Treatment of 2,4-dichlorophenol (DCP) in a sequential anaerobic (upflow anaerobic sludge blanket) aerobic (completely stirred tank) reactor system

Relationships between anaerobic consortia and removal efficiencies in an UASB reactor degrading 2,4 dichlorophenol (DCP)

“…At a COD removal efficiency of 74% the number of methanogen bacteria was higher in 2,4 DCP treating reactor (10 Â 10 9 MPN g À1 ) compared to the ice cream, brewery and penta chlorophenol wastewater (4 Â 10 3 -5 Â 10 5 MPN g À1 ) (Zhu et al, 1997;Montenegro et al, 2001;Suihko et al, 2005;Pearce et al, 2003). In the study performed by Sponza and Uluko¨y (2005), the highest methanogenic bacteria number (8 Â 10 7 MPN g À1 ) was obtained at an organic loading rate of 7.24 g COD l À1 day À1 .…”

Refractory organic pollutants and toxicity in pulp and paper mill wastewaters

“…Biological treatment (anaerobic and aerobic) is more economical compared to other methods and produces no secondary pollution (Sponza and Uluköy 2005). Aerobic processes are commonly used to treat effluents with low COD concentrations (COD < 1000 mg/L) and anaerobic processes for the treatment of effluent with high COD strength (COD > 4000 mg/L) (Seghezzo et al 1998).…”

Microbial degradation of chlorinated phenols

“…Three studies evaluated UASB reactors for the degradation of 2,4-DCP with readily biodegradable cosubstrates (Ning et al 1997;Kennedy et al 2001;Sponza and Ulukoy 2005). Volumetric loading of up to 144 g 24-DCP m -3 reactor d -1 with 78.7% removal efficiencies have been reported when molasses was utilized as the electron donor (Sponza and Ulukoy 2005). The specific 2,4-DCP-degrading activity of the granules obtained from the UASB reactors was 4.1 mg DCP g -1 VSS d -1 (Ning et al 1997).…”

“…A sequence of a UASB reactor and an aerobic suspended growth reactor eliminated 86% of 2,4-DCP in the presence of glucose; whereas, each individual reactor accomplished either 52 or 78% removal, respectively (Atuanya et al 2000). A similar sequence of UASB and an aerobic continuously stirred tank reactor (CSTR) resulted in 87% removal of 2,4-DCP supplied at 120 mg l -1 (Sponza and Ulukoy 2005). A sequence of an anaerobic filter combined with an aerobic bioreactor was utilized to treat 2,4,6-TCP supplied at 13 mg l -1 (Armenante et al 1999).…”