Nano silver chloride and alginate incorporated composite copolymer adsorbent for adsorption of a synthetic dye from water in a fixed bed column and its photocatalytic reduction.

Several functional adsorbents were synthesized by copolymerizing acrylic acid (AA) and hydroxyethyl methacrylate (HEMA) in the presence of sodium alginate in water. Silver chloride nano particles (AgClNP) were also incorporated in the polymer matrix by coprecipitation method. The resulting composite type functional adsorbents were used for adsorption of a synthetic dye, namely, brilliant cresyl blue (BCB) from water in batch and in continuous mode in a fixed bed column. The formation of the adsorbent, AgClNP and its incorporation in the polymer matrix were characterized while pH sensitivity was studied with pH reversibility test and point zero charge (PZC) study. The network parameters were also determined. The synthesis and process parameters were optimized with a central composite design (CCD) of response surface methodology (RSM) with respect to adsorption capacity as response in a batch study and the adsorbent showing optimum performance was further used for column study in a fixed bed. The effect of bed height, influent dye concentration and volumetric flow rate on dye adsorption were studied and the adsorption data showed close fitting to Adam-Bohart and Clark model. The photocatalytic degradation of the heterocyclic dye by the AgClNP incorporated adsorbent in the presence of UV radiation was also studied.