Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor

Abstract

The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35°C) was evaluated. The entire treatment system was operated at different hydraulic retention times (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for COD total ; 51-73% for COD colloidal and 20-55% for COD soluble was found at a total HRT of 5-10 h, respectively. By prolonging the HRT to 13.3 h, the removal efficiencies of COD total , COD colloidal and COD soluble increased up to 92, 89 and 80%, respectively. However, the removal efficiency of COD suspended in the combined system remained unaffected when increasing the total HRT from 5 to 10 h and from 10 to 13.3 h. This indicates that, the removal of COD suspended was independent on the imposed HRT. Ammonia-nitrogen removal in MBBR treating UASB reactor effluent was significantly influenced by organic loading rate (OLR). 62% of ammonia was eliminated at OLR of 4.6 g COD m -2 day -1 . The removal efficiency was decreased by a value of 34 and 43% at a higher OLR's of 7.4 and 17.8 g COD m -2 day -1 , respectively. The mean overall residual counts of faecal coliform in the final effluent were 8.9 9 10 4 MPN per 100 ml at a HRT of 13.3 h, 4.9 9 10 5 MPN per 100 ml at a HRT of 10 h and 9.4 9 10 5 MPN per 100 ml at a HRT of 5.0 h, corresponding to overall log 10 reduction of 2.3, 1.4 and 0.7, respectively. The discharged sludge from UASB-MBBR exerts an excellent settling property. Moreover, the mean value of the net sludge yield was only 6% in UASB reactor and 7% in the MBBR of the total influent COD at a total HRT of 13.3 h. Accordingly, the use of the combined UASB-MBBR system for sewage treatment is recommended at a total HRT of 13.3 h.

Next‐Generation Biofuels: Survey of Emerging Technologies and Sustainability Issues

“…[262] The main features of these reactors are the bacterial sludge immobilization inside the reactor. The most significant two-stage anaerobic reactors developed are the following: up flow anaerobic sludge blanket (UASB), [268,269] up flow and down flow anaerobic filters (UFAF, DFAF), anaerobic fluidized bed reactors (AFBR), [270,271] and anaerobic attached film expanded bed reactor (AAFEB). [272][273][274] Many industrial processes are running based on these technologies.…”

Upgrading of the Mirmohana Wastewater Treatment Plant in Kish Island, Iran, using a moving bed biofilm reactor

“…Although MBBR provides a long biomass retention time and hold high loading rates without any problems of clogging (15). However, on the basis of results, it can be concluded that with an increase in OLR ammonia concentration in the final effluent (11,17) and COD will be an increase. As shown in figure 5, average MLSS concentration in conventional ASP generally was 1291.14 ± 463.43 mg/L for wastewater treatment, whereas in the MBBR process high removal efficiency was obtained even at a relatively low MLSS concentration (average MLSS in the water phase = 190.1 ± 29.80 mg/L).…”

Review of Upflow Anaerobic Sludge Blanket Reactor Technology: Effect of Different Parameters and Developments for Domestic Wastewater Treatment

“…Therefore, posttreatment of anaerobically treated wastewater is usually required in order to improve the quality of effluent in accordance with the irrigation standards. This has been successfully done by conventional systems such as maturation ponds, waste stabilization ponds, polishing ponds, constructed wetlands, rotating biological contactors, moving bed biofilm reactor, downflow hanging sponge [60][61][62], and advanced oxidative processes (AOPs) [63,64].…”