Study On Treatment Of Organic Pharmaceuticals In Wastewater By Dielectric Barrier Discharge Plasma Technology

Pharmaceuticals and Personal Care Products?PPCPs?are emerging organic pollutants that have received attention in the past decade.The extensive use of drugs,the excretion of humans and animals,the unreasonable disposal of waste drugs,the discharge of pharmaceutical wastewater and the extensive use of personal care products such as toiletries and cosmetic protective products are source of PPCPs in water environments.Dielectric Barrier Discharge?DBD?plasma technology is a new advanced oxidation technology for the treatment of refractory organic wastewater.In order to more effectively utilize the physical effects of DBD?ultraviolet radiation,thermal energy,etc.?to increase the degradation effect and energy efficiency of the treatment system,TiO₂ and persulfate were added to this system,cooperated with DBD to degrade the organic drug carbamazepine in wastewater.The main findings are as follows:?1?The degradation rate of carbamazepine increased with the increase of discharge voltage,and then increased first and then decreased with the increase of carrier gas flow rate or solution initial pH.The optimal experimental conditions were:AC voltage of 10kV,carrier gas flow rate of 1.5 L/min,and initial pH of 5.?2?The increase of salt content in wastewater will reduce the degradation effect of DBD on carbamazepine and the energy efficiency of the system,and the inhibition effect of sodium sulfate on the degradation of carbamazepine in DBD system is greater.?3?In the salt-free wastewater,the TiO₂/DBD synergistic system improved the degradation rate of carbamazepine,H₂O₂ production and energy efficiency compared with DBD system alone.The energy efficiency of TiO₂/DBD synergistic system under400 mg/L TiO₂ is 1.28 times that of DBD system alone.In the high-salt?10000 mg/L NaCl?wastewater,the TiO₂/DBD synergistic system could not effectively improve the degradation rate of carbamazepine and energy efficiency.?4?In the salt-free wastewater,compared with the DBD system alone,the S₂O₈^2-/DBD synergistic system improve the degradation rate of carbamazepine,H₂O₂production and system energy efficiency.When the S₂O₈^2-concentration rose to 2000mg/L and the above,it does not better promote the degradation of carbamazepine.In high-salt?10000 mg/L NaCl?wastewater,100 and 500 mg/L S₂O₈^2-were not effective in promoting carbamazepine degradation,while at 1000,2000 and 5000 mg/L S₂O₈²,the degradation rate of carbamazepine increased by 9.1%,26.7%and 36.7%at the treatment time of 15 min,and the energy efficiency of persulfate/DBD synergy system at 5000 mg/L S₂O₈^2-concentration was 2.53 times that of DBD system alone.?5?HPLC-MS was used to analyze the degradation products of carbamazepine in wastewater.In the solution of 10 mg/L CBZ,10 mg/L CBZ+400 mg/L TiO₂ and 10 mg/L CBZ+10000 mg/L NaCl+5000 mg/L S₂O₈^2-,there were 6?P180,P198,P251,P267,P271,P287?,4?P180,P253,P271,P287?and 6?P180,P198,P251,P253,P267,P271?kinds of degradation products of carbamazepine,respectively.