Study On Enhancement Of Aerobic Degradation Of Phenol Containing Wastewater By Magnetic Biochar

Phenol-containing wastewater has a number of features that make it challenging to treat biologically,including high toxicity,poor degradation capability,high chemical oxygen consumption,and complicated composition.As of right now,there is no cost-effective way to remove it using traditional treatment technologies.Aerobic degradation of phenol-containing wastewater cannot satisfy the stringent wastewater treatment criteria,despite the advantages of aerobic biotechnology’s cheap operating costs and effective treatment.The effectiveness and mechanism of aerobic degradation of magnetic charcoal enhanced with 2,4,6-trichlorophenol were analyzed,as well as the system stability,in the current study.Magnetic biochar was optimally prepared by using loofah as a carbon precursor and nano-Fe3O4 loading,and it was used to strengthen aerobic sludge to degrade phenol-containing wastewater by sequential batch reactor（SBR）was explored and the resutls as follows:（1）According to the SEM findings,magnetic biochar has many pores and uniformly dispersed Fe3O4 particles both on the surface and within the pores.The results of the test on specific surface area reveal that magnetic biochar has a specific surface area of 301.32 m²/g and average pore sizes for adsorption and desorption of3.18 nm and 3.59 nm,respectively,which fall inside the mesoporous category.The synthesized magnetic biochar contains Fe₃O₄ phase,according to the XPS data.The XRD data revealed that the antispinel structure remained unchanged and that the magnetic biochar was compatible with the typical XRD spectra of Fe3O4.According to the findings of infrared spectroscopy,Fe was successfully loaded onto biochar when typical Fe-O absorption peaks with varying strengths occurred in the wavenumber 400–700 cm-1 area.In addition,in the magnetic biochar leaching experiment,the concentration of several major heavy metal ions is much lower than the permitted leaching concentration,in line with the national emission standards.The above results show that the properties of magnetic biochar prepared are safe and reliable.（2）The removal rate of 2,4,6-trichlorophenol and COD enhanced by magnetic biochar was found to be highest when p H=8.5,which remained above 80%,according to research on the effects of environmental factors on the enhanced aerobic system of magnetic biochar.This finding suggests that it was more favorable for the active expression of microbial degradation under neutral alkaline conditions.The magnetic biochar group outperformed the control group in terms of COD removal rate,trichlorophenol removal rate,dehydrogenase activity,and PN/PS values under various p H conditions,suggesting that it could enhance the performance of activated sludge degradation under various p H values.The effect of increased aerobic 2,4,6-trichlorophenol degradation by magnetic biochar was best at a dissolved oxygen concentration of 6.5 mg/L,indicating that aerobic microorganism growth rate and metabolic activity were higher at high dissolved oxygen concentration,which was beneficial for thoroughly mineralizing organic matter.Additionally,under various conditions of dissolved oxygen concentration,the rate of COD removal,the rate of trichlorophenol removal,the concentration of dehydrogenase,and the rate of 2,4,6.It improves the performance of sludge sedimentation and effluent quality by stimulating key enzymes involved in metabolism.With the help of magnetic biochar,the ultimate removal rates of COD and 2,4,6-trichlorophenol were revealed to be 71.2%and 89.6%,respectively.These rates were 1.3 times and 1.28 times greater than those in the control group.The effluent BOD₅/COD increased by 30%and the TU decreased by 54%.（3）The experimental results demonstrate that magnetic biochar can enhance the dehydrogenase activity and catalase activity of microorganisms,increase the biomass in aerobic activated sludge,and increase the concentration of extracellular polymer.Additionally,the average particle sizes of the magnetic biochar group and blank control group are,respectively,179.8 m and 26.9 m,demonstrating that magnetic biochar can alleviate the issue of poor sludge.The dominant bacteria with the ability to degrade 2-4-6 trichlorophenol were enriched in granular sludge,primarily Proteobacteria,Actinobacteriota,and Firmicutes,which increased by 10.2%,23.8%,and 14.7%,respectively.At the same time,it improved microbial diversity and richness.The addition of magnetic biochar improved the removal rate of COD and trichlorophenol,but it also increased the activity of microbial cells,improved the bioflocculation of activated sludge,and strengthened the impact resistance of aerobic bacteria.In comparison to the blank control group,the COD removal rate and trichlorophenol removal rate of the magnetic biochar group were significantly higher,and the SVI value was lower.In conclusion,the prepared magnetic biochar enhanced aerobic degradation of2,4,6-trichlorophenol has a significant impact and significantly increases the stability of the process,which not only successfully resolves the issue of aerobic and efficient degradation of phenolic compounds but also realizes the secondary utilization of agricultural and forestry wastes,which has significant economic and social benefits.This article offers a theoretical framework and fresh suggestions for the aerobic decomposition of phenolic compounds improved by magnetic biochar.