PTCN/CaO_(2)/vis体系降解海水养殖废水中CIP:机理与归趋

Degradation of CIP in mariculture wastewater by PTCN/CaO_(2)/vis system:Mechanism and fate

本文拟建立掺磷管状氮化碳(PTCN)/CaO_(2)/可见光(vis)体系,将其应用于海水养殖废水中处理目标污染物环丙沙星(CIP),并探究该体系反应机理及抗生素CIP的环境归趋.实验结果表明,PTCN/CaO_(2)/vis体系具备良好的抗生素降解能力,在实验条件下CIP的表观降解速率常数k_(obs)为7.15×10^(-2)min^(-1);单因素实验表明,在酸性条件下,体系表现出更强的CIP降解效能,水中共存因子对体系降解CIP存在一定的影响;同时,体系降解污染物能力随CIP浓度降低而逐渐增强;此外,该体系表现出优异的可循环性能,PTCN在5次循环后,CIP的降解率仍能保持82.5%.体系降解CIP过程中,活性物质O_(2)-占主导地位,1O_(2)和h+这两种活性物质也起到一定的贡献作用;相标污染物CIP在体系中的降解过程包括脱羧反应和哌嗪环氧化;降解过程中大多数中间产物对水生生物表现出更为友好的特征;最后,通过延长体系降解时间,能有效消除CIP抗菌活性.

s:Abuse of antibiotics presents a significant threat to both human health and environmental ecology.To combat this issue,a phosphorus-doped tubular carbon nitride(PTCN)/CaO_(2)/visible light(vis)system would be developed and applied to effectively remove the pollutant ciprofloxacin(CIP)from mariculture wastewater.Meanwhile,the reaction mechanism of this system and the environmental fate of the antibiotic CIP would be investigated in this work.Experimental results indicated that the PTCN/CaO_(2)/vis system exhibited excellent potential for degradation of antibiotics.The observed apparent degradation rate constant(k_(obs))of CIP under the experimental conditions was 7.15×10^(-2)min^(-1).Single-factor experiments had revealed that the system exhibited enhanced CIP degradation efficiency in acidic conditions.However,the presence of co-existing factors in water did influence the system’s ability to degrade CIP.Moreover,as the concentration of CIP increases,the system's capacity to degrade pollutant decreases.Additionally,the system displayed superior recyclability,maintaining a degradation rate of 82.5%after five cycles of PTCN.The process of CIP degradation by the system was primarily dominated by the active ingredient O_(2)·-,while the active substances 1O_(2)and h+also contributed to the process.As the target pollutant CIP underwent decarboxylation and piperazine epoxidation,a majority of the intermediate products produced were found to be more environmentally friendly towards aquatic organisms.Finally,by prolonging the system’s degradation time,the antibacterial activity of CIP could be effectively eliminated.