Preparation of a novel lactose-lignin hydrogel catalyst with self-reduction capacity for nitrogenous wastewater treatment

A novel carboxylated lactose/sodium lignosulfonate/polyacrylic acid hydrogel composites with self-reduction capacity was successfully synthesized by self-assembly method.The hydrogel with well-developed porous structure provided abundant anchoring points and reduction capacity for transforming Ag^(+)into silver nanoparticles.Silver nanoparticles dispersed among the network of hydrogel and the composites exhibited catalytic capacity.The catalytic performance was evaluated via degradation of p-nitrophenol,rhodamine B,methyl orange and methylene blue,which were catalyzed with corresponding reaction rate constants of 0.04338,0.07499,0.04891,and 0.00628 s^(–1),respectively.In addition,the catalyst exhibited stable performance under fixed-bed condition and the corresponding conversion rate still maintained more than 80%after 540 min.Moreover,the catalytic performance still maintained effective in tap water and simulated seawater.The catalytic efficiency still remained 99.7%with no significant decrease after 8 cycles.