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USBF Performance in Treating Sugar Industries Wastewater
M Ahmadi, H Ganjidoust, B Ayati,
Volume 1, Issue 2 (3-2009)
Abstract

Background and Objectives: Upflow Sludge Blanket Filtration (USBF) system is a modification  of the conventional activated sludge process that incorporates an anoxic zone with an upflow sludge blanket filtration clarifier in one bioreactor. It has no inherent capacity limits and is used in a wide range of applications in municipal, industrial and agricultural wastewater treatment. The main objective of this study was to evaluate the performance of a continuous USBF reactor for the treatment of sugar industrial wastewater.
Materials and Methods: Sixty liter laboratory pilot scale plant was made of plexiglass consists of   14 liter anoxic zone, 38 liter aerobic zone and 8 liter clarifier. Used molasses for raw wastewater was obtained from Varamin Sugar Company. During the study, the wastewater has been initially fed to anoxic zone of the bioreactor. It mixed with recycled activated sludge returned from the clarifier and the mixed liquor entered into aerobic zone of the bioreactor. From aeration zone, the mixed liquor passed through the sludge zone at the bottom of the clarifier which was then separated by upflow sludge blanket filtration and then the clear water discharged from the system. To complete the internal circulation loop, collected activated sludge at the bottom of the clarifier was recycled to the anoxic zone.
Results: Experimental studies indicated that average removal efficiency of COD with HRTs from 21  to 26 hours in the aerobic zone and from 8 to 10 hours in the anoxic zone were from 77 to 97 percent depended on input feed (1000 to 30000 mg/L).
Conclusion: USBF as an advanced biological process had a proper COD removal efficiency for the biological treatment of sugar industries wastewater compared to other researchers methods.


ِDetermining the Efficiency of WWTP in Khoy Power Plant and Improving  Phosphorus Removal by Anoxic-Oxic Process
M Aghanejad, A.r Mesdaginia, F Vaezi,
Volume 2, Issue 1 (7-2009)
Abstract

Backgrounds and Objectives: Now a days modified activated sludge ways are used for standard removing nutrient substances from waste water that is named Enhanced biological phosphorus removal One of the most suitable ways is Anoxic-Oxic(A/O) process. The goal of this research is investigation and solving existing problems of Khoy power plant(P.P) waste water treatment plant(WWTP)and optimizing of phosphorus removal in it.
Materials and Methods: This research is done full scale in this treatment plant. The treatment plant was operating with extended aeration process, and some problems had, so in the first stage with in investigation of total efficiency, problems and their reasons determined. In the second stage after operational modifications existing problems was solved and real efficiency of treatment plant particularly for phosphorus(P) removal determined. In the third stage changes, system converted to A/O process and new system was tested with Changing parameters like food/microorganism(F/M), return sludge ratio(RAS)and sludge retention time(SRT)
Risults: In the first stage the most important problems were over concentration of BOD,TSS, and P in effluent of treatment plant and overgrows of alga observed in parts of treatment plant and effluent receiving conduit. The main reason of high concentration of P was considered releasing of sludge. In the second stage operating condition modification efficiency of P removal increased from 50to 62 percent. In the end of third stage value of P removal reached to %82 and the most suitable of anoxic contact time was determined 3to4 hours, SRT terry day and F/M ratio o.12,that the most effective change has been the decrease of SRT to three days.
Conclusion: Adjusting of operating factors like SRT,RAS, sludge processing way in WWTP can increase P removal in them with in total efficiency remaining, such as in this case it was %12. In waste water treatment particularly for P removal the A/O process is suitable so in this project its effect on P removal efficiency has been %20.


The investigation of biological degradation of sodium dodecyl sulfate and its associated COD in wastewater using anoxic baffled reactor
Samira Mojab, Seyed Gholamreza Moussavi, Sakine Shekoohiyan,
Volume 18, Issue 1 (5-2025)
Abstract
Background and Objective: This study investigated the efficiency of an anoxic baffled reactor (AnBR) system for the biological treatment of synthetic wastewater containing sodium dodecyl sulfate (SDS) as a representative anionic surfactant, with the goal of enabling safe discharge into the environment.
Materials and Methods: The research aimed to examine the effects of SDS concentration as a substrate, hydraulic retention time (HRT), and the type of electron acceptor (nitrate or organic materials) in the AnBR reactor. Daily measurements of influent and effluent wastewater were conducted to assess surfactant, chemical oxygen demand (COD), and nitrate levels.
Results: The average COD removal efficiencies at SDS concentrations of 200, 250, 350, and 500 mg/L were 99.6%, 99.8%, 99.6%, and 99.3%, respectively, under steady-state conditions. The SDS removal efficiency for all concentrations was 99.8 ± 0.2%. As the HRT decreased from 24 to 4 hours, the COD removal efficiency dropped from 99.4% to 90.9%. At an SDS concentration of 250 mg/L and an HRT of 4 hours, the effluent SDS concentration was 11 mg/L, which meets the discharge standards for surface water (1.5 mg/L). The removal of nitrate from the influent indicated a significant decrease in system efficiency, demonstrating that nitrate was consumed as an electron acceptor and SDS was degraded under anoxic conditions. PCR testing revealed that Bacillus species were the dominant bacteria in the AnBR.
Conclusion: Given the high removal efficiencies of SDS and COD, this process can be recommended for the degradation of anionic surfactants in wastewater from industries producing such pollutants.
 

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