Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements(REEs);however,simultaneous remov...Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements(REEs);however,simultaneous removal of both REEs and ammonium is generally hindered since most acidophilic organisms are positively charged.Accordingly,immobilization of acidophilic Galdieria sulphuraria(G.sulphuraria)by calcium alginate to improve its affinity to positively charged REEs has been used for simultaneous bioremoval of REEs and ammonium.The results indicate that 97.19%,96.19%,and 98.87%of La,Y,and Sm,respectively,are removed by G.sulphuraria beads(GS-BDs).The adsorption of REEs by calcium alginate beads(BDs)and GS-BDs is well fitted by both pseudo first-order(PFO)and pseudo second-order(PSO)kinetic models,implying that adsorption of REEs involves both physical adsorption caused by affinity of functional groups such as-COO-and -OH and chemical adsorption based on ion exchange of Ca^(2+) with REEs.Notably,GS-BDs exhibit high tolerance to La,Y,and Sm with maximum removal efficiencies of 97.9%,96.6%,and 99.1%,respectively.Furthermore,the ammonium removal efficiency of GS-BDs is higher than that of free G.sulphuraria cells at an initial ammonium concentration of 100 mg L^(-1),while the efficiency decreases when initial concentration of ammonium is higher than 150 mg L^(-1).Last,small size of GS-BDs favors ammonium removal because of their lower mass transfer resistance.This study achieves simultaneous removal of REEs and ammonium from acidic mining drainage,providing a potential strategy for biotreatment of REE tailing wastewater.展开更多
Over the past twenty years,various commercial technologies have been deployed to remove ammonia(NH4eN)from anaerobic digestion(AD)liquors.In recent years many anaerobic digesters have been upgraded to include a pre-tr...Over the past twenty years,various commercial technologies have been deployed to remove ammonia(NH4eN)from anaerobic digestion(AD)liquors.In recent years many anaerobic digesters have been upgraded to include a pre-treatment,such as the thermal hydrolysis process(THP),to produce more biogas,increasing NH4eN concentrations in the liquors are costly to treat.This study provides a comparative techno-economic assessment of sidestream technologies to remove NH4eN from conventional AD and THP/AD dewatering liquors:a deammonification continuous stirred tank reactor(PNA),a nitrification/denitrification sequencing batch reactor(SBR)and thermal ammonia stripping process with an ammonia scrubber(STRIP).The SBR and PNA were based on full-scale data,whereas the STRIP was designed using a computational approach to achieve NH4eN removals of 90e95%.The PNA presented the lowest whole-life cost(WLC)over 40 years,with£7.7 M,while the STRIP had a WLC of£43.9 M.This study identified that THP dewatering liquors,and thus a higher ammonia load,can lead to a 1.5e3.0 times increase in operational expenditure with the PNA and the SBR.Furthermore,this study highlighted that deammonification is a capable and cost-effective nitrogen removal technology.Processes like the STRIP respond to current pressures faced by the water industry on ammonia recovery together with targets to reduce nitrous oxide emissions.Nevertheless,ammonia striping-based processes must further be demonstrated in WWTPs and WLC reduced to grant their wide implementation and replace existing technologies.展开更多
基金financial support from the Anhui Provincial Natural Science Foundation-China(1908085QB70)the Natural Science Fund of the Education Department of Anhui Province(KJ2021A0031)+1 种基金Anhui University(Startup Fund-China Y040418343)the Horizontal Cooperation Project of Fuyang Municipal Government-Fuyang Normal University(SXHZ202102)。
文摘Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements(REEs);however,simultaneous removal of both REEs and ammonium is generally hindered since most acidophilic organisms are positively charged.Accordingly,immobilization of acidophilic Galdieria sulphuraria(G.sulphuraria)by calcium alginate to improve its affinity to positively charged REEs has been used for simultaneous bioremoval of REEs and ammonium.The results indicate that 97.19%,96.19%,and 98.87%of La,Y,and Sm,respectively,are removed by G.sulphuraria beads(GS-BDs).The adsorption of REEs by calcium alginate beads(BDs)and GS-BDs is well fitted by both pseudo first-order(PFO)and pseudo second-order(PSO)kinetic models,implying that adsorption of REEs involves both physical adsorption caused by affinity of functional groups such as-COO-and -OH and chemical adsorption based on ion exchange of Ca^(2+) with REEs.Notably,GS-BDs exhibit high tolerance to La,Y,and Sm with maximum removal efficiencies of 97.9%,96.6%,and 99.1%,respectively.Furthermore,the ammonium removal efficiency of GS-BDs is higher than that of free G.sulphuraria cells at an initial ammonium concentration of 100 mg L^(-1),while the efficiency decreases when initial concentration of ammonium is higher than 150 mg L^(-1).Last,small size of GS-BDs favors ammonium removal because of their lower mass transfer resistance.This study achieves simultaneous removal of REEs and ammonium from acidic mining drainage,providing a potential strategy for biotreatment of REE tailing wastewater.
基金funding provided by Thames Water Utilities Ltd.and the Engineering and Physical Sciences Research Council(EPSRC)through their funding of the STREAM Industrial Doctoral Centre(IDC)EP/L015412/1.
文摘Over the past twenty years,various commercial technologies have been deployed to remove ammonia(NH4eN)from anaerobic digestion(AD)liquors.In recent years many anaerobic digesters have been upgraded to include a pre-treatment,such as the thermal hydrolysis process(THP),to produce more biogas,increasing NH4eN concentrations in the liquors are costly to treat.This study provides a comparative techno-economic assessment of sidestream technologies to remove NH4eN from conventional AD and THP/AD dewatering liquors:a deammonification continuous stirred tank reactor(PNA),a nitrification/denitrification sequencing batch reactor(SBR)and thermal ammonia stripping process with an ammonia scrubber(STRIP).The SBR and PNA were based on full-scale data,whereas the STRIP was designed using a computational approach to achieve NH4eN removals of 90e95%.The PNA presented the lowest whole-life cost(WLC)over 40 years,with£7.7 M,while the STRIP had a WLC of£43.9 M.This study identified that THP dewatering liquors,and thus a higher ammonia load,can lead to a 1.5e3.0 times increase in operational expenditure with the PNA and the SBR.Furthermore,this study highlighted that deammonification is a capable and cost-effective nitrogen removal technology.Processes like the STRIP respond to current pressures faced by the water industry on ammonia recovery together with targets to reduce nitrous oxide emissions.Nevertheless,ammonia striping-based processes must further be demonstrated in WWTPs and WLC reduced to grant their wide implementation and replace existing technologies.
