LAUSR

Chlorpyrifos (O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate) is a broad spectrum organophosphate pesticide which is widely used in agriculture and residential pest control throughout the world. It is moderately toxic to humans, which persists in nature for relatively long period due to its physicochemical and structural properties, low volatilization, affecting environmental matrices. Thus has been selected as model pollutant for degradation using hybrid treatment method of Hydrodynamic Cavitation (HC). It was found that Chlorpyrifos in real effluent sample can be degraded with orifice induced cavitating conditions. Effect of various process parameters such as operating inlet pressure (over range of 3-8 bars), operating temperatures (with sets of intense cooling, moderate cooling and uncontrolled operation) and pH (natural pH = 10, neutral = 7 and acidic = 3) is investigated for extent of degradation of Chlorpyrifos. Results reflect that an optimum value of inlet pressure (5 bars) gave maximum removal/degradation of 72.7%, high temperature and acidic pH of 3 are suitable. To study the effect of intensification, ozone was used as an intensifying agent. Ozone alone gave 12.2% degradation, but when combined with hydrodynamic cavitation, it resulted into 100% efficiency in 45 minutes of treatment time. Work presented in this paper can be said to be concluding to the effective use of hydrodynamic cavitation in combination with ozone for the degradation of Chlorpyrifos in real wastewaters.