Treatment options for wastewater effluents from pharmaceutical companies

Coupling granular activated carbon adsorption with membrane bioreactor treatment for trace organic contaminant removal: Breakthrough behaviour of persistent and hydrophilic compounds

“…Several previous studies have proposed the use of GAC filtration for the removal of trace organic contaminants from surface water or biologically treated wastewater (Dickenson and Drewes, 2010;Kim et al, 2010;Deegan et al, 2011;Grover et al, 2011;Hernández-Leal et al, 2011). In line with a previously reported preliminary study (Nguyen et al, 2012), the data reported here (Figure 2) confirm that initially GAC post-treatment could significantly improve the removal of the compounds which demonstrated low to moderate removal by MBR treatment (i.e., diclofenac, fenoprop, carbamazepine, naproxen, metronidazole and ketoprofen).…”

“…Table 3 shows the Langmuir and Freundlich isotherm parameters (q m and K f , respectively) for the compounds that demonstrated relatively rapid breakthrough from the GAC column. Our isotherm data conform to a general trend found in the literature regarding a relatively higher adsorption capacity of the neutral compounds carbamazepine (Nowotny et al, 2007;Serrano et al, 2010;Deegan et al, 2011) and metronidazole (Rivera-Utrilla et al, 2009) in comparison to that of the ionized compounds, namely, diclofenac (Nowotny et al, 2007;Serrano et al, 2010) and naproxen (Nowotny et al, 2007;Serrano et al, 2010). However, the isotherm parameters did not demonstrate any …”

“…This however, is not surprising, given the fact that the single-solute isotherms were obtained in ultrapure water (Milli-Q), and for analytical reasons the isotherms were obtained at equilibrium concentrations higher than that applied to the GAC column (Section 2.3). In fact, inaccuracies arising from a mismatch between equilibrium concentration and actual loading (Yu et al, 2008) and the effect of competition with bulk organics (Deegan et al, 2011;Zhang et al, 2011) have been previously documented. The fact that the MBR permeate concentration (i.e., feed to the GAC column) was not completely stable for individual compounds, and varied within a few thousands of ng/L between the compounds (Figure 3), may have been also responsible for such deviation.…”

“…Granular activated carbon (GAC) adsorption has routinely been used as a tertiary treatment process in the water industry. The potential of GAC for the removal of pesticides and other emerging trace organic contaminants in drinking water treatment has been widely demonstrated (Yu et al, 2008;Kim et al, 2010;Deegan et al, 2011;Behera et al, 2012).…”

“…However, much of the available literature focused on the removal of trace organic contaminants by GAC from surface water (Kim et al, 2010;Deegan et al, 2011;Grover et al, 2011;Hernández-Leal et al, 2011) and only a few have investigated the use of GAC adsorption for the removal of trace organic contaminants from biologically treated effluent (Dickenson and Drewes, 2010;Grover et al, 2011;Hernández-Leal et al, 2011). Significant competition with bulk organics for adsorptive sites is usually a common phenomenon associated with such applications, and this has important implications to the life and serviceability of GAC columns.…”