Effect of hydraulic retention time, temperature, and organic load on a horizontal subsurface flow constructed wetland treating cheese whey wastewater

摘要

BACKGROUND: One of the main components of dairy wastewaters is cheese whey. Although different technologies have been used extensively in the past for cheese-whey treatment, constructed wetlands (CWs) applications are limited. Furthermore, the effect of crucial operational parameters (e.g. temperature, pollutant loading rate) have not been thoroughly studied. Having this in mind, two horizontal subsurface flow pilot-scale CW units (one planted and one unplanted) were used to treat secondary cheese whey, in order to examine the effect of different chemical oxygen demand (COD) influent concentrations (1200 to 7200 mg L-1), hydraulic residence times (8, 4, 2 and 1 day) and temperature (2.4 to 32.9 degrees C).