Azarpira Hossein, Rasolevandi Tayebeh, Mahvi Amir Hossein
Department of Environmental Health Engineering, Social Determinants of Health Research Center, Saveh University of Medical Sciences, Saveh, Iran.
School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Heliyon. 2023 Oct 11;9(10):e20880. doi: 10.1016/j.heliyon.2023.e20880. eCollection 2023 Oct.
Diazinon (DIZ) and 4-Chloro-2-methylphenoxyacetic acid (MCPA) herbicide and widely used in agricultural lands. Present study investigates diazinon and 4-chloro-2-methylphenoxyacetic acid photo-reduction via UV/Sulfite (US) in as Advanced Reduction Processes (ARP). The ideal pH was Molar ratio of sulfite: DIZ or MCPA 1:1 and, 20 min reaction time, and pH 9, in which about 100 % reduction of DIZ and MCPA with a concentration of 10 mg L was achieved and the optimal conditions were considered. Kinetic investigation increasing DIZ and MCPA concentration from 5 to 20 mgL, increase about from 0.151 to 0.234 for DIZ and from 0.231 to 0.589 min. Also, reaction rate () increases about from 0.755 to 4.68 for DIZ and from 1.155 to 11.78 mg L.min. The amount of energy consumption in DIZ solution increased from 5 to 20, respectively, from 0.73 to 2.37, and in the reduction of MCPA from 0.47 to 1.49 kWh per cubic meter. According to experiments performed in 30 min with the US process, COD levels were reduced by about 46 % of both pollutants. It is important to note that the BOD/COD ratio rose from about 0.20 to 0.48 after 30 min. Since the index of biodegradability has grown high, it can be concluded that non-biodegradable COD (NBDCOD) convert to biodegradable COD (BDCOD) and toxicity is lower than of before of treatment. This study has been very suggesting that the UV/sulfite method produces effluent with a non-toxic and ecologically beneficial manner by biological treatment or discharge directly in environment.
二嗪农（DIZ）和4-氯-2-甲基苯氧基乙酸（MCPA）是广泛用于农田的除草剂。本研究通过紫外/亚硫酸盐（US）作为高级还原过程（ARP）来研究二嗪农和4-氯-2-甲基苯氧基乙酸的光还原。理想的pH值、亚硫酸盐与二嗪农或MCPA的摩尔比为1:1，反应时间为20分钟，pH值为9，在此条件下，浓度为10mg/L的二嗪农和MCPA实现了约100%的还原，并确定了最佳条件。动力学研究表明，将二嗪农和MCPA的浓度从5mg/L增加到20mg/L，二嗪农的反应速率从约0.151增加到0.234，MCPA的反应速率从0.231增加到0.589min⁻¹。此外，二嗪农的反应速率（）从0.755增加到4.68，MCPA的反应速率从1.155增加到11.78mg L⁻¹min⁻¹。二嗪农溶液中的能量消耗分别从5mg/L增加到20mg/L时，从0.73增加到2.37，MCPA还原时从0.47增加到1.49kWh/m³。根据在30分钟内用US工艺进行的实验，两种污染物的化学需氧量（COD）水平降低了约46%。需要注意的是，30分钟后生化需氧量/化学需氧量（BOD/COD）比值从约0.20上升到0.48。由于生物降解性指数升高，可以得出结论，不可生物降解的化学需氧量（NBDCOD）转化为可生物降解的化学需氧量（BDCOD），且毒性低于处理前。这项研究非常表明，紫外/亚硫酸盐法通过生物处理或以对环境无害的方式直接排放产生无毒且对生态有益的废水。
