Bleached kraft pulp mill sourced organic chemicals in sediments from a New Zealand River. Part II: Tarawera river

Abstract

The concentrations of resin acids, chlorophenolic compounds and resin acid derived neutral compounds (fichtelite, dehydroabietin, tetrahydroretene and retene) were measured in river sediments above and below the effluent discharges of two New Zealand pulp and paper mills. The two mills, a sulphonated chemithermomechanical pulp (CTMP) and tissue mill, and an integrated kraft and mechanical pulp and paper mill, discharge secondary treated effluent into the Tarawera River in New Zealand. No significant concentrations of pulp and paper mill sourced organic compounds were found at background sites. Below the CTMP mill slight increases in the concentrations of the resin acids and resin acid derived neutral compounds were measured. Elevated concentrations of all three compound classes were observed downstream of the second pulp and paper mill. Total concentrations of chlorophenolic compounds and resin acids in the river sediments from below the second mill effluent discharge reached to 17.0 ng g −1 and 23.1 μg g −1 dry weight respectively. Still higher concentrations of chlorophenolic compounds and resin acids, 58.7 ng g −1 and 94.5 μg g −1 respectively, were present in sediments from a downstream estuarine lagoon which was previously part of the river system. The organic carbon content in sediments was a principle constituent governing the concentrations of pulp and paper mill derived compounds in the New Zealand receiving water systems.