=9时,Cr(VI)截留系数大于0.9;外加Cl-, NO3-和SO42-使Cr(VI)截留系数降低,且SO42-比NO3-和Cl-的影响更大;控制聚电解质/金属质量比为80及pH=9,当浓缩因子为20时,Cr(VI)浓度从初始的5 mg/L浓缩至82.6 mg/L;对浓缩液解络合,控制Cl-浓度为0.15 mol/L,解络合率为71.1%,以Cl-溶液对解络合液进行洗涤,Cr(VI)洗脱率可达95.9%. 聚季铵盐-22可循环使用.     

陶瓷膜微滤-聚合物强化超滤处理高浓度含镍废水

实验研究了0.5 mm孔径陶瓷膜对高浓度含镍废水的微滤行为,以聚丙烯酸钠(PAAS)强化超滤技术深度处理陶瓷膜渗透液,考察了PAAS与金属质量比(rp/m)和pH值对恒容超滤膜通量(J)和镍截留系数(RNi)的影响,研究了超滤浓缩、解络合、洗涤及PAAS循环使用过程. 结果表明,pH=9时,陶瓷膜浓缩时J先快速降低、缓慢下降后再较快降低,RNi接近1,当体积浓缩因子从1增大到10时,截留液镍浓度(Cr)从5562.71 mg/L浓缩至55507.76 mg/L,渗透液镍浓度(Cp)为13.26 mg/L. PAAS强化恒容超滤时,J不随rp/m变化,随pH值增大而增大,RNi随rp/m或pH值增大而增大;超滤浓缩时,控制pH=9和rp/m=9,RNi接近1,Cr呈线性递增,Cp"0.05 mg/L;在pH=3条件下对超滤浓缩液解络合,解离平衡时间为9 min,解络合率为81.9%;以pH=3的盐酸溶液洗涤解络合液,镍洗脱率为98.8%. 再生PAAS络合性能良好,可循环使用.     

聚电解质强化超滤技术处理钨(Ⅵ)

以聚季铵盐-6(PQ6)强化超滤技术处理钨(Ⅵ),考察了渗滤对PQ6预处理的影响.结果表明,随渗滤体积增加PQ6截留系数逐渐增大到1,PQ6损失率为12.7%,膜通量(J)轻微增大.研究了pQ6与金属质量比r和pH值对钨截留系数(Rw)和J的影响,当r从1增大到3,Rw线性递增,此后趋于1,PQ6对钨(Ⅵ)的络合容量[PQ6/钨(Ⅵ)]为3.0 mg/mg;当pH值从3增大到9时,Rw基本不变:J随r增大略有下降,但不随pH值变化.在r=3和pH=7的条件下,当体积浓缩因子为16时,J下降15.2%,Rw接近1,截留液钨浓度从20 mg/L增大到317.5 mg/L渗透液钨浓度约为0.04 mg/L,钨(Ⅵ)被有效浓缩.     

聚季铵盐强化超滤分离铼(Ⅶ)

以聚季铵盐-6强化超滤技术分离铼(Ⅶ),考察聚季铵盐与金属质量比w、pH值、外加盐、运行时间和操作压力对铼截留系数R和膜通量J的影响,结果表明:当w从1增大到7时,R迅速递增,w达到7时的R为0.995,继续增大w,R逐渐趋于1;J随w增大略有下降;当pH值从3增大到8时,R和J几乎不随pH值变化而变化;随着外加盐质量浓度递增,R逐渐递减至不变,J略有下降;随着运行时间延长,R基本不变,J轻微衰减;当操作压力增大时,R不变,J呈线性快速递增。研究铼(Ⅶ)-聚季铵盐体系的超滤浓缩行为,控制w=7,pH=7,温度25℃和压力60 kPa,当体积浓缩因子为40时,J仅衰减20.1%,在浓缩过程中R均接近1,截留液铼质量浓度从5 mg/L增大到198.3 mg/L,渗透液铼质量浓度约为0.04 mg/L,铼被有效浓缩。     

络合-超滤技术深度处理矿山重金属废水

采用壳聚糖络合-超滤技术深度处理有色金属矿山重金属废水,考察了pH值、壳聚糖/铅离子质量比(P/M)、离子强度、运行时间等因素对Pb2+、Cd2+截留率和膜通量的影响。结果表明,在原水Pb2+、Cd2+的质量浓度分别为1.0、0.1 mg/L,pH值为7,P/M值为6的条件下,Pb2+和Cd2+的截留率分别达到96.62%和96.26%,出水满足GB 3838—2002《地表水环境质量标准》中Ⅲ类标准的要求。NaCl浓度的增大使重金属离子的截留率有所降低;随着运行时间的延长,膜通量逐渐减小最后趋于稳定,而运行时间对Pb2+、Cd2+的截留率影响不大。     

UV/Fe3+/H2O2催化-混凝联合工艺处理络合铜镍废水

采用UV/Fe3+/H2O2催化-混凝联合工艺对难处理络合铜镍电镀废水进行了研究,考察了Fe3+和H2O2初始浓度、初始pH值、温度、反应时间及混凝液pH、混凝剂质量浓度对处理过程的影响,探讨了废水的降解途径和机理.结果表明在体系初始pH=3,温度50℃,H2O2和Fe3+初始浓度分别为1.5×10-4mo1/L、2.5×10-5mo1/L,反应时间60min,混凝液pH=8及混凝剂质量浓度为500mg/L的条件下,废水的COD去除率为96.98%,Cu2+为99.91%,Ni2+为99.92%,处理水达到国家一级排放要求.同时依据GC/MS对X-GN降解最终产物的分析结果,推导出废水的基本降解机理和途径.     

络合-陶瓷膜耦合技术处理低浓度含铜废水

采用孔径为200nm的陶瓷膜,以聚丙烯酸(PAA)为络合剂,含Cu2+废水为模拟废水,研究了络合-陶瓷膜耦合技术处理低浓度含铜废水过程。重点考察了运行时间、络合剂浓度、络合剂/金属离子质量浓度比(P/M)、溶液pH、离子强度、操作压力等对膜通量及Cu2+截留率的影响。结果表明,当P/M≥5、pH为5~6时,Cu2+的截留率接近100%,膜通量较高且趋于稳定;外加盐(NaCl和Na2SO4)导致Cu2+截留率下降,可以通过增加P/M值多级处理达到对Cu2+的理想去除。     

花青素在光度法测定Fe~(3+)中的应用

利用从紫甘蓝中提取的花青素与Fe~(3+)发生络合反应,建立了一种分光光度法定量测定Fe~(3+)的新方法。在pH值4.0的乙酸-乙酸钠缓冲溶液中花青素与Fe~(3+)发生络合反应,当Fe~(3+)浓度在0.1~1.0 mg/10 m L范围内时,与吸光度呈良好的线性关系,相关系数R2=0.9984,线性方程为A=0.2462C+0.4985,该方法灵敏度高、反应迅速、重现性好。     

石煤氯化钠焙烧水浸液纳滤提钒过程

采用石煤氯化钠焙烧浸出液为原料,研究了驱动压力、料液pH值及钒浓度对钒纳滤浓缩效果的影响,并考察了Cl-在纳滤过程中的行为. 结果表明,在驱动压力10.0~12.5 kg/cm2和pH值5.16~6.15的优化条件下,料液中的钒(V2O5)可纳滤浓缩到35 g/L以上. pH值6.15时,钒的截留率最高,达92%. 浓缩液按沉钒化学计量的2.2倍加入NH4Cl,沉淀得到的NH4VO3经500℃煅烧1 h得到的V2O5产品纯度为98.6%.     

Experimental studies on extraction of cobalt ions from dilute aqueous solutions by using complexation-ultrafiltration process

The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid) sodium salt (PAASS). Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process. The kinetics of complexation reaction was studied for PAASS with Co²⁺. Results showed that, under a large excess of PAASS, it takes 65, 55 and 40 min at pH 5, 6 and 7, respectively, to get the equilibrium of complexation. The reaction kinetics can be described by a pseudo-first-order equation. Then, the effects of various parameters on the extraction of Co²⁺ were examined in detail. Results indicated that loading ratio, pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R. Furthermore, a concentration experiment was carried out at pH 7. With increasing volume concentration factor, membrane flux declines slowly, and R value is always about 1. The concentrated retentate was used further for a decomplexation experiment. The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%. After the decomplexation step, a diafiltration experiment was performed at pH 2.5. Cobalt ions can be extracted satisfactorily from the retentate, and a purified PAASS is obtained.     

Experimental studies on extraction of cobalt ions from dilute aqueous solutions by using complexation-ultrafiltration process

The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid) sodium salt (PAASS). Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process. The kinetics of complexation reaction was studied for PAASS with Co²⁺. Results showed that, under a large excess of PAASS, it takes 65, 55 and 40 min at pH 5, 6 and 7, respectively, to get the equilibrium of complexation. The reaction kinetics can be described by a pseudo-first-order equation. Then, the effects of various parameters on the extraction of Co²⁺ were examined in detail. Results indicated that loading ratio, pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R. Furthermore, a concentration experiment was carried out at pH 7. With increasing volume concentration factor, membrane flux declines slowly, and R value is always about 1. The concentrated retentate was used further for a decomplexation experiment. The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%. After the decomplexation step, a diafiltration experiment was performed at pH 2.5. Cobalt ions can be extracted satisfactorily from the retentate, and a purified PAASS is obtained.     

化学镀铜体系的电化学性能

对乙二胺四乙酸二钠(EDTA×2Na)与酒石酸钾钠(TART)双络合化学镀铜液进行了电化学研究,考察了络合剂与2,2￠-联吡啶对阴、阳极极化反应的影响. 结果表明,化学镀铜阳极极化受电化学与扩散混合控制,阴极极化受扩散控制;EDTA×2Na与TART通过竞争络合与竞争放电影响极化反应,而2,2￠-联吡啶以弥散吸附方式改变极化阻抗影响铜的沉积;在优化镀液(EDTA×2Na 13.35 g/L, TART 13.35 g/L, 2,2￠-联吡啶15 mg/L)中化学镀铜,镀速达14.83 mg/min,所得镀层均匀致密.     

络合-超滤过程处理重金属工业废水

以废水回用为目的,研究了络合 超滤耦合过程处理重金属工业废水。利用聚丙烯酸(PAA)为络合剂和含Zn2+和Cu2+的重金属废水,讨论了各种因素,如操作压力、膜面流速、重金属与络合添加剂的质量比、pH、体积浓缩因子对超滤过程的影响。在NaCl或Na2SO4存在的条件下,对Zn2+和Cu2+仍可达到100%的去除。在较高的离子强度下,如0.203mol/L时,对Zn2+和Cu2+的截留率仍可达到95%以上。经过浓缩的重金属废水,可回收重金属,而透过液可达到回用水的标准。     

异辛醇-甲苯萃取盐湖卤水中硼酸的动力学

引言 硼及其化合物在国民经济中用途极为广泛[1],但是我国主要的硼原料之一硼镁矿石却日趋枯竭,于是开发液体硼矿资源--含硼盐湖卤水成为当务之急.近年来杨卉芃等[2]、李文强[3]、杨存道等[4]分别以沉淀法、离子交换法和结晶法对盐湖卤水提硼工艺进行了研究,并取得了一定的成果.     

无氰碱性锌镍合金电镀中配位剂的选择

介绍了碱性锌镍合金电镀对配位剂的要求,列举了可选用的配位剂种类,从热力学角度和动力学角度分析了配位剂的选择原则:从热力学角度来考虑,配位剂与金属离子所形成的配离子的稳定常数值应适中;从动力学角度来看,配位剂应能与镍离子形成具有表面活性的配离子,以利于镍配离子的电极反应。建议采用复合配位剂,如酒石酸钾钠加多胺,几个胺(多胺)类化合物的组合,或者多聚膦酸盐。     

不同pH值下酚类的络合萃取

络合萃取法分离极性有机物稀溶液具有高效性和高选择性。在已有工作基础上,利用三正辛胺(TDA)、磷酸三丁酯(TBP)为络合剂,正辛醇、甲墓异丁基酮(MIBK)或煤油为稀释剂,在较宽的pH值条件下实验测定了酚类稀溶液的萃取相平衡分配系数;讨论了络合剂种类、络合剂浓度、稀释剂种类以及被萃取溶质种类对络合萃取相平衡分配系数的影响;提出了同时考虑络合萃取作用和物理萃取作用的平衡分配系数的表达式。     

Q235钢上中温化学镀镍磷合金工艺

采用正交试验考察了镀液中配位剂柠檬酸钠和乳酸钠含量及pH对Q235碳钢上中温化学镀层沉积速率的影响,研究了稳定剂苯并三氮唑、硫代硫酸钠及其复配对镀液稳定性和沉积速率的影响.得到较理想的工艺配方及操作条件为:NiS046H2O30 g/L,NaH2PO2·H2O 30 g/L,乳酸50 g/L,柠檬酸钠2 g/L,CH3...     

对氨基酚稀溶液的络合萃取

络合萃取法分离极性有机物稀溶液具有高效性和高选择性。本文在原有工作的基础上，利用三正辛胺、磷酸三丁酯或Ｐ２０４为络合剂，正辛醇或煤油为稀释剂，在不同的ＰＨ值条件下实验测定了对氨基酚稀溶液的萑取相平稳分析系数。     

Parametric studies for strontium separation and volume reduction of a simulated nuclear waste solution

Volume reduction of a radioactive waste solution and recovery of the long-lived radionuclides are very much essential for effective nuclear waste management. A combination of complexation and nanofiltration for selective separation of strontium from a simulated Intermediate-Level Waste (ILW) solution has been studied. The advantages of nanofiltration membranes such as high retention, low operating pressure, and higher permeate flux were explored for the “concentrate and contain” strategy of waste management. An ethylenimine (EI) oligomer mixture containing primary, secondary, and tertiary amines as functional groups was used as a complexing ligand. The key process parameters, such as the EI concentration, feed pH, and initial strontium concentration, were optimized for strontium rejection. Statistical design of experiments was adopted to study the individual effects and combined interaction effects of these parameters. The optimization of these process parameters for strontium rejection and permeate flux was carried out using central composite design (CCD). The EI concentration and feed pH showed significant but opposing effects on strontium rejection and permeate flux. A strontium rejection of 98% was obtained for an EI concentration of 2.85 g/l and a feed pH of 8. The volume of the strontium-containing waste solution was successfully reduced to 10% of the initial volume.