بهبود قابليت تجزيه پذيري بيولوژيك 2،4،6 تري كلروفنل با استفاده از فرايند اكيداسيون فنتون

Biodegradability enhancement of 2,4,6 trichlorophenol (TCP) by fentonʹs oxidation process

Introduction: Several reports have indicated that chlorophenols are toxic chemicals and recalcitrant to biodegradation. Advanced oxidative processes (AOPs) are one of the most effective processes for degradation of persistent compounds. Since the mineralization of recalcitrant compounds by AOPs often requires long reaction time and strong dose of oxidant, combination of this process with biological one is considered as one efficient and economic method. Methods: In this work treatment of 2,4,6 TCP wastewater by Fentonʹs is oxidation in batch reactor and combination of Fenton reaction with activated sludge for removal of TCP in continues mode were studied. Results: Initial concentration of 2,4,6 TCP was 0.6 mM and in pH = 3, [H2O2] =1.8 mM [Fe2+] = 0.6 mM 99% of TCP was degraded in first minute after the reaction was started COD analysis indicated that TCP did not mineralize because COD reduction was only < 37%. Chloride ion increasing from o mg/L to 40mg/L, PH decreasing from 3 to 2.74 and UV215 absorbance decreasing from 3.2 to 0.6 indicated that generated intermediates toxicity reduced and biodegradability enhanced Pilot study of Fentonʹs oxidation / activated sludge integration for treatment of 2,4,6 TCP wastewater showed that intermediates in effluent from Fenton reactor (operating at [H2O2] /[Fe^2+] =3, [H2O2]/ [TCP]=3, pH=3, reaction Time = 1 hr [TCP]o = 120 mg/L aqu COD = 150 mg/L). Degraded by Activated sludge process and COD reduction were -- 75%. Increasing of aeration Time from 6 hr to 18 hr has no significant effect on removal efficiency (p=0.005). Increasing of concentration of TCP has no significant effect on removal efficiency (p=0.005). Increasing of glucose into the aeration tank caused that COD removal efficiency increased from 75% to 92%. Conclusion: Results from this stady indicated that fentonʹs oxidation process is an effective method for biodegradability Enhancement of 2,4,6 TCP and generated intermediates from fentonʹs qxidation of 2.4,6 TCP are easily Biodeyradable compounds.