Leaching characteristics and potential risk of heavy metals from drip irrigation pipes and mulch substrate in agricultural ecosystems

Muyesaier Tudi; Linsheng Yang; Jiangping Yu; Binggan Wei; Yuan Xue; Fang Wang; Linfeng Li; Qiming Jimmy Yu; Huada Daniel Ruan; Qin Li; Ross Sadler; Des Connell

doi:10.1016/j.scitotenv.2023.163573

Leaching characteristics and potential risk of heavy metals from drip irrigation pipes and mulch substrate in agricultural ecosystems

Sci Total Environ. 2023 Jul 15:882:163573. doi: 10.1016/j.scitotenv.2023.163573. Epub 2023 Apr 17.

Authors

Muyesaier Tudi¹, Linsheng Yang², Jiangping Yu³, Binggan Wei⁴, Yuan Xue⁵, Fang Wang⁶, Linfeng Li⁷, Qiming Jimmy Yu⁸, Huada Daniel Ruan⁹, Qin Li¹⁰, Ross Sadler¹¹, Des Connell¹²

Affiliations

¹ Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, No. 11 Datun Road, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Queensland Micro and Nanotechnology Centre, Brisbane 4111, QLD, Australia; School of Engineering and Built Environment, Griffith University, Brisbane 4111, QLD, Australia.
² Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, No. 11 Datun Road, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, No. 11 Datun Road, Beijing 100101, China.
⁴ Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, No. 11 Datun Road, Beijing 100101, China. Electronic address: weibg@igsnrr.ac.cn.
⁵ China Astronaut Research and Training Center, No 26, Beiqing road, Haidian District, Beijing 100094, China.
⁶ College of Life Sciences, University of Chinese Academy of Sciences, 101408 Beijing, China.
⁷ College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
⁸ School of Engineering and Built Environment, Griffith University, Brisbane 4111, QLD, Australia.
⁹ Beijing Normal University-Hong Kong Baptist University United International College, 2000 Jintong Road, Tangjiawan, Zhuhai, Guangdong Province, China.
¹⁰ Queensland Micro and Nanotechnology Centre, Brisbane 4111, QLD, Australia; School of Engineering and Built Environment, Griffith University, Brisbane 4111, QLD, Australia.
¹¹ School of Medicine, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia.
¹² School of Environment and Science, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia.

PMID: 37076001
DOI: 10.1016/j.scitotenv.2023.163573

Abstract

Drip irrigation is a valuable method for optimising water and fertiliser usage, motivating its increasing use. However, the ecological effects of drip irrigation fertilisation have not been sufficiently evaluated, limiting its effective and widespread use. Within this context, we aimed to determine the effects and potential ecological risks of using polyethylene irrigation pipes and mulch substrate under various drip irrigation conditions as well as burning of waste pipes and mulch substrate. Laboratory simulations of field conditions were used to determine the distribution, leaching, and migration pattern of heavy metals (Cd, Cr, Cu, Pb, and Zn) from plastic drip irrigation pipes and agricultural mulch substrate into various solutions. Maize samples obtained from drip-irrigated fields were analysed to determine the presence of heavy metal residues and assess the risk of heavy metal contamination. Heavy metal leaching from pipes and mulch substrate was high under acidic conditions, while the migration of heavy metals from plastic products was low in alkaline water-soluble fertiliser solutions. After combustion, heavy metal leaching from pipes and mulch residues increased considerably, with the migration capacity of Cd, Cr, and Cu increasing by >10-fold. Heavy metals in plastic pipes migrated primarily to the residue (bottom ash), whereas those from mulch substrate migrated to the fly ash component. Under experimental conditions, the migration of heavy metals from plastic pipes and mulch substrate had a negligible effect on the heavy metal content in aqueous environments. Although heavy metal leaching increased, the effect on water quality under actual irrigation conditions was relatively minor (in the order of 10^-9). Thus, the use of plastic irrigation pipes and mulch substrate did not result in significant heavy metal contamination and potential risk to the agriculture ecosystem. Our study findings provide evidence for the effective application and widespread promotion of drip irrigation and fertiliser technology.

Keywords: Combustion; Contamination; Irrigation technology.