屏蔽氯离子干扰高盐榨菜废水中COD的测定方法
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摘要
高盐废水中氯离子的存在会严重干扰COD的测定,因此,如何屏蔽氯离子干扰准确测定其COD的难点之一。为研究高盐榨菜废水中更为准确的COD测定方法,实验中采用了2种屏蔽氯离子的方法:硫酸汞屏蔽法和硝酸银屏蔽法,屏蔽后再通过传统回流冷凝法来测定实验模拟配水水样中的COD,并比较两种方法的屏蔽效果。结果表明:硫酸汞屏蔽法的最佳HgSO4/Cl-值为40,此时误差最小,为1.43%,硝酸银滴定法的误差为0.21%,得出硝酸银屏蔽法的屏蔽效果较好;再分别用这两种方法屏蔽榨菜废水中的氯离子后测定其COD值,结果显示两种方法测定的COD相差了20 mg/L,而硫酸汞屏蔽法更适合于榨菜废水中COD的测定。综合以上2种方法的屏蔽特点,采用先用硝酸银滴定氯离子浓度,再添加少量的硫酸汞的联合方法测定榨菜废水中的COD值,结果表明此方法更可靠。
Chlorides in the wastewater with high salt seriously interrupts the determination of chemical oxygen demand( COD). Therefore,chloride mask in wastewater has been an important and difficult issue in recent years. In the present work,experiment design is used for more accurate and precise COD determination method of pickled mustard wastewater. Two methods for masking chloride are adopted: HgSO 4 masking method and AgNO 3 masking method. After masking chloride,use the traditional reflux digestion method to test COD in the experimental sample. The results show that when the ratio of HgSO 4 to Cl-is 40,the chloride mask results in a minimum error of 1. 43%,and the minimum error is 0. 21% when AgNO 3 is used. Obviously,AgNO 3 masking method is superior to HgSO 4 masking method. However,when these two methods are used in pickled mustard wastewater,there is a COD value difference of 20 mg / L and HgSO 4 masking method is more accurate. By considering the characteristics of the two methods above,a combined method is proposed,which AgNO 3 is added equivalently according to the concentration of Cl-first,and then a few amounts of HgSO 4 are added to prevent the free Cl-in wastewater. The facts show that combined method is more reliable.
Chlorides in the wastewater with high salt seriously interrupts the determination of chemical oxygen demand( COD). Therefore,chloride mask in wastewater has been an important and difficult issue in recent years. In the present work,experiment design is used for more accurate and precise COD determination method of pickled mustard wastewater. Two methods for masking chloride are adopted: HgSO 4 masking method and AgNO 3 masking method. After masking chloride,use the traditional reflux digestion method to test COD in the experimental sample. The results show that when the ratio of HgSO 4 to Cl-is 40,the chloride mask results in a minimum error of 1. 43%,and the minimum error is 0. 21% when AgNO 3 is used. Obviously,AgNO 3 masking method is superior to HgSO 4 masking method. However,when these two methods are used in pickled mustard wastewater,there is a COD value difference of 20 mg / L and HgSO 4 masking method is more accurate. By considering the characteristics of the two methods above,a combined method is proposed,which AgNO 3 is added equivalently according to the concentration of Cl-first,and then a few amounts of HgSO 4 are added to prevent the free Cl-in wastewater. The facts show that combined method is more reliable.
引文
[1]国家技术监督局.GB11914-89水质化学需氧量的测定重铬酸钾法[S].北京:中国标准出版社,1991.
[2]Dharmadhikari D M,Vanerkar A P,Barhate N M.Chemical oxygen demand using closed microwave digestion system[J].Environment Science Technology,2005,39(16):6198-6201.
[3]Domini C E,Hidalgo M,Marken F,et al.Comparison of the three optimized digestion methods for rapid determination of chemical oxygen demand:closed microwaves,open microwaves and ultrasound irradiation[J].Analytica Chimica Acta,2006,561(1/2):210-217.
[4]袁英贤,丁少军,陈寒玉.微波消解-分光光度法测定COD的研究[J].环境工程,2007,25(5):76-81.YUAN Yingxian,DING Shaojun,CHEN Hanyu.Determination of COD Cr with microwave digestionspectrophotometry[J].Environmental Engineering,2007,25(5):76-81.
[5]蒋欣,陈剑宁,罗声,等.微波消解光度法测定COD及综合效益分析[J].环境科学与技术,2006,29(9):44-45.JIANG Xin,CHEN Jianning,LUO Sheng,et al.Detection of COD cr by microwave digestion photometric method and its unified benefits analysis[J].Environmental Science and Technology,2006,29(9):44-45.
[6]韦利杭.高氯废水中CODcr的快速测定[J].中国环境监测,1997,13(4):42-44.WEI Lihang.Determination of COD in wastewater samples containing high chloride level by a rapid method[J].Environmental Monitoring in China,1997,13(4):42-44.
[7]Thompson K C,Mendham D,Best D,et al.Simple method for minimizing the effect of chloride on the chemical oxygen-demand test without the use of mercury salts[J].Analyst,1986,111:483-485.
[8]林诗敏,王茀跃,白书明.差减法测定高氯废水的COD值[J].中国给水排水,2009,25(24):79-81.LIN Shimin,WANG Fuyue,BAI Shuming.Determination of COD of high chloride wastewater by subtraction method[J].China Water and Wastewater,2009,25(24):79-81.
[9]常光玲,刘云,邱晓国.无汞高银低压消解法与氯气校正法测定高氯水体中化学需氧量的比较研究[J].化学分析计量,2009,18(2):40-42.CHANG Guangling,LIU Yun,QIU Xiaoguo.Research on determination of COD in high chlorine water by mercuryfree,high-silver,low-pressure digestion method compared with chlorine emendation method[J].Chemical Analysis and Meterage,2009,18(2):40-42.
[10]田桂芝,孙彩兰,许云峰.还原性物质对化学需氧量(COD)测定的影响及消除方法[J].辽宁城乡环境科技,2007,27(1):53-64.TIAN Guizhi,SUN Cailan,XU Yunfeng.The effects and degradation methods of reducible maters on measurement of chemical oxygen demand(COD)[J].Liaoning Urban and Rural Environmental Science and Technology,2007,27(1):53-64.
[11]APHA.Standard Methods for the Examination of Water and Wastewater[S].Washington,DC:American Public Health Association,1999.
[12]Vyrides I,Stuckey D C.A modified method for the determination of chemical oxygen demand(COD)for samples with high salinity and low organics[J].Bioresource Technology,2009,100(2):979-982.
[13]国家环境保护局.GB11896-89水质氯化物的测定硝酸银滴定法[S].北京:中国标准出版社,1990.
[14]Canelli E,Mitchell D G,Pause R W.Improved determination of chemical oxygen demand in water and wastes by a simplified acid dichromate digestion[J].Water Research,1976,10(4):351–355.
[15]邢长城,孙也.COD快速消解法测定高含氯废水的探讨[J].能源环境保护,2008,22(5):32-34.XING Changcheng,SUN Ye.Study on the COD fast determination in wastewater with high concentration of chloride[J].Energy Environmental Protection,2008,22(5):32-34.
[16]赵亚乾.Cl-,NH3和H2O2对COD测定的影响[J〗.上海环境科学,1995,14(8):32-34.ZHAO Yaqian.Effect of chloride,ammonia and hydrogen peroxide on COD measurement[J].Shanghai Environmental Science,1995,14(8):32-34.
[17]宋志铭,赵淑芳,刘春颖.以硫酸镍为催化剂测定高氯废水CODcr的研究[J].环境科学管理,2011,36(6):97-99.SONG Zhiming,ZHAO Shufang,LIU Chunying.Study on CODcr Measurement in High-chlorine wastewater with nickel sulfate as catalyst[J].Environmental Science and Management,2011,36(6):97-99.
[18]刘娟,吴浩宇.高氯废水COD测定方法的探究[J].工业水处理,2011,31(4):66-69.LIU Juan,WU Haoyu.Discussion on the determination of the COD of high chloride-containing wastewater[J].Industrial Water Treatment,2011,31(4):66-69.
[2]Dharmadhikari D M,Vanerkar A P,Barhate N M.Chemical oxygen demand using closed microwave digestion system[J].Environment Science Technology,2005,39(16):6198-6201.
[3]Domini C E,Hidalgo M,Marken F,et al.Comparison of the three optimized digestion methods for rapid determination of chemical oxygen demand:closed microwaves,open microwaves and ultrasound irradiation[J].Analytica Chimica Acta,2006,561(1/2):210-217.
[4]袁英贤,丁少军,陈寒玉.微波消解-分光光度法测定COD的研究[J].环境工程,2007,25(5):76-81.YUAN Yingxian,DING Shaojun,CHEN Hanyu.Determination of COD Cr with microwave digestionspectrophotometry[J].Environmental Engineering,2007,25(5):76-81.
[5]蒋欣,陈剑宁,罗声,等.微波消解光度法测定COD及综合效益分析[J].环境科学与技术,2006,29(9):44-45.JIANG Xin,CHEN Jianning,LUO Sheng,et al.Detection of COD cr by microwave digestion photometric method and its unified benefits analysis[J].Environmental Science and Technology,2006,29(9):44-45.
[6]韦利杭.高氯废水中CODcr的快速测定[J].中国环境监测,1997,13(4):42-44.WEI Lihang.Determination of COD in wastewater samples containing high chloride level by a rapid method[J].Environmental Monitoring in China,1997,13(4):42-44.
[7]Thompson K C,Mendham D,Best D,et al.Simple method for minimizing the effect of chloride on the chemical oxygen-demand test without the use of mercury salts[J].Analyst,1986,111:483-485.
[8]林诗敏,王茀跃,白书明.差减法测定高氯废水的COD值[J].中国给水排水,2009,25(24):79-81.LIN Shimin,WANG Fuyue,BAI Shuming.Determination of COD of high chloride wastewater by subtraction method[J].China Water and Wastewater,2009,25(24):79-81.
[9]常光玲,刘云,邱晓国.无汞高银低压消解法与氯气校正法测定高氯水体中化学需氧量的比较研究[J].化学分析计量,2009,18(2):40-42.CHANG Guangling,LIU Yun,QIU Xiaoguo.Research on determination of COD in high chlorine water by mercuryfree,high-silver,low-pressure digestion method compared with chlorine emendation method[J].Chemical Analysis and Meterage,2009,18(2):40-42.
[10]田桂芝,孙彩兰,许云峰.还原性物质对化学需氧量(COD)测定的影响及消除方法[J].辽宁城乡环境科技,2007,27(1):53-64.TIAN Guizhi,SUN Cailan,XU Yunfeng.The effects and degradation methods of reducible maters on measurement of chemical oxygen demand(COD)[J].Liaoning Urban and Rural Environmental Science and Technology,2007,27(1):53-64.
[11]APHA.Standard Methods for the Examination of Water and Wastewater[S].Washington,DC:American Public Health Association,1999.
[12]Vyrides I,Stuckey D C.A modified method for the determination of chemical oxygen demand(COD)for samples with high salinity and low organics[J].Bioresource Technology,2009,100(2):979-982.
[13]国家环境保护局.GB11896-89水质氯化物的测定硝酸银滴定法[S].北京:中国标准出版社,1990.
[14]Canelli E,Mitchell D G,Pause R W.Improved determination of chemical oxygen demand in water and wastes by a simplified acid dichromate digestion[J].Water Research,1976,10(4):351–355.
[15]邢长城,孙也.COD快速消解法测定高含氯废水的探讨[J].能源环境保护,2008,22(5):32-34.XING Changcheng,SUN Ye.Study on the COD fast determination in wastewater with high concentration of chloride[J].Energy Environmental Protection,2008,22(5):32-34.
[16]赵亚乾.Cl-,NH3和H2O2对COD测定的影响[J〗.上海环境科学,1995,14(8):32-34.ZHAO Yaqian.Effect of chloride,ammonia and hydrogen peroxide on COD measurement[J].Shanghai Environmental Science,1995,14(8):32-34.
[17]宋志铭,赵淑芳,刘春颖.以硫酸镍为催化剂测定高氯废水CODcr的研究[J].环境科学管理,2011,36(6):97-99.SONG Zhiming,ZHAO Shufang,LIU Chunying.Study on CODcr Measurement in High-chlorine wastewater with nickel sulfate as catalyst[J].Environmental Science and Management,2011,36(6):97-99.
[18]刘娟,吴浩宇.高氯废水COD测定方法的探究[J].工业水处理,2011,31(4):66-69.LIU Juan,WU Haoyu.Discussion on the determination of the COD of high chloride-containing wastewater[J].Industrial Water Treatment,2011,31(4):66-69.