Spatial and Temporal Distribution Characteristics of Different Forms of Phosphorus in Three Sorts of Rivers around Lake Taihu

: Different forms of phosphorus from the upper reaches of river to lower reaches of river in nine rivers were analyzed to clarify the pollution characteristics of industrial effluent, agriculture effluent and sanitary wastewater to Lake Taihu in February (low water period), May (average water period) and August (abundant water period) of 2009. The results showed that total phosphorus (TP) dissolved total phosphorus (DTP) and soluble reactive phosphorus ( SRP) mass concentration all showed decreasing trend while enzymatic phosphorus (EHP) mass concentration increased with the increase of algal biomass from low water period to abundant water period. Mass concentrations of several forms of phosphorus were all the highest in the rivers impacted by sanitary wastewater, but sanitary wastewater's self-purification capabity from the upper reaches of river to lower reaches of river was the best, and the pollution to Lake Taihu was the lowest. Pollution from rivers impacted by industrial effluent was the highest. Mass concentration of EHP was higher than that of SRP in most cases, so EHP played an important role in Cyanbacterial harmful algal blooms events in Lake Taihu.