PHOSPHORUS FRACTIONS AND PHOSPHATE SORPTION- RELEASE CHARACTERISTICS RELEVANT TO STREET DUSTS OF MEGA-CITY, CHENGDU, SOUTHWEST CHINA

摘要

The phosphorus fractions and phosphate sorption and release characteristics of the street dusts from Chengdu City were investigated. The results indicated that the total phosphorus (TP) contents in the street dusts varied from 0.58mg/g to 0.84mg/g; inorganic phosphorus (IP) was the major fraction of TP; Calcium bound phosphorus (Ca-P) was the main fraction of IP. For all the street dusts samples, the rank order P-fractions was Ca-P> organic phosphorus (OP)>Phosphorus bound to Al, Fe, and Mn oxides and oxyhydroxides (Fe/Al-P). Phosphate sorption on the street dusts mainly occurred within 3h and then reached to equilibrium in 14h. The phosphate sorption capacity ranged from 194.78mg/kg to 945.81mg/kg and the phos-phate sorption efficiency ranged from 57.17 L/kg to 330.86L/kg; there was no significant correlation between street dust compositions and the maximum phosphate sorption capacity, phosphate sorption efficiency. The amounts of P released from the street dusts were strongly in positive correlations with the contents of Fe/Al-P and OP. It indicated that Fe/Al-P and OP were main released fractions, and it can release P easily.