微波作用下氧化碱浸铜冶炼烟灰脱砷的动力学

采用微波氧化辅助Na2S-NaOH浸出体系对铜冶炼烟灰（简称"烟灰"）进行研究。结果表明：当温度60℃,NaOH和烟灰的投加量比例为5 g：10 g,Na2S和烟灰的投加量比例为8 g：10 g,固液比为1：20时,砷的浸出率为98.45%。动力学研究表明：砷的浸出过程在313~343 K内符合"未反应收缩核"模型,浸出过程受未反应核周围残留固体膜层扩散控制,经拟合得出浸出动力学方程,浸出表观活化能Ea=13.46 kJ·mol-1。     

海泡石活化废酸复合絮凝剂处理印染废水的研究

利用海泡石酸活化所产生废液的特性,制备一种处理印染废水的新型复合絮凝剂。通过实验,分析了印染废水的pH值﹑海泡石废酸复合絮凝剂的投加剂量及静置时间对处理印染废水效果,并且在相同实验条件下与硫酸铁及海泡石原矿处理印染废水分别做了对比实验。实验结果表明:海泡石活化废酸复合絮凝剂处理印染废水能取得良好的效果。     

KFR-2特种饰面型防火涂料的热解动力学分析

利用梅特勒TA4000,25-TC15型热分析仪对KFR-2特种饰面型防火涂料和普通乳胶漆涂料进行了TG和DSC分析,研究了KFR-2特种饰面型防火涂料和普通乳胶漆涂料的降解过程.在分析动力学理论模型基础上,分析数据,确定了KFR-2特种饰面型防火涂料和普通乳胶漆涂料的热力学参数,活化能.通过分析比较得出,与普通乳胶漆相比,KFR-2特种饰面型防火涂料由于添加了阻燃成分,使活化能显著提高,热稳定性明显加强,体系耐热性能好,阻燃效果明显.     

粒度对煤矸石活化效率的影响

煤矸石煅烧活化是煤矸石为原料提取铝、硅等化工原料的重要环节,煤矸石破碎粒度对煅烧活化效率有重要影响。文章以山西潞安的煤矸石为原料,利用煅烧活化-酸溶法提取煤矸石中的铝,研究了粒度对煤矸石活化效率的影响。实验确定铝溶出的较优工艺条件为:煅烧温度650℃、20%盐酸225mL/100g煤矸石、固液比1:3、酸浸时间3h,在此工艺条件下研究矸石粒度对铝和铁溶出的影响。结果表明:物料粒度对活化效果影响显著,当物料粒度为60～80目时,铝的溶出率最大达到79%;物料与空气充分接触有利于提高活化效果,动态煅烧活化效率显著高于静态煅烧,粒度对煅烧效果产生的重要影响很大程度来源于空气接触比表面积。     

珠江三角洲地区气溶胶分档活化特性与闭合实验

使用SMPS与CCNC系统相结合,于2011年12月在广州番禺大气成分站开展了40~200nm气溶胶粒子的分档活化观测.活化率曲线和统计结果显示0.109%、0.20%、0.39%、0.67%四个过饱和比下临界干粒径Dmid依次为143.7,99.5,74.7,62.6nm;对应的截断粒径Dcut为171.9, 119.1, 90.2, 72.5nm.进一步分析表明,气溶胶粒子的活化能力主要受粒径控制,成分与混合状态的影响在活化临界位置附近最为显著.本次观测结果与华北地区和周边城郊地区相比,气溶胶活化能力较弱.闭合实验计算得到的CCN数浓度与观测值存在很好的相关性(R2=0.9477),计算值较观测值高约16%.考虑到仪器系统误差等因素,认为两者闭合良好.对CCN数浓度计算中使用的3个因子,即气溶胶数浓度NCN、气溶胶谱型NSD、活化率曲线ARSR进行了敏感性实验,结果显示各因子对CCN数浓度的影响程度存在如下关系:NCN> NSD> ARSR.     

Removal of chromium(VI) by ZnCl2 activated coir pith carbon

The adsorption of chromium(VI) onto ZnCl₂ activated carbon developed from coir pith was investigated to assess the possible use of this adsorbent. The influence of contact time, adsorbent dose, Cr(VI) concentration, pH and temperature were investigated. The two theoretical adsorption isotherms, namely, Langmuir and Freundlich were used to describe the experimental results. The Langmuir adsorption capacity (Q ₀) was found to be 120.5?mg Cr(VI) per g of the adsorbent. The adsorption followed the second-order kinetics and was found to be maximum at pH 2.0. The pH effect and the desorption studies showed that ion exchange mechanism might be involved in the adsorption process. The effects of foreign ions such as chloride, sulphate, phosphate, selenite, molybdate, nitrate and perchlorate on the removal of Cr(VI) have been investigated. The removal of Cr(VI) from synthetic ground water was also tested. The results show that ZnCl₂ activated coir pith carbon is effective for the removal of Cr(VI) from water.     

影响断层活化的破碎带特征参数敏感性分析

为研究破碎带对断层活化的影响,选取破碎带宽度、岩石内摩擦角、粘结系数及抗拉强度作为破碎带的特征参数,采用FLAC3D模拟工作面推进对断层的影响,借助正交表确定模拟方案,通过对正交试验结果进行方差分析,以此研究影响断层活化的破碎带特征参数敏感性。结果表明:破碎带特征参数对断层活化的敏感性主次顺序为破碎带宽度﹥岩石内摩擦角﹥岩石粘结系数﹥岩石抗拉强度,且断层破碎带宽度越大,岩石内摩擦角越小,断层活化可能性也就越高,而岩石粘结系数与抗拉强度对断层活化影响较小。     

柠檬酸对三峡水库消落区土壤中汞活化及甲基化的影响

利用室内模拟实验,用不同浓度柠檬酸溶液分别浸提和培养土壤,探讨了植被根系分泌物的主要成分柠檬酸对三峡库区消落带土壤中汞活化及甲基化的影响.结果表明,添加柠檬酸后浸提液中汞含量在达到最高值之前均高于对照组(0 mmol·L~(-1)),且随柠檬酸浓度的增加而增大.0、1、2、4、5、6、8 mmol·L~(-1)浓度下最大汞溶出量随柠檬酸浓度的增加先增大而后保持稳定,分别占供试土壤总汞的1.03%、1.67%、1.99%、2.47%、2.68%、2.73%、2.73%.培养实验中,土壤甲基汞(Me Hg)含量在前3 h内基本维持稳定,随后除对照组增加缓慢外,其余组均开始上升,且上升速率随柠檬酸浓度的升高而增大.在同一培养时段内,土壤Me Hg含量及增加量随柠檬酸浓度的升高而增大.表明柠檬酸对土壤中无机汞向甲基汞的转化过程有一定的促进作用,且促进作用随着柠檬酸浓度的增加而愈加显著.     

紫外光强化Fe(Ⅱ)-EDTA活化过硫酸盐降解直接耐酸大红4BS

为探索硫酸根自由基对偶氮染料的降解能力,以直接耐酸大红4BS（下称大红4BS）为模拟污染物,通过UV/Fe（Ⅱ）-EDTA/PDS（PDS为过硫酸钠）体系,探讨了初始c（PDS）、Fe（Ⅱ）/EDTA（摩尔比）、无机盐阴离子等对大红4BS降解的影响.结果表明,大红4BS的脱色率随着初始c（PDS）的增加而增大,当c（PDS）超过15 mmol/L时无显著变化.Fe（Ⅱ）/EDTA比在5:1时效果最好,5 min时使0.038 0 mmol/L大红4BS的脱色率达到93.6%.反应符合二级动力学模型.HCO₃-、Cl-、NO₃-、SO₄2-等无机盐阴离子表现出明显抑制作用,c（无机盐阴离子）在100 mmol/L条件下,脱色率分别降低66.9%、13.2%、12.1%、9.43%.利用紫外可见光谱,依据其结构与特征吸收的关系,初步推测自由基离子对大红4BS降解的途径:苯环最先遭到破坏,随后偶氮键断裂、萘环开裂.研究显示,UV光可有效强化Fe（Ⅱ）-EDTA活化过硫酸盐形成SO₄-·自由基,对偶氮染料具有很好的脱色能力,最佳反应条件[PDS:Fe（Ⅱ）:EDTA（摩尔比）为15:5:1]下,大红4BS在10 min时脱色率高达98.1%.      

Degradation of carbon tetrachloride in thermally activated persulfate system in the presence of formic acid

The thermally activated persulfate (PS) degradation of carbon tetrachloride (CT) in the presence of formic acid (FA) was investigated. The results indicated that CT degradation followed a zero order kinetic model, and CO ₂ ^– · was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl^– had a negative effect on CT degradation, and high concentration of Cl^– displayed much strong inhibition. Ten mmol·L^–1HCO ₃ ^– promoted CT degradation, while 100 mmol·L^–1NO ₃ ^– inhibited the degradation of CT, but SO ₄ ^2– promoted CT degradation in the presence of FA. The measured Cl–concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation (ISCO) remediation for CT contaminated site.