Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 40019, India.
Ultrason Sonochem. 2012 Sep;19(5):1051-60. doi: 10.1016/j.ultsonch.2012.02.011. Epub 2012 Mar 8.
The present work deals with application of sonochemical reactors for the degradation of dichlorvos containing wastewaters. The sonochemical reactor used in the work is a simple ultrasonic horn type operating at 20 kHz with a power rating of 270 W. The effect of different operating parameters such as operating pH, temperature and power density on the extent of degradation has been investigated initially followed by intensification studies using additives such as hydrogen peroxide, Fenton's reagent and CCl(4). It has been observed that low frequency sonochemical reactors can be effectively used for treatment of pesticide wastewaters and acidic conditions and optimum values of temperature and power dissipation favors the degradation of dichlorvos. The efficacy of sonochemical reactors can be further enhanced by using different additives at optimized loadings. Complete removal of the pesticide at the given loading has been obtained using an optimized combination of ultrasound and Fenton's chemistry. The controlling mechanism for the sonochemical degradation has been confirmed to be the free radical attack based on the studies involving radical scavengers. The novelty of the present work is clearly established as there have been no earlier studies dealing with degradation of dichlorvos pesticide using sonochemical reactors operating at low frequency which offers distinct advantage in terms of cost and the stability of the reactor.
本工作研究了声化学反应器在降解含敌敌畏废水中的应用。本工作中使用的声化学反应器为简单的超声变幅杆式，工作频率为 20 kHz，功率为 270 W。初步考察了不同操作参数（如操作 pH 值、温度和功率密度）对敌敌畏降解程度的影响，然后使用添加剂（如过氧化氢、芬顿试剂和 CCl(4)）进行强化研究。结果表明，低频声化学反应器可有效用于处理农药废水，在酸性条件下，最佳温度和功率耗散值有利于敌敌畏的降解。通过在优化的负载下使用不同的添加剂，可以进一步提高声化学反应器的效率。在给定的负载下，通过优化的超声和芬顿化学组合可以完全去除农药。基于涉及自由基清除剂的研究，证实了声化学降解的控制机制是自由基攻击。本工作的新颖性是显而易见的，因为以前没有研究过使用低频声化学反应器降解敌敌畏农药，这在成本和反应器稳定性方面具有明显的优势。
