Chlorination by-products from ferulic acid (a lignin model compound) and biologically treated thermomechanical chemithermomechanical pulp mill effluents

A lignin model compound (4-hydroxy-3-methoxycinnamic acid) was chlorinated under conditions similar to those used in drinking water treatment. Various chlorophenols were identified in solvent extracts including chloroguaiacols, chloro-4-vinylguaiacols, chlorocatechols and chlorovanillins. Compounds identified as significant disinfection by-products in chlorinated drinking waters (chloroform, dichloroacetic acid, tricholoracetic acid and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) were associated with higher chlorine doses (satisfying 75% of the chlorine demand). Filtered, biologically treated thermomechanical (TMP) and chemithermomechanical (CTMP) effluents diluted in natural waters were chlorinated at doses which ensured a measurable free chlorine residual after 20 h. Aquatic humic substances in natural waters influenced the impact of mill effluents on drinking water quality. Detected by-products included the chlorinated disinfection by-products noted above, but only one detectable chlorophenol, 2,4,6,-trichlorophenol. By-product concentrations were higher in solutions containing CTMP mill effluents and humic river water.