Phosphorus Migration Characteristics And Source Identification Of Rock Phosphorus In The Eastern Mountainous Area Of Chaohu

Chaohu eutrophication has focused on controlling the input of anthropogenic sources,and few studies on natural sources?Petrous Phosphate?.Chaohu belongs to the geological phosphorus-rich area,the north shore area is widely distributed with the ancient phosphorus-bearing metamorphic rock series,through the natural weathering and artificial development into the external environment,and with the water migration into the Chaohu Lake,the contribution of eutrophication cannot be ignored.In this paper,the geological phosphorus-rich area?Guishan-Ma'anshan area?in Chaohu Lake Basin is the focus of the study.The content,distribution and migration characteristics of phosphorus in the area are studied from the hydrological and geochemical characteristics of the study area,Phosphate Oxygen Isotope Tracing technology,to explore the source of phosphorus,especially phosphorus phosphate rock phosphate contribution,can let us more in-depth understanding of Chaohu north shore area of phosphorus source and migration process,but also for the lake basin phosphorus Pollution control to provide the relevant theoretical basis.By analyzing the 12 water samples,DIP is the main form of dissolved phosphate in water,accounting for about 30% of TP;TPP is the main form of TP,with an average ratio?TPP / TP?of over 60%.The high percentage is likely to reflect the migration of the source rocks of phosphorus.The changes of phosphate concentrations in the three pathways varied.The change trend of TP in path 1 is similar to that of DIP,but it is opposite to TPP.The concentration of two dissolved phosphate in the path is low,TP is similar to TPP.The concentration of phosphoate in the three forms of T3 was significantly higher than that of the other points,and the other concentrations were similar.The T9 to T10 had a slight increase in the process,and the influence of some agricultural sources could be added.The results showed that the main forms of soil phosphate were apatite and the average content of seven phosphorus forms were: HCl-P>Residual-P>NaOH-IP> NaHCO₃-IP>H₂O-P>NaHCO₃-OP>NaOH-OP.HCl-P is the main form of soil phosphate,combined with the geological characteristics of phosphorus-rich in Chaohu Lake,it can be concluded that the source of phosphate is an important phosphorus pool in the study area,and the effect on eutrophication of Chaohu Lake can not be neglected.The ?18OP of soil sediments in the study area ranged from 9.7 ‰ to 18.4 ‰,and T2S-3 and T2M-4 reflected the source of phosphate rock.T2S-2 and T2M-2 3 reflect the human-influences.T5-point soil sediment data reflect the point of phosphorus mainlyfrom phosphate rock and agricultural fertilization.T10 points reflect the point of the main phosphorus from the phosphate,the path?3?not subject to biological fractionation.Compared with Blake?2010?,17.7‰¹9.9‰ reflect the biofraction of phosphate fractionation process,which can be considered in the study area of phosphorus bioavailability is not high,phosphate oxygen isotope fractionation is very small.The whole area of phosphate rock is an important source of phosphorus,agricultural fertilization and domestic sewage also have a certain contribution.