تنقية كهروكيميائية لمياه الصرف الصحى من المبيدات الفطرية والحشرية بإستخدام طرق أكسدة متطورة

Photolysis studies have been carried out in aqueous solutions using UV- photo catalytic system to elucidate the photochemical behavior of some fungicides waters.. HPLC has been used for residues determination. Results clearly exhibited that, carbendazim and metalaxyl were almost stable in the dark while UV irradiation decreased their stabilities. T1/2 ranged between 2.26 and 8.88 hr. for carbendazim fungicide and from 0.5 to 2.57 hr. for metalaxyl under the conditions of photo-Fenton reactions. The degradation rate of the two tested fungicides were greatly enhanced by Fe(III) than Fe(II). H2O2 accelerated the photodegradation of the two fungicides under photo-Fenton reactions. Consequently, treatment of Fe(III)/ H2O2/UV gave the highest percentage of dissipation (%D) since, after 360 min of irradiation it reached to 85.50% for carbendazim and 99.98% for metalaxyl. The photodegradation of carbendazim and metalaxyl were greatly enhanced by irradiation under ZnO+H2O2/UV compared to ZnO/UV alone. The effect of the system ZnO+ H2O2+UV was as equal as that of the photo-Fenton system FeCl3+H2O2+UV. The half-life values under ZnO/UV were 9.63 and 4.81 hr. for carbendazim and metalaxyl, but the values of T1/2 were decreased under ZnO+H2O2/UV to 4.03 and 0.78 hr., respectively. There was a positive relationship between the percentage of fungicides dissipation and the irradiation time for the allrunning treatments.