Immobilized cholesterol oxidase (COD) membrane with higher catalytic activity is important for biosensor. In this paper, several procedures for immobilizing COD based on cellulose acetate (CA) membrane are studied. Re...Immobilized cholesterol oxidase (COD) membrane with higher catalytic activity is important for biosensor. In this paper, several procedures for immobilizing COD based on cellulose acetate (CA) membrane are studied. Reasons causing different catalytic activities are also discussed.展开更多
It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis（ACE） to study receptor-ligand interactions or to screen natural products and compounds synt...It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis（ACE） to study receptor-ligand interactions or to screen natural products and compounds synthesized by combinatorial chemistry. In this paper, we developed a new method of immobilizing HEK293 cells on the inner wall of a capillary column. Four important experimental conditions were optimized, including cell injection density, PLL concentration, cell culturing time and sterile processing method. Immobilized cell-coated capillary columns prepared under the optimized experimental conditions exhibited good uniformity, stability and durability, which were suitable for capillary electrophoresis. The method could also be used to immobilize HEK293 cells over-expressing certain membrane receptors on the inner wall of a capillary. In this way, cell-coated capillary columns could be applied to ACE drug screening targeting certain membrane proteins.展开更多
The hydrophilic, macroporous and beaded ternary copolymer of glycidyl methacrylate （GMA）/methacrylamide（MA）/N,N＇-methylene-bis（acrylamide）（MBAA）was synthesized using the industrial agents by inverse suspensio...The hydrophilic, macroporous and beaded ternary copolymer of glycidyl methacrylate （GMA）/methacrylamide（MA）/N,N＇-methylene-bis（acrylamide）（MBAA）was synthesized using the industrial agents by inverse suspension polymerization. The apparent activity of the immobilized penicillin G acylase reached 1096 IU/g for hydrolysis penicillin G on the beads with diameter of 0.11-0.13 ram, and it changed hardly after 50 cycles. It can be expected to be a good potential in industrial application,展开更多
Soil contamination by heavy metal(loid)s is a considerable environmental concern,and immobilization is a promising way to reduce toxicity.In recent years,modified/engineered biochars have gained enormous attention for...Soil contamination by heavy metal(loid)s is a considerable environmental concern,and immobilization is a promising way to reduce toxicity.In recent years,modified/engineered biochars have gained enormous attention for their use in soil remediation,and various studies have reported notable results from their application and their ability to immobilize heavy metal(loid)s.In this review,a summary of publications on the utilization of modified biochars is presented to address the heavy metal(loid)threat in soils.Various modified/engineered biochars were described from the review of relevant publications.Modification causes great changes in biochar surface chemistry,such as increases in pore volume,surface functional groups,and metal binding sites,which can be observed through various analytical techniques,including Brunauer-Emmett-Teller,X-ray photoelectron spectroscopy,X-ray diffraction,Fourier transform infrared spectroscopy,and magnetism.Such analytical approaches elucidate immobilization mechanisms of adsorption,precipitation,surface complexation,and cation exchange between biochar and metal(loid)ions.In addition,the performance of biochar in remediating heavy metal(loid)s also leads to considerable improvements in soil conditions.Additionally,many factors that influence metal(loid)immobilization by biochar in soil,such as pH,redox potential,microorganisms,and climate regime,are highlighted.Finally,this paper emphasizes that using modified biochars as an immobilizing agent for remediation of heavy metal(loid)-polluted soils is promising and would be practicable if a comprehensive mechanism of their long-term stability in soil is well elucidated.展开更多
Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic...Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.展开更多
In trace metal (TM)-contaminated agricultural soils,management of TM availability is important for safe crop production.In addition,maintenance or improvement of soil quality is vital for sustainable crop cultivation....In trace metal (TM)-contaminated agricultural soils,management of TM availability is important for safe crop production.In addition,maintenance or improvement of soil quality is vital for sustainable crop cultivation.Decreased TM phytoavailability and increased soil quality can be achieved by the application of various immobilizing agents to soil,which can supply both macronutrients and organic matter.This study investigated the long-term influences of four common immobilizing agents on soil biogeochemical properties and the phytoavailability of TMs in mixed metal-contaminated soil from a cultivated upland near an abandoned mining site.Lime (L),gypsum (G),fly ash (F),and animal manure-based compost (C) were applied to pots containing contaminated soil,either individually or in combination.After incubation for three years under sequential cultivation of two crops and fallow,soil biogeochemical properties were determined,and Brassica rapa plant bioassay was performed.The phytoavailability of all TMs (both cationic metals and anionic metalloids) remained significantly lower in soils treated with immobilizing agents even after three years,when compared with the no-agent control (CK) soil.In addition,the soil quality was significantly improved by treatment with immobilizing agents.For instance,the C and L+C treatments were the most effective in improving soil physical (bulk density,porosity,and water-resistant aggregate stability),chemical (pH,organic matter,total nitrogen,cation exchange capacity,and plant-available phosphorus,magnesium,and potassium),and biological (microbial biomass carbon and dehydrogenase activity) properties.The improvement of soil properties and lowering of TM bioavailability were also consistent with the most significant increase in B.rapa biomass production observed in the C treatment,followed by the L+C,G+F,L,G,F,and L+G treatments,as compared with that in CK.These results indicate that the function of the TM-immobilizing agent as a soil quality conditioner,in addition to its TM immobilizing effect,should be considered when selecting such agents for agricultural or ecological applications.展开更多
For solving the radioactive waste storage problem, there is an idea to store immobilized waste at deep sea. Solidifier material, such as cement should be resistance to saline environment for deep sea storage. So, this...For solving the radioactive waste storage problem, there is an idea to store immobilized waste at deep sea. Solidifier material, such as cement should be resistance to saline environment for deep sea storage. So, this research objective is to study the performance of cementation method in immobilizing strontium waste in saline environment. Research was conducted by immobilizing strontium waste using Portland pozzolanic cement, white cement and composite Portland cement. Cement, 65 ppm Sr(NO3)2, sand and water were mixed and cast. Strontium waste varied in 2 v/o, 4 v/o, 6 v/o and 8 v/o. After 28 days curing, the cement block’s compressive strength and leaching rate on saline water were analyzed. Determination of compressive strength was done by using Universal Wood Testing. The density of blocks was measured by picnometer at 25°C. Compressive strength test for Portland pozzolanic cement at various w/c was conducted to confirm the effect of w/c in increasing the strength. For testing strontium leaching rate in water containing 35 ppm NaCl, cement blocks have been immersed in saline water for 21 days. 25 ml samples were taken and analyzed by Atomic Absorption Spectrophotometer. Strontium leaching rate on block containing pH 9 of waste was compared to the previous research data of strontium leaching rate on water to know the effect of saline water. To adjust the pH, 1 MNaOH was added into the waste. Effects of various cement type and filler materials (sand, zeolite and baryte) on Portland pozzolanic cement were also compared. The results show that there were almost no effects of salt on immobilized strontium waste, except in pH 9 waste (0.00224 over to0.000199 g/cm2·days). Strontium leaching rates on all cemented waste still meet the IAEA’s standard, so the safety of cemented strontium waste disposal at saline environment could be ensured.展开更多
D-allulose,a low-calorie rare sugar,can be biosynthesized by D-allulose 3-epimerase(DAE).Here,DAE was covalently immobilized on polyethyleneimine-modified diatomite using two methods:a biopolymer coating approach(DAE@...D-allulose,a low-calorie rare sugar,can be biosynthesized by D-allulose 3-epimerase(DAE).Here,DAE was covalently immobilized on polyethyleneimine-modified diatomite using two methods:a biopolymer coating approach(DAE@PEI-GA@PDP)and a direct attachment method(DAE-GA@PEI@PDP).Both immobilized DAE enzymes exhibited enhanced thermal stability and broader pH tolerance compared to the free DAE.They also exhibited excellent reusability and maintained more than 70%of their activity after 10 cycles.Additionally,a multienzyme cascade system was developed to produce D-allulose from low-cost D-glucose using immobilized glucose isomerase(GI)and immobilized DAE enzymes.This system obtained 76 g/L D-allulose from 500 g/L Dglucose.Notably,the application was extended to fruit tea drinks,successfully transforming high-calorie sugars(D-glucose and D-fructose)into D-allulose.This research offers a promising immobilization strategy for DAE on silica-based materials and provides robust biocatalysts for creating functional fruit tea drinks aimed at diabetics and individuals with specific dietary needs.展开更多
The combination of photodynamic therapy(PDT)and chemodynamic therapy(CDT)in tumor treatment has attracted considerable attention.However,tumor hypoxia and glutathione(GSH)overproduction in the tumor tissue restricted ...The combination of photodynamic therapy(PDT)and chemodynamic therapy(CDT)in tumor treatment has attracted considerable attention.However,tumor hypoxia and glutathione(GSH)overproduction in the tumor tissue restricted the progress of their applications.Herein,a Mn-porphyrinic metal-organic framework(Mn-TCPP)was constructed by the one-pot method and further used for immobilizing glucose oxidase(GOx)to obtain GOx@Mn-TCPP.GOx would rapidly exhaust endogenous glucose into hydrogen peroxide(H_(2)O_(2))and gluconic acid,thus shutting off the energy supply of tumor cells for starvation treatment.Mn-TCPP catalyzed H_(2)O_(2)to produce oxygen,regulating the hypoxic tumor microenvironment and in turn improving^(1)O_(2)generation under laser irradiation.Interestingly,Mn-TCPP can reduce reactive oxygen species consumption owing to the redox reaction between Mn^(3+)and GSH,thus greatly enhancing PDT.Furthermore,benefiting from GOx-mediated starvation therapy,Mn^(2+)produced by Mn^(3+)reduction can react with sufficient intracellular H_(2)O_(2)to generate·OH with high cytotoxicity through a Fenton-like reaction.After treatment by GOx@Mn-TCPP under laser irradiation in vitro,the cell viability of 4T1 and A549 tumor cells reached to 20%,reflecting GOx@Mn-TCPP could give full play to the advantages of PDT/CDT/starvation therapy.The results in vivo demonstrated that GOx@Mn-TCPP mediated synergistic cascade therapy could significantly inhibit tumor growth and improve the therapeutic effect.展开更多
Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hy...Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hydrogen evolution with high efficiency and low cost,definitely hinder the practical application of photocatalytic hydrogen production from water.[Fe Fe]-hydrogenase,an excellent natural biological enzyme catalyst bearing unique organometallic clusters with noble-metal-free element,is most efficient in reducing protons to hydrogen and demonstrates remarkable turnover frequencies(TOF 6000–9000 s1 per active site)[2].展开更多
Microbial degradation is the primary mechanism for purifying polycyclic aromatic hydrocarbon(PAH)contamination in environments,and biochar immobilization is an effective technology to enhance biodegradation,but the pr...Microbial degradation is the primary mechanism for purifying polycyclic aromatic hydrocarbon(PAH)contamination in environments,and biochar immobilization is an effective technology to enhance biodegradation,but the process parameters of the immobilization technology still require further systematic evaluation.Here,biochars derived from pig manure(PM),bamboo(BB),rice straw(RS),and soybean straw(SS)were used as carriers of Mycobacterium sp.ZL7,and the optimal biochar dosage of 1:30(w/V)and immobilization time of 24 h were determined.The immobilization effects followed the order of RS>SS>PM>BB.Scanning electron microscopy and physicochemical properties revealed that porous structures acted as shelters for bacteria,and high nitrogen content,large pore size and high-water holding capacity played important driving roles in immobilization.In the single-substrate system,pyrene removal rates of the PM-,RS-and SS-immobilized materials were greater than 96%,which were significantly higher than those of the biochar alone or the free strain.An orthogonal design experiment in historically PAH-contaminated soil further revealed that,compared with free strains,immobilized materials combined with high moisture content and moderate salicylic acid or Brij 30 can effectively increase the abundance of bacteria and the nidA gene,and enhance the dehydrogenase and polyphenol oxidase activities.The removal rate of total PAHs increased by 8.53%-30.45%after 24 d.Moreover,biochar with strong immobilization capacity showed better PAH removal effects.This study provides a scientific basis and practical reference for biochar-immobilized microorganisms to enhance the self-purification of PAH-contaminated soil.展开更多
Photocatalytic nitrogen fixation (PNF) is a promising alternative to the Haber-Bosch process.It achieves green ammonia production by utilizing solar energy for nitrogen fixation under mild conditions.While nanoscale p...Photocatalytic nitrogen fixation (PNF) is a promising alternative to the Haber-Bosch process.It achieves green ammonia production by utilizing solar energy for nitrogen fixation under mild conditions.While nanoscale photocatalysts offer enhanced performance due to their high surface area and abundant active sites,their small size makes them difficult to recover and prone to agglomeration.These bottlenecks severely limit industrial application.A promising solution is to immobilize the catalysts onto support surfaces.This paper provides a systematic review of recent advances in the design of immobilized photocatalysts for ammonia synthesis.It begins by outlining the key benefits of immobilization strategies,particularly in improving catalyst stability,recyclability,and overall photocatalytic performance.The working mechanisms and features of various immobilization techniques are then categorized and explained,covering physical adsorption/deposition,chemical bonding,in situ growth,and hybrid physico-chemical methods.Supported materials and common substrate types are also summarized.Furthermore,the widely used configurations of photoreactors suitable for immobilized systems are introduced.Finally,the review identifies current research limitations and challenges,and offers perspectives on future developments in the field of immobilized photocatalysis.展开更多
We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as ...We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.展开更多
Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They eff...Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They effectively reduce the mobility and bioavailability of heavy metals through various mechanisms such as adsorption,precipitation,and oxidation-reduction.This paper provides an in-depth exploration of the cuttingedge applications of various nanomaterials,including nanometallic,nano non-metallic materials,nanoclay and mineral materials,and nano modified biochar materials,in the remediation of heavy metal-contaminated soils.It specifically focuses on the key factors influencing the remediation efficacy of these nanomaterials,as well as the underlying remediation mechanisms and methods for performance optimization.The aims of this paper are to provide guidance for the further application of nanomaterials in the field of soil heavy metal remediation,and to offer insights that could promote the effective control of soil heavy metal pollution.展开更多
Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in thi...Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in this process.Methods: 8-week-old male C57BL/6J mice were carried out combined exercise for 10 weeks. One week before the end of the intervention, mice underwent cast immobilization. Additionally, to investigate the potential mechanism in exercise-induced protection of skeletal muscle, mice in the exercise preconditioning group were administered TC-E-5003(an inhibitor of Prmt1 enzymatic activity). Exercise performance, muscle mass, and the cross-sectional area(CSA) of muscle fibers were analyzed. Besides, Prmt1 and Sestrin1(Sesn1) were either overexpressed or inhibited in C2C12 myotubes to elucidate the underlying mechanism.Results: Exercise preconditioning not only significantly improved muscle mass and motor ability in immobilized mice but also inhibited excessive activation of degradation pathways and enhanced protein synthesis. Importantly, Prmt1 mediated the protective effects of exercise preconditioning on muscle atrophy. Mechanistically,Prmt1 regulated the p38 mitogen-activated protein kinase(p38)/activating transcription factor 2(ATF2)pathway, which modulates Sesn1 expression. Sesn1 acts as a downstream of Prmt1 and ATF2, contributing to the myoblast differentiation and skeletal muscle regeneration through AMP-Activated protein kinase α2(AMPKα2)/transcriptional co-activator PPAR-γ co-activator-1 α(PGC-1α) signaling pathway.Conclusions: Taken together, our results highlighted the effectiveness of exercise preconditioning in preventing muscle atrophy via the Prmt1-Sesn1 pathway.展开更多
Immobilized microalgae technologies(IMTs)involve the fixing of free-living microalgae onto specialized carriers through physical adsorption,chemical cross-linking,or biological interactions to enhance cell retention,m...Immobilized microalgae technologies(IMTs)involve the fixing of free-living microalgae onto specialized carriers through physical adsorption,chemical cross-linking,or biological interactions to enhance cell retention,metabolic stability,and stress resistance.These have emerged as multifunctional and sustainable platforms for environmental remediation,extending their applications beyond wastewater treatment to include soil and air purification.This review categorizes advanced IMT carriers into three major types:(1)inorganic engineered materials(e.g.,biochar-nanoparticle hybrids),(2)functionalized organic polymers(e.g.,pH-responsive hydrogels),and(3)bio-derived scaffolds(e.g.,fungal-algal and algal-bacterial consortia).They enhance microalgal retention,metabolic activity,and microalgal stress resistance,enabling the effective removal of nitrogen,phosphorus,heavy metals,organic pollutants,and airborne particulates across diverse environmental matrices.We highlight key cooperative mechanisms—such as extracellular polymeric substance(EPS)-mediated adhesion,quorum sensing,and metabolic synergy—that underpin pollutant removal and biomass stability.Particular emphasis is placed on integrating smart technologies,including magnetic microrobots,3D/4D-printed scaffolds,and AI-guided optimization,which improve the scalability,adaptability,and environmental responsiveness of IMT systems.By synthesizing the advances in materials science,microbial ecology,and environmental engineering,this review defines the future direction of research into IMTs as a next-generation bioengineering strategy for the integrated management of water,soil,and air pollution.展开更多
D-Allulose,a low-calorie functional sweetener popular among the obese population,can be biosynthesized using D-allulose 3-epimerase(DAE).However,there are currently no commercially viable immobilized DAE enzymes on th...D-Allulose,a low-calorie functional sweetener popular among the obese population,can be biosynthesized using D-allulose 3-epimerase(DAE).However,there are currently no commercially viable immobilized DAE enzymes on the market for the large-scale production of D-Allulose.In this study,immobilizing the DAE enzyme was developed based on polymer-activated diatomite with surface enhancement using crosslinkers.Specifically,the amino groups of polyethyleneimine were successfully carried on the porous diatomite and then activated by glutaraldehyde to form a biopolymer coating.The obtained carrier was firmly covalently linked to the DAE enzyme via the Schiff-base reaction.The constructed immobilized DAE with a“core-shell”structure showed a high specific activity of 2088.93±9.85 U/g and an excellent conversion rate of 34.4%.This biocatalyst was stable within a wide temperature and pH range.It also showed outstanding thermal stability,the half-lives of the immobilized DAE were 109 and 124 times that of the free DAE at 55℃ and 60℃,respectively.Moreover,the immobilized DAE remained at about 81.33%of the initial enzyme activity after 8 recycles.The results of this study may contribute to the cost reduction of D-Allulose industrial production and provide a potential immobilized enzyme strategy for future large-scale manufacturing of D-Allulose.展开更多
Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms ...Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.展开更多
Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceeding...Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose amajor hazard in production.However,the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions.In this study,free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared,at the same time,biomineralizationmechanisms and mineral characteristicswere further explored.The results showthat bacterial concentration and carbonic anhydrase activitywere higher when additionally adding ferric ion based on calcium ion;the content of protein,polysaccharides,deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to control.Calcium ions were biomineralized into calcite and vaterite with mul-tiple morphology.Due to iron doping,the crystallinity and thermal stability of calcium carbonate decreased,the content of O-C=O,N-C=OandC-O-PO_(3) increased,the stable carbon isotope values became much more negative,andβ-sheet in minerals disappeared.Higher calcium concentrations facilitated ferric ion precipitation,while ferric ions hindered calcium precipitation.The immobilized bacteria performed better in ferric ion removal,with a precipitation ratio exceeding 90%.Free bacteria performed better in calcium removal,and the precipitation ratio reached a maximum of 56%.This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.展开更多
Arsenic(As)pollution in soils is a pervasive environmental issue.Biochar immobilization offers a promising solution for addressing soil As contamination.The efficiency of biochar in immobilizing As in soils primarily ...Arsenic(As)pollution in soils is a pervasive environmental issue.Biochar immobilization offers a promising solution for addressing soil As contamination.The efficiency of biochar in immobilizing As in soils primarily hinges on the characteristics of both the soil and the biochar.However,the influence of a specific property on As immobilization varies among different studies,and the development and application of arsenic passivation materials based on biochar often rely on empirical knowledge.To enhance immobilization efficiency and reduce labor and time costs,a machine learning(ML)model was employed to predict As immobilization efficiency before biochar application.In this study,we collected a dataset comprising 182 data points on As immobilization efficiency from 17 publications to construct three ML models.The results demonstrated that the random forest(RF)model outperformed gradient boost regression tree and support vector regression models in predictive performance.Relative importance analysis and partial dependence plots based on the RF model were conducted to identify the most crucial factors influencing As immobilization.These findings highlighted the significant roles of biochar application time and biochar pH in As immobilization efficiency in soils.Furthermore,the study revealed that Fe-modified biochar exhibited a substantial improvement in As immobilization.These insights can facilitate targeted biochar property design and optimization of biochar application conditions to enhance As immobilization efficiency.展开更多
基金Funded by the Fund of the Doctoral Program of Higher Ed-ucation( No.98049703)
文摘Immobilized cholesterol oxidase (COD) membrane with higher catalytic activity is important for biosensor. In this paper, several procedures for immobilizing COD based on cellulose acetate (CA) membrane are studied. Reasons causing different catalytic activities are also discussed.
基金The National Natural Science Foundation(Grant No.81373372)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20130001110059)
文摘It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis（ACE） to study receptor-ligand interactions or to screen natural products and compounds synthesized by combinatorial chemistry. In this paper, we developed a new method of immobilizing HEK293 cells on the inner wall of a capillary column. Four important experimental conditions were optimized, including cell injection density, PLL concentration, cell culturing time and sterile processing method. Immobilized cell-coated capillary columns prepared under the optimized experimental conditions exhibited good uniformity, stability and durability, which were suitable for capillary electrophoresis. The method could also be used to immobilize HEK293 cells over-expressing certain membrane receptors on the inner wall of a capillary. In this way, cell-coated capillary columns could be applied to ACE drug screening targeting certain membrane proteins.
基金supported by the National Natural Science Foundation of China(No.20564002)the State Key Program of Fundamental Research(No.2004CCA05900).
文摘The hydrophilic, macroporous and beaded ternary copolymer of glycidyl methacrylate （GMA）/methacrylamide（MA）/N,N＇-methylene-bis（acrylamide）（MBAA）was synthesized using the industrial agents by inverse suspension polymerization. The apparent activity of the immobilized penicillin G acylase reached 1096 IU/g for hydrolysis penicillin G on the beads with diameter of 0.11-0.13 ram, and it changed hardly after 50 cycles. It can be expected to be a good potential in industrial application,
基金supported by the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-18-073A1)the National Major Science and Technology Program for Water Pollution Control and Treatment of China(No.2015ZX07205-003).
文摘Soil contamination by heavy metal(loid)s is a considerable environmental concern,and immobilization is a promising way to reduce toxicity.In recent years,modified/engineered biochars have gained enormous attention for their use in soil remediation,and various studies have reported notable results from their application and their ability to immobilize heavy metal(loid)s.In this review,a summary of publications on the utilization of modified biochars is presented to address the heavy metal(loid)threat in soils.Various modified/engineered biochars were described from the review of relevant publications.Modification causes great changes in biochar surface chemistry,such as increases in pore volume,surface functional groups,and metal binding sites,which can be observed through various analytical techniques,including Brunauer-Emmett-Teller,X-ray photoelectron spectroscopy,X-ray diffraction,Fourier transform infrared spectroscopy,and magnetism.Such analytical approaches elucidate immobilization mechanisms of adsorption,precipitation,surface complexation,and cation exchange between biochar and metal(loid)ions.In addition,the performance of biochar in remediating heavy metal(loid)s also leads to considerable improvements in soil conditions.Additionally,many factors that influence metal(loid)immobilization by biochar in soil,such as pH,redox potential,microorganisms,and climate regime,are highlighted.Finally,this paper emphasizes that using modified biochars as an immobilizing agent for remediation of heavy metal(loid)-polluted soils is promising and would be practicable if a comprehensive mechanism of their long-term stability in soil is well elucidated.
文摘Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.
基金supported by Gyeongsang National University Grant in 2020–2021。
文摘In trace metal (TM)-contaminated agricultural soils,management of TM availability is important for safe crop production.In addition,maintenance or improvement of soil quality is vital for sustainable crop cultivation.Decreased TM phytoavailability and increased soil quality can be achieved by the application of various immobilizing agents to soil,which can supply both macronutrients and organic matter.This study investigated the long-term influences of four common immobilizing agents on soil biogeochemical properties and the phytoavailability of TMs in mixed metal-contaminated soil from a cultivated upland near an abandoned mining site.Lime (L),gypsum (G),fly ash (F),and animal manure-based compost (C) were applied to pots containing contaminated soil,either individually or in combination.After incubation for three years under sequential cultivation of two crops and fallow,soil biogeochemical properties were determined,and Brassica rapa plant bioassay was performed.The phytoavailability of all TMs (both cationic metals and anionic metalloids) remained significantly lower in soils treated with immobilizing agents even after three years,when compared with the no-agent control (CK) soil.In addition,the soil quality was significantly improved by treatment with immobilizing agents.For instance,the C and L+C treatments were the most effective in improving soil physical (bulk density,porosity,and water-resistant aggregate stability),chemical (pH,organic matter,total nitrogen,cation exchange capacity,and plant-available phosphorus,magnesium,and potassium),and biological (microbial biomass carbon and dehydrogenase activity) properties.The improvement of soil properties and lowering of TM bioavailability were also consistent with the most significant increase in B.rapa biomass production observed in the C treatment,followed by the L+C,G+F,L,G,F,and L+G treatments,as compared with that in CK.These results indicate that the function of the TM-immobilizing agent as a soil quality conditioner,in addition to its TM immobilizing effect,should be considered when selecting such agents for agricultural or ecological applications.
文摘For solving the radioactive waste storage problem, there is an idea to store immobilized waste at deep sea. Solidifier material, such as cement should be resistance to saline environment for deep sea storage. So, this research objective is to study the performance of cementation method in immobilizing strontium waste in saline environment. Research was conducted by immobilizing strontium waste using Portland pozzolanic cement, white cement and composite Portland cement. Cement, 65 ppm Sr(NO3)2, sand and water were mixed and cast. Strontium waste varied in 2 v/o, 4 v/o, 6 v/o and 8 v/o. After 28 days curing, the cement block’s compressive strength and leaching rate on saline water were analyzed. Determination of compressive strength was done by using Universal Wood Testing. The density of blocks was measured by picnometer at 25°C. Compressive strength test for Portland pozzolanic cement at various w/c was conducted to confirm the effect of w/c in increasing the strength. For testing strontium leaching rate in water containing 35 ppm NaCl, cement blocks have been immersed in saline water for 21 days. 25 ml samples were taken and analyzed by Atomic Absorption Spectrophotometer. Strontium leaching rate on block containing pH 9 of waste was compared to the previous research data of strontium leaching rate on water to know the effect of saline water. To adjust the pH, 1 MNaOH was added into the waste. Effects of various cement type and filler materials (sand, zeolite and baryte) on Portland pozzolanic cement were also compared. The results show that there were almost no effects of salt on immobilized strontium waste, except in pH 9 waste (0.00224 over to0.000199 g/cm2·days). Strontium leaching rates on all cemented waste still meet the IAEA’s standard, so the safety of cemented strontium waste disposal at saline environment could be ensured.
基金supported by the National Key R&D Program of China[grant number 2022YFC2104904]Major Science and Technology Innovation Projects in Dezhou City,Shandong Province[grant number DZJBGS-2022-0010-2]the Shandong Province Key R&D Program[grant number 2022CXPT018].
文摘D-allulose,a low-calorie rare sugar,can be biosynthesized by D-allulose 3-epimerase(DAE).Here,DAE was covalently immobilized on polyethyleneimine-modified diatomite using two methods:a biopolymer coating approach(DAE@PEI-GA@PDP)and a direct attachment method(DAE-GA@PEI@PDP).Both immobilized DAE enzymes exhibited enhanced thermal stability and broader pH tolerance compared to the free DAE.They also exhibited excellent reusability and maintained more than 70%of their activity after 10 cycles.Additionally,a multienzyme cascade system was developed to produce D-allulose from low-cost D-glucose using immobilized glucose isomerase(GI)and immobilized DAE enzymes.This system obtained 76 g/L D-allulose from 500 g/L Dglucose.Notably,the application was extended to fruit tea drinks,successfully transforming high-calorie sugars(D-glucose and D-fructose)into D-allulose.This research offers a promising immobilization strategy for DAE on silica-based materials and provides robust biocatalysts for creating functional fruit tea drinks aimed at diabetics and individuals with specific dietary needs.
基金supported by the Natural Science Foundation of Shandong Province(Nos.ZR2023MB139,ZR2023QB057)the Key R&D Projects of Linyi City(2022022)。
文摘The combination of photodynamic therapy(PDT)and chemodynamic therapy(CDT)in tumor treatment has attracted considerable attention.However,tumor hypoxia and glutathione(GSH)overproduction in the tumor tissue restricted the progress of their applications.Herein,a Mn-porphyrinic metal-organic framework(Mn-TCPP)was constructed by the one-pot method and further used for immobilizing glucose oxidase(GOx)to obtain GOx@Mn-TCPP.GOx would rapidly exhaust endogenous glucose into hydrogen peroxide(H_(2)O_(2))and gluconic acid,thus shutting off the energy supply of tumor cells for starvation treatment.Mn-TCPP catalyzed H_(2)O_(2)to produce oxygen,regulating the hypoxic tumor microenvironment and in turn improving^(1)O_(2)generation under laser irradiation.Interestingly,Mn-TCPP can reduce reactive oxygen species consumption owing to the redox reaction between Mn^(3+)and GSH,thus greatly enhancing PDT.Furthermore,benefiting from GOx-mediated starvation therapy,Mn^(2+)produced by Mn^(3+)reduction can react with sufficient intracellular H_(2)O_(2)to generate·OH with high cytotoxicity through a Fenton-like reaction.After treatment by GOx@Mn-TCPP under laser irradiation in vitro,the cell viability of 4T1 and A549 tumor cells reached to 20%,reflecting GOx@Mn-TCPP could give full play to the advantages of PDT/CDT/starvation therapy.The results in vivo demonstrated that GOx@Mn-TCPP mediated synergistic cascade therapy could significantly inhibit tumor growth and improve the therapeutic effect.
文摘Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hydrogen evolution with high efficiency and low cost,definitely hinder the practical application of photocatalytic hydrogen production from water.[Fe Fe]-hydrogenase,an excellent natural biological enzyme catalyst bearing unique organometallic clusters with noble-metal-free element,is most efficient in reducing protons to hydrogen and demonstrates remarkable turnover frequencies(TOF 6000–9000 s1 per active site)[2].
基金supported by the National Key Research and Development Project of China(Nos.2023YFC3709700 and 2024YFC3713800).
文摘Microbial degradation is the primary mechanism for purifying polycyclic aromatic hydrocarbon(PAH)contamination in environments,and biochar immobilization is an effective technology to enhance biodegradation,but the process parameters of the immobilization technology still require further systematic evaluation.Here,biochars derived from pig manure(PM),bamboo(BB),rice straw(RS),and soybean straw(SS)were used as carriers of Mycobacterium sp.ZL7,and the optimal biochar dosage of 1:30(w/V)and immobilization time of 24 h were determined.The immobilization effects followed the order of RS>SS>PM>BB.Scanning electron microscopy and physicochemical properties revealed that porous structures acted as shelters for bacteria,and high nitrogen content,large pore size and high-water holding capacity played important driving roles in immobilization.In the single-substrate system,pyrene removal rates of the PM-,RS-and SS-immobilized materials were greater than 96%,which were significantly higher than those of the biochar alone or the free strain.An orthogonal design experiment in historically PAH-contaminated soil further revealed that,compared with free strains,immobilized materials combined with high moisture content and moderate salicylic acid or Brij 30 can effectively increase the abundance of bacteria and the nidA gene,and enhance the dehydrogenase and polyphenol oxidase activities.The removal rate of total PAHs increased by 8.53%-30.45%after 24 d.Moreover,biochar with strong immobilization capacity showed better PAH removal effects.This study provides a scientific basis and practical reference for biochar-immobilized microorganisms to enhance the self-purification of PAH-contaminated soil.
基金support for carrying out this work was provided by the Doctoral Research Foundation of Weifang University(2024BS20)Science and Technology Development Plan Foundation of Weifang(2024GX017).
文摘Photocatalytic nitrogen fixation (PNF) is a promising alternative to the Haber-Bosch process.It achieves green ammonia production by utilizing solar energy for nitrogen fixation under mild conditions.While nanoscale photocatalysts offer enhanced performance due to their high surface area and abundant active sites,their small size makes them difficult to recover and prone to agglomeration.These bottlenecks severely limit industrial application.A promising solution is to immobilize the catalysts onto support surfaces.This paper provides a systematic review of recent advances in the design of immobilized photocatalysts for ammonia synthesis.It begins by outlining the key benefits of immobilization strategies,particularly in improving catalyst stability,recyclability,and overall photocatalytic performance.The working mechanisms and features of various immobilization techniques are then categorized and explained,covering physical adsorption/deposition,chemical bonding,in situ growth,and hybrid physico-chemical methods.Supported materials and common substrate types are also summarized.Furthermore,the widely used configurations of photoreactors suitable for immobilized systems are introduced.Finally,the review identifies current research limitations and challenges,and offers perspectives on future developments in the field of immobilized photocatalysis.
基金the Science and Technology R&D Major Project of Jiangxi Province(No.20244AFI92001)the National Natural Science Foundation of China(Nos.22071033 and 21801047)for the financial supports.
文摘We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.
基金the Natural Science Research Initiation Fund Project of China West Normal University(No.23KE001)the National Natural Science Foundation of China(Nos.42407186,42277033,and 42171045)+1 种基金the Basic Research Foundation of Yunnan Province(No.202401AT070304)the Central Public-interest Scientific Institution Basal Research Fund(No.Y2024QC28)for their financial support。
文摘Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They effectively reduce the mobility and bioavailability of heavy metals through various mechanisms such as adsorption,precipitation,and oxidation-reduction.This paper provides an in-depth exploration of the cuttingedge applications of various nanomaterials,including nanometallic,nano non-metallic materials,nanoclay and mineral materials,and nano modified biochar materials,in the remediation of heavy metal-contaminated soils.It specifically focuses on the key factors influencing the remediation efficacy of these nanomaterials,as well as the underlying remediation mechanisms and methods for performance optimization.The aims of this paper are to provide guidance for the further application of nanomaterials in the field of soil heavy metal remediation,and to offer insights that could promote the effective control of soil heavy metal pollution.
基金funded by research grants from the National Natural Science Foundation of China (32171135 and 32371168)。
文摘Purpose: This study aimed to explore the effects of a 10-week combined exercise regimen on immobilizationinduced muscle atrophy and elucidate the possible function of Protein arginine methyltransferase 1(Prmt1) in this process.Methods: 8-week-old male C57BL/6J mice were carried out combined exercise for 10 weeks. One week before the end of the intervention, mice underwent cast immobilization. Additionally, to investigate the potential mechanism in exercise-induced protection of skeletal muscle, mice in the exercise preconditioning group were administered TC-E-5003(an inhibitor of Prmt1 enzymatic activity). Exercise performance, muscle mass, and the cross-sectional area(CSA) of muscle fibers were analyzed. Besides, Prmt1 and Sestrin1(Sesn1) were either overexpressed or inhibited in C2C12 myotubes to elucidate the underlying mechanism.Results: Exercise preconditioning not only significantly improved muscle mass and motor ability in immobilized mice but also inhibited excessive activation of degradation pathways and enhanced protein synthesis. Importantly, Prmt1 mediated the protective effects of exercise preconditioning on muscle atrophy. Mechanistically,Prmt1 regulated the p38 mitogen-activated protein kinase(p38)/activating transcription factor 2(ATF2)pathway, which modulates Sesn1 expression. Sesn1 acts as a downstream of Prmt1 and ATF2, contributing to the myoblast differentiation and skeletal muscle regeneration through AMP-Activated protein kinase α2(AMPKα2)/transcriptional co-activator PPAR-γ co-activator-1 α(PGC-1α) signaling pathway.Conclusions: Taken together, our results highlighted the effectiveness of exercise preconditioning in preventing muscle atrophy via the Prmt1-Sesn1 pathway.
基金supported by the National Natural Science Foundation of China(No.32202158).
文摘Immobilized microalgae technologies(IMTs)involve the fixing of free-living microalgae onto specialized carriers through physical adsorption,chemical cross-linking,or biological interactions to enhance cell retention,metabolic stability,and stress resistance.These have emerged as multifunctional and sustainable platforms for environmental remediation,extending their applications beyond wastewater treatment to include soil and air purification.This review categorizes advanced IMT carriers into three major types:(1)inorganic engineered materials(e.g.,biochar-nanoparticle hybrids),(2)functionalized organic polymers(e.g.,pH-responsive hydrogels),and(3)bio-derived scaffolds(e.g.,fungal-algal and algal-bacterial consortia).They enhance microalgal retention,metabolic activity,and microalgal stress resistance,enabling the effective removal of nitrogen,phosphorus,heavy metals,organic pollutants,and airborne particulates across diverse environmental matrices.We highlight key cooperative mechanisms—such as extracellular polymeric substance(EPS)-mediated adhesion,quorum sensing,and metabolic synergy—that underpin pollutant removal and biomass stability.Particular emphasis is placed on integrating smart technologies,including magnetic microrobots,3D/4D-printed scaffolds,and AI-guided optimization,which improve the scalability,adaptability,and environmental responsiveness of IMT systems.By synthesizing the advances in materials science,microbial ecology,and environmental engineering,this review defines the future direction of research into IMTs as a next-generation bioengineering strategy for the integrated management of water,soil,and air pollution.
基金supported by the National Key R&D Program of China[grant number 2022YFC2104904]Major Science and Technology Innovation Projects in Dezhou City,Shandong Province[grant number DZJBGS-2022-0010-2].
文摘D-Allulose,a low-calorie functional sweetener popular among the obese population,can be biosynthesized using D-allulose 3-epimerase(DAE).However,there are currently no commercially viable immobilized DAE enzymes on the market for the large-scale production of D-Allulose.In this study,immobilizing the DAE enzyme was developed based on polymer-activated diatomite with surface enhancement using crosslinkers.Specifically,the amino groups of polyethyleneimine were successfully carried on the porous diatomite and then activated by glutaraldehyde to form a biopolymer coating.The obtained carrier was firmly covalently linked to the DAE enzyme via the Schiff-base reaction.The constructed immobilized DAE with a“core-shell”structure showed a high specific activity of 2088.93±9.85 U/g and an excellent conversion rate of 34.4%.This biocatalyst was stable within a wide temperature and pH range.It also showed outstanding thermal stability,the half-lives of the immobilized DAE were 109 and 124 times that of the free DAE at 55℃ and 60℃,respectively.Moreover,the immobilized DAE remained at about 81.33%of the initial enzyme activity after 8 recycles.The results of this study may contribute to the cost reduction of D-Allulose industrial production and provide a potential immobilized enzyme strategy for future large-scale manufacturing of D-Allulose.
基金Projects(2019NY-200,2020ZDLNY06-06,2020ZDLNY07-10)supported by the Key Research and Development Program of Shaanxi Province,ChinaProject(2019YFC1803604)supported by the National Key Research and Development Program of China。
文摘Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.
基金supported by the National Natural Science Foundation of China(Nos.42072136,41972108,and 42106144)the Natural Science Foundation of Shandong Province(Nos.ZR2023MD063,ZR2020MC041,and ZR2020QD089)+1 种基金the Key Laboratory of Marine Biogenetic Resources,Third Institute of Oceanography,Ministry of Natural Resources(No.SKDZK20230127)the Foreign visiting scholar funded by Shandong Provincial government.
文摘Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose amajor hazard in production.However,the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions.In this study,free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared,at the same time,biomineralizationmechanisms and mineral characteristicswere further explored.The results showthat bacterial concentration and carbonic anhydrase activitywere higher when additionally adding ferric ion based on calcium ion;the content of protein,polysaccharides,deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to control.Calcium ions were biomineralized into calcite and vaterite with mul-tiple morphology.Due to iron doping,the crystallinity and thermal stability of calcium carbonate decreased,the content of O-C=O,N-C=OandC-O-PO_(3) increased,the stable carbon isotope values became much more negative,andβ-sheet in minerals disappeared.Higher calcium concentrations facilitated ferric ion precipitation,while ferric ions hindered calcium precipitation.The immobilized bacteria performed better in ferric ion removal,with a precipitation ratio exceeding 90%.Free bacteria performed better in calcium removal,and the precipitation ratio reached a maximum of 56%.This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.
基金supported by the National Key Research and Development Program of China(No.2020YFC1808701).
文摘Arsenic(As)pollution in soils is a pervasive environmental issue.Biochar immobilization offers a promising solution for addressing soil As contamination.The efficiency of biochar in immobilizing As in soils primarily hinges on the characteristics of both the soil and the biochar.However,the influence of a specific property on As immobilization varies among different studies,and the development and application of arsenic passivation materials based on biochar often rely on empirical knowledge.To enhance immobilization efficiency and reduce labor and time costs,a machine learning(ML)model was employed to predict As immobilization efficiency before biochar application.In this study,we collected a dataset comprising 182 data points on As immobilization efficiency from 17 publications to construct three ML models.The results demonstrated that the random forest(RF)model outperformed gradient boost regression tree and support vector regression models in predictive performance.Relative importance analysis and partial dependence plots based on the RF model were conducted to identify the most crucial factors influencing As immobilization.These findings highlighted the significant roles of biochar application time and biochar pH in As immobilization efficiency in soils.Furthermore,the study revealed that Fe-modified biochar exhibited a substantial improvement in As immobilization.These insights can facilitate targeted biochar property design and optimization of biochar application conditions to enhance As immobilization efficiency.
