Synthesis Of New Chelating Resins And Their Application In Nickel Ion Removal

With the rapid development of electroplating industry,nickel plating surface treatment processes are involved,which will produce a large amount of nickel containing wastewater.They may cause serious environmental pollution and enormous waste of nickel resources.How to purify nickel-containing wastewater and effectively recover and reuse valuable metal nickel ions is in high demand currently.Chelating resin is a cross-linked functional polymer material,which can selectively chelate specific metal ions from the aqueous solution containing various metal ions according to the formation of special coordination bonds between the functional atoms and metal ions.Then the chelated metal ions are washed off under appropriate conditions.It is widely used as adsorbent due to its strong ionic binding force,high selectivity and excellent regeneration ability.Currently,the chelating resins as nickel ion adsorbents have some disadvantages involving small adsorption capacity,low selectivity,poor separation performance,high cost,etc.Therefore,it is of great practical significance and research value to develop chelating resins with high selectivity,high adsorption capacity,low price,easy availability and recyclability for resource recovery and environmental protection.Based on the above research background,we used phosphate ester compounds to modify polystyrene resin,silica gel microsphere resin and glass microbead resin to synthesize nickel-ion chelated resins.Specifically,with primary amine-containing resin,chloromethyl-containing resin,silica gel microspheres and glass microbeads as the matrix resins,triethylamine as acid binding agent,chelating resins were synthesized by nucleophilic substitution reactions.We used the newly synthesized chelating resins as nickel ion adsorbents for nickel-containing wastewater purification.The experimental results showed that the synthesized resins had high selectivity for nickel ions with the extraction rate as high as 94% at P H = 4.0.In addition,the resin can be recycled up to10 times or more with high extraction efficiency maintained.All these results provide a new method for efficient utilization and recovery of nickel resources.