抄録
A laboratory sediment-water microcosms experiment for three lakes were conducted over 20-d incubation period. These lakes included different types of an oligotrophic, a mesotrophic, and a dystrophic lake. Two sets of microcosms for each lake were acidified to pH=4.5 with surfulic acid and nitric acid, and one of them was treated with chloroform to suppress the biological activities. All treatments demonstrates rapid pH recovery, but the acid-neutralization capacity varied between types of lakes. Cation exchange was the main process in the oligotrophic and the mesotrophic lake, whereas the biological reduction of nitrate and sulfate was the main process in the dystrophic and the mesotrophic lake. In the microcosms treated with chloroform, the acid neutralization by the biological reduction of nitrate and sulfate was suppressed and was replaced by cation exchange.
