High Removal Efficiency Research Articles

Environmental Catalysis for NOx Reduction by Manipulating the Dynamic Coordination Environment of Active Sites.

Nowadays, it is challenging to achieve SO2-tolerant environmental catalysis for NOx reduction because of the thermodynamically favorable transformation of reactive sites to inactive sulfate species in the presence of SO2. Herein, we achieve enhanced low-temperature SO2-tolerant NOx reduction by manipulating the dynamic coordination environment of active sites. Engineered by coordination chemistry, SiO2-CeO2 composite oxides with a short-range ordered Ce-O-Si structure were elaborately constructed on a TiO2 support. A dynamic coordination environment of active sites is demonstrated from a Ce-O-Si local structure to a low-coordinated Ce-SO42- species in the presence of SO2. The low-coordinated Ce-SO42- species as new active sites maintain a high NO removal efficiency by preserving the good adsorption and activation capacity of NO and NH3 reactants. This work proposes a new notion to improve the SO2 resistance of catalysts by regulating the coordination environment of sulfated active sites, which is of significance for SO2-tolerant environmental catalysis in practical applications.

Engineered alginate-polyethyleneimine and sludge-aluminosilicate biochar composites for greywater treatment: Performance evaluation and models for designing pilot-scale systems.

Greywater, originating from kitchen sinks and toilets, constitutes 75-80 % of the domestic wastewater produced in homes and can be reclaimed for non-potable uses. This study synthesized novel sludge-derived aluminosilicates and alginate-polyethyleneimine (PEI) biochar composites. The aluminosilicates offer a sustainable approach to sludge management, while alginate-polyethyleneimine presents a green biochar modification approach. Their performance in fixed bed columns for treating greywater was compared with zinc chloride, calcium alginate, and PEI-biochar composites. The CatBoost machine learning algorithm also predicted contaminant removal efficiency and breakthrough parameters. The morphological and chemical analyses showed that the modification techniques improved the physiochemical properties of the biochar, which in turn influenced contaminant removal efficiency. With its enhanced surface area and pore structure, zinc chloride-biochar demonstrated notable effectiveness in removing organic matter (highest COD removal efficiency 96.1 %). PEI-biochar exhibited a high removal efficiency for nitrates (highest value of 95.5 %), attributed to the positive amine groups. Aluminosilicate-biochar was the most effective at removing ammonium due to its high cation exchange capacity. The CatBoost algorithm successfully stimulated E. coli, total nitrogen, COD removal efficiencies, and breakthrough parameters from greywater using biochar (R2 > 0.7). Future research should conduct a pilot-scale study for this technology, explore the use of modified biochar arranged in multilayers for treating greywater, use of biochar for removing emerging contaminants in greywater, and optimize predictive models for greywater treatment. The insights from our study provide valuable guidance for effective and sustainable greywater treatment.

Defect-rich Co/N-doped hierarchically porous carbons for rapid and highly efficient adsorption of organophosphorus pesticides from environmental water.

Organophosphorus pesticides (OPPs) severely pollute various environmental water due to their excessive use, and it is extremely urgent to develop novel adsorbents with high adsorption capacities, rapid removal rate and easily recovery for the removal of OPPs. In this study, defect-rich Co/N-doped hierarchically porous carbons (Co/N-DHPCs) were constructed by pyrolyzing acid-etched ZIF-67 precursor. The developed Co/N-DHPCs possessed rich defects, well-developed hierarchical porous structure, high specific surface area and excellent magnetic property, and exhibited large adsorption capacities of 103.81∼126.10 mg g-1 and high removal efficiencies of 94.06 %∼100.00 % for fenitrothion, fenthion and phosalone within 15 min. The exceptional adsorption performance of Co/N-DHPCs could be attributed to the pore-filling effect, hydrophobic and π-π interactions, as well as the new active sites formed by rich defects and N heteroatoms doping. In addition, the magnetic property of Co/N-DHPCs enabled rapid and straightforward separation from aqueous solution. The Co/N-DHPCs also showed good reusability with removal efficiencies of 85.24 % after five consecutive recycles. Furthermore, the developed Co/N-DHPCs demonstrated remarkable removal efficiencies of OPPs in seven environmental water samples, particularly in high-salt seawater. This work provides a kind of reliable adsorbents for removing pollutants in environmental water.

Electrosynthesis of Silane-Modified Magnetic Nanoparticles for Efficient Lead Ion Removal.

The removal of heavy metal ions, such as lead (Pb2+), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb2+ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe2O3) phase. IONPs were characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). A novel electrochemical method was developed for the silanization of IONPs using tetraethoxysilane (TEOS), (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES). The resulting silane-modified IONPs were evaluated for the magnetic removal of Pb2+ ions, with TEOS-modified IONPs demonstrating superior performance. This material exhibited a high adsorption capacity of 519 mg/g at a Pb2+ ion concentration of 300 ppm, and high removal efficiency across a range of Pb2+ ion concentrations, attributed to its Fe2O3@SiO2 core-shell structure. This study highlights the potential of the electrochemical synthesis and silanization of nanoparticles for heavy metal remediation in water.

Influencing Factors and Purification Performance of a Negative Ion Air Purifier for Indoor Ammonia Gas Removal

The negative ion air purifier (NIAP) has been used for capturing particulate matter. Nevertheless, the knowledge on its effectiveness in removing other air pollutants such as ammonia gas remains limited. In this study, the effect of an NIAP for indoor ammonia gas removal was evaluated through a series of experimental studies. The applicability and different influencing, operating, and environmental factors on the ammonia gas removal performance were firstly investigated by conducting a series of experiments. Then, in order to understand the performance of the NIAP and the spatial distribution of ammonia gas and other by-products, indoor field measurements of ammonia gas, ozone, and negative ion concentrations in a real bathroom were performed for different cases with the NIAP turned on and off. The results indicated that negative ions were effective in reducing ammonia gas concentration. The operating and environmental factors including upstream wind speed, degree of operating voltage, and initial ammonia gas concentration have great influences on the ammonia gas removal efficiency of the NIAP. The highest removal efficiency can reach to 95.8%, when the upstream wind speed was 0.8 m/s and the degree of operating voltage was at gear 3 (3.0 kV). The purification efficiency of ammonia gas for the NIAP could reach up to 80%.

Development of New Biosorbent Based on Crosslinked Chitosan Beads with High Brilliant Blue FCF Removal Efficiency.

Effluents containing synthetic anionic dyes can pose a risk to ecosystems, and they must be treated before their release to the environment. Biosorption, a simple and effective process, may be a promising solution for treating these effluents. In this work, chitosan beads were crosslinked with epichlorohydrin to produce a highly stable and performant biosorbent to remove Brilliant Blue FCF dye. The biosorbent was characterized by determining the functional groups on its surface, as well as its elemental composition, crystallinity, and surface morphology. Crosslinking with epichlorohydrin significantly improved the biosorption capacity of chitosan beads. A maximum biosorption capacity of 600 mg/g corresponding to 99% removal efficiency was observed at pH 3.0, a biosorbent dose of 0.5 g/L, an initial dye concentration of 300 mg/L, a contact time of 10 h, and a temperature of 323 K. The biosorption of Brilliant Blue FCF dye in chitosan beads crosslinked with epichlorohydrin was well described by the Langmuir isotherm and followed an adsorption kinetic of pseudo second order. The thermodynamic parameters indicate a spontaneous biosorption process. The presence of anions such as NO3- and SO42- could interfere with the biosorption of Brilliant Blue FCF on the chitosan crosslinked beads, but Cl- did not interfere in biosorption process. Over three biosorption/desorption cycles, the biosorbent showed a removal efficiency of 97% and a desorption rate of over 98%. Chitosan is available worldwide and is a low-cost biomaterial, presenting high potential to be used as a biosorbent to treat industrial effluents containing anionic compounds, such as dyes.

Composite Treatment Module for Removing Acidity and Metal (Loid)S from Acid Rock Drainage

This study evaluates a two-stage approach for remediating acid rock drainage (AMD) generated from an abandoned coal mine site. The method combines the adsorption and chemical precipitation properties of drinking water treatment residue (WTR) in a continuous flow-through fluidized filter bed with hydroponic phytoremediation using Vetiver grass to remove dissolved metal(loid)s. In the first stage, the filter demonstrated exceptionally high removal efficiencies for several metals, including up to 99.67% of Al (<1 mg/L), 99.46% of Fe (<2 mg/L), and 92.48% of As. Significant removal efficiencies were also achieved for Zn (69.24%) and Cu (62.85%). However, relatively low removal efficiencies were observed for Mn (12.50%), Ni (26.74%), and Co (21.36%). Additionally, the system effectively reduced acidity, increasing the pH from 2.67 to a near-neutral level of 6.13. The second stage, a 30-day Vetiver grass treatment, further reduced Mn concentrations by 56.9%, improving upon the limited Mn removal observed in the fluidized filter column. This underscores the complementary role of hydroponic phytoremediation in enhancing the overall metal removal process. This innovative and cost-effective system demonstrates significant potential for AMD remediation, achieving simultaneous removal of metal(loid)s and neutralizing acidity in contaminated mine water.

Optimizing biochar-based column filtration systems for enhanced pollutant removal in wastewater treatment: A preliminary study.

This study aims to test the efficiency of biochar-based substrates in removing chemical and bacteriological pollutants from wastewater and to determine the optimal percentage of biochar (BC) to implement for large-scale filters (e.g., constructed wetlands). So, a preliminary test was conducted on a lab column scale for wastewater treatment of decanted wastewater using column filtration systems (CFS) integrated with BC (BC-based CFSs) at different concentrations (0%, 10%, 25%, and 50%). The BC used here was produced from exhausted olive pomace (pyrolised at T 590°C, residence time of 2h and a heating rate of 10°C min-1). The results revealed that the BC incorporated into the CFS improved the efficiency of nitrogen species removal (total nitrogen (TN) 64-65%, total kjeldahl nitrogen (TKN) 75%-77%, organic nitrogen (ON) 78%-87%, and NH4+-N 57%-69%); phosphorus species (total phosphorus (TP) 39%-44%, PO43- 38%-42%); total and soluble chemical oxygen demand (TCOD (44%-56%), and SCOD (33%-51%) respectively); and total suspended solids (TSS) 87%-92%, compared to the control filter (CFS0). Bacteriological analysis focused on faecal bacteria indicators, including total coliforms (TC), faecal coliforms (FC), faecal streptococci (FS), as well as the pathogen Staphylococcus (SP) and total aerobic mesophilic flora (TAMF). The highest removal efficiencies were observed for CFS10. Based on this preliminary study, the efficiency of CFS in removing pollutants from wastewater is optimal with a small amount of BC (10%) from both water quality and economic points of view.

High-Efficiency Catalytic Ozonation Degradation of Ni Complex Wastewater Using Mn-N Codoped Active Carbon Catalyst.

With the rapid development of electroless nickel (Ni) plating industry, a large amount of Ni complex wastewater is inevitably produced, which is a serious threat to the ecological environment. Herein, a novel Mn-N codoped active carbon (Mn-N@AC) catalyst with high catalytic ozonation ability was synthesized by the impregnation precipitation method and was characterized by BET, XRD, Raman, SEM, FTIR, and TPR. Meanwhile, Mn-N@AC showed excellent catalytic ozonation ability, stability, and applicability. When Ni-EDTA (TOC = 400, Ni = 58.05 mg/L) was used as simulated wastewater, the removal efficiency of TOC and total Ni reached 97.8 and 92.7%, respectively, and after three cycles, the TOC removal efficiency was still up to 93.6%. When Ni-EDTA wastewater was replaced with Ni-citrate, Ni-tartaric, and Ni-malate, the TOC removal efficiency remained above 93%. In addition, mechanistic insights by quenching experiments and EPR verified the high removal efficiency of TOC mainly attributed to indirect oxidation of ·OH and ·O2-, and the potential mechanism was proposed. The work provides insights into the deep removal of Ni complex wastewater by catalytic ozonation with low cost and high efficiency.

A Review of Sources, Hazards, and Removal Methods of Microplastics in the Environment

The prevalence of microplastics in a wide range of environmental media has attracted increasing attention worldwide. This review article provides a comprehensive and systematic review of the nature, sources, hazards, and removal methods of microplastics in the environment. In contrast to previous studies focusing on the sources and risks of microplastics in a single environment, this article comprehensively analyses atmospheric, terrestrial runoff, marine and freshwater sources of microplastics and explores the hazards they pose to the environment and the health of humans and other organisms. Microplastics cause multiple adverse effects on aquatic and terrestrial organisms through accumulation, including growth inhibition, oxidative stress, inflammation, organ damage, and germ cell abnormalities. They may also enter the food chain and affect human health. This article summarizes the latest research progress on microplastic removal technologies from biological, physical, and chemical perspectives, with high efficiency, sustainability, and degradability for biological removal and adsorption and filtration being more effective for physical removal. This provides valuable information for future research related to microplastics. We advocate for a reduction in the use of microplastics and provide references for solving the problem of microplastic pollution.

Experimental and ANN based process optimization for bioremediation of Cr6+ and Cd2+ by green adsorbent prepared from Artocarpus Heterophyllus leaves

The effective removal of toxic pollutants from water and waste water, is a challenging issue for environmental protection. In the present work, the performance of Artocarpus Heterophyllus (jackfruit) leaves have been examined for reduction of toxic Cr (VI) and Cd (II) from synthetic wastewater. Characterization of the adsorbent was made to evaluate the surface morphology and chemical composition, by Scanning Electron Micrograph (SEM) and Energy Dispersive Spectroscopy (EDS). Characteristic surface groups [Fourier Transform Infra-Red (FTIR)], surface area and surface structure [Brunauer–Emmett–Teller, (BET)] were also determined. The influences of various factors which control the removal process were studied experimentally in batch method and optimized. High removal efficiency was obtained at pH ≤ 2 for Cr (VI); and for Cd (II) it was ≥ 6. The experimental data were tested using different kinetic and isotherm models. Artocarpus Heterophyllus leaf was found suitable to remove 99.7 % Cr (VI) and 98.4 % Cd (II) from a strength of 20 mg L-1 solution at 0.5 g L-1 adsorbent concentration, at their respective favorable pHs. The reaction followed pseudo second order kinetic model for both the cases. The calculated sorption energy of 16.16 and 12.68 kJ mol-1, suggested chemical nature for both the cases. Desorption studies showed the effective reuse of Artocarpus Heterophyllus leaf for three times. The relatively high equilibrium adsorption capacity of 32.29 and 20.37 mg g-1 for Cr (VI) and Cd (II) respectively, suggested use of Artocarpus Heterophyllus leaf as a reasonably good green bio-adsorbent. The modeling of the complex adsorption process based on artificial neural network approach exhibited reliability and high degree of proficiency (R values of 0.999) in the model’s prediction and experimental data indicated its applicability in forecasting removal efficiency for both the metal ions.

High-performance cellulose acetate fibers-loaded Al[sbnd]ca layered double oxide adsorbents towards efficient elimination of anionic pollutants: Mechanism adsorption and RSM-CCD approach

In the present research, we investigate Congo red (CR) removal by layered double hydroxide and oxide AlCa on cellulose acetate (CA) fiber as anion-adsorbents in aqueous solution. The as-prepared composite was characterized by FE-SEM, XRD, FTIR, EDS-mapping and BET-BJH analyses. The CR adsorption ability on AlCa LDH/CA and AlCa LDO/CA adsorbents was evaluated. The removal property, dye adsorption and filtration properties of the AlCa LDO/CA composite were studied for removal CR based on central composite design (CCD) technique through investigating operational variables (temperature, adsorbent dosage, pH and contact time). The fabricated AlCa LDO/CA composite indicates a high removal efficiency up to 98.7 % for the CR removal in the 16 min. The data of the adsorption equilibrium were described by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms, and exhibited that AlCa LDH/CA fibers and AlCa LDO/CA fibers followed a pseudo-second-order kinetic model and Langmuir isotherm. The stability of Al-Ca-LDO/CA fibers nanocomposite was indicated that it was >95 % after eight cycles for removal of CR in the batch method on stirrer. The findings illustrated that appropriate AlCa LDO/CA fiber could be an efficient technique for CR elimination.

Odorant production surges induced by exogenous oxidative stress: An overlooked risk in PAA-based moderate preoxidation for algal-laden water.

Moderate preoxidation is feasible for odor-producing algae treatments, usually requiring trade-offs in algal removal and integrity maintenance. However, dosing oxidants may cause internal oxidative homeostasis imbalances and secondary odorous metabolite responses, adding new trade-offs for moderate treatments. Peracetic acid (PAA)/Fe processes are promising strategies in moderate treatments and thus were applied to examine how to achieve the following three trade-offs: good algal removal, no odorant increases and no releases. For algal removal, the highest removal efficiency was 71.1 %, 87.0 % and 98.1 %, respectively, in PAA/Fe(Ⅲ) separate, PAA/Fe(Ⅱ) separate and PAA/Fe(Ⅱ) simultaneous process. Odorant responses always followed a pattern of "promotion-low dosages, inhibition-high dosages", with the highest production reaching 3.91-fold of the control without PAA addition, well above odorant threshold concentrations (500 ng/L). Instant releases did not occur, yet with delayed releases observed during sludge retention in sedimentation tanks (5, 16 h). It was verified that exogenous oxidative stress stimulated odorant generation with multiple reactive species. Among them, PAA oxidant was crucial in algal removal and odorant promotion; R-O· and ·OH caused odorant generation and degradation, respectively. Overall, PAA/Fe(Ⅱ) processes were more suitable for moderate treatments, simultaneously avoiding odorant increases and allowing sludge retention. This work provides a novel perspective for moderate preoxidation, highlighting instant odorant generation and delayed releases triggered by exogenous PAA stressors.

High dye removal and H2O2 production efficiency of KOH-activated bagasse cellulose carbon aerogel-ZnO composite material

High dye removal and H2O2 production efficiency of KOH-activated bagasse cellulose carbon aerogel-ZnO composite material

Removal of phenol from water using fenchol-menthol hydrophobic deep eutectic solvent

Hydrophobic deep eutectic solvents (HDESs) are regarded as a potential green alternative to conventional organic solvents in separation processes such as liquid-liquid extraction, due to their favourable properties, such as lower vapour pressure and tunable properties. The present work investigated the application of HDES which is synthesised from fenchol and menthol, in the removal of phenol from water. The HDES was synthesised experimentally at a fenchol mole fraction range of 0.1 to 0.9. The experimental results showed that stable liquidus HDES was successfully formed when the fenchol mole fraction in the HDES was 0.2 – 0.9. Further investigation showed that HDES with a fenchol mole fraction of 0.2, which had a low viscosity and high stability in water, had the highest phenol removal efficiency. The phenol removal process was highly sensitive to solution pH and solution-to-HDES ratio. In contrast, phenol removal was less affected by initial concentration and temperature. A high phenol removal efficiency of up to 95.9% was achieved in this study, which further showed the positive feasibility of HDES to serve as an alternative to conventional organic solvents in the liquid-liquid extraction of phenol from water.

Assessing the aerobic/anoxic enrichment efficiency at different C/N ratios: pilot scale polyhydroxyalkanoates production from waste activated sludge

Polyhydroxyalkanoates (PHA) can be produced using fermentation products of an excess sewage sludge fermentation process. An efficient method to enrich a PHA-producing community is an aerobic-feast/anoxic-famine enrichment strategy. The effect of different carbon to nitrogen (C/N) feed ratios of 1, 2 and 3.5 g COD/g N on the process performance was studied. The study was executed on a pilot plant scale using fermented waste activated sludge as the organic carbon source. The system's performance was monitored in terms of removing contaminants, producing PHA, and reducing N2O emissions. The results indicated that a lower C/N ratio results in lower PHA production, with PHA content in the sludge of 20, 24 and 36 % w/w for C/N ratios of 1, 2 and 3.5 g COD/g N, respectively. At the lowest C/N ratio, the highest nitrite accumulation rate (77%), nitrification efficiency (89%) and denitrification efficiency (89%) were observed, but the N2O production was also the highest (0.77 mg N2O-N/L). The long-term comprehensive monitoring carried out in this study revealed high carbon and ammonia removal efficiencies (never below 80%) despite the C/N shifts and high COD and ammonia concentrations. At the same time, the system showed relatively low PHA production and high environmental impact in terms of high gaseous N2O emission. These findings question the sustainability of the aerobic-feast/anoxic-famine enrichment strategy for PHA production in full-scale plants.

Enhanced removal of sulfonamide antibiotics in water using high-performance S-nZVI/BC derived from rice straw.

Sulfonamide antibiotics (SAs) are widely used in the biomedical field but pose an environmental risk as ecotoxic pollutants. Developing eco-friendly methods to degrade SAs into harmless compounds is crucial. In this work, biochar (BC) was prepared from rice straw via pyrolysis and used to support S-nZVI, thereby forming the S-nZVI/BC composites. The results show high SAs removal efficiency (up to 98.3%) at optimal Fe/C and Fe/S molar ratios of 3:1 and 50:1, respectively, with strong tolerance to coexisting ions. Furthermore, the effectiveness of S-nZVI/BC(Fe3/C1, Fe50/S1) sample was validated using five real wastewaters, and the results showed consistent performance, stability and reusability. Mechanistic studies revealed that S-nZVI/BC synergized with persulfate to enhance the reactivity of sulfate-free radical (SO4-·) and Fe2+. The degradation pathways of SAs, involving electrophilic substitution and nucleophilic attack, were elucidated by density functional theory (DFT) calculations. These insights were instrumental in comprehending the degradation mechanism of SAs. Additionally, the degradation dynamics of ten SAs were further analyzed using quantitative structure-activity relationship (QSAR) models and principal component analysis (PCA). Hence, this work highlights the potential of S-nZVI/BC for industrial wastewater treatment, providing insights into the degradation mechanisms and pathways of SAs.

Multisite synergistic interaction induced selective adsorption of CB5-Ti3C2T2 complex for strontium ion: A combined theoretical and experimental study.

In this work, we use a well-defined water-soluble macrocyclic molecule cucurbit[5]uril (CB5) to modify 2D Ti3C2T2 MXene and assemble a novel high-performance adsorbent CB5-Ti3C2T2 for Sr ion by density functional theory and experimental methods. The structural stabilities of two distinct types of CB5-Ti3C2T2 (T = F, O and OH) complexes, i.e., CB5-Ti3C2T2(V) and CB5-Ti3C2T2(P) configurations are proved by binding energy and ab initio molecular dynamics (AIMD) simulations. Calculations of adsorption properties reveal that all the considered CB5-Ti3C2T2 complexes can act as efficient adsorbents for Sr ion, among which CB5-Ti3C2O2 complex possesses the best performance. The high affinity (the calculated adsorption energies < -7.6 eV) and selectivity of CB5-Ti3C2T2 complex for Sr ion are attributed to the synergistic effect between CB5 molecule and Ti3C2T2 MXene in the adsorption process, which arises from the multisite interactions of portal carbonyl groups of CB5 and surface functional groups of Ti3C2T2 towards Sr. Finally, CB5-Ti3C2T2 complex was successfully synthesized, and experimental results confirm its synergistic effect, good selectivity and high removal efficiency for Sr ions. In the treatment of strontium-containing wastewater with low concentrations, the distribution coefficient and decontamination factor of CB5-Ti3C2T2 for Sr were determined to be as high as 2.88 × 105 mL/g and 144.9, respectively, and the separation factor (SFSr/Ca) achieved a notable value of 67. 5. This work is expected to present a new strategy for the construction of high-performance MXene-based adsorbent for radionuclide elimination.

Magnetic nanoparticle modified moss Biochar: A novel solution for effective removal of enrofloxacin from aquaculture water.

The presence of residual antibiotics in water constitutes a potential threat to aquatic environments. Therefore, designing environmentally friendly and efficient biochar adsorbents is crucial. Aquaculture by-product moss (bryophyte) was transformed into biochar, which can eliminate antibiotics from wastewater through adsorption. This study successfully fabricated moss biochar (BC) and magnetically modified moss biochar (MBC), and explored their adsorption performance for enrofloxacin (ENR). Characterization analyses revealed that the specific surface area, total pore volume, and the quantity of functional groups of the MBC were significantly larger than those of the BC. The Langmuir isotherm model suggests that the maximum adsorption capacities of BC and MBC for ENR are 7.24mgg⁻1 and 11.62mgg⁻1. The adsorption process conforms to a pseudo-second-order kinetic model. Studies carried out at different temperatures disclose the spontaneous and endothermic thermodynamic characteristics of the system. Under neutral conditions, the adsorption efficiency attains its peak. The existence of various coexisting ions in water exerts a negligible influence on the adsorption process; furthermore, when the concentration of humic acid (HA) ranges from 0 to 20mg/L, the removal rate remains above 90%. In actual water samples, the antibiotic removal rate can be as high as 96.84%. After three cycles of reuse, the structure of MBC remains unchanged while maintaining a high removal efficiency. The primary mechanisms for antibiotic adsorption by MBC involve electrostatic interactions, hydrophobic interactions, pore-filling effects, hydrogen bonding, and π-π interactions. This reusable magnetic moss biochar provides a promising research direction for effectively eliminating antibiotics from water sources.

Insights into the effects of phenolic compounds on the growth of Chlorella vulgaris: The case of olive mill wastewater.

Olive mill wastewaters (OMWW) are characterized by a large concentration of pollutants, among which polyphenols represent a large part. This study investigated the effect of different dilutions of a culture medium enriched with olive-derived phenolic compounds on Chlorella vulgaris growth and its ability to degrade each one of them. In particular, polyphenols were precisely identified and quantified by HPLC-DAD analysis, showing high removal efficiency by C. vulgaris cells. Notably, in a 20% (v/v) medium simulating OMWW, polyphenol reduction reached 83%, and COD reduction was as high as 98%, without compromising microalgae growth or biomass productivity. To further assess the scalability of this bioremediation strategy, the study also examined the performance of C. vulgaris cultivated in an unsterilized OMWW medium at the optimal concentration of 20% (v/v). The results confirmed that the proposed process could be successfully implemented under non-sterile conditions, a crucial factor for transitioning to pilot and large-scale industrial applications, with the system maintaining a polyphenol degradation efficiency of over 75% within 14days. Overall, the proposed green and potentially cost-effective process is a sustainable solution for the degradation of phenolic compounds from OMWW and the management of such high-polluting waste.