The effects of acidification on arsenic concentration and speciation in offshore shallow water system

Abstract

The effects of acidification on speciation and transportation of arsenic in shallow seawater system were investigated based on data from acidification simulation experiments in lab scale tanks, in which enhanced levels of pCO2 corresponding to pHT were processed. The results showed that: (1) the concentration of DIAs (Dissolved inorganic arsenic), As5+ and As3+ in the overlying water increased with experimental CO2 enrichment; (2) while the ratio of As5+/As3+ decreased; (3) acidification could cause more DIAs transport into the overlying water from sediments or suspended particulate matters, and would be favorable to the existence of As3+. Thus, DIAs is available to microorganisms and can be taken in effectively by microorganisms in the shallow water system, resulting in toxic effects of As on microorganisms and thus the inhibition of the growth of microorganisms.