Sustainability
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2023
·Vol. 15
·期 15
·11867
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IF 3.9
Na Chai,Lihui Gao,Shulei Li,Zilong Ma,Lingni Li,Ming Hu
Modified persimmon peel–montmorillonite composites (PMHC-KOH/NaHCO3) for efficient and rapid removal of methylene blue (MB) were synthesized using hydrothermal carbonization and simple alkali impregnation. The surface properties and material compositions of the hydrochars were determined with SEM, zeta potential, and XRD, and the adsorption mechanism of MB on two modified hydrochars was analyzed with FTIR, XPS, and DFT calculation. The results showed that modified hydrochars with a rough surface structure and rich oxygen-containing groups exhibited a strong affinity for MB, and the adsorption capacity of PMHC-NaHCO3and PMHC-KOH for MB reached 121.28 mg/g and 278.41 mg/g, respectively, with PMHC-KOH achieving more rapid adsorption of MB, at a rate of 0.043 g/mg/min. After five adsorption/desorption cycles, the two modified hydrochars still maintained a high adsorption rate of MB (92.32%/98.43%). The excellent adsorption performance of the modified hydrochars was attributed to hydrogen bonding, π-π interaction, electrostatic attraction, and ion exchange. DFT calculations revealed that oxygen-containing groups of the modified hydrochars played an important role in the adsorption of MB and confirmed that electrostatic attraction, hydrogen bonding, and π-π interactions were the key forces for rapid and efficient adsorption of MB. The prepared adsorbents gave full play to the regenerative applicability of agricultural waste, the simple alkali impregnation method eliminated the need for the additional cost of pyrolysis and activation, and their application in MB adsorption realized the treatment of waste with waste.Keywords:alkali-modified hydrochar;methylene blue;oxygen-containing functional groups;adsorption
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Scientific Reports
·
2024
·Vol. 14
·期 1
·1-13
·
IF 3.8
Liu Tonglinxi,Liu Wen,Li Xinyue,Wang Hanyu,Lan Yushan,Zhang Shengmin,Wang Yujun,Liu Huiqing
Antibiotics, as emerging persistent pollutants, pose significant threats to human health. The effective and low-cost removal of ciprofloxacin (CIP) from wastewater has become an important research focus. In this study, fly ash (FA) was used as the raw material, and modified fly ash (MFA) was prepared by varying microwave power, alkali concentration, and immersion time to investigate its adsorption characteristics for CIP. Results showed that the optimal preparation conditions for MFA with the most effective adsorption of CIP, using the Box-Behnken response surface methodology, were a microwave power of 480 W, an alkali concentration of 1.5 mol/L, and a modification time of 3 h. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analyses revealed that after modification, the glassy structure of FA is destroyed, the specific surface area is increased, and obvious hydroxyl O–H absorption peaks appear. Both FA and MFA exhibited adsorption processes for CIP that conformed to pseudo-second-order kinetics and the Langmuir equation. Maximum adsorption of CIP (9.61 and 12.67 mg/g) was achieved at pH = 6. With increasing temperature, the adsorption capacity of both FA and MFA for CIP decreased, indicating an exothermic process. The adsorption capacity of CIP decreased with increasing ion concentration, with the impact order of ions being Al 3+ > Ca 2+ > Na + . The results show that pore filling, electrostatic interaction, ion exchange and complexation are the main ways of CIP adsorption by FA. Microwave alkali modified fly ash is an economical and efficient adsorbent for CIP removal in water, realizing the purpose of “treating waste with waste”. This study provides a scientific basis for controlling CIP treatment in wastewater.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
SPECTROSCOPY LETTERS
·
2020
·
IF 0.88
Jianyu Chen,Jing Zhang,Wen Wang,Xiulan Ma,Yaxin Guo,Fangyuan Sun,Yujun Wang
Due to the norfloxacin will enter the natural water body with the effluent of the sewage treatment plant and cause water environment pollution, the research on how to effectively remove norfloxacin has become a hot topic. This experiment used hydrochloric acid and sodium hydroxide to study the modification of fly ash. The structure characteristics and properties of modified fly ash were determined by scanning electron microscope, X-ray diffractometer and infrared spectrometer, and the adsorption process of norfloxacin by fly ash was analyzed. It was found that the surface of fly ash modified by acid and alkali was rougher and the voids increased, which provided a rich adsorption site for the adsorption reaction of norfloxacin on fly ash, moreover, the specific surface area of sodium hydroxide modified fly ash increased the most, and the ability to adsorb norfloxacin was the strongest. The adsorption process characteristics showed that the adsorption reaction of norfloxacin is spontaneous, exothermic, disordered, and when the temperature increased, the adsorption amount of norfloxacin by fly ash was decreased, and the adsorption effect of fly ash on norfloxacin was the strongest under the pH = 7.0, yet inhibited when the adding of Ca2+ in the solution.
研究领域:
环境科学
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污染控制
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DOI
高影响因子
Results in Chemistry
·
2025
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IF 4.2
Hui Wang,Haoliang Wang,Siyamak Shahab,Hezhang Cheng,Mikhail Atroshko,Xianpeng Wang,Meng Ye
The widespread presence of antibiotic residues in aquatic environments, resulting from the extensive use of antibiotics in livestock and aquaculture, has driven the search for effective remediation methods. Adsorption, particularly using biochar, has emerged as a promising approach. In this study, rice straw-derived biochar (denoted as B5) modified with phosphoric acid (H 3 PO 4 -modified B5, PB5) and potassium hydroxide (KOH-modified B5, KB5) at the same concentration was investigated for ciprofloxacin (CIP) adsorption. PB5 exhibited a maximum Langmuir adsorption capacity of 25.6 mg/g for CIP, surpassing KOH-modified (8.77 mg/g) and unmodified biochar (3.71 mg/g). The optimized pH for adsorption was 3.0–7.0, where electrostatic interactions and hydrogen bonding dominated. Characterization revealed that acid-base modification altered the surface morphology, pore structure, and functional groups of biochar. PB5 exhibited a rougher surface, increased porosity, and enhanced oxygen-containing functional groups, while KB5 had a more pronounced increase in large specific surface area (SSA). Adsorption experiments indicated a multistage process involving chemisorption, external diffusion, and intraparticle diffusion. The pseudo-second-order model and the Freundlich isotherm best described the adsorption behavior, indicating chemisorption-dominated non-homogeneous adsorption. Density Functional Theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) analysis identified the -COOH group on biochar as the main active site for CIP adsorption, with a strong dual-force interaction. pH and anion studies showed that pH affected adsorption via electrostatic interactions, and divalent anions, especially SO 4 2− , inhibited adsorption, more so for PB5 due to its larger pore size. This study elucidates the distinct adsorption mechanisms of acid and alkali-modified biochar for CIP, providing valuable insights for the design and optimization of biochar for antibiotic removal in water treatment, Further research should explore diverse antibiotic models and advanced research tools to address real-world environmental challenges.
研究领域:
环境科学
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水处理技术
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污染物修复
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材料科学
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抗生素去除
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产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2022
·
IF 3.475
Maoyou Ye,Yi Fang,Hongjing Xiang,Hui Liu,Huimin Yan,Bingmin Wang,Xinle Lin,Jialin Liang,Wei Qian
Currently, ofloxacin (OFX) is widely used in various medical treatment and aquaculture industries. However, its production and application produces waste which pollutes the natural environment and causes ecological damage. The application of biochar is a crucial way to remove OFX antibiotics from wastewater. In this paper, bagasse was used as the material to be pyrolyzed to obtain bagasse biochar (BC). BC was modified with HNO3 and KOH to prepare acid-modified sugarcane biochar (HBC) and alkali-modified sugarcane biochar and subsequently applied to the treatment of ofloxacin wastewater. The results showed that the adsorption capacity of HBC was 2.2 times higher than that of BC, and it had better adsorption performance. When the dosage of acid-modified biochar was 1 g/L and the initial pH of the solution was 7.0, the OFX removal rate reached 88.5% after 90 min of reaction. HBC has good stability, and the OFX removal efficiency is still up to 78.5% after 5 cycles. According to the adsorption simulation results, the adsorption of the three biochar materials is more consistent with the Freundlich adsorption model, and the simulated linear correlation coefficient is higher than 0.99. The Kfr value of HBC is 6.6042, which exhibits the highest adsorption capacity. Moreover, the three biochars exhibit better simulation results in pseudo-second-order kinetics fitting, and the linear correlation coefficients are above 0.99. The adsorption mechanism of bagasse biochar for ofloxacin in wastewater was π-π electron donor–acceptor interactions. The results show that bagasse biochar has good feasibility in the treatment of ofloxacin wastewater.
研究领域:
环境科学
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废水处理
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Zhenggang Huang,Chuanming Zhang,Chunyang Shen,Lili Jin,Yaxiong Zeng,Baohong Guan
Ammonia nitrogen (NH 4 + -N) is one of the regular indexes and the most important contaminants in drinking water. However, it is still a great challenge to remove low concentration NH 4 + -N from drinking water in a safe way. Here we used NaX zeolite and alkali-modified NaX zeolite (NaX-A) as adsorbents and catalysts for ozonation to remove NH 4 + -N in water without adding any chemicals. The zeolites present significant adsorption of NH 4 + -N with Freundlich adsorption affinity of 2.10–3.27 mg 1-n ·L -n ·g −1 by ion-exchange on the bridged Si-O-Al groups. The NaX-A catalytic ozonation achieves 26.7 % of NH 4 + -N removal and up to 75.0 % of gaseous products selectivity in 20 min. The NH 4 + -N oxidation rate constant is raised by 10.7 times over O 3 /NaX-A compared with single ozonation. The alkali modification stimulates the formation of acid sites in NaX-A, and thus improve the adsorption of NH 4 + -N and the decomposition of O 3 into hydroxyl radicals (·OH) for the conversion of NH 4 + -N to gaseous products. This study provides new insights into catalytic ozonation by alkali-modified zeolites to remove NH 4 + -N in water via coupling adsorption with catalytic ozonation.
研究领域:
环境科学
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化学工程
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水处理技术
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产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiaofang You,Wenqi Zhang,Xiaoteng Li,Chuandong Ma,Zhisen Li,Qingbiao Wang,Zhenhua Wang,Lin Li
In this study, alkali-modified municipal sludge (AS) was mixed with low-rank coal to prepare AS-coal water slurry (ASCWS). The influence of AS on the slurrying performance of coal water slurry (CWS) was investigated, and the slurrying mechanism of municipal sludge-CWS (SCWS) was elucidated. Research on the alkali modification of municipal sludge showed that the effectiveness of the modifiers was in the order Ca(OH) 2 > NaOH > KOH > K 2 CO 3 . Considering the apparent viscosity of the slurry as the evaluation criterion, the optimal alkali modification scheme was determined through the response surface optimization test, and 19.99 % Ca(OH) 2 was suitable to modify the sludge for 14.61 h Compared with the unmodified sludge, the content of oxygen-containing functional groups on the surface of AS was reduced, and the flocculent structure was disrupted, which helped improve the slurry formation performance of the SCWS. Blending the sludge with the CWS enhanced the stability of the slurry, and the water separation rates for the SCWS and ASCWS decreased from 18.62 % to 5.00 % and 5.26 %, respectively. The mechanism study showed that the zeta potential values of SCWS and ASCWS decreased from −10.67 mV to –32.23 mV and −39.22 mV, respectively. The increased electronegativity of the slurry owing to the addition of sludge facilitated particle dispersion and enhanced slurry stability. The adsorption patterns of sodium poly[(naphthaleneformaldehyde)sulfonate] (MF) on coal, sludge, and modified sludge were consistent with the Langmuir adsorption model. The pseudo-second-order kinetic model accurately described the adsorption process of MF on coal, sludge, and modified sludge.
研究领域:
能源科学
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环境工程
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化学工程
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产品关联
DOI
高影响因子
Sustainability
·
2022
·Vol. 14
·期 10
·5892
·
IF 3.889
Zhifeng Liu,Xun Fang,Lingyuan Chen,Bo Tang,Fengmin Song,Wenbin Li
We used three purple soil (Hechuan, Jialing, and Cangxi) samples from the Jialing River basin as the research objects and added different proportions of an acid–base modifiedAlternanthera philoxeroidesbiochar (Cm) to the purple soil to study the effect of Cmon the adsorption of chlortetracycline (CTC) in the purple soil. The results indicated the following: (1) At 30 °C and pH = 6, the soil adsorption capacity increased with an increasing initial concentration of CTC. The maximum adsorption amount of CTC for each tested sample was in the range of 2054.63–3631.21 mg/kg, and the adsorption capacity in different Cmamended soils was ranked in the order of 10% Cm> 5% Cm> 2% Cm> CK. The adsorption capacity of CTC increased with an increase in the proportion of Cm. Furthermore, under the same addition ratio of Cm, Hechuan soil was found to have a better adsorption effect for CTC than Jialing and Cangxi soil. (2) The Langmuir model was the most suitable for fitting the adsorption behavior of CTC on different purple soils, and the fitting coefficients were all greater than 0.9, indicating that the adsorption of CTC on each soil sample occurred via monolayer adsorption. The thermodynamic experiment results showed that an increase in temperature was beneficial to the process of CTC adsorption, which was a spontaneous, endothermic, and entropy-adding process. (3) At pH = 6, the ionic strength ranged from 0.01 to 0.5 mol/L and the adsorption capacity of CTC of the soil samples decreased with an increase in ionic strength. In the range of pH 2–10, the adsorption capacity of CTC in all the soil samples decreased with an increase in pH. The inhibition capacity of CTC in the soil samples under acidic conditions was notably higher than that under alkaline conditions.Keywords:Alternanthera philoxeroides;biochar;modification;chlortetracycline;adsorption capacity;Jialing River
研究领域:
环境科学
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土壤学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Bo Lv,Wen Fan,Feishuo Jiao,Yutong Jiao,Baolin Xing
Gasification slag landfill has caused serious environmental pollution in coal chemical sector. Therefore, the utilization of coal gasification slag as a precursor for adsorbent production represents a significant avenue for the sustainable management of this industrial by-product. However, there are few researches on the systematic alkali modification of gasification slag. In this study, an optimized alkali modification process employing a 3 mol/L NaOH solution, a liquid-to-solid ratio of 10:1, conducted at 100 °C for a duration of 10 h, resulted in the production of a high-performance adsorbent, i.e., alkali modified coal gasification slag (CGS-OH). Besides, The formation of an axial crystal structure zeolite crystal on the adsorbent surface. Under optimal adsorption conditions with a pH of 6, an adsorbent dosage of 3 g/L, and a temperature of 25 °C, CGS-OH exhibits the optimal adsorption performance for removal of Pb 2 + , characterized by a high removal rate of 95.77 % and substantial equilibrium adsorption capacity of 47.5 mg/g. Herein, the adsorption kinetics of the above process are well described by the pseudo-second-order kinetic model ( R 2 = 0.9981), indicating that the adsorption process is predominantly governed by a chemical adsorption mechanism, primarily involving electrostatic attraction and ion exchange at the adsorbent's surface. This research underscores the potential of CGS-OH as a cost-effective and high-performance adsorbent for Pb 2+ removal, offering significant implications for industrial wastewater treatment and environmental remediation strategies. It also provides a feasible path for the high-value utilization of industrial by-products in coal chemical sector.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Arabian Journal of Chemistry
·
2022
·
IF 6.212
Jingbo Wang,Yaxin Kang,Huatai Duan,Yi Zhou,Hao Li,Shanguo Chen,Fenghua Tian,Lianqing Li,Marios Drosos,Changxun Dong,Stephen Joseph,Genxing Pan
Co-pyrolysis of straw and Ca(OH) 2 is a feasible modification method to improve the adsorption capacity of biochar for Cd. However, few studies have quantitatively analyzed the contribution of different adsorption mechanisms of alkali-modified biochar. In this study, the alkali-modified (Ca) biochar were prepared by co-pyrolyzing lime (Ca(OH) 2 ) and soybean straw (SBB) or rape straw (RSB) at 450 °C. The adsorption mechanism was investigated by a series of experiments and was provided by quantitative analysis. The maximum adsorption capacities of Cd 2+ by Ca-SBB and Ca-RSB were calculated to be 78.49 mg g −1 and 49.96 mg g −1 , which were 1.56 and 1.48 times higher than SBB (50.40 mg g −1 ) and RSB (33.79 mg g −1 ), respectively. Compared with the original biochar (SBB, RSB), alkali-modified biochar (Ca-SBB and Ca-RSB) were found to have faster adsorption kinetics and lower desorption efficiencies. The mechanism study indicated that Ca(OH) 2 modification effectively enhanced the contribution of ion exchange and decreased the contribution of functional groups complexation. After Ca(OH) 2 modification, precipitation and ion exchange mechanisms dominated Cd 2 + absorption on Ca-SBB, accounting for 49.85% and 34.94% of the total adsorption, respectively. Similarily ion exchange and precipitation were the main adsorption mechanism on Ca-RSB, accounting however for 61.91% and 18.47% of total adsorption, respectively. These results suggested that alkali-modified biochar has great potential to adsorp cadmium in wastewater.
研究领域:
环境科学
·
土壤修复
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DOI
高影响因子
SPECTROSCOPY LETTERS
·
2019
·
IF 1.081
Wen Wang,Xiulan Ma,Jing Sun,Jianyu Chen,Jing Zhang,Yujun Wang,Jihong Wang,Hao Zhang
The levels of enrofloxacin have exceeded acceptable standards in the water environment of many global regions, and the problem of pollution caused by enrofloxacin needs to be solved urgently. In this study, phosphoric acid and potassium hydroxide were used to modify corn stalk biochar. The properties and structure of the modified biochar were studied by scanning electron microscopy, infrared spectrometer, X-ray diffraction spectroscopy, and other analytical methods. Other factors influencing enrofloxacin adsorption were assessed using the equilibrium adsorption method. The surface area of the acid- and alkali-modified biochar was found to increase 10- and 14-fold, respectively. The equilibrium adsorption capacity of enrofloxacin on the acid- and alkali-modified biomass carbon increased by 27.80% and 54.08%, respectively. The quasi-second-order kinetic equation and Langmuir equation described the adsorption process of the biochars accurately. At pH = 5.0, the biochars had the highest levels of enrofloxacin adsorption. The adsorption of enrofloxacin onto the biochars negatively correlated with the concentration of Ca2+ in the background solution.
研究领域:
环境科学
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生物学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 47
·期 3
·1256-1267
·
IF 3.925
Lei Yin,Hui Yang Li,Tingting Ge,Yuchao Li,Cuncun Zuo,Ming Wang,GuangJun Cui,Haofei Huang,Lin Guo
A series of acid–base-loaded γ-Al2O3 catalysts was applied as the catalysts for the isomerization of 3/4-methyl-tetrahydro phthalic anhydride. With a basic metal (K or Na) as the basic source and phosphorus (P) as the acid source, γ-Al2O3 was modified by equal volume immersion. NH3/CO2-TPD, XRD, TEM/EDS, BET, and TGA were used to analyze the catalysts, and 15%-K/Al2O3 and 10%-P/Al2O3 were determined as the most appropriate catalysts. The isomers were qualitatively and quantitatively analyzed using nuclear magnetic resonance (1H-NMR) and infrared spectroscopy (IR), and the reaction mechanism for the isomer formation was proposed. With 3-MTHPA as the substrate, the acid/base reaction temperature was 165/150 °C, the reaction time was 3 h and the amount of the catalyst added was 3%. A new type of continuous isomeric fixed-bed reactor was designed. The stability of the catalyst was tested, and the activity loss was 4.6–6.6% after 10 hours of operation.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）