Activation of Jordanian Bentonite by Hydrochloric Acid and Its Potential for Olive Mill Wastewater Enhanced Treatment

Table 1

Main characteristics of OMWW sample, untreated and treated with raw and activated bentonite.

Parameters	Untreated OMWW	Literature ranges values	Reference	Treated OMWW with raw bentonite	Treated OMWW with activated bentonite	% removal using raw bentonite	% removal using activated bentonite
pH	4.63	4.9–6.50	[26]	5.74	5.08	----	----
Conductivity, ms/cm	19.89	13–50	[27, 28]	19.4	16.9	----	----
Sodium (Na^+), mg L^−1	297.9	200–570	[29, 30]	186.4	114.6	37.4	61.5
Potassium (K^+), mg L^−1	6366.3	639–10800	[31]	4075.1	2215.7	35.9	65.2
Total phenolic content, g GAE/L	1.34	0.26–10.7	[31, 32]	0.85	0.42	36.6	65.7
Alkalinity (CaCO3), mg L^−1	2000	3150–9070	[33]	1500	500	25.0	75.0
Total chlorine, mg L^−1	20	33.3–142.7	[34]	15	7	25.0	65.0
Phosphate (), mg L^−1	4120	31.8–1820	[35]	460	155	88.8	96.2
Nitrate (-N), mg L^−1	360	350–390	[36]	230	28	36.1	92.2
COD, mg L^−1	12000	1900–220000	[37, 38]	7030	2295	41.4	80.9
DO, mg L^−1	600	n.d.	----	297	274	50.5	54.3
TDS, mg L^−1	34700	5900–103200	[37, 39]	13140	11010	62.1	71.2
ORP, mv	259800	n.d.	----	73300	61100	71.8	76.5
Salt, mg L^−1	26700	11900–32000	[33]	9930	6010	62.8	77.5

n.d.: not determined.