Response to the Commentary on “Arsenic mobility in the arsenic-contaminated Yangzonghai Lake in China”

• Water temperature stratification exists in Lake Yangzonghai in summer.
• The total arsenic concentration increased with depth in summer.
• Enhanced microbial activity promoted the release of arsenic from sediment.
• The competitive anions’ role in arsenic release needs further verification.

This is the response to “Commentary on ‘Arsenic mobility in the arsenic-contaminated Yangzonghai Lake in China’ by Changliang Yang et al. [Ecotoxicology and Environmental Safety, 107(2014)321-327]” (by Jing Chen et al.). To doubts and questions raised by Chen et al., we give further explanations and provide more relevant evidences. The water temperature stratification existed in Lake Yangzonghai in summer, and affected by which arsenic concentration with water depth was uneven and peaked in the bottom layer in summer. In the case of adding carbon source (glucose) and maintaining anerobic state, enhanced microbial activity promoted the release of arsenic from sediment to water which was observed in the laboratory experiments. Errors might exist in sampling, determination and calculation, but they would not change the main conclusions of the article.