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Background and Objectives: One of the complete treatment processes for industrial and municipal wastewater treatment is membrane bio reactor process which has dominant potential in process and operation sections. This study was conducted to compare the performance of extended aeration activated sludge (EAAS) with submerged membrane bio reactor (SMBR) systems in the treatment of strength wastewater, in the same condition. Materials and Methods: The initial activated sludge was brought from the Plascokar Saipa wastewater plant. The Plexiglas reactor with effective volume of 758 L was separated by a baffle into the aeration and secondary sedimentation parts with effective volumes of 433 L and 325 L, respectively. The chemical oxygen demand (COD) concentration of the influent wastewater of the EAAS and SMBR systems were between 500-2700 and 500-5000 mg/L, respectively. Results: Results showed that the SMBR system produced a much better quality effluent than EAAS system in terms of COD, biochemical oxygen demand (BOD5), total suspended solids (TSS) and ammonium. By increasing the COD concentration, the concentration of mixed liquor suspended solids (MLSS) and the removal efficiency of organic matter in the SMBR system, were increased regularly, however the removal efficiency of COD in the EAAS system was irregular. Conclusion: The average BOD5/COD ratio of effluent in the EAAS and SMBR systems were 0.708±0.18 and 0.537±0.106, respectively. These show that the organic matters in the effluent of the SMBR system was less degradable and thereupon more biological treatment was achieved. Nitrification process was completely done in the SMBR system while the EAAS system could not achieve to complete nitrification. [ABSTRACT FROM AUTHOR]

A combined system including sonocatalysis and photocatalysis was applied for catalytic degradation of tetracycline (TC) antibiotic using TiO 2 decorated on magnetic activated carbon (MAC@T) in coupling with ultraviolet (UV) and ultrasound (US) irradiations. MAC was fabricated via magnetization of AC using Fe 3 O 4 nanoparticles. FESEM, EDS, TEM, BET, XRD, PL, VSM and UV-visible DRS techniques were used to characterize the catalyst features. The performance of MAC@T/UV/US system was examined under impact of different input variable such as catalyst loading, solution pH, initial TC concentration, US power, scavenging agents, chemical oxidants and co-exiting anions. The degradation rate was enhanced substantially when MAC@T coupled with US and UV irradiations. At optimal conditions, over 93% TC and 50% TOC were removed under 180 min reaction. Whereas, the complete removal of TC was obtained after 60 min treatment, when MAC@T/UV/US coupled with oxidants. Decreasing sequence of the inhibitory effect of anions was chloride > bicarbonate > phosphate > nitrate > sulfate. Both Fe leaching and loss of the decontamination were slight with reused times, indicating MAC@T has a high stability and reusability. According to trapping tests, holes, OH and 1 O 2 were contributed in the degradation process. In conclusion, integration of MAC@T composite and US/UV for enhancing catalytic degradation efficiency can be introduced as a successful and promising technique, owing to excellent catalytic activity, easy recovery, good adsorption capacity and high durability and recycling potential., (Copyright © 2019 Elsevier B.V. All rights reserved.)