Effect of Sheep Manure Biochar Application Under Flooding Condition on the Availability of Pb and Zn in Heavy Metal Contaminated Soil

Yu HE; Yunxia LUO; Xian FAN; Zirun YANG; Pengfei GAO; Qi WANG; Xiaojuan SU

doi:10.16768/j.issn.1004-874X.2024.07.013

Guangdong nongye kexue (Jul 2024)

Effect of Sheep Manure Biochar Application Under Flooding Condition on the Availability of Pb and Zn in Heavy Metal Contaminated Soil

Yu HE,
Yunxia LUO,
Xian FAN,
Zirun YANG,
Pengfei GAO,
Qi WANG,
Xiaojuan SU

Affiliations

Yu HE: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China
Yunxia LUO: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China
Xian FAN: Agricultural Science of Honghe Prefecture, Honghe 661199, China
Zirun YANG: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China
Pengfei GAO: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China
Qi WANG: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China
Xiaojuan SU: College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China

DOI: https://doi.org/10.16768/j.issn.1004-874X.2024.07.013
Journal volume & issue: Vol. 51, no. 7
pp. 142 – 150

Abstract

Read online

【Objective】The study was conducted to explore the effect of sheep manure biochar on the availability of Pb and Zn in soil polluted by compound heavy metals under flooding conditions, and provides the basis for controlling heavy metal pollution of farmland soil.【Method】Using the polluted farmland soil near a lead-zinc mining area in Yunnan as the research object, static culture experiments were conducted to study the effects of different addition rates of sheep manure biochar (0%, 2.5%, 5.0% and 7.5%) on the pH and availability of Pb and Zn in polluted soil under flooding condition. And the ecological and environmental risks were evaluated by the toxicity characteristics leaching procedure (TCLP).【Result】Compared with the control, the soil pH value of sheep manure biochar treatment increased by 0.04-0.11 units, and the mass fractions of soil available Pb and Zn were significantly reduced by 32.01%-58.09% and 6.44%-9.15%, respectively. The soil pH and mass fractions of soil available Pb and Zn showed extremely significant negative correlation and significant negative correlation, respectively. From the perspective of heavy metal occurrence forms, sheep manure biochar significantly promoted the passivation of Pb and Zn. Among them, 5.0% sheep manure biochar treatment had the best passivation effect, promoting the transformation of heavy metal Pb into more stable forms in soil, resulting in the highest mass fractions of oxidizable and residual forms, which were 64.05% and 27.50%, respectively. In the soil, Zn mainly transformed into an oxidizable state, but residual Zn showed a decreasing trend with a relatively small decrease. The mass fractions of Pb and Zn extracted by TCLP significantly decreased with the increase of biochar addition rate, effectively reducing the ecological risk of polluted farmland soil.【Conclusion】For heavy metal contaminated farmland soil near lead-zinc mining areas, the method of flooding combined with applying sheep manure biochar can reduce the availability and ecological risks of Pb and Zn in soil. The addition amount of 5.0% sheep manure biochar has the best passivation effect on soil heavy metals Pb and Zn.

Published in Guangdong nongye kexue

ISSN: 1004-874X (Print)
Publisher: Guangdong Academy of Agricultural Sciences
Country of publisher: China
LCC subjects: Agriculture
Website: http://gdnykx.cnjournals.org/gdnykx/ch/index.aspx

About the journal

Abstract

Keywords