Forms and Bioavailability of Phosphorus in the Suspended Solids of A2/O Process

To investigate the potential bioavailability and mobility of phosphorus (P) in suspended solids, the Standards, Measurements and Testing (SMT) programmers was employed to characterize the distribution of P in suspended solids from different treatment stage of KunmingWWTP.Results showed that: the main form of total phosphorus (TP) in suspended solids was inorganic phosphorus (IP) ,which accounted for 47%~60%.Amongdifferent forms of inorganic phosphorus, Iron-phosphorus was the dominant forms accounted for 82 % of total phosphorus while calcium-phosphorus was only the minor par. Throughout the process, the trend of changes in content is close between total phosphorus and organ phosphorus. Bioavailable phosphorus in suspended solids ranged from 5.903 mg·g^-1to7.376mg·g^-1 and occupied 89.64%to94.16% of the total phosphorus pool.