醋酸-醋酸铵缓冲体系中柠檬酸、草酸和苹果酸对高岭石的溶解特征

采用间歇法(batch method)模拟研究醋酸-醋酸铵缓冲体系中柠檬酸、草酸和苹果酸三种低分子量有机酸对高岭石的溶解特征。结果表明:柠檬酸、草酸和苹果酸三种有机酸均能显著促进高岭石的溶解,溶解能力都是随其浓度和酸度的升高而增强;当有机酸浓度为1mmol/L,pH3.5时,草酸>柠檬酸>苹果酸;pH5.5和pH4.5时,柠檬酸>草酸>苹果酸;而当有机酸浓度≥5mmol/L时,草酸>柠檬酸>苹果酸,且对高岭石的溶解能力都大于无机酸。当柠檬酸、草酸和苹果酸浓度为1mmol/L时,反应级数(nHL)分别为0.09、0.27和0.18,速率常数(kHL)分别为4.03×10-13、2.62×10-12和4.73×10-13;当其浓度为5mmol/L时,其反应级数(nHL)分别为0.16、0.37和0.16,速率常数(kHL)分别为1.38×10-12、2.32×10-11和4.97×10-13;其浓度为10mmol/L时,反应级数(nHL)分别为0.18、0.34和0.16,速率常数(kHL)分别为2.17×10-12、2.60×10-11和6.05×10-13。对于柠檬酸和草酸而言,在促进高岭石溶解的作用上,相对于质子,配体的贡献是主要的;而对于苹果酸而言,配体的贡献是次要的。配体促进溶解速率(RL)可以用配体浓度的指数形式来表示。对柠檬酸、草酸和苹果酸而言,pH5.5时,分别为RL=10-13.01[配体]0.23、RL=10-13.28[配体]0.70和RL=10-13.72[配体]0.38;pH4.5时,分别为RL=10-13.00[配体]0.51、RL=10-13.03[配体]1.05和RL=10-14.07[配体]0.77;pH3.5时,分别为RL=10-12.99[配体]0.64、RL=10-12.72[配体]0.89和RL=10-14.61[配体]1.69。     

环境保护与湿法生产硬质纤维板技术改造的探讨

本文主要探讨了环境保护与湿法生产硬质纤维板技术改造问题，提出了切实可行的污水处理措施。     

钢结硬质合金冷作模具硼-硫复合渗强化工艺

为了使钢结硬质合金制成的冷作模具的使用寿命进一步提高,研究了一种硼一硫共渗强化新工艺,试验结果表明,渗硼模具的使用寿命比未渗硼模具提高了10多倍,硼～硫复合渗透模具的使用寿命又比单一渗硼模具提高了50％～70％。     

废旧电冰箱聚氨酯硬质泡沫塑料回收处理技木研究

从废旧电冰箱聚氨酯硬泡塑料的回收、处理、资源化等方面阐述了国内外的研究技术现状.近年来我国电冰箱报废量剧增,聚氨酯硬泡塑料是电冰箱最主要的塑料品种,具有资源性和环境污染的双重特性.从循环经济和清洁生产的理念出发,提出我国进行废旧电冰箱聚氨酯硬泡塑料的回收处理处置,有利于促进我国可持续发展和建设“美丽中国”.     

废冰箱、冷柜隔热保温层聚氨酯泡沫塑料的资源化回收利用技术开发成功

废冰箱、冷柜经拆解后会产生大量的硬质聚氨酯泡沫塑料，目前国内处理这类物料主要采用焚烧和丢弃的办法。焚烧聚氨酯泡沫塑料会产生大量的浓烟及十分刺鼻的气味，对大气环境会产生严重污染；如随意丢弃硬质聚氨酯泡沫塑料，因这类废塑料的难以降解性同样会造成对环境的污染和资源的浪费。     

Electrochemical remediation of copper contaminated kaolinite by conditioning anolyte and catholyte pH simultaneously

This report examined electrochemical remediation of copper contaminated kaojinite by controlling electrolytes‘ pH for both of anolyte and catholyte simultaneously.Results showed the electrokinetic process and remediation efficiency varied obviously when different buffer systems,including citric acid(test 1),nitric acid EDTA(test 2)and nitric acid(test 3),were used to control catholyte pH AND Na2CO3 was used at the same time to control all anolyte one.It was found that under such pH condition soil‘s pH in soil column kept at 3.0-7.0 successfully,and correspondingly no copper precipitation and decrease of soil electroconductivity appeared.which are usually observed in electrokinetic process due to OH^- introduction into soil cojumn by electrochemical reaction occurred in cathode.Electroosmosis flow rates were almost equal for these three tests,indicating that these buffers did not affect Zeta-potential of kaolinite within the examined duration.More acid and basic solution was added into electrokinetic cell when nitric acid was used as buffer than when nitric acid EDTA and then citric acid were used.Due to introduction of large amounts of ions into soil column,significant higher current was observed for test 3 than other two.Analysis of copper speciation and total quantity in kaolinite indicated that 22.5%,23.74%and 55.65% Cu were removed from kaolinite for test 1,test 2 and test 3 respectively after only 10 days‘ electrokinetic remediation.