Effect Of Artificial Aeration On Carbon And Phosphorus In In Glyceria Spiculosa Wetland Of Xiaoxingkaihu Lake By Inputting Different Iron Dosage

Exogenous iron(Fe)inputs not only affect the removal of phosphorus(P)in water body,but influence the transformation of the morphological transformation of soil elements in wetland,as well as the accumulation variances of elements in different organs of wetland plants.The aim of this paper was to study the synthetic effect of iron inputs and artificial aeration on carbon and phosphorus in Glyceria spiculosa wetland of Xiaoxingkai Lake.In order to clarify the mechanism,the indoor simulation experiment and the sedimentation experiment were implemented to simulate the effects of different iron input intensity and the aeration treatment on the environmental factors,the phosphorus removal in water body and the accumulation and allocation of elements among different compartments(water,soil and plant).Finally,this paper also compared and analyzed from the aspects of the phosphorus removal efficiencies,the carbon accumulation of wetland plant and the transformation of soil iron,which will help to understand the wetland ecosystem biochemical processes and provide the theoretical basis for the wetland protection and restoration.The main results were presented as following:1.Three different Fe:P ratios under the aeration treatment to some extent can control the total phosphorus concentration in water body.When Fe:P was 5,the removal efficiencies of total phosphorus in water body gradually increased over time,while the removal efficiencies were shown the trend with sharp fluctuations under the Fe:P ratio of 6/10.2.Differences in accumulation of elements of G.spiculosa different organs existed were listed as follows,Fe: root > steam leaf;P: steam leaf > root;TOC: steam leaf > root.The tolerance of G.spiculosa to iron inputs was 10 mg/L.3.Total phosphorus in wetland soil was half composed of organic phosphorus and inorganic phosphorus.Every inorganic phosphorus species existed obvious differences,dominated with Fe bound P(45%).As a result,Xiaoxingkai Lake soil has extremely higher internal phosphorus loading,which is closely related to serious eutrophication and algae outbreaks.4.The correlation between amorphous iron,iron activity(amorphous iron/free iron)and organic carbon was significant(p < 0.05)under the Fe:P ratio of 5,yet no connection with iron activity and organic carbon under the Fe:P ratio of 10.Therefore,the increase of organic carbon,that is,the increase of organic matter,is beneficial to the increase of soil amorphous iron content,but does not necessarily enhance the soil iron oxide activity.5.As for the stability of wetland ecosystem,in order to maintain the normal growth of G.spiculosa,the iron concentration of the water body should not exceed 10 mg/L.Within the tolerant range of G.spiculosa,the iron inputs(≤ 5 mg/L)can be properly introduced to control the phosphorus concentration of the water body,thereby purifying the water quality and recovering the contaminated water.