Treatment of low strength wastewater using compact submerged aerobic fixed film (SAFF) reactor filled with high specific surface area synthetic media

Abstract

Studies on laboratory-scale submerged aerobic fixed film reactor (SAFF) packed with synthetic media having specific surface area of 165 m2/m3 with a void volume of 89% were carried out to assess its performance under various organic loading rates (OLR) and hydraulic retention times (HRT). Synthetic wastewater having chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of 400 ± 10% and 210 ± 10% mg/L respectively was fed and the reactor was subjected to OLRs ranging from 0.37 to 1.26 kg COD/m3.d. It was observed that steady sloughing of biofilm occurs within the SAFF reactor all the times and average concentration of sloughed biomass in the effluent was 26 mg/L. The COD and BOD removal efficiencies varied between 85 and 89% and 86 to 94%, respectively. The kinetic studies demonstrated that SAFF reactor followed Stover–Kincannon and Grau models, with high correlation coefficients (R2) of 0.9977 and 0.9916, respectively. Thus, the values of kinetic coefficients such as maximum substrate utilization rate, Umax = 64.1 g/(L.d); saturation value constant, KB = 72.31 g/(L.d) and Grau second-order substrate removal rate constant, Ks = 2.44 day−1 can be useful to develop and design large scale SAFF reactors. Finally, the study reveals that the optimum range for OLR can vary within 0.68–0.94 kg COD/m3.d.

Efficiency Limiting Factors of Petrochemical Wastewater Treatment Using Hybrid Biological Reactor

“…On average, the COD/BOD ratio was seen to be slightly less than 2, indicating good treatability potential of the petrochemical wastewater. In general, the highest removal efficiency was achieved under the low flow high air scenario and reached 77% removal of COD, similar to results obtained by Gurjar et al (2019). In contrast, the initial concentration, aeration, and flow rates (hydraulic residence varied greatly as indicated by the ranges and averages of Table 1), similar efficiencies; although of lower values, have been observed for all six scenarios except for the high flow anaerobic scenario with up to 42.3%.…”

“…It has been documented that the efficiency of biological treatment processes is dependent on the type and strength of wastewater, concentration of pollutants, OLR, oxygen supply, and nutrient content (Andersson et al, 2008;Chavan & Mukherji, 2010;Schneider & Topalova, 2013;Gurjar et al, 2019;Wang et al, 2019;Wang et al, 2017;Fu et al, 2016;Rava & Chirwa, 2016). The OLR, in turn, is dependent on the wastewater organic concentration and flow and likewise affects the hydraulic residence time, cell residence time, and biomass detachment rates (Metcalf & Eddy, 2014).…”

“…Numerous investigations have experimented with biofilms to treat wastewater and recover nutrients, heavy metals, and other pollutants (Andersson et al, 2008;Chavan & Mukherji, 2010;Schneider & Topalova, 2013). Some attempts to look into the potential of fixed-film processes, particularly hybrid biological reactors, have demonstrated promising potential in some instances (Gurjar et al, 2019;Wang et al, 2019;Wang et al, 2017;Fu et al, 2016;Rava & Chirwa, 2016). The studies have reported varied operational scenarios, including wastewater strength, organic loading rates, hydraulic residence time, the concentration of toxic, and hard to degrade organic compounds and organics to nutrient ratios.…”

“…The studies have reported varied operational scenarios, including wastewater strength, organic loading rates, hydraulic residence time, the concentration of toxic, and hard to degrade organic compounds and organics to nutrient ratios. Gurjar et al (2019) used synthetic wastewater, where the COD and BOD concentrations were 400 and 210 mg/l, respectively, maintaining a BOD/COD ratio of approximately 2 in a laboratory-scale submerged aerobic fixed film reactor packed with synthetic media for OLRs ranging from 0.37 to 1.26 kg-COD/m 3 d, the COD and BOD removal efficiencies varying between 85 and 89% and 86 to 94%, respectively. It is worth noting that the wastewater used in this study is representative of normal strength similar to domestic wastewater, and the hydraulic retention times are relatively high (8 to 25 h) (Gurjar et al, 2019).…”

Moving Bed Biofilm Reactor (MBBR) for Decentralized Grey Water Treatment: Technical, Ecological and Cost Efficiency Comparison for Domestic Applications

“…Expanding the use of the system for domestic use may increase its economy of scale and so reduce the initial capital cost for small and medium domestic applications worldwide (e.g., homes gardening, sanitation, commercial, and landfills) (Gurjar et al, 2019).…”