The Adsorption Research Of Heavy Metal Ions In Aqueous Solution By Modified Sponges

Water is the source of lives.However,with the booming development of industrialization without valid environmental monitoring,water contamination with heavy metals have been a serious threat to the public health and the ecosystem.It is essential to take effective measures to remove the heavy metals for bringing the water environment back to normal.Adsorption is a valid way to collect heavy metal ions in water,which is remarkable in industry and reaearch.High porsity,high specific surface area,good ion chelating capacity,low energy consumption,environmental firendliness and low cost are the characteristics of ideal adsorbent.According to these characteristics,a good adsorbent can be designed.The sponge have a great advantage in adsorption after modificaton owing to its high specific area and porsity.The main work is as followed:1.Pristine melamine formaldehyde sponge was modified with silane coupling agent,polyethylenimine（PEI）and carbon disulfide（CS₂）step by step and the product were named MF-NH₂ sponge、MF-PEI sponge and MF-PEI/CS₂ sponge accordingly.The initial ionic concentration,pH value and the adsorption time were set to study their influence to adsorption.Multi-component adsorption and regeneration experiment are also conducted.The MF-PEI/CS₂ sponge showed rapid adsorption ability and high adsorption selectivity.2.Metal-organic frameworks is a new type of crystalline material with good adsorption ability,which is composed of metal ion and organic ligands.ZIF-8 is a typical type of metal-organic frameworks,which is composed of zinc ion and 2-methylimidazole.A batch of ZIF-8 powder with a radius of 200 nm was made in water,and the powder was attached to the surface of sponge skeleton with the protection of polydopamine.The ZIF-8 powder constituted 20%of the weight of the modified sponge.Adsorption experiment on copper ions and benzotriazole were conducted and the influende of pH value,adsorption time and initial concentration on adsorpton capacity were studied.Finally,Langmuir model and Freundlich model were used to match the adsorption data.The modified polyurethane sponge show great ability of adsorption to copper ions and benzotriazole.