CONCENTRATIONS AND REMOVAL OF ORGANIC WASTEWATER COMPOUNDS AT A CONVENTIONAL ACTIVATED SLUDGE AND PILOT MEMBRAME BIOREACTOR/REVERSE OSMOSIS FACILITY

A conventional activated sludge wastewater treatment plant and pilot membrane bioreactor (MBR) wastewater plant with reverse osmosis (RO) and advanced oxidation processes (AOP) were sampled three times during August through October 2005 for over 70 organic compounds (including pharmaceuticals, detergent degradates, plasticizers and a variety of other widely used compounds) in order to assess the ability of these processes to remove a wide variety of organic wastewater compounds at a wastewater facility in southern New Jersey. Results for the second round of sampling (in September 2006) show that plant influent concentrations of organic compounds and total number of compounds detected (380 microgram/L and 47 compounds, respectively) were decreased by both activated sludge (15.8 microgram/L and 42 compounds) and the MBR process (12.4 microgram/L and 36 compounds). The three rounds of data indicated that the MBR process reduced concentrations of organic compounds better than the activated sludge process; in particular, octyphenol ethoxylates and fecal sterols were better removed by the MBR process than by the AS process. Concentrations of organic compounds were further reduced by the RO process, with a total organic compounds concentration of 0.72 microgram/L and 5 compounds detected; the detected compounds included 1,4 dichlorobenzene, tribromoethane, 5-methyl-1 H-benzotriazole, and caffeine. With the exception of 5-methyl-1 H-benzotriazole, concentration of all of these compounds detected in the RO effluent were less than .02 microgram/L. The samples treated with AOP following the RO process had no detectable organic compounds; AOP treatment after MBR treatment had only two compounds detected with a total concentration of .38 micrograms per liter. Overall, these results indicate that advanced wastewater treatment processes following MBR treatment can significantly reduce the concentration and number of organic wastewater compounds.