Pilot-scale study of removal of anionic surfactants with trickling filter

• Main Author: Guo, Feng
• Format: Others
• Language: English
• Published: University of British Columbia 2009
• Subjects: Anionic surfactants; Trickling filter; MBAS and trickling filter model
• Online Access: http://hdl.handle.net/2429/4080

Anionic surfactants are wildly used in many industrial and household applications. Because anionic surfactants are used so widely, significant attention has focused on the removal of these contaminants from wastewater. Among various treatment techniques, biofiltration, such as trickling filter technologies, has been employed in many wastewater treatment plants (WWPTs) to remove anionic surfactants. However, current knowledge of the efficacy of trickling filter to remove anionic surfactants from wastewaters is limited. The present study characterized the performance of a high rate (i.e. roughing) trickling filter to remove anionic surfactants both at lab-scale and pilot-scale. Lab-scale tests investigated the biodegradation of anionic surfactants under controllable conditions were compared with those from previous studies by others. Pilot-scale tests investigated the efficacy of a trickling filter at removing anionic surfactants from a wastewater over an extended period of time. The data from the pilot-scale tests were used to model the performance of trickling filter at removing anionic surfactants from the wastewater, using first order and modified Velz models. The lab-scale tests indicated that high molecular weight anionic surfactants degrade faster than the low molecular weight surfactants. The biodegradation rates observed in the present study were similar to those from pervious studies by others. The pilot-scale tests indicated that roughing trickling filter could remove 11% to 29% of anionic surfactants and 4% to 22% of COD from the wastewater. Higher molecular weight anionic surfactants were more degradable. The experimental data could be accurately modeled using the modified Velz model (R² value more than 0.9). The degradation rates of modified Velz model for total anionic surfactants, high molecular weight anionic surfactants and COD were 0.053±0.0057, 0.088±0.0048 and 0.119±0.0111 (mIs)0.5 respectively. The pilot-scale test results indicated that a high rate (i.e., roughing) trickling filter was not capable of effectively removing anionic surfactants in the primary effluent at Lions Gate WWTP because a relatively large trickling filter area would be required to achieve the required surfactant removal efficiency.