Study on the Adsorption of Heavy Metals in Sludge by Calcium Alginate Cross-Linked Zeolite Microspheres
Dajun Ren 1,   Yi Yao 2  
,   Beibei Chai 3, 4  
More details
Hide details
School of Architecture and Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
School of Metallurgy, Xi’an University of Architecture and Technology, Xi’an 710055, China
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, China
Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, China
Beibei Chai   

College of Energy and Environmental Engineering, Hebei University of Engineering, China
Submission date: 2020-09-29
Final revision date: 2020-12-03
Acceptance date: 2020-12-03
Online publication date: 2021-05-12
This study successfully prepared a calcium alginate cross-linked zeolite microsphere, a heavy metal adsorbent, to reduce the harmful heavy metal content in sludge and improve the efficiency of sludge resource utilization. The effects of temperature, dosage, and stirring time on the adsorption effect were investigated by atomic absorption spectrophotometry and BCR (European Community Bureau of Reference) method, and the ecological risk of heavy metals in sludge before and after treatment was evaluated via the geoaccumulation index. The following results were obtained: after the sludge was treated with calcium alginate cross-linked zeolite microspheres, the total amount of heavy metals decreased, and the proportion of stable state increased. At temperatures within 10ºC-25ºC, the following trend was observed: the higher the temperature, the higher the adsorption efficiency. When the dosage was controlled at 0.5-2 g/500 ml and the stirring time was 2-3 h, a good adsorption effect was achieved. The pollution level of Pb and Zn in the sludge was reduced after adsorption treatment from unpolluted to moderately polluted to unpolluted, and that of Cd and Cu was reduced from moderately to heavily polluted to moderately polluted.