Dual Functional Alginate‐Polyethylene Polyamine Composite Aerogel Toward Sensing and Extracting Copper Ions in Water

Abstract

AbstractIn this study, a new type of sodium alginate‐polyethylene polyamine composite aerogel (Alg‐PEMA) was synthesized to detect and remove excess copper ions (Cu2+) in water. First, a classic acylation reaction was used to graft polyethylene polyamine onto alginate, which was then gelatinized in a calcium ion solution and vacuum freeze‐dried to prepare the final Alg‐PEMA adsorbent. Experimental results showed that the as‐prepared Alg‐PEMA can remove 99.2 % of Cu2+ (0.1 mM) in water, and the maximum adsorption capacity for Cu2+ is 46.78 mg/g. Alg‐PEMA can also be used for qualitative colorimetric detection of Cu2+ in aqueous solution. The detection limit for Cu2+ is as low as 0.64 mg/L, which is lower than the WHO standard for drinking water Cu2+ content (2.0 mg/L). Its green and safe raw materials, simple desorption and regeneration process, and stable detection and adsorption performance indicate that the Alg‐PEMA adsorbent has broad application prospects in the treatment of Cu2+‐containing wastewater.