Table 1.

The sample codes for the prepared adsorbents

Sample code	Material	Synthesis method	Precipitating agent	Heating source	Synthesis temperature	Final pH
Z	Zinc hydroxide	Conventional precipitation	Ammonium hydroxide	––	Room temperature	7.15
ZU	Zinc hydroxide	Homogenous precipitation	Urea	M.W	95 ℃	6.22
ZC	Zinc-carbon composite	Homogenous precipitation	Urea	M.W	95 ℃	6.01
C	Carbonized date stones	Calcination of date stones	–-	Horizontal tube furnace	600 ℃	–-