Onsite wastewater treatment of household industry (Saa paper pulping) by hybrid subsurface flow constructed wetland system

Abstract

The pilot-scale hybrid subsurface flow constructed wetland system, i.e. vertical subsurface flow constructed wetland (VSF) and horizontal subsurface flow constructed wetland (HSF), was used to treat Saa paper pulping wastewater. Three VSFs, each with surface areas of 0.78 m2 , were operated at the hydraulic loading rates (HLRs) of 1.3 - 67.0 cm/d. The treatment efficiency of VSF was relatively low and it was only suitable as pretreatment step. The effluent of one VSF was further treated by HSF, having surface areas of 3 m2 . The hybrid system was operated for 3 runs at HLRs of VSF/HSF at 5.0/1.3, 13.4/3.4 and 67.0/ 59.7 cm/d, respectively. The hybrid system's performances were better, especially in terms of color removal. Due to various constraints, partial treatment by hybrid system targeting at BOD and color removal of 76 % and 55 %, respectively, is suggested.