TY  - JOUR
EP  - 1190
N2  - Lab-scale GAC sandwich slow sand filters with different GAC layer depths were evaluated for the first time to remove selected pharmaceutical and personal care products (PPCPs) (namely DEET, paracetamol, caffeine and triclosan, 25??g/L). Coarse sand (effective grain size of 0.6?mm) was used instead of conventional fine sand. In addition to single sand and GAC filters, GAC sandwich filters were assessed at three filtration rates (i.e. 5?cm/h, 10?cm/h and 20?cm/h) to compare removals. Sandwich filter with 20?cm GAC achieved the best average PPCP removal (98.2%) at 10?cm/h rate. No significant difference of average PPCP removal was found between 10 and 20?cm/h filtration rates for the three GAC sandwich filters (p?>?0.05). Among the selected PPCPs, DEET, the recalcitrant compound, was most effectively removed by the GAC sandwich filters. Combining the GAC layers with the slow sand filters significantly enhanced the removal of the target PPCP compounds (p?<?0.05), demonstrating that both adsorption and biodegradation contributed to the removals. Furthermore, pseudo-second-order equation (Type 1) could best represent the adsorption kinetics of the four target PPCP compounds onto GAC. In relation to other quality parameters, sandwich filter with 20?cm of GAC also showed good average removals of chemical oxygen demand (COD) of 65.8% and total organic carbon (TOC) of 90.3%, but occurrence of ammonium up to 0.76?mg/L concentration indicated inapplicability of filtration rate of 5?cm/h. No significant difference was found between 10?cm/h and 20?cm/h filtration rates for nitrogen and phosphate removals (p?>?0.05). Results of this lab-scale investigation show that GAC sandwich slow sand filter is potentially an effective process for removing PPCPs from tertiary wastewater.
AV  - public
JF  - Science of The Total Environment
VL  - 635
UR  - http://doi.org/10.1016/j.scitotenv.2018.04.198
A1  - Li, J
A1  - Zhou, Q
A1  - Campos, LC
KW  - Adsorption kinetics
KW  -  GAC sandwich slow sand filtration
KW  -  PPCPs
KW  -  Removal
ID  - discovery10050634
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
SP  - 1182
SN  - 1879-1026
Y1  - 2018/09/01/
TI  - The application of GAC sandwich slow sand filtration to remove pharmaceutical and personal care products
ER  -