The Exploration Of Infrared-light Improved Pollutant Transformation By Anoxygenic Photosynthetic Bacteria

The major development trend is to reduce greenhouse gas emissions and recycle valuable resources in the future of global wastewater and solid waste treatment industries.The development of environmental biotechnology and renewable energy has provided many new opportunities and possibilities for the environmental protection industry.Anoxygenic photosynthetic bacteria(APB)can rapidly utilize nutrients(e.g.organic matter,nitrogen,phosphorus)that come from the polluted environment,and the process will produce high quality of single cell protein simultaneously.It is a promising technology for wastewater or solid waste treatment and reclamation.This study explored the feasibility that monochromatic near-infrared(MNIR)improved APB for the treatment of food wastewater and poly(lactic)acid(PLA)textiles,and it would aim to provide reference for the application of APB in wastewater or solid waste treatment.Firstly,the MNIR LED is selected as light source for analyzing the effects of three key factors(light quality,light intensity and photoperiod)on APB food wastewater treatment.The results show that light quality is determined as the main influencing factor,and the system with 850 nm infrared LED has the highest ammonia nitrogen and COD removal rate.At the same time,the system obtains the highest APB biomass and bacteriochlorophyll a production.Energy consumption assessment show that MNIR LED save about 80%comparing with the continuous light.The exploration of PLA biodegradation using photosynthetic-microbial fuel cell(Photo-MFC)under the action of continuous light.The results show that the highest weight loss of PLA textiles was 26.67%after the operation of Photo-MFC for 32 days when gelatin wastewater is selected as inducer,the value is 17.39%higher than the control.The system can still maintain bioelectricity generation when the gelatin is stopped as the inducer,and the stable current density is 4.4 ± 0.2 mA/cm2.SEM and FT-IR analysis reveal that the PLA textiles appear biochemical degradation in Photo-MFC system.High-throughput sequencing analysis show that the dominant bacteria community in the stable operating Photo-MFC contain Rhodopseudomonas(41.88%),Acetobacteroides(26.92%)and Pseudomonas(10.46%).Therefore,APB has an absolute advantage.On that basis,the effects of MNIR on APB are studied for PLA textiles biodegradation in the Photo-MFC system.SEM and FT-IR analysis show that 850 um MNIR LED could enhance the biodegradation of PLA textiles and maintain the sustainable bioelectricity generation(50 ±10 mV).Pigment extraction reveal that the sediment contains a lot of bacteriochlorophyll,which indirectly proves that 850 nm MNIR LED can enhance APB activity in the Photo-MFC system.The application of MNIR save energy consumption of APB treatment technology.At the same time,it also provides the feasibility for the optical manipulation of the dominant APB in the biological system.