Disinfection of raw wastewater and activated sludge effluent using Fenton like reagent

Background and objectives: water shortage problems have led to find either new water resources or improvewastewater treatment technologies in order to reuse. due to less performance of previous units in microbialremoval, disinfection has become a necessary step in wastewater treatment plants. in the present studyperformance of hydrogen peroxide (hp) and modified fenton’s reagent (hp + cu++) was considered for thedisinfection of raw wastewater (rw) and activated sludge effluent (ase).materials and methods: plastic containers of 10-liter volume each were used for rw and ase sampling. microbiologicalanalyses of the rw and ase were performed in triplicate; before and after the disinfection process. fecal coliforms wereanalyzed by the direct (without enrichment) multiple fermentation tube procedure.results: the results showed that using hp alone did not have any significant disinfection capability. in rw and ase, thehighest dose used in this study could reduce fecal coliforms (fc)s by only 1.54 and 1.16 log-inactivation,respectively. however, maximum removal efficiency of modified fenton in rw and ase was 4.63 and 3.41log-inactivation, respectively. the results suggested that cu++ ions used in combination with h2o2 producedvery rigorous synergistic effect, and hp disinfection capacity increased significantly.conclusion: hydrogen peroxide, when applied alone, was not successful in disinfecting of either rw or ase,and neither the who guideline nor the iranian standard could be met. however, modified fenton showed verysignificant disinfection potential and could reduce fcs under world health organization (who) guideline andiranian national standard for agricultural irrigation.