Biomimetic Synthesis of Hydroxyapatite in Presence of Imidazole-4,5-dicarboxylic Acid Grafted Chitosan for Removing Chromium(VI)

Table 1

Levels and factors of orthogonal experiment design.

Level	pH	Initial concentration of Cr(VI) (mg·L^−1)	Dosage of HAP (mg·L^−1)	Adsorption time (min)
1	3.00	25	200	90
2	5.00	50	400	120
3	7.00	100	800	150
4	9.00	200	1000	180