Understanding the cadmium passivation and nitrogen mineralization of aminated lignin in soil

Haoran Wang; Jiamin Liang; Pengju Huo; Lidan Zhang; Xiaolin Fan; Shaolong Sun

doi:10.1016/j.scitotenv.2023.162334

Understanding the cadmium passivation and nitrogen mineralization of aminated lignin in soil

Sci Total Environ. 2023 May 15:873:162334. doi: 10.1016/j.scitotenv.2023.162334. Epub 2023 Feb 20.

Authors

Haoran Wang¹, Jiamin Liang¹, Pengju Huo¹, Lidan Zhang¹, Xiaolin Fan¹, Shaolong Sun²

Affiliations

¹ College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, China.
² College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, China. Electronic address: sunshaolong328@scau.edu.cn.

PMID: 36813204
DOI: 10.1016/j.scitotenv.2023.162334

Abstract

Aminated lignin (AL) was prepared and first applied to remediation of cadmium (Cd) pollution in soil. Meanwhile, the nitrogen mineralization characteristics of AL in soil and its effect on soil physicochemical properties were elucidated by soil incubation experiment. The results showed that the Cd availability was dramatically lowered in soil by adding the AL. The DTPA-extractable Cd content of AL treatments was considerably reduced by 40.7-71.4 %. The soil pH (5.77-7.01) and absolute value of zeta potential (30.7-34.7 mV) enhanced simultaneously as the AL additions increased. The content of soil organic matter (SOM) (99.0-264.0 %) and total nitrogen (95.9-301.3 %) were gradually enhanced due to high C (63.31 %) and N (9.69 %) content in AL. Moreover, AL significantly elevated the content of mineral nitrogen (77.2-142.4 %) and available nitrogen (95.5-301.7 %). The first-order kinetic equation of soil nitrogen mineralization revealed that AL greatly enhanced nitrogen mineralization potential (84.7-143.9 %) and reduced environmental pollution by lowering the loss of soil inorganic nitrogen. AL could effectively reduce the availability of Cd through direct (self-adsorption) and indirect effects (improvement of soil pH, SOM and reduction of soil zeta potential), thereby achieving passivation of Cd in soil. In short, this work will develop a novel approach and technical support for soil heavy metal remediation, which is of great significance for improving the sustainable development of agricultural production.

Keywords: Aminated lignin; Cadmium; Nitrogen mineralization; Passivation mechanism; Soil physicochemical properties.