水溶液中腐殖酸和苯酚在ZH-02树脂上的双组分吸附

通过苯甲酰基修饰的苯乙烯-二乙烯苯吸附树脂ZH-02对水中腐殖酸和苯酚进行了单组分和双组分的静态吸附.结果表明,在腐殖酸为主要吸附质的二元组分溶液中,对苯酚的吸附量的影响可以利用IAST模型进行预测;而在不存在主要吸附质的二元溶液中,可以用单组分体系的平衡吸附量近似预算双组分竞争体系时各组分的平衡吸附量.     

利用马铃薯淀粉废水处理沉淀物制备高吸水性树脂的研究

利用凹凸棒和膨润土混合黏土处理马铃薯淀粉废水,COD去除率可达52.8%,然后以马铃薯淀粉废水处理沉淀物为主要原料,采用水溶液聚合法合成高吸水性树脂,研究了中和度、沉淀物量、交联剂量、引发剂量等因素对吸水性树脂吸水倍率的影响。实验结果表明:当中和度50%、处理沉淀物8 g、交联剂0.015 g、引发剂0.15 g时,吸蒸馏水倍率可达793 g/g,吸自来水倍率可达227 g/g。     

Cation exchange resin supported nanoscale zero-valent iron for removal of phosphorus in rainwater runoff

Self-made cation exchange resin supported nanoscale zero-valent iron （R-nZVI） was used to remove phosphorus in rainwater runoff. 80% of phosphorus in rainwater runoff from grassland was removed with an initial concentration of 0.72 mg. L-1 phosphorus when the dosage of R-nZVl is 8 g per liter rainwater, while only 26% of phosphorus was removed when using cation exchange resin without supported nanoscale zero-valent iron under the same condition. The adsorption capacity of R-nZVI increased up to 185 times of that of the cation exchange resin at a saturated equilibrium phosphorous concentration of 0.42 mg. L-1. Various techniques were implemented to characterize the R-nZVI and explore the mechanism of its removal of phosphate. Scanning electron microscopy （SEM） indicated that new crystal had been formed on the surface of R-nZVI. The result from inductive coupled plasma （ICP） indicated that 2.1% of nZVI was loaded on the support material. The specific surface area was increased after the load of nanoscale zero-valent iron （nZVI）, according to the measurement of BET-N2 method. The result of specific surface area analysis also proved that phosphorus was removed mainly through chemical adsorption process. X-ray photoelectron spectroscopy （XPS） analysis showed that the new product obtained from chemical reaction between phosphate and iron was ferrous phosphate.     

Choice of chelating antidotes for acute cadmium intoxication∗

During acute oral intoxication by cadmium compounds, gastrointestinal epithelial damage contributes to immediate toxicity. However, secondary systemic toxicity may develop due to intestinal uptake of cadmium. This review presents an evaluation of the effects of chelators on the acute toxicity of cadmium after parenteral or oral exposure and on the intestinal uptake of cadmium. This review shows:

1. Chelating agents may affect the acute toxicity of cadmium in a variety of ways depending on the exposure route for cadmium and administration route for the chelator.

2. With regard to survival, systemic toxicity of absorbed cadmium is of major importance, as intraperitoneal administration of chelators could eliminate or reduce mortality due to orally administered cadmium chloride.

3. Lipophilicity of chelators and their cadmium complexes may result in extensively augmented intestinal uptake. However, hydrophilic chelators may efficiently reduce the intestinal cadmium uptake.

4. For hydrophilic chelators, the stability of the cadmium complex is an important determining factor of efficacy.

5. The optimal oral antidote towards orally administered cadmium are the BAL analogs, especially DMSA, while the optimal intraperitoneal antidotes towards orally or intraperitoneally administered cadmium are the higher members of the polyaminopolycarboxylate family, especially TTHA.

6. When administered simultaneously (DMSA orally and TTHA intraperitoneally), these chelators synergistically reduce the whole‐body retention of cadmium.

In conclusion, chelation treatment in acute oral cadmium intoxication should first prevent/reduce intestinal damage and uptake by rapid oral administration of a chelating antidote and then alleviate systemic toxicity due to absorbed cadmium and enhance renal/biliary cadmium excretion by parenteral administration of a chelating antidote.     

DVB-MMA共聚物树脂吸附水相苯酚的研究

以二乙烯基苯(DVB)和甲基丙烯酸甲酯(MMA)的混合液为单体,分别采用悬浮聚合法和溶剂热法合成高分子树脂PDMA和PDVB.通过BET、IR、SEM对样品的结构和形貌进行表征,对比2种方法合成吸附树脂的性能差异,并考察各高分子树脂对水中苯酚的吸附效果.结果表明,采用悬浮聚合法制备的DVB-MMA共聚物树脂在2~4nm和5~30nm范围内均有明显孔径分布,具有较大的比表面积566m2/g. DVB-MMA共聚物树脂(PDMA-XF)对4500mg/L苯酚溶液的饱和吸附量为170.4mg/g,其酯羰基中的氧原子与酚羟基当中的氢原子产生氢键作用,这些分子间的氢键作用有助于吸附水中苯酚.     

D201树脂对双组分萘系化合物的吸附分离

用D201强碱性阴离子交换树脂自双组分水溶液中选择吸附分离1-氨基-2-萘酚-4-磺酸(1,2,4-酸)和2-萘酚,考察了溶液pH值、浓度、温度、树脂床高及流速等因素对吸附和分离系数的影响.结果表明,在pH 3—6时,树脂对1,2,4-酸有较高的吸附量及吸附选择性,利于1,2,4-酸与2-萘酚的选择性吸附分离.温度对吸附的影响较小,等温吸附规律符合Freundlich模型.动态吸附表明,至1,2,4-酸的泄漏点时,吸附流出液中几乎只含2-萘酚,1,2,4-酸被吸附于树脂上.随着树脂床层的增长或初始浓度和流速的减小,都使泄漏点推迟及分离系数提高.载酚酸的树脂柱可用15%质量比的NH4Cl和20%体积比的乙醇混合液定量洗脱1,2,4-酸.     

两性高分子螯合絮凝剂和氯化钙对羟基亚乙基二膦酸预镀铜废水的去除性能

以羟基亚乙基二膦酸(HEDP)预镀铜废水为处理对象,考察两性高分子螯合絮凝剂(ACPF)和CaCl2对其处理效果.结果表明,单独使用ACPF或CaCl2,用量大,残余Cu2+和COD浓度均不能达到电镀污染物排放标准(GB21900—2008);将ACPF和CaCl2配合使用,Ca2+可与HEDP螯合生成HEDP—Ca沉淀,促进ACPF与Cu2+螯合;且Ca2+还可与废水中的酒石酸根离子形成溶解度很小的结晶,促进絮体的形成和沉降.因此,处理药剂的用量明显降低,Cu2+和COD残余浓度均能达标.适宜的处理条件为:弱碱或碱性条件下,ACPF投加量为3.0 g.L-1,CaCl2投加量为2.0 g.L-1,Cu2+和COD的去除率分别达99.74%和97.5%,残余浓度分别为0.335和25.27 mg.L-1.     

Tl(Ⅰ)与Tl(Ⅲ)在UV - H2O2体系中的价态转化

建立了chelex-100螯合树脂分离技术与石墨炉原子吸收联用测定水体中Tl(Ⅰ)与Tl(Ⅲ)的方法,分别考察了光化学氧化中pH值、H2O2投加量、光照强度对Tl(Ⅰ)的氧化效果。方法的Tl(Ⅰ)与Tl(Ⅲ)检出量均为0.5μg/L。两者共存时各自加标回收率大于95%。结果表明,在偏酸性环境(pH=3.0),投加适量30%H2O2,光照强度大有利于Tl(Ⅰ)的氧化。当pH=2.91,投加30%H2O2为5 mL,UV照射10min后,Tl(Ⅰ)的转化率达90%。研究表明,光化学氧化可有效转化水体中不易被物理化学法去除的Tl(Ⅰ)和容易被物理吸附、化学沉淀方法去除的Tl(Ⅲ)。     

反应条件对矿用充填发泡树脂活性的影响研究

采用二价金属A作为催化剂,合成矿用发泡树脂。通过测定树脂的固含量、黏度、凝胶时间、羟甲基指数等,研究反应温度、时间和催化剂用量对矿用发泡树脂活性的影响。试验结果表明:随着反应时间的延长、温度的升高、催化剂用量的增加,树脂的黏度和固含量逐渐增加,而树脂中残余B、残余C和凝胶时间逐渐减少。在较高温度下,羟甲基指数随着反应时间的延长先增加后减少;在较低温度下,羟甲基指数随着反应时间的延长先减少后增加;较大的催化剂用量有利于树脂缩合反应,较低的用量有利于促进B与C的羟基化反应。     

HCR处理环氧树脂废水的中试

对某化工厂的高浓度环氧树脂废水进行HCR中试研究。当进水COD容积负荷为7.5~12 kg/(m3.d)时,COD的去除率达85%。结果证明HCR反应系统处理效率高,抗负荷冲击性能强,系统运行稳定。