Adsorption of pharmaceuticals from aqueous solutions using biochar derived from cotton gin waste and guayule bagasse

Abstract Biochars produced from cotton gin waste (CG) and guayule bagasse (GB) were characterized and explored as potential adsorbents for the removal of pharmaceuticals (sulfapyridine-SPY, docusate-DCT and erythromycin-ETM) from aqueous solution. An increase in biochar pyrolysis temperature from 350 οC to 700 οC led to an increase in pH, specific surface area, and surface hydrophobicity. The electronegative surface of all tested biochars indicated that non-Coulombic mechanisms were involved in adsorption of the anionic or uncharged pharmaceuticals under experimental conditions. The adsorption capacities of Sulfapyridine (SPY), Docusate (DCT) and Erythromycin (ETM) on biochar were influenced by the contact time and solution pH, as well as biochar specific surface area and functional groups. Adsorption of these pharmaceutical compounds was dominated by a complex interplay of three mechanisms: hydrophobic partitioning, hydrogen bonding and π–π electron donor–acceptor (EDA) interactions. Despite weaker π–π EDA interactions, reduced hydrophobicity of SPY− and increased electrostatic repulsion between anionic SPY− and the electronegative CG biochar surface at higher pH, the adsorption of SPY unexpectedly increased from 40% to 70% with an increase in pH from 7 to 10. Under alkaline conditions, adsorption was dominated by the formation of strong negative charge-assisted H-bonding between the sulfonamide moiety of SPY and surface carboxylic groups. There seemed to be no appreciable and consistent differences in the extent of DCT and ETM adsorption as the pH changed. Results suggest the CG and GB biochars could act as effective adsorbents for the removal of pharmaceuticals from reclaimed water prior to irrigation. High surface area biochars with physico-chemical properties (e.g., presence of functional groups, high cation and anion exchange capacities) conducive to strong interactions with polar-nonpolar functionality of pharmaceuticals could be used to achieve significant contaminant removal from water. Graphic Abstract

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Development and Characterization of Composite Carbon Adsorbents with Photocatalytic Regeneration Ability: Application to Diclofenac Removal from Water

Catalysts ◽

10.3390/catal11020173 ◽

2021 ◽

Vol 11 (2) ◽

pp. 173

Author(s):

Velma Beri Kimbi Yaah ◽

Satu Ojala ◽

Hamza Khallok ◽

Tiina Laitinen ◽

Marcin Selent ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Functional Groups ◽

Specific Surface Area ◽

Palm Kernel ◽

Hydrothermal Carbonization ◽

Carbon Composite ◽

Carbon Adsorbents ◽

Regeneration Ability ◽

Activation Temperature

This paper presents results related to the development of a carbon composite intended for water purification. The aim was to develop an adsorbent that could be regenerated using light leading to complete degradation of pollutants and avoiding the secondary pollution caused by regeneration. The composites were prepared by hydrothermal carbonization of palm kernel shells, TiO2, and W followed by activation at 400 °C under N2 flow. To evaluate the regeneration using light, photocatalytic experiments were carried out under UV-A, UV-B, and visible lights. The materials were thoroughly characterized, and their performance was evaluated for diclofenac removal. A maximum of 74% removal was observed with the composite containing TiO2, carbon, and W (HCP25W) under UV-B irradiation and non-adjusted pH (~5). Almost similar results were observed for the material that did not contain tungsten. The best results using visible light were achieved with HCP25W providing 24% removal of diclofenac, demonstrating the effect of W in the composite. Both the composites had significant amounts of oxygen-containing functional groups. The specific surface area of HCP25W was about 3 m2g−1, while for HCP25, it was 160 m2g−1. Increasing the specific surface area using a higher activation temperature (600 °C) adversely affected diclofenac removal due to the loss of the surface functional groups. Regeneration of the composite under UV-B light led to a complete recovery of the adsorption capacity. These results show that TiO2- and W-containing carbon composites are interesting materials for water treatment and they could be regenerated using photocatalysis.

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Effects of Wet Oxidation Process on Biochar Surface in Acid and Alkaline Soil Environments

Materials ◽

10.3390/ma11122362 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2362 ◽

Cited By ~ 6

Author(s):

Qinya Fan ◽

Liqiang Cui ◽

Guixiang Quan ◽

Sanfei Wang ◽

Jianxiong Sun ◽

...

Keyword(s):

Specific Surface ◽

Adsorption Capacity ◽

Surface Area ◽

Functional Groups ◽

Specific Surface Area ◽

Contaminated Soils ◽

Soil Conditions ◽

Acid Oxidation ◽

Wet Oxidation ◽

Alkaline Soil

Biochar has been studied for remediation of heavy metal-contaminated soils by many researchers. When in external conditions, biochar in soils ages, which can transform its structural properties and adsorption capacity. This study was conducted with two oxidation processes, HNO3/H2SO4 and NaOH/H2O2, to simulate the effects of biochar in acid and alkaline soil conditions. The results show that the oxygen-containing functional groups increased in aged biochar, which led to improve the ratio of oxygen and carbon (O/C). Nitro functional groups were found in the acid-oxidation treated biochar. Destroyed ditches and scars were observed on the surface of aged biochar and resulted in growth in their specific surface area and porosity. Specific surface area increased by 21.1%, 164.9%, and 63.0% for reed-derived biochar treated with water washing, acid oxidation, and basic oxidation, respectively. Greater peaks in the Fourier Transform Infrared Spectroscopy (FTIR) results were found in C–O and O–H on the surface of field-aged biochar. Meanwhile, mappings of energy-dispersive spectroscopy showed that biochar aged in soil was abundant in minerals such as silicon, iron, aluminum, and magnesium. In summary, biochar subjected to wet oxidation aging had an increased capacity to immobilize Cd compared to unaged biochar, and the adsorption capacity of oxidized biochar increased by 28.4% and 13.15% compared to unaged biochar due to improvements in porosity and an increase in functional groups.

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Bi2WO6 Nanoparticles Prepared by Combustion Synthesis with Different Fuels and their Photocatalytic Activity

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.604.93 ◽

2014 ◽

Vol 604 ◽

pp. 93-101

Author(s):

Maris Kodols ◽

Sabine Didrihsone ◽

Janis Grabis

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Citric Acid ◽

Ethylene Glycol ◽

Specific Surface ◽

Crystallite Size ◽

Combustion Synthesis ◽

Surface Area ◽

Specific Surface Area ◽

Solution Ph

The influence of glycine, glycerine, ethylene glycol and citric acid fuel and their ratio to NO3- on formation and dispersity of Bi2WO6 nanoparticles prepared by combustion synthesis has been studied. The pure crystalline Bi2WO6 with specific surface area 24,8 m2/g and crystallite size of 28 nm was obtained by using glycerine as fuel at its ratio to NO3- of 0,67. The photocatalytic activity of the prepared Bi2WO6 in degradation of methylene blue depended on its specific surface area of samples and solution pH.

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Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.129-131.784 ◽

2010 ◽

Vol 129-131 ◽

pp. 784-788 ◽

Cited By ~ 2

Author(s):

Min Wang ◽

Qiong Liu ◽

Dong Zhang

Keyword(s):

Photocatalytic Activity ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Photocatalytic Property ◽

Precipitation Method ◽

X Ray Diffraction ◽

Experimental Conditions ◽

Triclinic Phase ◽

Xrd Patterns

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.

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Bio-polishing sludge adsorbents for dye removal

Polish Journal of Chemical Technology ◽

10.1515/pjct-2016-0065 ◽

2016 ◽

Vol 18 (4) ◽

pp. 15-21 ◽

Cited By ~ 1

Author(s):

Muhammad Abbas Ahmad Zaini ◽

Norulaina Alias ◽

Mohd. Azizi Che Yunus

Keyword(s):

Methylene Blue ◽

Specific Surface ◽

Surface Area ◽

Functional Groups ◽

Specific Surface Area ◽

Treatment Strategies ◽

Blue Dye ◽

Surface Functional Groups ◽

Adsorption Capacities ◽

Maximum Removal

Abstract The objective of this work is to evaluate the removal of methylene blue dye by bio-polishing sludge-based adsorbents. The adsorbents were characterized according to the specific surface area, pH upon the treatment and surface functional groups. The adsorption of dye was carried out at room temperature, and the adsorption data were analyzed using the isotherm and kinetics models. The bio-polishing sludge is rich in ash content, and the presence of surface functional groups varied with the treatment strategies. The specific surface area of adsorbents is between 7.25 and 20.8 m2/g. Results show that the maximum removal of methylene blue by sludge adsorbents was observed to have the following order: untreated sludge (SR) > zinc chloride-treated (SZ) > microwave-dried (SW) = potassium carbonate-treated (SK) > acid-washed (SH). The maximum adsorption capacities for SR and SZ as predicted by the Langmuir model are 170 and 135 mg/g, respectively. Although SR demonstrates a higher maximum removal than SZ, the latter exhibits greater removal intensity and rate constant even at high dye concentration. The bio-polishing sludge is a promising adsorbent for dye wastewater treatment.

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Structure and Catalytic Soot Combustion of Perovskite La-Mn-O Hollow Microfibers via Gel-Precursor Transformation Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.2289 ◽

2012 ◽

Vol 538-541 ◽

pp. 2289-2292

Author(s):

Xiao Xiao Meng ◽

Feng Lin He ◽

Jiang Ying Shen ◽

Xiang Qian Shen

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

High Surface ◽

Thermo Gravimetric Analysis ◽

Transformation Process ◽

High Catalytic Activity ◽

Gravimetric Analysis ◽

Soot Combustion ◽

Aspect Ratios

The nanocrystalline perovskite La-Mn-O hollow microfibers were prepared by the gel-precursor transformation process from reagents of metal salts and citric acid. The gel precursor and resultant products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The specific surface area was measured by the Brunauere-Emmette-Teller method. The catalytic performance of soot combustion was evaluated by thermo-gravimetric analysis under model conditions. The nanocrystalline La-Mn-O hollow microfibers calcined at 650 °C for 6 h are characterized with diameters of 2-8 µm, aspect ratios (length/diameter) about 5-15, a micro-tunnel with an estimated ratio 1/3 of the hollow diameter to fiber diameter, and a high specific surface area of 36.7 m2/g that is 1.9 times higher than the counterpart nanosized powder. This nanocrystalline La-Mn-O hollow microfibers catalyst exhibit a high catalytic activity for the soot combustion, with a low T50 of 397°C, which is largely owing to the high surface area and the micro-tunnel structure.

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N, S-Codoped Activated Carbon Material with Ultra-High Surface Area for High-Performance Supercapacitors

Polymers ◽

10.3390/polym12091982 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1982

Author(s):

Qinghua Yuan ◽

Zhuwen Ma ◽

Junbiao Chen ◽

Zhenrui Huang ◽

Zeming Fang ◽

...

Keyword(s):

Activated Carbon ◽

Specific Surface ◽

Specific Capacitance ◽

Surface Area ◽

Specific Surface Area ◽

Carbon Material ◽

High Surface ◽

Koh Activation ◽

Supercapacitor Electrode ◽

Tobacco Stalk

The recycling of macromolecular biowastes has been a problem for the agriculture industry. In this study, a novel N, S-codoped activated carbon material with an ultrahigh specific area was produced for the application of a supercapacitor electrode, using tobacco stalk biowastes as the carbon source, KOH as the activating agents and thiourea as the doping agent. Tobacco stalk is mainly composed of cellulose, but also contains many small molecules and inorganic salts. KOH activation resulted in many mesopores, giving the tobacco stem-activated carbon a large specific surface area and double-layer capacitance. The specific surface area of the samples reached up to 3733 m2·g−1, while the maximum specific capacitance of the samples obtained was up to 281.3 F·g−1 in the 3-electrode tests (1 A·g−1). The doping of N and S elements raised the specific capacitance significantly, which could be increased to a value as high as 422.5 F·g−1 at a current density of 1 A·g−1 in the 3-electrode tests, but N, S-codoping also led to instability. The results of this article prove that tobacco stalks could be efficiently reused in the field of supercapacitors.

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Adsorption of Cr(VI) Ions using Activated Carbon Produced from Indian Water Chestnut (Trapa natans) Peel Powder

Asian Journal of Chemistry ◽

10.14233/ajchem.2020.22482 ◽

2020 ◽

Vol 32 (4) ◽

pp. 876-880

Author(s):

Maninder Singh ◽

D. P. Tiwari ◽

Mamta Bhagat

Keyword(s):

Heavy Metals ◽

Metal Ions ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Metal Ion ◽

Ion Concentration ◽

Solution Ph ◽

Indian Water ◽

Trapa Natans

The indiscriminate discharge of heavy metals into water and soil from anthropogenic practices is becoming prominent threat to the environment. Heavy metals like chromium, cadmium, lead, arsenic, nickel etc. are heavily toxic and carcinogenic in nature. This study emphasizes the adequacy of activated water chest nut (Trapa natans) peel powder as a new adsorbent material for removal of chromium(VI) metal ions. Adsorption experiments were performed in batch process. Various process parameters like contact time, temperature, solution pH, dose of adsorbent, metal ion concentration etc. were optimized. The physico-chemical properties of adsorbent material were characterized by FTIR and XRD. The morphology, topology of adsorbent surface was characterized by scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) which revealed a highly porous structure and available specific surface area. The adsorption capacity (maximum) was counted as 59.17 mg/g and specific surface area was found 23.467 m2/g at a pH 7. The adsorption process for Cr(VI) ions was in a good agreement with Langmuir isotherm. The process also followed pseudo second order kinetics. The obtained result shows that activated water chest nut (Trapa natans) peel powder (AWCPP) can be a hopeful low-cost and eco-friendly bio-adsorbent for removal of Cr(VI) metal ions and also better adsorbent than other various reported adsorbents.

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Effects of Carbonization on the Co-Activation of Sludge and Biomass to Produce Activated Coke

Journal of Energy Resources Technology ◽

10.1115/1.4050499 ◽

2021 ◽

Vol 143 (10) ◽

Author(s):

Liwei Wang ◽

Lin Lu ◽

Minghua Li ◽

Yulin Liu ◽

Xiaohan Ren ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Functional Groups ◽

Specific Surface Area ◽

Proximate Analysis ◽

Carbonization Temperature ◽

Activation Method ◽

Physical Activation ◽

Activation Process ◽

Activated Coke

Abstract Activated coke was prepared by mixing sewage sludge and waste poplar bark biomass from furniture manufacturing. The physical activation method of these feedstocks with steam for 1 h at 850 °C was implemented. The elemental composition, pore distribution, microstructure, and surface functional groups of the activated coke products were analyzed by proximate analysis, ultimate analysis, N2 adsorption, scanning electron microscopy, and Fourier transform infrared spectroscopy, respectively. The effects of different mixing ratios of sludge and biomass, preactivation carbonization temperature, and activation method on the activated coke were investigated. When the proportion of biomass was two-thirds of the total feedstock mass and the carbonization temperature was 300 °C, the produced activated coke had the highest specific surface area and the most extended micropore structure. Water vapor (steam) activation was found to be beneficial to the formation of oxygen-containing functional groups. This study established that steam is beneficial to pore expansion and promotes pore development. It was found that the carbonaceous feedstocks acquired initial porosity through carbonization in nitrogen, which proved to be instrumental in the ensuing activation process. After sequential carbonization and activation, the produced active coke acquired a higher specific surface area and microporosity, compared with the active coke produced by activation alone.

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Synthesis, Characterisation, and Photocatalytic Behaviour of Mesoporous ZnS Nanoparticles Prepared Using By-Product Templating

Australian Journal of Chemistry ◽

10.1071/ch17192 ◽

2017 ◽

Vol 70 (10) ◽

pp. 1099 ◽

Cited By ~ 4

Author(s):

Hosein B. Motejadded Emrooz ◽

Ali R. Rahmani ◽

Francisco J. Gotor

Keyword(s):

Electron Microscopy ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Diffuse Reflectance Spectroscopy ◽

High Surface ◽

Ultrasonic Waves ◽

Soft Template ◽

Bandgap Energy ◽

Zns Nanoparticles

High surface area mesoporous ZnS nanoparticles (MZN) were obtained with the aid of the by-product of the synthesising reaction. This by-product, namely NaNO3, can be considered as a soft template responsible for the formation of pores. Ethanol and water were chosen as the synthesis media. Ultrasonic waves were used as an accelerator for the synthesis of MZNs. Photocatalytic activities of the synthesised samples for the degradation of methylene blue (MB) were investigated under ultraviolet irradiation. Synthesised specimens were characterised using field emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, diffuse reflectance spectroscopy, N2-physisorption, and FT-IR spectroscopy. Results indicated that the synthesis media has a pronounced effect on the surface properties of the final porous particles by several mechanisms. The specific surface area of the MZN samples synthesised in water and ethanol were determined to be 53 and 201 m2 g−1, respectively. The difference in the specific surface area was attributed to the weak solvation of S2− ions (Na2S·5H2O in ethanol) and also to the by-product of the synthesis reaction. The photocatalytic behaviour of the mesoporous ZnS nanoparticles synthesised in these two media were investigated and the results have been interpreted with the aid of effective surface area, pore volume, and bandgap energy of the specimens.

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