Rich Functional Groups Research Articles

Strong nestedness and turnover effects on stand productivity in a long-term forest biodiversity experiment.

Multispecies planting is an important approach to deliver ecosystem functions in afforestation projects. However, the importance of species richness vs specific species composition in this context remains unresolved. To estimate species or functional group richness and compositional change between two communities, we calculated nestedness, where one community contains a subset of the species of another, and turnover, where two communities differ in species composition but not in species richness. We evaluated the effects of species/functional group nestedness and turnover on stand productivity using 315 mixed plots from a pool of 40 tree species in a large forest biodiversity experiment in subtropical China. We found that the greater the differences in species or functional group nestedness and turnover, the greater the differences in stand productivity between plots. Additionally, the strong effects of both nestedness and turnover on stand productivity developed over the 11-yr observation period. Our results indicate that selection of specific tree species is as important as planting a large number of species to support the productivity function of forests. Furthermore, the selection of specific tree species should be based on functionality, because beneficial effects of functional group composition were stronger than those of species composition.

The facile preparation of polydopamine-modified sepiolite and its adsorption properties and microscopic mechanism for cadmium ion

Natural sepiolite (SEP) has the characteristics of cation exchange, abundant reserves, low cost, and environmental friendliness, but its adsorption capacity for heavy metal pollutants is limited. Because polydopamine (PDA) molecules contain rich functional groups such as phenolic and amino groups, in the present work, dopamine and natural sepiolite were utilized as raw materials to prepare polydopamine-modified sepiolite composite (SEP/PDA) by simple co-precipitation method. According to Langmuir isotherm model, the maximum adsorption capacity of SEP/PDA for Cd2+ can reach 203.21 mg/g at 298 K. At the initial concentration of 100 mg/L, the adsorption capacity was 2.9 times that of natural sepiolite. The composite material has good reusability and anti-cationic interference performance and has 100 % removal ability of low concentration Cd2+ in actual electroplating wastewater. Density Functional Theory (DFT) calculations were performed to obtain the electronic structure information. To elucidate the microscopic mechanism, molecular surface analyses, Interaction Region Indicator (IRI), Atom In Molecules (AIM) theory, Bond Order Density (BOD), and Electron Localization Function (ELF) were conducted. These analyses revealed that the amino nitrogen and phenolic oxygen atoms in the dopamine molecules donate lone pair electrons to coordinate with cadmium ions. Polydopamine, which possesses multiple oxidation states, contains catechol, quinone, and indole or a lesser extend pyrrole groups that can complex with cadmium ions, resulting in the formation of a surface complex. This coordination significantly enhances the adsorption properties of the SEP/PDA composite.

Laccase immobilized on amino modified magnetic biochar as a recyclable biocatalyst for efficient degradation of trichloroethylene

Bioremediation of trichloroethylene (TCE) contaminated groundwater has recently attracted considerable attention. In this study, laccase was immobilized on amino modified magnetic pine biochar (MBC-NH2) by adsorption-crosslinking-covalent binding method, and its application in the degradation of TCE was evaluated. MBC-NH2 was obtained from pine sawdust by calcination, magnetic modification and amino modification. MBC-NH2 had high specific surface area (71.3 m2/g), rich surface functional groups and good magnetism. Under the conditions of 25 °C, pH = 4, glutaraldehyde (GA) concentration of 7 %, crosslinking time of 1 h, laccase concentration of 0.75 mg/mL, and immobilization time of 7 h, the loading capacity of laccase on MBC-NH2 carrier was as high as 782 mg/g. Compared with free laccase, immobilized laccase showed higher pH stability and thermal stability, and its activity remained 48.5 % after being reused for 10 times, and 80.8 % after being stored at 4 °C for 30 days. The immobilized laccase exhibited a good degradation effect on TCE. At 25 °C, pH = 4, immobilized laccase concentration of 0.35 g/L, and initial TCE concentration of 10 mg/L, the degradation efficiency of TCE by immobilized laccase was as high as 92.1 % within 48 h. In addition, the degradation products of TCE were analyzed, and the results showed that immobilized laccase could degrade TCE into non-toxic products through epoxidation, hydroxylation, and dechlorination. The immobilized laccase biocatalyst prepared in this study can achieve efficient degradation of TCE, which provides a feasible solution for chlorinated pollution of water resources. These research results are of great significance for the synthesis of biocatalysts for the efficient degradation of chlorinated hydrocarbons.

Synthesis of porous functional biochar through template method and plasma modification for Pb2+ removal: Performance and mechanism

Rich pore structures and functional groups are crucial for adsorbents used for heavy metal removal. In this study, porous functional biochar from corn straw was synthesized using a zinc template method and plasma modification. The impact of synthesis and adsorption conditions on Pb2+ removal by porous biochar was investigated, and the mechanism was elucidated. The results demonstrated that porous biochar prepared at 600 oC, with a biomass-to-template ratio of 3:1, heating rate of 10 oC/min and further modification by steam plasma (60 kV, water vapor content of 1%, 5 min) achieved a remarkable Pb2+ removal efficiency of 90.94% in aqueous solutions, with an adsorption capacity of 87.2 mg/g. During adsorption, some Pb2+ was reacted with C-OH groups on the biochar to form Pb(OH)2, while the remaining Pb2+ was transferred to PbCO3 through reactions with ZnO in the biochar and soluble CO2 in water. This indicated that ZnO particles and C-OH functional groups generated through plasma modification and the template method on the surface of biochar were primarily responsible for Pb2+ removal. Both methods effectively enhanced the adsorption and removal performance of the biochar.

An eco-friendly approach for graphene nanoplatelets by innovative wet thermal expansion and liquid-phase exfoliation

Cost-effective synthesis of high-structural integrity graphene nanoplatelets (GNPs) remains a grand challenge. This study presents an innovative, environmentally friendly and efficient method for synthesizing high-quality GNPs by integrating wet thermal expansion with liquid-phase exfoliation. The thermal expansion of a wet graphite intercalation compound (GIC) in a semi-closed system improves the expansion effectiveness, minimizes the release of fine dust and improves the hydrophilicity of the resulting product. These improvements significantly enhance the effectiveness and efficiency of the subsequent liquid-phase exfoliation by shearing, which produces GNPs in pure water within 30 min with an overall productivity of 38.24 %. GNPs exhibit desirable properties, e.g. few layers (1–2 nm thick), large lateral dimension (a few microns), high sp2 hybridized carbon content (86 %), rich surface functional groups yet a low oxidation level (C/O ratio = 21.7 and electrical conductivity of ∼ 2055 S cm−1). The simplicity, adjustability and scalability of this method, combined with environmental friendliness, make it highly suitable for various applications and pave the way for further advancements in sustainable nanotechnology practices.

Application and Research Progress of Biochar in Environment Pollution Control

Biochar is a carbon-rich material with a wide range of raw materials, low cost, and environmental friendliness. It has a range of advantages such as high porosity and rich surface functional groups. Recently, the application of biochar to control environmental pollution and to improve soil quality have become increasingly widespread. To systematically summarize the application status, efficiency, shortage and development prospects of biochar in environmental pollution control, this article concludes the viewpoints from resent research of biochar materials in marine oil, soil pollution control and industrial wastewater, and made the prospect of biochar materials application in the environmental pollution control and remediation.

Construction of Chitosan-biochar/ZnO/NiO composites for efficient photocatalytic removal of Congo red and tetracycline

The combination of photocatalyst and biochar is an effective strategy to improve the overall photocatalytic activity, but it is still a challenge to find photocatalyst with excellent photocatalytic activity and biochar with large surface and rich oxygen functional groups. In this study, a novel CS-biochar/ZnO/NiO composite with adsorption-photocatalytic performance was constructed using chitosan as biochar source, and exploited for visible-light-driven photocatalytic degradation of tetracycline (TC) and Congo red (CR). The superior photocatalytic activity of CS-biochar/ZnO/NiO than pristine ZnO, NiO and CS-biochar/ZnO under visible light, and 63 %-CS/ZnO/NiO composite has the best photocatalytic activity. The photodegradation efficiency for CR was 94.5 % within 100 min, and the apparent rate constant (k) was 0.0206 min−1, which is about 1.87 and 3.89 times that ZnO and NiO, respectively. For TC, the photodegradation efficiency was 90 % within 45 min, and k was 0.0377 min−1, which is about 1.74 and 2.86 times that bare NiO and ZnO, respectively, which attribute to the synergistic effect between ZnO/NiO and CS-biochar improved the activity of photocatalysts. This work presents a straightforward approach for improving photocatalytic antibiotic and dye degradation through the construction of bifunctional "hybrid" material, which have great potential for application in the removal of contaminants.

Glycerol conversion and power generation in microbial fuel cells: insect exuviae biochar as electrodes and insect frass as biostimulants

Abstract Insects are a suitable raw material for refinement into biodiesel owing to their high fat content, but the refining process produces large amounts of insect waste and glycerol as a byproduct. Biochar electrodes were produced from insect waste for application in microbial fuel cells (MFCs), and experiments were performed to evaluate the electrochemical performance and glycerol conversion efficiency. The biochar was characterized by rich functional groups (O–H, O=C=O, C=C, C=O) and high microporosity, which favored the colonization of microbes. Among the electrode configurations considered, the optimal configuration was a biochar anode and carbon cloth cathode (B-MFC), showing the highest glycerol conversion efficiency (>95%). The B-MFC also exhibited the highest power density (122.3 mA/m3), 1.46-2.34 times that of the other MFCs tested. Adding Nitrogen-rich insect frass to the anode tank further stimulated microbial growth and increased power production, with the highest voltage output of 443.2 mV at 10 mg/L nitrogen concentration, 1.18 times higher than without addition. This study is the first to utilize insect exuviae as biochar electrodes in an MFC to solve the problems of excessive insect waste from biodiesel refinement and converting glycerol into a renewable energy source.

Optimization Design of the Multidimensional Heterostructure toward Lightweight, Broadband, Highly Efficient, and Flame-Retarding Electromagnetic Wave-Absorbing Composites.

A novel multidimensional electromagnetic wave-absorbing material was developed by combining carboxylated carbon nanotubes (CNT) with graphene oxide (GO) through multidimensional design, and cobalt/nickel-based metal organic frameworks (Co/Ni-MOF) were subsequently loaded onto the GO surface via its rich functional groups to form the composite absorbing material CNT-rGO-Co/Ni-MOF. Incorporating 25 wt % of CNT-rGO-Co/Ni-MOF into the paraffin matrix led to a remarkable RLmin value of -43 dB at 16.4 GHz, with an effective absorbing bandwidth (EAB) exceeding 4 GHz, all within a thickness of just 1.5 mm, showcasing its "lightweight, broadband, and high efficiency" characteristics. The exceptional electromagnetic wave absorption performance was attributed to multi-interface polarization loss, resistance loss, and magnetic medium loss. Furthermore, when incorporating 10 wt % of CNT-rGO-Co/Ni-MOF, the heat release capacity and peak heat release rate of EP/CNT-rGO-Co/Ni-MOF10 decreased by 59.2 and 52.6%, respectively.

Highly porous carbon with rich inherent groups for ultrahigh adsorption of organic dyes from wastewater

Activated carbon from renewable biomass or its waste to purify various dyeing wastewater from textile industry is highly desired. In this work, porous activated carbon was prepared by using silk waste as precursor via a simple one-step carbonization process. The obtained SWC-1-800 had ultrahigh adsorption for anionic dye AR73 and cationic dye MB owing to its ultrahigh specific surface area (2774 m2 g−1) and rich functional groups. SWC-1-800 had an increased adsorption capacity reaching 1310 and 928 mg g−1 for AR73 and MB respectively as the initial concentration up to 1000 mg L−1. Moreover, the adsorption capacity was stable under a wide range of Na+ and SDS concentration. By adjusting the temperature and pH value, the maximum adsorption capacity reached 1337 and 1000 mg g−1 for AR73 and MB respectively, keeping the removal rate of AR73 and MB more than 80 % after 5 adsorption cycles. Besides, SWC-1-800 demonstrated quite good adsorption ability for many other kinds of dyes, which adsorption capacity as high as 1998 mg g−1 (Rh B). The adsorption mechanism was further proposed according to the structural characteristics, inherent functional groups and adsorption properties. Using silk waste-derived carbon to effectively absorb the harmful dyes in the wastewater shows dual value for cleaner production via a “waste-waste to clean products” model, which has great application potential in dyeing wastewater purification.

Magnetic graphene oxide grafted boronic acid-decorated metal-organic frameworks for selective enrichment of cis-diol-containing nucleosides

In this study, a novel magnetic graphene oxide grafted boronic acid-decorated metal-organic frameworks (Fe3O4@GO@BA-MOF) composite was developed for the selective enrichment of cis-diol-containing nucleosides. It is noteworthy that the amino-functionalized Fe3O4 was prepared by polyethyleneimine (PEI) as modifier, resulting in excellent durability and stability of magnetic nanoparticles under different environment, as well as introducing rich active functional groups for post-modification. GO with large surface area and abundant multi-active group was covalently bonded on amino-rich Fe3O4 as interlayer to facilitate the growth of BA-MOF with high boronic acid grafting density for selective capture of nucleosides. Due to the multi-interactions, especially the boronate affinity as well as the synergistic effect, the Fe3O4@GO@BA-MOF composite exhibited superior selectivity and adsorption capacity to nucleosides. Under the optimal conditions, an efficient magnetic solid-phase extraction-high-performance liquid chromatography technique was established using Fe3O4@GO@BA-MOF composite for the purpose of extracting and detecting nucleosides in urine, with recoveries ranging from 90.69 % to 110.36 %, relative standard deviations below 8.5 % and detection limits ranging from 0.004 to 0.010 μg mL−1. This study offers a new approach for preparation of high grafting density of boronic acid-decorated magnetic MOF, which is promising in selective enrichment of cis-diol-containing compounds in biological analysis.

Natural insect-derived Nanoparticle: An ultra-bright and instantaneous Labeled signal tag for green and efficient Immunochromatographic assay of chloramphenicol

With the increasing international attention to environmental protection, higher requirements are put forward for green detection technology with simple preparation, sustainable material application, and efficient result output. Herein, we firstly proposed the natural insect-derived nanoparticle with ultra-bright and instantaneous labeling capability as a signal tag for stable and efficient immunochromatographic assay (ICA) to meet above challenges. The FDA-approved insect-extracted carmine (E120) nanoparticles (CANPs) were specifically regulated by pH changes to enhance dispersity and produce an ultra-bright color as signal tags. Notably, owing to the rich functional groups in CANPs, the CANPs-probe formed rapidly and efficiently (less than 1 min) to improve the reproducibility and precision, getting rid of the high cost and resources (9-fold reduction of mAbs). As proof of concept, the CANPs-based ICA strategy realized ultra-bright red bands on the test trip, without background within 15 min for chloramphenicol (CAP) detection, attained more than 457-fold improvements in LOD over classic AuNP-ICA and a 5-fold reduction in cost in each detection. Its excellent application potential has been verified in different natural waters with recoveries ranging from 91.93-126.45 %. This study reveals a promising strategy for green detection technology for antibiotics in natural water.

Innovative iron‑manganese modified microalgae biochar for efficient phosphate iron removal from water: Preparation and adsorption mechanisms

This study developed a novel FeMn composite biochar (FMBC) with the pyrolysis raw resource of Chlorella, applying for phosphates removal from the aqueous. Under optimal conditions, the FMBC prepared from microalgae achieved a phosphate removal rate of approximately 91.6 % (adsorption capacity: 23.23 mg/g) within 120 min, demonstrating superior adsorption performance compared to the pristine biochar. Response Surface Methodology (RSM) was applied for FMBC preparation optimization. To improve the metal loading capacity of biochar, Ethylene Diamine Tetraacetic Acid (EDTA) was used as a chelating agent during the preparation process. The optimum preparation conditions for FMBC were Fe/biomass(w/w) ratio of 1.25, Mn/biomass(w/w) ratio of 1.10, pyrolysis time of 120 min, and pyrolysis temperature of 650 °C, which presented a large specific surface area (14.681 m2/g), pore volume (0.036 cm3/g) with the rich oxygen-containing functional groups. Phosphorus removal kinetic and isotherm process were better described by pseudo-second-order model and the Dubinin-Radushkevinch (D-R) isotherm. In addition, the optimal adsorption conditions for FMBC were as follows: biochar dosage of 0.1 g, initial pH of 7.0, adsorption temperature of 25 °C, and initial phosphate concentration of 50 mg/L. Physical adsorption, surface complexation, precipitation, electrostatic attractions, and ion exchange were responsible for phosphate adsorption process by FMBC. The main innovation of this study is the use of explosive growth algae to prepare metal-modified biochar for phosphorus removal from water bodies, to realize the goals of resource utilization of waste biomass and eutrophication control in water, which are significant for sustainable development.

Enhancing aqueous zinc-ion energy storage performance with ion-mediating carbon quantum dots-modified separators regulating zinc deposition behavior

Aqueous zinc-ion batteries (AZIBs) hold promising applications owing to their safety, cost-effectiveness, and competitive capacity. However, issues such as zinc dendritic formation and side reactions severely impede their practical viability. Utilizing carbon quantum dots (CQDs) to modify cheap, tenacious, and highly hydrophilic filter paper (FP) as separator effectively improves the electrochemical performance of zinc ion energy storage systems. The structured arrangement of CQDs redistributes zinc ion transport and induces uniform zinc icon deposition, thereby improving zinc ion reaction kinetics. Moreover, the rich functional groups on the surface of CQDs readily form hydrogen bonds with active H2O, further inhibiting corrosion reactions. With the assistance of CQDs, the FP-CQDs separator maintains high ionic conductivity and a high zinc-ion transference number, ensuring dendrite-free and corrosion-resistant operation with high coulombic efficiency and a prolonged lifespan of 1200 h at 1 mA cm−2. Zn//AC hybrid capacitors incorporating FP-CQDs separator demonstrate superior capacity retention compared to those using FP separator alone, with a high capacity retention after 600 cycles at 1 A/g, while Zn//V2O5 full batteries also exhibit excellent cycling stability. Given these findings, this study presents a new composite separator for advanced aqueous zinc-ion energy storage systems.

Selective adsorption of methylene blue dye by a flocculation sludge-derived adsorbent prepared by carboxymethyl chitosan-based flocculants

The flocculation of dyeing wastewater generated a large amount of sludge that was often disposed as refractory hazardous waste. The resource utilization of flocculation sludge was of great significance in terms of low treatment cost of sludge, low environmental risk and high usage efficiency of reactive dyes. Herein, a flocculation sludge-derived (FSD) adsorbent was prepared via cross-linking of flocculation sludge yielding by carboxymethyl chitosan-based flocculants and dyes. FSD adsorbent had excellent selective adsorption performance for methylene blue (MB) treatment. The highest removal rate of MB and adsorption capacity of FSD adsorbent were 96.48 % and 354.7066 mg/g, attributing to its rich functional groups, negative charges and special micropore structure. FSD adsorbent owned the favorable regeneration efficiency and stability. Its removal rate of MB was still above 71.8 % after 6 regeneration-adsorption cycles. Its leaching rate of dyes was only 0.0016 mg/mg that was rather lower than common dried flocculation sludge. The adsorption processes of FSD adsorbent were complex in accordance with its characteristics, adsorption isotherms, adsorption kinetics and theoretical calculation. Multiple adsorption mechanisms were present in the treatment of dyeing wastewater by FSD adsorbent. The resource utilization of flocculation sludge, as adsorbents, was a potential candidate in field application.

Sudden change of fish functional compositions during a drought in the wet season of the middle Yangtze River, China

Climate anomalies such as drought may lead to cascading effects on river ecosystems, ultimately resulting in the change of aquatic biocenosis. Here, we investigated functional assemblies of fish communities at three sites below the Gezhouba Dam of the middle Yangtze River in China before and during a drought event from 2021 to 2022. As the drought proceeded, the richness of the fish functional groups decreased, and the abundance of demersal/invertivore species increased. These changes might indicate adaptive responses of fish communities to the reduction in water volume and shrinkage in habitat areas. The shifts in functional structure also caused fish communities to become more similar during the drought. The null model based on functional traits showed a distance effect of the fish community assembly rules. The communities close to the dam were structured more stochastically under drought stress, which may be attributed to the impact of ecological operation by cascade hydro-junctions. In contrast, the communities far away from the dam were structured by environmental filtering. Our results support the hypothesis that the natural hydrological regime is the main force driving the spatiotemporal dynamic of riverine fish assemblages, and the drought stress on fish communities may need more attention to cope with future biodiversity loss under global climate changes.

Analyzing Species Diversity in Rocky Intertidal Communities over Multiple Spatial Scales among Understudied Eastern Pacific Ecoregions

Many gaps in our theoretical understanding of the variations in the diversity and structure of intertidal communities exist for the Eastern Pacific. In order to fill some of these gaps, we censused intertidal communities and compared patterns of diversity on multiple spatial scales using several measures in alpha (α) and beta (β) diversities at twenty-one sites in a cold temperate, a warm temperate and a tropical Eastern Pacific ecoregion that were unique in terms of research effort and each with distinct geographic features. Diversity and richness on all spatial scales were compared using area curves, Hill numbers, ordination and cluster analyses, and the Hutcheson’s t-test with post hoc PERMANOVA, which revealed significant differences in diversity within and among ecoregions. Functional group and species richness and abundance were found to be highest in the cold and warm temperate ecoregions, and the functional group richness was second highest in the tropical Guayaquil ecoregion. The Bray–Curtis similarity method proved useful for determining patterns of small-scale intertidal zonation, while the Sorensen–Dice method suggested high indices of similarity in the functional group and subclass structures among all ecoregions.

Landscape crop diversity contributes to higher pollination effectiveness and positively affects rapeseed quality in Mediterranean agricultural landscapes

Pollination is crucial for biodiversity and food security. Heterogeneous agricultural landscapes have a positive effect on pollinator abundance and enhance crop production and quality. In this study, we explored the effects of three landscape features (past crop diversity measured as the Equivalent Richness of crop functional Groups in the previous year [ERGp], semi-natural habitat percentage [SNH], and mean field size [MFS]) and pollinator densities (wild bees [WB] and honey bees [HB]) on pollination and seed quantity and quality in rapeseed crops. Surveying the pollinator density in 20 rapeseed fields revealed a positive relationship with ERGp in the landscape. A pollinator exclusion experiment compared bagged and open-pollinated self-compatible rapeseed plants and revealed insect pollination effectiveness (fruits per flower and number of seeds per pod) and seed quality (oil content). Seed parameters were evaluated in relation to pollinator density (WB-HB) and landscape characteristics. The ERGp emerged as a crucial landscape feature that positively impacted WB density. When insect pollinators were excluded, plants exhibited reduced pollination effectiveness and seed quality. Analysis of open-pollinated plants highlighted ERGp as the most influential variable, positively affecting both sets of parameters. The MFS and SNH showed different but important relationships. Total tocopherol and α-tocopherol were positively correlated with pollinator density in HB, whereas WB showed a positive correlation with γ-tocopherol levels. Increased ERGp positively affected pollinator density and pollination effectiveness, thereby improving oilseed rape production quantity and quality. This study provides new insights into agroecosystem management and pollinator-friendly practices.

Hierarchically porous structure based on humic acid endogenous modified carbon electrodes for microbial electrochemical system energy recovery and electroactive biofilm conditioning

The microbial electrochemical system (MES) holds promise for in synchronously wastewater treatment and resource utilization, yet it is hampered by suboptimal electron transfer efficiency between the electrode and exoelectrogen. Generating highly active biofilms and facilitating efficient electron exchange at the anode-bacteria interface are critical for MES enhancement. Customization of electrode components and structure can be achieved through endogenous modification of the carbonizing precursor. Herein, we introduced oxygen-containing groups and heteroatoms into the carbon skeleton by doping with humic acid during the fabrication of phenolic-based carbon electrodes. This process was further refined by combining endogenous humic acid doping with controlled pore generation techniques using an anionic active agent and sacrificial templates, establishing a dual-channel optimization strategy for component and structural regulation. Consequently, the resulting sodium humic acid-modified porous electrodes (SHEs) exhibited superior wettability (48 ± 1.5°) and enhanced redox activity owing to their rich oxygenic functional groups. The hierarchical porous architecture and roughened surface texture of the SHEs contributed to their notable capacitance (1280 mF) and biocompatibility. Specifically, the SHEPS samples achieved the highest energy density of 4200 ± 48 mW m−2 and fostered a biofilm with Geobacter content of 78%. The synergistic interaction between exoelectrogens and non-exoelectrogens bolstered the electrochemical performance and stability of the biofilm. This study introduces a novel approach for the synchronous regulation of endogenous components and structure, guiding the design of high-performance, free-standing 3D electrodes for MES applications. These electrodes promote the development of highly electrochemically active biofilms and efficient energy capture, propelling MES towards practical implementation.

Phosphate adsorption characteristics of CeO2-loaded, Eucommia ulmoides leaf residue biochar

In this study, a Ce-loading biochar (Ce-BC) was synthesized by the optimal modification method of pre-pyrolysis impregnation, a pyrolysis temperature at 600 °C, and a CeCl3 concentration of 1.00 mol L−1 for efficient adsorption phosphorus (P) from wastewater. The results revealed that Ce-BC could achieve a maximum P removal rate of 100% under specific conditions: an adsorbent concentration of 2.00 g L−1, an initial solution pH of 3.00, an adsorption temperature of 25 °C, and an initial P concentration of 20.00 mg L−1. The adsorption process followed the quasi-secondary kinetic model, suggesting the Ce-BC was particularly effective in acidic environments. Meanwhile, Ce-BC has a strong resistance to anion interference and good cycling performance (the P adsorption capacity of Ce-BC was 59.77% of its initial value after four cycles). Field emission scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) indicated that Ce-BC contained a porous structure and rich functional groups (hydroxyl and carboxyl), and compounds of CeO2 and MgCeO3 were formed. The Ce loading favored the exchange with P through ligands, inner-sphere complexation, ion exchange, and electrostatic interaction to form inner-sphere complex-cerium P (CePO4), and the surface complex of Ce-O-P replaced O-H. In addition, the Ce-BC adsorption columns substantially affected P removal in actual wastewater. Overall, Ce-BC is a promising material for the treating P-containing acidic wastewater.