Organic loading rate (OLR), Hydraulic Retention Time (HRT) and up flow velocity are important parameters significantly affecting microbial ecology and characteristics of anaerobic reactors. In this study, Performance of an anaerobic hybrid reactor (UASB/Filter) at mesophilic condition was evaluated in a 15.4 L reactor receiving petrochemical wastewater. The temperature of influent was adjusted by an inline heat exchanger at around 35 ˚C. The reactor was seeded with flocculent sludge from a UASB plant treating dairy wastewater. The sludge was acclimatized to petrochemical wastewater in twostage operation. After 39 weeks, a COD reduction of 70.3% was obtained at OLR=2.0 kg m-3 d-1 and HRT=18 h. Under steady state conditions, experiments were conducted at OLRs of between 0.5 and 24 kg TCOD m-3 d-1 , hydraulic retention times (HRT) of 4-48 h and up flow velocities 0.021-0.25 m h-1. Removal efficiencies in the range of 42-86% were achieved at feed TCOD concentrations of 1000- 4000 mg L-1 . The biogas production data used for determination of biogas production kinetics. The values of Gmax and GB estimated as 11.173 LL-1d -1 and 85.83 g L-1d -1 , respectively.

No abstract

In this study, advanced oxidation processes (UV, UV/H 2 O 2 , UV/H 2 O 2 /Fe(II) and UV/H 2 O 2 /Fe(III)) were investigated in lab-scale experiments for degradation of phenol or benzene hydroxy in aqueous solution. The study showed that the photo-Fenton process, (a mixture of hydrogen peroxide and ferrous or ferric ion), was the most effective treatment process under acidic conditions and produced a higher rate of degradation of phenol at a very short radiation time. It accelerated the oxidation rate by 4-5 times the rate for the UV/H 2 O 2 process. The reaction was influenced by the pH, the input concentration of H 2 O 2 and the amount of the iron catalyst and the type of iron salt. The experimental results showed that the optimum conditions were obtained at a pH value of 3, with 6 mmol/1 H 2 O 2 , and 0.5 mmol/1 Fe(II) for the UV/H 2 O 2 /Fe(II) system and 6 mmol/l H 2 O 2 and, 0.4 mmol/1 Fe(III) for the UV/H 2 O 2 /Fe(III) system. As for the UV processes, UV/H 2 O 2 /Fe(III) showed the highest degradation rate.

In this study, advanced oxidation processes (UV, UV/H2O2, UV/H2O2/Fe(II) and UV/H2O2/Fe(III)) were investigated in lab-scale experiments for degradation of phenol sulfonic acid (PSA) in aqueous solution. The study showed that the UV/H2O2 process has removal percentage 90.9, 93.0 and 94.4 for neutral, basic and acidic conditions in 20 minutes respectively. The experimental results showed that the optimum conditions were obtained at a pH value of 3, with 4 mmol/1 H2O2, and 0.25 mmol/1 Fe(II) for the UV/H2O2/Fe(II) system and 6 mmol/l H2O2 and, 0.4 mmol/1 Fe(III) for the UV/H2O2/Fe(III) system. The reaction was influenced by the pH, the input concentration of H2O2 and the amount of the iron catalyst and the type of iron salt. As for the UV processes, UV/H2O2 showed the highest degradation rate under acidic conditions