Study On Adsorption Of Two Estrogens In Water By Sand Loam And Biochar

In this paper,we characterized the sandy loam(R)and two kinds(at 350?,450?derived)biochar(S350,S450),and investigated the adsorption of steroid estrogen(E2,E3)by the soil and the effects of biochar were studied.We also tried to illustrate the adsorption mechanism by the absorption model the physi-chem parameters.The results are as follows:1 Characterization of sandy loam and the matter with biological carbon(1)Thermogravimetric analysis indicated that the content of organic matter in sandy loam,R was low and was high in biochar,S350,S450.After 1.5%biochar was added to the sandy loam,the interaction between minerals and organic matter was changed.The results also showed that sequence of the affinity with water in soil and biochar was:S350>S450>R>RS350>RS450.(2)The results of elemental analysis showed that the content of carbon in soil was3.97%.S350 and S450 content of 62.18%and 65.18%.Adding bio-carbon to soil samples reduced the oxygen-containing functional groups and polarity,increased the carbon content and aromatic.It suggested that the chemical reactions occur in the addition process.(3)Infrared spectroscopy analysis illustrated that both sandy loam and biochar contain the unsaturated compounds and the functional groups such as C-H,O-H and C=O.The number of the oxygen-containing functional groups and the unsaturated bonds in the sandy loam with the addition of biochar was reduced.(4)Laser particle size and BET analysis showed that the sandy soil particle size had different changes before and after adding bio-carbon.The addition of S350 and S450increased the particle size and specific surface area.The microporous area increased by378.2%after addition of S350,but was reduced by 83.3%after the addition of S450.2 The adsorption of sandy loam and the effects of the bio-carbon after and the establishment of isothermal adsorption model.(1)The adsorption of E2 and E3 on the soils of R,RS350 and RS450 increased with the increase of equilibrium concentration,but the adsorption rate increased with the initial concentration Increase and decrease.The adsorption properties of E2 were better than those of E3.The adsorption of E2 on the adsorbed agent was R>RS350>RS450 at low concentration and R>RS450>RS350 at high concentration.The adsorption of E3 on the adsorbent showed R>RS450>RS350 at low concentration and high concentration.(2)The regression results of adsorption isotherm model show that the adsorption of E2 and E3 on sandy loam is suitable for F model,and the adsorption of E2 on sandy loam is consistent with L model.At the same time,all the constants of 1/n of F–type were less than 1,indicating that the adsorption behavior was nonlinear adsorption.(3)The adsorption constants of logK_f of E2 and E3 in sandy loam were 2.3830 and1.7504,respectively,which indicated that the adsorption of sand on soil was better than that of E3.The adsorption of E2 was performed the sequence of R>RS350>RS450and that of E3 performed that of R>RS450>RS350.In summary,the sandy loam on the farm has high adsorption of steroid estrogen E2 in water,followed by E3 adsorption.The addition of 1.5%bio-carbon did not increase the adsorption effect of sandy loam.The characterization data shows that the organic matter content of the tested sandy loam is low and contains certain aromatic substances.The addition of 1.5%bio-carbon partly changed the mineral-organic matter,interfacial area,oxygen-containing group number,polarity,and organic matter content of sandy loam.The combined effect of these changes may be the main reason for the inhibition of sandy loam adsorption after adding biochar.