| Antibiotics are the largest drugs on production and usage in the world.As a typical antibiotic,tetracycline antibiotics?TCs?have been extensively used in clinical medical and animal husbandry.Due to the large amount of toxic substances contained in the antibiotic wastewater and its bacteriostatic effect,the traditional wastewater treatment methods cannot achieve good results.As one of the advanced oxidation processes,pulsed corona discharge plasma?PCDP?has attracted extensive attention in wastewater treatment.PCDP has the characteristics of simple operation,high removal efficiency of pollutants,no selectivity and no secondary pollution etc.However,the energy utilization of PCDP was relatively low which limited its development.Hence,the combination of PCDP and other methods was investigated by some researchers.The combination of PCDP and adsorption method is an effective wastewater treatment method.As one of the most widely existing substances in nature,soil has received intensive attention from many researchers.Beacause of the abundant of functional groups and pore structure,soil has become a cheap and easily available adsorbent.Based on this,the combination of PCDP and soil particles?SPs?was used for the treatmet of typical antibiotic?Tetracycline hydrochloride,TCH?wastewater.In the present study,the characteristic of PCDP/SPs system and the removal efficiency of TCH were analyzed,and the degradation process and mechanism of TCH in PCDP/SPs were investigated,the results are as follows:1.The interaction between PCDP and SPs was investigated by analyzing the active species,the state of discharge,and the physicochemical properties of SPs.The results displayed that the SPs could significantly promote the discharge state of PCDP,prolong the lifetime of plasma channels,and improve the concentration of active substances.PCDP had little effect on physical properties?BET surface area,cation exchange capacity,and organic matter?of SPs.And the chemical property of SPs was influenced by PCDP,the surface functional groups of SPs were changed after the discharge treatment.2.The removal efficiency of TCH in wastewater by PCDP system,SPs adsorption system and PCDP/SPs system was compared,and results illustrated that the removal efficiency of TCH and energy utilization of PCDP were significantly enhanced.This is because SPs can adsorb many TCH molecules and creats a high TCH concentration on its surface and adjacent surrounding area,which leads to an increase in the collision probability between TCH molecules and active species,and the removal efficiency of TCH gets improved.3.The effects of SPs parameters,electrical factors and solution conditions on the removal efficiency of TCH were investigated,and the results showed that the removal efficiency of TCH was significantly different with different SPs,the removal efficiency of TCH in PCDP/LS system was highest,followed by PCDP/BS system,and the removal efficiency in PCDP/RS system was lowest.With an increase in the discharge peak voltage,pulsed frequency and a decrease in the SPs size,the removal efficiency of TCH increased.Upon increasing the initial TCH concentration and the solution conductivity,the removal efficiency decreased.The weight of SPs had a significant effect on TCH removal,but the addition of excessive SPs had little effect on TCH removal.4.The changes of actives matters were analyzed in PCDP/SPs system,and the result showed that·OH and O3 played important roles in the degradation of TCH.The TCH could be degraded effectively in PCDP/SPs system,including dissolved in solution and adsorbed on SPs.The TCH varied to low molecule organic matter by physical and chemical effects generated in PCDP/SPs system,and was further degraded and evolved into CO2,H2O,and inorganic ions. |
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