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Updated: Dec 23, 2025
Immobilization of Multi-biocatalysts in Alginate Beads for Cofactor Regeneration and Improved Reusability
Published on: April 22, 2016
Urea formaldehyde modified alginate beads with improved stability and enhanced removal of Pb2+, Cd2+, and Cu2
Ping Qu1, Yuncong Li2, Hongying Huang3
1Recycling Agriculture Research Center, Jiangsu Academy of Agricultural Sciences, Key laboratory of Crop and livestock Integrated Farming, Ministry of Agriculture, Nanjing, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu Province, 210014, China; Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 32606, USA; Soil and Water Science Department, Tropical Research and Education Center, University of Florida, Homestead, FL, 33031, USA.
Abstract:
Urea formaldehyde (UF) was grafted onto the backbone of alginate to prepare microbeads as an adsorbent for the removal of heavy metal ions from aqueous solutions. The expensive alginate was crosslinked with cheaper UF at different ratios (1: 2.5∼1: 12.5) to produce sturdy alginate-UF beads at lower cost. Characterization results showed that UF modification enhanced the pore network and structural stability of the beads, which can be attributed to the reduced intermolecular forces and plentiful of nitrogen and oxygen donor atoms of the beads. The swelling of air-dried alginate-UF beads in different solutions was much lower than that of the unmodified alginate beads, confirming the improved stability. The replacement of alginate with UF at different ratios either did not affect or increased the adsorption of heavy metal ions (Pb2+, Cd2+, and Cu2+) on the beads. For example, the adsorption capacities of Pb2+, Cd2+, and Cu2+ on air-dried alginate-UF (1: 2.5) beads were 1.66, 0.61, and 0.80 mmol/g, which were 39.88%, 9.29%, and 9.52% higher than those of the corresponding unmodified alginate beads, respectively. The adsorption of heavy metals on the alginate-UF beads was mainly controlled by ion exchange, complexation, and electrostatic interaction mechanisms.
