The selective adsorption performance of nanoscale humic acid based ion exchange composite resin for Ni2+/Cd2+ was investigated from multi-ionic co-existing system. On this basis

a novel resource recovery process for Ni/Cd wastewater

which included multi-column series

saturated adsorption and concentrated circulation

was developed. The micro-morphology

chemical structure

heat resistance

element composition change and pore size distribution of nanoscale humic acid based ion exchange composite resin were characterized by SEM

FTIR

TG-DTG

XPS and BET. The experimental results showed that the ion exchange composite resin had the advantage of fast adsorption rate [0.55—1.50 mg·(g·min)-1]

high exchange capacity(139 or 148 mg·g-1 for Ni2+/Cd2+ on Ca2+ and Mg2+ coexisting system)and excellent selectivity behavior

high elution concentration and purity for Ni2+/Cd2+ (45.15 g·L-1 or 39.17 g·L-1

and QNi(Ⅱ)/Qtotal 0.989

QCd(Ⅱ)/Qtotal 0.994). After 200 adsorption-regeneration cycles

the physical and chemical structures of the adsorptive composite resin were still kept stable performance

and the section morphology and exchange capacity basically remain unchangeable

showing that it can be reused. The specific surface area

average pore diameter and pore volume were 1189.85 m2·g-1

30.2 nm and 0.96 cm3·g-1

respectively with good thermal stability. The nitrogen content decreased from 16% to 12%

oxygen content increased from 26.49% to 29.96% and ionic exchange capacity rose from 5.38 mmol·g-1 to 6.06 mmol·g-1.