摘要
针对被典型除草剂禾大壮与莠灭净污染原水的应急处理工艺进行了研究.结果表明,活性炭吸附和预氯化是有效去除禾大壮和莠灭净的2种措施.拟二级动力学模型和Freundlich吸附等温线模型可分别较好地描述粉末活性炭对原水中禾大壮和莠灭净的吸附过程和吸附平衡.40 mg/L的粉末活性炭可将浓度为200μg/L的禾大壮或莠灭净污染完全去除,粉末活性炭的最佳投加位置是混凝前20 min,颗粒活性炭柱(高20 cm)对2种农药的去除效果都较为显著,可以作为粉末活性炭的有效补充保证一定的安全系数.有效氯投加量为2.5 mg/L时虽然也可将2种农药氧化去除,但生成的产物及其毒性有待于进一步研究.粉末活性炭与1 mg/L的KMnO4预氧化联用并没有提高禾大壮和莠灭净的去除效果,粉末活性炭与1.5 mg/L的Cl2联用的去除效果与二者投加顺序有关.当浓度均为200μg/L左右的禾大壮与莠灭净同时污染原水时,粉末活性炭的投加量增至50 mg/L可将它们完全去除,Cl2的用量提高至3 mg/L可将它们全部氧化.
Emergent treatment of source water polluted by representative herbicide molinate and ametryn was researched. The results indicate that activated carbon adsorption and prechlorination could achieve high efficiencies to remove the herbicides. The pseudo second-order adsorption kinetic model and Freundlich adsorption isotherm model can be used to describe the adsorption process and the adsorption equilibrium of molinate and ametryn adsorbed by powdered activated carbon （PAC） in raw water respectively. Either molinate or ametryn of about 200 μg/L in water could be completely removed by 40 mg/L PAC. The best PAC adding point was 20 min before coagulation. The two herbicides were easily removed by granular activated carbon （GAC） column （20 cm high） which can be the available supplement of PAC treatment to strengthen safety. The C12 dosage of 2.5 mg/L could oxidize the two herbicides completely, but the chlorination products as well as their toxicity need further study. PAC adsorption combined with 1 mg/L KMnO4 preoxidation didn＇t improve the removal efficiencies of molinate and ametryn. The effect of PAC adsorption combined with 1.5 mg/L prechlorination depends on their adding sequence. When source water was simultaneously contaminated by the two herbicides both about 200 μg/L, the PAC and Cl2 dosage have to be increased to 50 mg/L and 3 mg/L respectively, then both herbicides can be removed or oxidized fully.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2008年第9期2493-2500,共8页
Environmental Science
基金
江苏省科技厅社会发展计划项目(BS006039)
“十一五”国家科技支撑计划项目(2006BAJ08B06)
国家高技术研究发展计划(863)项目(2002AA601130,2004AA649410)
关键词
水源水
突发污染
禾大壮
莠灭净
活性炭
预氧化
source water
emergent pollution
molinate
ametryn
activated carbon
preoxidation
