Article http://dx.doi.org/10.26855/ijfsa.2024.03.004

Remediation of Copper Contaminated Soil by Char Derived from Used Disposable Baby Diapers


A. Kavinthini1,*, A. D. Igalavithana2

1Department of Soil Science, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka.

2CSIRO, Waite Campus, Urrbrae, Australia.

*Corresponding author: A. Kavinthini

Published: April 11,2024


Plastic, including used disposable baby diapers (UDD), is a growing soil pollutant due to increasing single-use plastic consumption. UDDs contain 50% plastic such as super absorbent polymers that take over 100 years to degrade. This study focused on pyrolysis as a recycling method to produce plastic char from UDDs, evaluating its efficacy in the soil as an amendment to immobilize the copper in contaminated soil. Uncontaminated soil was spiked (240 mg/kg) with copper (ll) sulphate. Based on the thermogravimetric analysis of UDD, 550°C was selected as the pyrolysis temperature. The plastic char produced was characterized before being applied to the soil. The contaminated soil was incubated after applying plastic char at the rates of 0% (control), 1%, and 2.5%. Immobilization of Cu was measured after one month of incubation by single extraction using 1M NH4OAc and consecutive extraction using 0.01 M CaCl2 methods. The soil pH, electrical conductivity, and availability of Na, Mg, K, P, Ca, and N were ana-lyzed. The consecutive extraction analysis revealed a significant (p < 0.05) reduction in extractable Cu concentration in the soil treated with plastic char and the immobilization percentage of copper by plastic char was 86%. The decrease was uniform for both plastic char doses. The properties of plastic char, such as its high pH (11.27), ash content (36.68%), and Electrical conductivity-EC (0.03 dS/m), likely contributed to increasing soil pH and facilitating Cu immobilization. Furthermore, the presence of functional groups such as C-H, C=O, OH, N-H, P-H, and C-Cl and carboxylic acid-like functional groups on the surface of plastic char, along with its high fixed carbon content (48.14%), likely supported the im-mobilization of Cu. In addition, it has 70 cmol+kg-1 at 550°C. These findings indicate that plastic char derived from UDD can be effectively utilized to immobilize Cu in contaminated soil. The pyrolysis of UDD represents a promising waste management practice that minimizes environmental pollution.


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How to cite this paper

Remediation of Copper Contaminated Soil by Char Derived from Used Disposable Baby Diapers

How to cite this paper: A. Kavinthini, A. D. Igalavithana. (2024) Remediation of Copper Contaminated Soil by Char Derived from Used Disposable Baby DiapersInternational Journal of Food Science and Agriculture8(1), 26-33.

DOI: http://dx.doi.org/10.26855/ijfsa.2024.03.004