含铬革屑碱水解动力学的研究

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• 英文论文题名：The kinetics of alkaline hydrolysis of chrome shavings
• 论文作者：罗艳华 ; 陈沛海 ; 王全杰 ; 石磊
• 英文论文作者：LUO Yanhua ; CHEN Peihai ; WANG Quanjie ; SHI Lei ; Shaanxi University of Science and Technology ; Yantai University
• 年：2016
• 作者机构：陕西科技大学;烟台大学;
• 论文关键词：含铬革屑 ; 碱水解 ; 动力学
• 英文论文关键词：chrome shavings ; alkali hydrolysis ; kinetics
• 会议召开时间：2016-07-27
• 会议录名称：2016第十一届全国皮革化学品学术交流会暨中国皮革协会技术委员会第21届年会摘要集
• 英文会议录名称：Abstracts of 2016 the 11th National Conference on Leather Chemicals & 21st Annual Convention of China Leather Science and Technology Commission
• 语种：中文
• 分类号：TS59
• 学会代码：ZGHG
• 会议名称：2016第十一届全国皮革化学品学术交流会暨中国皮革协会技术委员会第21届年会
• 会议地点：中国山东济南
• 主办单位：中国皮革协会技术委员会、中国皮革协会皮革化工专业委员会、中国化工学会精细化工专业委员会
• 学会名称：中国化工学会
• 页数：2
• 文件大小：71k
• 原文格式：O
• 会议级别：全国

摘要

采用邻苯二甲醛法测游离氨基浓度,pH计测OH~-浓度,二苯碳酰肼分光光度法测铬含量,探讨碱性条件下革屑水解反应的动力学。分析表明,随着水解时间的延长,OH~-与肽键反应逐渐生成游离氨基,OH~-浓度先降低后平缓,而氨基浓度先增加后平缓。对肽键的水解进行伪一级动力学分析说明,用NaOH水解时,反应前1.5 h铬的沉淀反应对肽键的断裂影响较大,之后影响可忽略,对1.5 h后的数据线性拟合得出,R=0.97644,k=-0.00479 min~(-1);用NaOH+CaO混合液水解时,低铬浓度对水解影响较弱,故对所有数据线性拟合,R--0.97915,k=0.00375 min~(-1),符合伪一级动力学特征。用NaOH水解,pH为11.2时,铬浓度出现最低值;用NaOH+CaO混合液水解,该最低值出现在pH约11.1。使用碱水解时,三价铬沉淀的最佳pH区间为11.0-11.3。
This study aimed at the kinetics of the hydrolysis reaction of leather shavings under alkaline conditions.The concentration of free amino groups was measured by the method of two formaldehyde(OPA),the concentration of OH~- was obtained by pH mater,determination of chromium content by two- benzene-carbon-hydrazine spectrophotometry.The results showed that with the increase of hydrolysis time,OH~- react with a peptide bond to form a free amino group,OH~-concentration gradually reduce and eventually leveled off,an amino increasing concentrations,and ultimately flatten.In the reaction of the former 1.5 h,the precipitation reaction of chromium has an effect on peptide bond fracture process.After that,its effects can be ignored.Therefore,after the 1.5 h part as the basis for linear fitting,R=0.97644,k=0.00479 min~(-1).For NaOH + CaO mixed hydrolyzate,it has little effect on the peptide bond hydrolysis because of the low concentration of chromium,we make a linear fitting of all the dates,R=0.97915,k=0.00375 min~(-1),in accord with pseudo first order kinetic characteristics.By hydrolysis with NaOH,the minimum value of the concentration of chromium appears at about pH 11.2.When using CaO+NaOH hydrolysis,the chromium concentration was lower than that of an order of magnitude when using NaOH alone,and the lowest value of Cr concentration appeared at pH 11.1.In summary,the use of alkaline hydrolysis,trivalent chromium precipitation optimum pH was 11.0-11.3.

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