复合二氧化氯的制备及其用于城市污水回用消毒  

Preparation of disinfectant containing both chlorine dioxide and chlorine for safe urban reuse

作　　者：樊金红[1] 王红武[1] 马鲁铭[1] 

机构地区：[1]同济大学城市污染控制国家工程研究中心,上海200092

出　　处：《化工学报》2012年第2期578-583,共6页CIESC Journal

基　　金：国家科技支撑计划项目(2008BAJ08B21);上海环保研发公共服务平台项目(10DZ2291100)~~

摘　　要：在酸性环境中通过NaCl电解协同NaClO2化学氧化方法制备的复合二氧化氯溶液中ClO2和自由氯浓度分别达到70%和20%左右,系统地研究了电流密度(A)、NaClO2与NaCl质量比(B)、电解时间(C)对复合溶液中组分浓度和质量百分数的影响,并将复合溶液用于城市污水二级处理出水的消毒。结果表明,复合溶液中自由氯的浓度主要受因素C和A的影响,ClO2的浓度主要受因素C和B的影响,而A对副产物ClO2-和ClO3-的影响最大。总大肠菌群数在105～108个.L-1的城市污水二级处理出水采用复合溶液消毒时,当其中ClO2投加量为4mg.L-1,自由氯含量不低于1.20mg.L-1,经30min接触后出水生物学指标满足GB/T 18920—2002的要求。既降低了消毒剂的使用量,又减少了消毒副产物ClO2-的生成。To achieve simultaneously maximum disinfection and minimum toxicity a mix disinfectant of chlorine dioxide and chlorine are found to be efficient for disinfection of drinking water and urban reused waste-water.However,transportation and reservation of the mixture may threat to environmental safety.Therefore,on-site preparation is necessary for field use.At present,preparation methods of the mix disinfectant have chemical reduction of sodium chlorate and electrolysis of sodium chloride,and the content of chlorine dioxide in mixture obtained is usually below 30%.To get high chlorine dioxide content,a method for the preparation of the mix disinfectant was proposed ： electrolyzing sodium chloride（NaCl）was followed by a chemical oxidation of sodium chlorite（NaClO2）in an undivided electrolysis reactor,in which the content of ClO2 in the mix disinfectant can be controlled.The effect of current density（A）,mass ratio of NaClO2：NaCl（B）,electrolysis time（C）on the concentration and mass percentage of ClO2,free chlorine,ClO-2 and ClO-3 was investigated systematically.Under the electrolysis conditions： current density 41.67—83.33 A·m-2,mass ratio of NaClO2 and NaCl 1∶3—3∶3 and reaction time 5—15 min,the mass percentage of chlorine dioxide（ClO2）and free chlorine reached 70% and 20% in electrolysis solution.The yield of free chlorine was mainly controlled by factors C and A,that of ClO2 did by factors C and B,and that of by-products of ClO-2 and ClO-3 did by factor A.When urban sewage after secondary treatment with the total coliforms of 105—108 cfu·L-1was disinfected by the mix disinfectant prepared with the new method at conditions of ClO2 dosage 4 mg·L-1,free chlorine 1.20 mg·L-1 and contact time 30 min,the total coliforms in the urban sewage meet the requirement of the water quality standard for urban miscellaneous consumption GB/T 18920—2002.Meanwhile,decreasing use of disinfectants and reducing generation of ClO-2 are reached.

关 键 词：二氧化氯 自由氯 电解 污水消毒 

分 类 号：O646[理学—物理化学] TQ085.4[理学—化学]