Low-molecular-weight organic acids inhibit the methane-dependent arsenate reduction process in paddy soils

Anaerobic methane oxidation (AOM) can drive soil arsenate reduction, a process known as methane-dependent arsenate reduction (M-AsR), which is a critical driver of arsenic (As) release in soil. Low molecular weight organic acids (LMWOAs), an important component of rice root exudates, have an unclear influence and mechanism on the M-AsR process. To narrow this knowledge gap, three typical LMWOAs-citric acid, oxalic acid, and acetic acid-were selected and added to As-contaminated paddy soils, followed by the injection of