Table 6.

Hydraulic retention time and overall removal efficiency of GEM removal by column filters of different cross sectional areas, PG doses, and packing heights at constant dosage. Experimental conditions: ECs-contaminated DW influent adjusted at 10.5 mg/L of EC; room temperature at 22 ± 3 °C.

Contaminant	Test	Diameter of Column, mm	Material Dosage	Packing Height, mm	HRT through Reactive Layer, min	Overall Removal Efficiency %
GEM	Different cross sectional area	18	500 mg PG	25	11.45	73.75
		40	500 mg PG	5	11.31	91.14
	Different PG doses	18	500 mg PG	25	11.45	73.75
		18	50 mg PG	10	4.58	67.44
		40	500 mg PG (PG/SND 0.5% wt.)	45	47.50	86.38
		40	100 mg PG (PG/SND 0.5% wt.)	18	19.00	70.75
		40	250 mg PG (PG/SND 0.5% wt.)	27.5	29.03	70.74
		40	350 mg PG (PG/SND 0.5% wt.)	30	31.67	74.62
	Different packing heights at constant dosage	18	50 mg PG (PG/SND 0.25% wt.)	30	6.41	69.11
		18	50 mg PG	10	4.58	67.44
		40	100 mg PG (PG/SND 0.5% wt.)	18	19.00	70.75
		40	100 mg PG (PG/SND 0.25% wt.)	27.5	29.03	70.88
		40	100 mg PG (PG/SND 0.1% wt.)	45	47.50	81.94