Interaction of Ca2+ and Fe3+ in co-precipitation process induced by Virgibacillus dokdonensis and its application.

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 a major 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, biomineralization mechanisms and mineral characteristics were further explored. The results show that bacterial concentration and carbonic anhydrase activity were 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 multiple morphology. Due to iron doping, the crystallinity and thermal stability of calcium carbonate decreased, the content of OC = O, NC = O and CO-PO3 increased, the stable carbon isotope values became much more negative, and ß-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.

Predicting the efficiency of arsenic immobilization in soils by biochar using machine learning.

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.

Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium.

Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened. The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II) and Mn(II) by Pseudomonas taiwanensis (marked as P4) and Pseudomonas plecoglossicida (marked as G1) contains rich reactive oxygen functional groups, which play critical roles in the removal efficiency and immobilization of heavy metal(loid)s in co-contamination system. The isolated strains P4 and G1 can grow well in the following environments: pH 5-9, NaCl 0-4%, and temperature 20-30°C. The removal efficiencies of Fe, Pb, As, Zn, Cd, Cu, and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system (the initial concentrations of heavy metal(loid) were 1 mg/L), approximately reaching 96%, 92%, 85%, 67%, 70%, 54% and 15%, respectively. The exchangeable and carbonate bound As, Cd, Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil, thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s. This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.

Immobilization of laccase on magnetic PEGDA-CS inverse opal hydrogel for enhancement of bisphenol A degradation in aqueous solution.

Endocrine disruptors such as bisphenol A (BPA) adversely affect the environment and human health. Laccases are used for the efficient biodegradation of various persistent organic pollutants in an environmentally safe manner. However, the direct application of free laccases is generally hindered by short enzyme lifetimes, non-reusability, and the high cost of a single use. In this study, laccases were immobilized on a novel magnetic three-dimensional poly(ethylene glycol) diacrylate (PEGDA)-chitosan (CS) inverse opal hydrogel (LAC@MPEGDA@CS@IOH). The immobilized laccase showed significant improvement in the BPA degradation performance and superior storage stability compared with the free laccase. 91.1% of 100 mg/L BPA was removed by the LAC@MPEGDA@CS@IOH in 3 hr, whereas only 50.6% of BPA was removed by the same amount of the free laccase. Compared with the laccase, the outstanding BPA degradation efficiency of the LAC@MPEGDA@CS@IOH was maintained over a wider range of pH values and temperatures. Moreover, its relative activity of was maintained at 70.4% after 10 cycles, and the system performed well in actual water matrices. This efficient method for preparing immobilized laccases is simple and green, and it can be used to further develop ecofriendly biocatalysts to remove organic pollutants from wastewater.

Electrochemical reconfiguration of iron-modified Ni3S2 surface induced oxygen vacancies to immobilize sulfate for enhanced oxygen evolution reaction.

There is an urgent need for highly active, durable, and low-cost electrocatalysts to overcome the shortcomings of high overpotential in the oxygen evolution reaction (OER) process. In this work, the nickel-iron hydroxysulfate rich in sulfate and oxygen vacancies (SO42-@Fe-NiOOH-Ov/NiS) is legitimately constructed. SO42-@Fe-NiOOH-Ov/NiS only requires a low overpotentials of 190 mV and 232 mV at 10 mA cm-2 and 100 mA cm-2 current densities in 1 M KOH, with excellent stability for 200 h at 100 mA cm-2 current density. In situ Raman spectroscopy and Fourier transform infrared spectroscopy demonstrated the stable adsorption of more SO42- on the surface of catalyst. Density functional theory calculations testify surface reconstruction, doped Fe and oxygen vacancies significantly reduced the adsorption energy of sulfate on the surface. More importantly, the formation of *OOH to O2 is facilitated by the highly hydrogen bonding between SO42- and *OOH, accelerating the OER process.

Removal of TBP sorbed on wood by Trametes versicolor through solid-state fermentation.

The use of white-rot fungi is a promising approach for removing organophosphate flame retardants (OPFRs) from wastewaters. Immobilization in wood for this purpose ensures the predominance of the fungus but also contributes to OPFRs sorption. This work focused on the ability of T. versicolor to degrade tributyl phosphate (TBP) sorbed in wood. This initially underwent ten sorption cycles, each involving exposure to a 10 mg·L-1 TBP solution. Throughout each cycle, the wood exhibited a sustained sorption capacity (0.035 ± 0.002 mg TBP·g. dry wood-1 per cycle). The wood residues obtained after each sorption cycle were inoculated with T. versicolor. After 60 days of inoculation, fungus degraded over 90 % of TBP in each cycle's wood residue. However, fungal growth was inhibited, resulting in a 43 % decrease in biomass compared to controls. The fact that biomass remained active and capable of degrading TBP suggests that the growth decrease is likely due to the formation of transformation products. An increase in toxicity units (from 13.64 to 87.86 at the end) was associated with the accumulation of 3-hydroxybutyl dihydrogen phosphate (OH-MBP). However, subsequent experiments demonstrated that given sufficient time, the fungus not only degraded OH-MBP but also produced a non-toxic effluent.

Polydopamine-modified 3D flower-like ZnMoO4 integrated MXene-based label-free electrochemical immunosensor for the food-borne pathogen Listeria monocytogenes detection in milk and seafood.

Listeria monocytogenes is a gram-positive bacterium that causes listeriosis in humans. This contaminates the ready-to-eat food products and compromises their safety. Thus, detecting its presence in food samples with high sensitivity and reliability is necessary. Herein, we propose a label-free electrochemical immunosensor based on a mussel-inspired polydopamine-modified zinc molybdate/MXene (PDA@ZnMoO4/MXene) composite for effective and rapid detection of L. monocytogenes in food products. Spectrophotometry approaches were employed to examine the resulting composites. Voltammetry and impedimetry techniques were used to confirm the step-by-step assembly of the immunosensor and its sensitive detection of L. monocytogenes in various food products, such as milk and smoked seafood. The results demonstrated the practicality of the constructed immunosensor, with an appreciable linearity of 10-107 CFU/ml and a reasonably low detection limit (LOD, 12 CFU/ml). Moreover, the immunosensor exhibited excellent selectivity for microbial cocktails and acceptable repeatability, reproducibility, and storage stability. Thus, we believe that the proposed sensitive, reliable, and label-free immunosensor based on the PDA surface modification technique for detecting L. monocytogenes can be extended to monitor various food-borne pathogens to ensure food safety.

Synergistic sodium alginate- and biochar-immobilized cells for enhancing fermentative hydrogen production from food waste.

An immobilized hydrogen-producing consortium investigated biohydrogen production from food waste using a combination of sodium alginate and cassava rhizome biochar. We investigated the effect of varying the biochar concentration from 0 to 3% and the size of immobilized cells from 1 to 7 mm. Immobilized cells were prepared using 50% (v/v) enriched hydrogen-producing consortium, 2% (w/v) sodium alginate, and 0 to 3% (w/v) cassava rhizome biochar. The optimal conditions for achieving the highest hydrogen production in the batch fermentation reactor were identified as a biochar concentration of 2% (w/v) and an immobilized cell size of 2 mm. The highest hydrogen yield, maximum hydrogen production rate, and lag time recorded were 0.69 mmol H2/g-COD, 0.02 mmol H2/g-COD.h, and 41.51 h, respectively. This research highlights the potential of cassava biochar technology for efficient biohydrogen production from food waste, contributing to renewable energy generation and sustainable waste management.

Filamentous fungal pellets as versatile platforms for cell immobilization: developments to date and future perspectives.

Filamentous fungi are well-known for their efficiency in producing valuable molecules of industrial significance, but applications of fungal biomass remain relatively less explored despite its abundant and diverse opportunities in biotechnology. One promising application of mycelial biomass is as a platform to immobilize different cell types such as animal, plant, and microbial cells. Filamentous fungal biomass with little to no treatment is a sustainable biomaterial which can also be food safe compared to other immobilization supports which may otherwise be synthetic or heavily processed. Because of these features, the fungal-cell combination can be tailored towards the targeted application and be applied in a variety of fields from bioremediation to biomedicine. Optimization efforts to improve cell loading on the mycelium has led to advancements both in the applied and basic sciences to understand the inter- and intra-kingdom interactions. This comprehensive review compiles for the first time the current state of the art of the immobilization of animal, yeast, microalgae, bacteria, and plant cells in filamentous fungal supports and presents outlook of applications in intensified fermentations, food and biofuel production, and wastewater treatment. Opportunities for further research and development were identified to include elucidation of the physical, chemical, and biological bases of the immobilization mechanisms and co-culture dynamics; expansion of the cell-fungus combinations investigated; exploration of previously unconsidered applications; and demonstration of scaled-up operations. It is concluded that the potential exists to leverage the unique qualities of filamentous fungus as a cellular support in the creation of novel materials and products in support of the circular bioeconomy.

Exploiting the synergistic influence of AgNPs-TiO2NPs: enhancing phytostabilization of Pb and mitigating its toxicity in Vigna unguiculata.

In this study, a composite of silver and titanium dioxide nanoparticles (AgNPs-TiO2NPs) was examined for its synergistic effects on phytostabilization of lead (Pb) and mitigation of toxicity in cowpea (Vigna unguiculata (L) Walp). Seeds of V. unguiculata were wetted with water, 0.05 and 0.1 mgL-1 Pb and 25 mgmL-1 each of AgNPs, TiO2NPs, and AgNPs-TiO2NPs. Root lengths of V. unguiculata were reduced by 25% and 44% at 0.05 and 0.1 mgL-1 Pb, respectively, while shoot lengths were reduced by 2% and 7%. In V. unguiculata, AgNPs and TiO2NPs significantly improved physiological indicators and mitigated Pb effects, with TiO2NPs modulating physiological parameters more effectively than AgNPs. The composite (AgNPs-TiO2NPs) synergistically regulated V. unguiculata physiology better than individual nanoparticles. Compared to individual AgNPs and TiO2NPs, the composite (AgNPs-TiO2NPs) synergistically increased antioxidant activity by 12% and 9%, and carotenoid contents by 88%. Additionally, AgNPs-TiO2NPs effectively reduced malondialdehyde levels by 29%, thereby mitigating the effects of Pb on V. unguiculata better than individual nanoparticles. AgNPs-TiO2NPs enhanced Pb immobilization by 57%, reducing its translocation from soil to shoots compared to V. unguiculata wetted with water. The bioconcentration and translocation factors of Pb indicate that phytostabilization was most effective when the composite was used.

A synergetic interaction between silver nanoparticles and titanium dioxide nanoparticles (AgNPs-TiO₂NPs) was investigated in this study for their capability to promote phytostabilization of Pb pollution in cowpea (Vigna unguiculata (L) Walp). This study shows a notable improvement in plant physiological indices, antioxidant activity, and the immobilization of Pb when AgNPs-TiO₂NPs are employed in synergy, as opposed to using them separately. Additionally, the study demonstrates how nanoparticles can synergize to enhance phytostabilization, offering promising prospects for sustainable phytoremediation strategies in the environment.

Co-immobilization of lipase and ß-galactosidase in gelatin-carboxymethyl cellulose blend films used as an active packaging component.

ß-Galactosidase and lipase were co-immobilized in polymeric blends of gelatin (GEL) and carboxymethyl cellulose (CMC) synthesized with different ratios of GEL/CMC: A (0GEL:100CMC), B (25GEL:75CMC), C (50GEL:50CMC), D (75GEL:25CMC), E (100GEL:0CMC). The films obtained good electrostatic interaction and a regular and uniform structure. The addition of CMC increased the mechanical resistance of the films, the tensile strength being 35.04 ± 0.10 MPa for A (0GEL:100CMC) films and 19.17 ± 2.44 MPa for E (100GEL:0CMC) films. Thermogravimetry (TG) showed that the addition of the enzyme decreases the thermal stability of the films. Film B (25GEL:75CMC) showed greater affinity with the added enzymes and greater thermal stability, in addition to increasing the crystallinity by up to 5.8 % and forming more transparent films. CMC was the most hydrophilic polymer, with higher moisture content (17.35 ± 1.73 %) and PVA (0.398 ± 0.047 g.mm/h.m2.kPa), higher still after the addition of enzyme (22.91 ± 1.06 % and 1.136 ± 0.087 g.mm/h.m2.kPa). The enzymes showed greater interaction with the bulky groups of CMC and the film with the highest concentration of this polymer was the one that presented the best hydrolysis rate of lactose and triglycerides, enabling the production of films.

Mortality risk factors for adult trauma patients treated with halo brace for cervical spine fracture.

INTRODUCTION AND OBJECTIVES: Halo braces treat upper cervical spine fractures and serve as the most rigid form of external immobilization. Recently, halo braces have lost favor due to known complications and advances in surgical stabilization. This study aims to determine the contemporary incidence for use of halo braces and identify risk factors associated with mortality in trauma patients undergoing halo brace for cervical spine fractures. MATERIALS AND METHODS: The 2017-2019 Trauma Quality Improvement Program Database was queried for patients ≥18 years-old with a cervical spine fracture undergoing halo brace. Patients sustaining penetrating trauma and severe torso injuries (abbreviated injury scale >3 for the abdomen or thorax) were excluded. Bivariate and multivariable logistic regression analyses were performed. RESULTS: From 144,434 patients with a cervical spine fracture, 272 (0.2%) underwent halo brace and 14 (5%) of these died. Those who died were older (73.5 vs. 53 years-old, p = 0.011) and had higher rates of hypertension (78.6% vs 33.1%, p < 0.001) and chronic kidney disease (14.3% vs. 1.2%, p < 0.001). Glasgow Coma Scale ≤8 (46.2% vs. 8.2%, p < 0.001) and cervical spinal cord injury (71.4% vs. 21.3%, p < 0.001) were more common in patients who died. In addition, those who died more often sustained respiratory complications (7.1% vs. 0.4%, p = 0.004) and sepsis (7.1% vs. 0.4%, p = 0.004). On multivariable logistic regression analysis, only Glasgow Coma Scale ≤8 (OR 19.77, 3.04-128.45, p = 0.002) was associated with increased mortality. CONCLUSIONS: Only 5% of cervical spine fracture patients undergoing halo brace died. Respiratory complications and sepsis were more common in those who died. On multivariable analysis only Glasgow Coma Scale ≤8 remained an independent associated risk factor for mortality.

Ionic liquid supported hydrogel-lipase biocatalytic systems in asymmetric synthesis of enantiomerically pure S-ibuprofen.

Novel hydrogel biocatalysts with immobilized lipase, stabilized by ionic liquids (ILs) of different hydrophobicity, were synthesized and evaluated. Variations of the time of immobilization and ratio of substrates during hydrogel synthesis were considered to obtain the most stable biocatalyst with the highest activity. Physicochemical characterization proved the success of the hydrogel synthesis and enzyme deposition on the surface of the support. Nevertheless, the key objective was to produce a biocatalyst for further application in ibuprofen methyl ester resolution, with the aim of obtaining an enantiomerically pure product. The hydrogel biocatalysts obtained in the presence of 5 wt% ILs after 8 h of immobilization achieved the highest activity recovery of 62 %. After 10 reaction cycles, enzymatic activity was still above 60 %, and the negative effect of pH and temperature on the activity of immobilized lipase was much lower than in the case of the free enzyme. After application of the catalyst in the resolution of ibuprofen methyl ester, the enantiomeric excess and conversion rate of the process were obtained for the dynamic kinetic resolution in isooctane. A conversion rate of 95 % was achieved due to the stabilization of the biocatalyst with IL and its resulting high catalytic activity. The study thus provides the pharmaceutical industry with a new potential approach with a strong scientific foundation.

Reclamation of co-pyrolyzed dredging sediment as soil cadmium and arsenic immobilization material: Immobilization efficiency, application safety, and underlying mechanisms.

The safe management of toxic metal-polluted dredging sediment (DS) is imperative owing to its potential secondary hazards. Herein, the co-pyrolysis product (DS@BC) of polluted DS was creatively applied to immobilize soil Cd and As to achieve DS resource utilization, and the efficiency, safety, and mechanism were investigated. The results revealed that the DS@BC was more effective at reducing soil Cd bioavailability than the DS was (58.9-73.2% vs. 21.8-27.4%), except for the dilution effect, whereas the opposite phenomenon occurred for soil As (25.5-35.7% vs. 35.7-42.8%). The DS@BC immobilization efficiency was dose-dependent for both Cd and As. Soil labile Cd and As were transformed to more stable fractions after DS@BC immobilization. DS@BC immobilization inhibited the transfer of soil Cd and As to Brassica chinensis L. and did not cause excessive accumulation of other toxic metals in the plants. The appropriate addition of the DS@BC (8%) sufficiently alleviated the oxidative stress response of the plants and enhanced their growth. These findings indicate that the DS@BC was safe and effective for soil Cd and As immobilization. DS@BC immobilization decreased the diversity and richness of the rhizosphere soil bacterial community because of the dilution effect. The DS@BC immobilized soil Cd and As via direct adsorption, and indirect increasing soil pH, and regulating the abundance of specific beneficial bacteria (e.g., Bacillus). Therefore, the use of co-pyrolyzed DS as a soil Cd and As immobilization material is a promising resource utilization method for DS. Notably, to verify the long-term effects and safety of DS@BC immobilization, field trials should be conducted to explore the effectiveness and risk of harmful metal release from DS@BC immobilization under real-world conditions.

Ultrastable hierarchically porous nucleotide-based MOFs and their use for enzyme immobilization and catalysis.

Immobilization of free enzymes facilitates their recovery and reuse, while also enhances their enzymatic characteristics. Hierarchically porous metal-organic frameworks (HP-MOFs) are promising candidates for enzyme immobilization. However, fabrication of HP-MOFs with more kinds of components as ligands is still a challenge. Herein, ultrastable crystalline MOFs with micro-, meso- and macroporous structure were constructed using guanosine 5'-monophosphate (GMP) as organic ligand through templated emulsification method. HP-MOFs crystals with the near rhomb-like, rod-like and slab-like morphology were interestingly obtained from Zn2+, Cu2+ and Cd2+ respectively. The HP-MOFs immobilized enzymes exhibited an enhanced enzymatic activity and stability. In addition, the immobilized CALB (Candida antarctica lipase B) showed great glycerolysis and esterification performances for glycerides preparation, with diacylglycerols (DAG) content over 60 wt% and triacylglycerols (TAG) content over 90 wt% obtained respectively from glycerolysis and esterification. Moreover, it retained 82.32 % of its initial glycerolysis activity after six cycles of reuse in glycerolysis. The present study will provide clues and show new horizons to explore new organic ligands for HP-MOFs fabrication, as well as to expand the applications of HP-MOFs and their supported enzymes.

Recent advances in immobilization of radioactive cesium and strontium-bearing wastes in alkali activated materials A review.

This review discusses recent advances in the use of alkali-activated materials (AAMs) to host high heat and radiation-emitting cesium (Cs) and strontium (Sr) wastes. It examines the evolution of geopolymerization, mechanical properties, mineralogy, microstructure, and leaching behavior of Cs-and/or Sr-bearing AAMs, considering their chemical interaction with Cs and Sr nuclides and exposure to temperature and gamma radiation induced by Cs and Sr. The literature indicates that Cs and Sr slightly degrade the mechanical properties of AAMs, with Sr having a more pronounced effect. For AAMs with a low SiO2/Al2O3 ratio, decay heat from Cs and Sr can crystallize zeolitic phases, which are beneficial in the short term but detrimental in the long term because of their low stability against gamma radiation. Cs was immobilized via ion exchange within the aluminosilicate phase and Sr mainly by precipitation, but the immobilization of their respective daughter nuclides Ba and Zr was not demonstrated. Gamma radiation exposure does not significantly alter AAM properties, and nitrates in Cs and Sr-bearing wastes reduce gamma-induced water radiolysis. AAMs are promising hosts for Cs and Sr-bearing wastes, but further studies are needed using realistic Cs and Sr waste loading to evaluate the synergistic effects of Cs and Sr chemical behavior, decay heat, and gamma irradiation on the evolution of properties of waste forms, and the ability of AAMs to accommodate daughter nuclides Ba and Zr.

Revolutionizing biocatalysis: A review on innovative design and applications of enzyme-immobilized microfluidic devices.

Integrating microfluidic devices and enzymatic processes in biocatalysis is a rapidly advancing field with promising applications. This review explores various facets, including applications, scalability, techno-commercial implications, and environmental consequences. Enzyme-embedded microfluidic devices offer advantages such as compact dimensions, rapid heat transfer, and minimal reagent consumption, especially in pharmaceutical optically pure compound synthesis. Addressing scalability challenges involves strategies for uniform flow distribution and consistent residence time. Incorporation with downstream processing and biocatalytic reactions makes the overall process environmentally friendly. The review navigates challenges related to reaction kinetics, cofactor recycling, and techno-commercial aspects, highlighting cost-effectiveness, safety enhancements, and reduced energy consumption. The potential for automation and commercial-grade infrastructure is discussed, considering initial investments and long-term savings. The incorporation of machine learning in enzyme-embedded microfluidic devices advocates a blend of experimental and in-silico methods for optimization. This comprehensive review examines the advancements and challenges associated with these devices, focusing on their integration with enzyme immobilization techniques, the optimization of process parameters, and the techno-commercial considerations crucial for their widespread implementation. Furthermore, this review offers novel insights into strategies for overcoming limitations such as design complexities, laminar flow challenges, enzyme loading optimization, catalyst fouling, and multi-enzyme immobilization, highlighting the potential for sustainable and efficient enzymatic processes in various industries.

Review on microwave immobilization of soil heavy metals: Processes and mechanisms.

Soil contamination with heavy metals (HMs) is still a global issue. The maintenance of long-term stability of HMs in soil during immobilization remediation is a challenge. Microwave (MW) technology can promote the immobilization of HMs in the form of crystals and minerals, thus enhancing their resistance of corrosion. This review provides a comprehensive introduction to the basics of MW irradiation through 177 papers, and reviews the research progress of MW involvement in the immobilization of soil HMs in 10 years. The effects of MW parameter settings, absorber/fixative types and soil physicochemical properties on immobilized HMs are investigated. The immobilization mechanisms of HMs are discussed, high-temperature physical encapsulation and chemical stabilization are the two basic mechanisms in the immobilization process. MW has a unique heating method to achieve efficient remediation by shortening remediation time, reducing the activation energy of reactions and promoting the transformation of stabilization products. Finally, the current limitations of MW in the remediation of HMs contaminated soils are systematically discussed and the corresponding proposed solutions are presented which may provide directions for further laboratory studies. There are still serious problems in taking the results obtained in the laboratory to the full scale. Thus, process optimization, scale-up, design and demonstration are strongly desired. In summary, this review may help new researchers to seize the research frontier in MW and can serve as a reference for future development of MW technology in soil remediation.

Preparation of highly stable immobilized Candida antarctica lipase B (CALB) through adjusting the surface properties of carrier: Preparation, characterization and performance evaluation.

The stability of the immobilized lipase is the key factor that determines the economy and feasibility of its industrial application. Here, two robust immobilized Candida antarctica lipase B (CALB) were prepared through adjusting the surface properties of ECR1030 resin. Silane coupling agent (SCA) and dialdehyde cellulose (DAC) were employed to modify the carrier surface. Contact angle measurement showed that the hydrophobicity of the modified carrier increased first, and then decreased with the increase of the chain length of SCA. FTIR results showed that Si-O-Si bond and aldehyde group were attached to ECR1030, respectively, indicating that the ECR1030 resin was successfully modified. Meanwhile, the NH and CN bond were observed in the corresponding immobilized CALB, suggesting CALB was immobilized onto the modified carriers. The effects of immobilization conditions on CALB immobilization was further investigated, and the C8-ECR1030-CALB and DAC-ECR1030-CALB with the activity of 12,736 U/g and 11,962 U/g were obtained. Moreover, the stability of the immobilized lipases was evaluated and compared with the commercial Novozym 435. The C8-ECR1030-CALB and DAC-ECR1030-CALB exhibited comparable or superior stability to Novozym 435 and showed better deacidification effect than Novozym 435. This study paves road for further study involving preparation of highly stable immobilized lipase.

Engineered biochars for simultaneous immobilization of as and Cd in soil: Field evidence.

Agricultural soil contamination by potentially toxic elements (PTEs) such as arsenic (As) and cadmium (Cd) poses a serious threat to food security. Immobilization serves as a widely used approach for the remediation of PTEs contaminated soils, nevertheless, the long-term effectiveness for the simultaneous immobilization of both cations and oxyanions remains a challenge. In order to effectively enhance the synergistic immobilization effect of soil As and Cd contaminated by multiple elements and improve the ecological environment of farmland. In this study, a typical polluted tailings area farmland was selected for situ immobilization experiments, and biochar was prepared from cow manure (CMB), rice straw (RSB), and pine wood (PWB) as raw materials. On this basis, the pristine biochar was modified with ferric chloride (F), potassium permanganate (K), magnesium chloride (M), and aluminum chloride (A), respectively. Furthermore, the immobilization effect of modified biochar on As-Cd and the stress effect on soil respiration were investigated. The results showed that CMB and RSB reduced the bioavailability of heavy metals, potassium permanganate has strong oxidizing properties, and the strong oxidability of potassium permanganate stimulated the generation of more oxygen-containing functional groups on the surface of biochar, thereby enhancing the adsorption and complexation effect of modified materials on As and Cd. Among them, the extracted Cd concentration of Diethylenetriamine pentaacetic acid (DTPA) in KCMB and KRSB in 2020 decreased by 8.23-43.12% and 9.67-35.29% compared to other treatments, respectively. Meanwhile, the KCMB and KRSB treatments also reduced the enrichment of As and Cd in plant tissues. In addition, the dissolved organic carbon (DOC) content in KCMB treatment was relatively high, and the carbon stability of the material was weakened. Simultaneously, the soil respiration emission of KCMB treatment was increased by 5.63% and 11.93% compared to KRSB and KPWB treatments, respectively. In addition, the structural equation also shows that DOC has a large positive effect on soil respiration. In summary, the KRSB treatment effectively achieve synergistic immobilization of As-Cd and provide important guiding significance for green and low-carbon remediation of polluted farmland.