The classical Fenton oxidation process(CFOP)is a versatile and effective application that is generally applied for recalcitrant pollutant removal.However,excess iron sludge production largely restricts its widespread ...The classical Fenton oxidation process(CFOP)is a versatile and effective application that is generally applied for recalcitrant pollutant removal.However,excess iron sludge production largely restricts its widespread application.Fenton sludge is a hazardous solid waste,which is a complex heterogeneous mixture with Fe(OH)3,organic matter,heavy metals,microorganisms,sediment impurities,and moisture.Although studies have aimed to utilize specific Fenton sludge resources based on their iron-rich characteristics,few reports have fully reviewed the utilization of Fenton sludge.As such,this review details current sustainable Fenton sludge reuse systems that are applied during wastewater treatment.Specifically,coagulant preparation,the reuse of Fenton sludge as an iron source in the Fenton process and as a synthetic heterogeneous catalyst/adsorbent,as well as the application of the Fenton sludge reuse system as a heterogeneous catalyst for resource utilization.This is the first review article to comprehensively summarize the utilization of Fenton sludge.In addition,this review suggests future research ideas to enhance the cost-effectiveness,environmental sustainability,and large-scale feasibility of Fenton sludge applications.展开更多
The aim of this work was to investigate the effect of different surfactants on the removal efficiency of heavy metals in sewage sludge treated by a method combining bio-acidification with Fenton oxidation. Four surfac...The aim of this work was to investigate the effect of different surfactants on the removal efficiency of heavy metals in sewage sludge treated by a method combining bio-acidification with Fenton oxidation. Four surfactants were adopted such as anionic surfactant(sodium dodecyl benzene sulfonate, SDBS), nonionic surfactants(tween-20 and tween-60) and cationic surfactant(hexadecyl trimethyl ammonium chloride, HTAC), respectively. The indigenous sulfur-oxidizing bacteria in bio-acidification phase were enriched and cultured from fresh activated sludge obtained from a wastewater treatment plant. It is shown that different surfactants exhibited distinct effect on the removal efficiency of heavy metals from sewage sludge. The nonionic surfactants,especially tween-60, promotes the solubilization of heavy metals, while the anionic and cationic surfactants hinder the removal of heavy metals. Copper is efficiently leached. The removal efficiency of cadium is relatively lower than that of Cu due to the demand for rigorous p H value. Lead is leached with a low efficiency as the formation of low soluble Pb SO4 precipitates.展开更多
Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are...Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are produced,increasing treatment costs and restricting the method’s application.In this study,we developed a three-dimensional electro-Fenton system by adding iron-carbon filler and investigated the effects of different electrolytic cell structure arrangements,particle electrode dosages,sponge iron(SI)to granular activated carbon(GAC)dosage ratios,current densities,H_(2)O_(2)dosages,and cathodic aeration on nitrobenzene(NB)wastewater treatment.The optimal system conditions were a particle electrode dosage of 100 g/L,SI:GAC mass ratio of 3:1,current density of 30 mA/cm^(2),H_(2)O_(2)dosage of 50 mmol/L,cathodic aeration of 0.8 L/min,and hydraulic retention time of 120 min.The average NB removal rate and chemical oxygen demand reached 67.38%±1.05%and 70.60%±1.15%,respectively,for which the increase in Fenton sludge was 891.8 mg/L.Different from the traditional Fenton process,additional Fe(II)was not required in the process used herein,reducing iron sludge accumulation and lowering the operating costs of using Fenton sludge as a hazardous waste treatment.In addition,the process applied in this study was able to reduce the chemical amounts used and increase the treatment efficiency.The reductions in sludge treatment costs and secondary pollutants make the proposed process an efficient and sustainable alternative for treating NB wastewater.展开更多
基金support of the National Natural Science Foundation of China(Grant No.5210040121)Jiangsu Provincial Natural Science Foundation of Jiangsu Province(No.BK20210498)the fellowship of China Postdoctoral Science Foundation(No.2021M693420).
文摘The classical Fenton oxidation process(CFOP)is a versatile and effective application that is generally applied for recalcitrant pollutant removal.However,excess iron sludge production largely restricts its widespread application.Fenton sludge is a hazardous solid waste,which is a complex heterogeneous mixture with Fe(OH)3,organic matter,heavy metals,microorganisms,sediment impurities,and moisture.Although studies have aimed to utilize specific Fenton sludge resources based on their iron-rich characteristics,few reports have fully reviewed the utilization of Fenton sludge.As such,this review details current sustainable Fenton sludge reuse systems that are applied during wastewater treatment.Specifically,coagulant preparation,the reuse of Fenton sludge as an iron source in the Fenton process and as a synthetic heterogeneous catalyst/adsorbent,as well as the application of the Fenton sludge reuse system as a heterogeneous catalyst for resource utilization.This is the first review article to comprehensively summarize the utilization of Fenton sludge.In addition,this review suggests future research ideas to enhance the cost-effectiveness,environmental sustainability,and large-scale feasibility of Fenton sludge applications.
基金Project(21276069)supported by the National Natural Science Foundation of ChinaProject(CX2012B139)supported by the Hunan Province Innovation Foundation for Postgraduate,China
文摘The aim of this work was to investigate the effect of different surfactants on the removal efficiency of heavy metals in sewage sludge treated by a method combining bio-acidification with Fenton oxidation. Four surfactants were adopted such as anionic surfactant(sodium dodecyl benzene sulfonate, SDBS), nonionic surfactants(tween-20 and tween-60) and cationic surfactant(hexadecyl trimethyl ammonium chloride, HTAC), respectively. The indigenous sulfur-oxidizing bacteria in bio-acidification phase were enriched and cultured from fresh activated sludge obtained from a wastewater treatment plant. It is shown that different surfactants exhibited distinct effect on the removal efficiency of heavy metals from sewage sludge. The nonionic surfactants,especially tween-60, promotes the solubilization of heavy metals, while the anionic and cationic surfactants hinder the removal of heavy metals. Copper is efficiently leached. The removal efficiency of cadium is relatively lower than that of Cu due to the demand for rigorous p H value. Lead is leached with a low efficiency as the formation of low soluble Pb SO4 precipitates.
基金supported by the National Natural Science Foundation of China(Grant No.52360009)the Lanzhou Science and Technology Plan(China)(2023-3-86).
文摘Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are produced,increasing treatment costs and restricting the method’s application.In this study,we developed a three-dimensional electro-Fenton system by adding iron-carbon filler and investigated the effects of different electrolytic cell structure arrangements,particle electrode dosages,sponge iron(SI)to granular activated carbon(GAC)dosage ratios,current densities,H_(2)O_(2)dosages,and cathodic aeration on nitrobenzene(NB)wastewater treatment.The optimal system conditions were a particle electrode dosage of 100 g/L,SI:GAC mass ratio of 3:1,current density of 30 mA/cm^(2),H_(2)O_(2)dosage of 50 mmol/L,cathodic aeration of 0.8 L/min,and hydraulic retention time of 120 min.The average NB removal rate and chemical oxygen demand reached 67.38%±1.05%and 70.60%±1.15%,respectively,for which the increase in Fenton sludge was 891.8 mg/L.Different from the traditional Fenton process,additional Fe(II)was not required in the process used herein,reducing iron sludge accumulation and lowering the operating costs of using Fenton sludge as a hazardous waste treatment.In addition,the process applied in this study was able to reduce the chemical amounts used and increase the treatment efficiency.The reductions in sludge treatment costs and secondary pollutants make the proposed process an efficient and sustainable alternative for treating NB wastewater.
