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3 pages, 190 KiB

Open AccessEditorial

Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment

by Yongchang Sun and Tingting Wang

Water 2023, 15(7), 1320; https://doi.org/10.3390/w15071320 - 28 Mar 2023

Cited by 7 | Viewed by 1583

Abstract

With rapid industrial and economic development, the problem of water pollution poses a great threat to the environment and human health [...] Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

Research

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17 pages, 4358 KiB

Open AccessArticle

The Preparation of a Lignosulfonate/Chitosan–Graphene Oxide Hydrogel Biosorbent to Effectively Remove Cr(VI) from Wastewater: Adsorption Performance and Mechanisms

by Caohui Han, Xiaonan Liu, Tingting Wang, Xiaoyin Sun, Lu Bai and Yongchang Sun

Water 2022, 14(22), 3684; https://doi.org/10.3390/w14223684 - 15 Nov 2022

Cited by 2 | Viewed by 2133

Abstract

A lignosulfonate/chitosan–graphene oxide hydrogel (LCGH) composite was successfully synthesized to effectively remove Cr(VI) from wastewater. The physical–chemical properties of the prepared LCGH was characterized by SEM, FT-IR, XRD, XPS, and TGA. The results showed that LCGH had an cross-linked three-dimensional porous network structure [...] Read more.

A lignosulfonate/chitosan–graphene oxide hydrogel (LCGH) composite was successfully synthesized to effectively remove Cr(VI) from wastewater. The physical–chemical properties of the prepared LCGH was characterized by SEM, FT-IR, XRD, XPS, and TGA. The results showed that LCGH had an cross-linked three-dimensional porous network structure that was conducive to Cr(VI) adsorption, resulting in a high Cr(VI) adsorption capacity (564.2 mg/g). Thermodynamic analysis showed that Cr(VI) adsorption on LCGH was spontaneous endothermic and fitted well with the pseudo-second-order kinetic and Langmuir models. The reaction mechanisms for Cr(VI) removal were hydrogen bond, electrostatic attraction, and π-π interaction. LCGH demonstrated good reproducibility and its adsorption capacity of Cr(VI) could still maintained at 85.4% after 5 cycles of regeneration. The biosorbent LCGH was a low-cost and eco-friendly material, which has a good prospect for Cr(VI) wastewater removal. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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12 pages, 3451 KiB

Open AccessArticle

New Margin-Based Biochar for Removing Hydrogen Sulfide Generated during the Anaerobic Wastewater Treatment

by Younes Gaga, Safaa Benmessaoud, Mohammed Kara, Amine Assouguem, Abdullah Ahmed Al-Ghamdi, Fahad M. Al-Hemaid, Mohamed S. Elshikh, Riaz Ullah, Artur Banach and Jamila Bahhou

Water 2022, 14(20), 3319; https://doi.org/10.3390/w14203319 - 20 Oct 2022

Cited by 12 | Viewed by 2287

Abstract

The present research concerns the development of a new device and process intended for the purification and treatment of sulfurous elements, and more particularly, of hydrogen sulfide (H₂S) from the biogas produced at the time of the anaerobic fermentation in the [...] Read more.

The present research concerns the development of a new device and process intended for the purification and treatment of sulfurous elements, and more particularly, of hydrogen sulfide (H₂S) from the biogas produced at the time of the anaerobic fermentation in the purification stations. The controlled dumps or any other unit are likely to produce biogas with concentrations of H₂S harmful to the operation of the machines for the valorization of the produced biogas or deodorization. This device uses new biochar from a mixture of dehydrated digested sludge from sewage treatment plants and margins from traditional crushing units, followed by biological treatment in a liquid medium at a controlled temperature. The liquid medium is based on a margin (nutrient) with culture support (large granules of biochar) in suspension by the injection under the pressure of biogas coming from the biochar filter. Physico-chemical characterization of the biochar and a test practiced on the new device of raw biogas treatment were realized. The results showed that the newly synthesized biochar has a low specific surface and a highly undeveloped porosity. The spectrum corresponding to the images of the biochar reveals the presence of C, O, N, Al, Si, P, and Fe, as significant elements with the following respective percentages: 37.62%, 35.78%, 1.87%, 4.26%, 7.33%, 8.56%, and 4.58%. It is important to note that the C content of the biochar thus synthesized found by EDX is quite comparable to that estimated from ATG. Biogas treatment test results on the prototype object of the invention eliminated 97% of the H₂S from the biogas produced. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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18 pages, 5932 KiB

Open AccessArticle

Adsorption of Pesticides Using Wood-Derived Biochar and Granular Activated Carbon in a Fixed-Bed Column System

by Kalsoom, Sardar Khan, Rafi Ullah, Muhammad Adil, Abdul Waheed, Khalid Ali Khan, Hamed A. Ghramh, Hesham F. Alharby, Yahya M. Alzahrani, Sameera A. Alghamdi, Nadiyah M. Alabdallah and Fazli Rahim

Water 2022, 14(19), 2937; https://doi.org/10.3390/w14192937 - 20 Sep 2022

Cited by 13 | Viewed by 3633

Abstract

Pesticides have great potential to contaminate resources of drinking water by percolating and leaching, when applied in the agriculture sector as well as in domestic region. Activated carbon (AC) and Biochar (BCH) were used for adsorption in a fixed-bed column system. Both of [...] Read more.

Pesticides have great potential to contaminate resources of drinking water by percolating and leaching, when applied in the agriculture sector as well as in domestic region. Activated carbon (AC) and Biochar (BCH) were used for adsorption in a fixed-bed column system. Both of the adsorbent-packed columns indicated an increase in the breakthrough time for atrazine from 3350 to 5800 min and 3200 to 5700 min, chlorothalanil 3200–5600 min and 3150–5550 min, β-endosulfan 3050–5400 min and 2950–5400 min, and α-endosulfan 2900–5200 min and 2850–5200 min with bed heights from 10 cm to 15 cm, respectively. Similarly, when flow rate increased from 0.5 to 1.5 mL min⁻¹ and contaminant concentration from 50–100 µg L⁻¹, it resulted in a decrease in exhaust time. The models of Yoon–Nelson (R² = 0.9427) and Thomas (R² = 0.9921) describe the process of adsorption to be best well-under optimal conditions. Both the adsorbents would be efficiently utilized as the best adsorbents to remediate pesticide-contaminated water under optimal conditions. Pesticides adsorption onto adsorbents followed the order of atrazine > chlorothalanil > β-endosulfan > α-endosulfan. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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15 pages, 3348 KiB

Open AccessArticle

Manganese Modified Activated Alumina through Impregnation for Enhanced Adsorption Capacity of Fluoride Ions

by Yujia Gao, Kun You, Jinxiang Fu, Juliang Wang and Weiyi Qian

Water 2022, 14(17), 2673; https://doi.org/10.3390/w14172673 - 29 Aug 2022

Cited by 8 | Viewed by 2373

Abstract

Activated alumina, with low cost to implement and consistent performance, has been widely used as a defluoridation adsorbent in contaminated groundwater. However, its application was hampered by an undesirable adsorption capacity. In the recent research, an innovative adsorbent (manganese modified activated alumina, MAA) [...] Read more.

Activated alumina, with low cost to implement and consistent performance, has been widely used as a defluoridation adsorbent in contaminated groundwater. However, its application was hampered by an undesirable adsorption capacity. In the recent research, an innovative adsorbent (manganese modified activated alumina, MAA) was synthesized by impregnation method and showed a more significant adsorption capacity than that of freshly activated alumina. The scanning electron microscope, Brunauer, Emmett and Teller, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared verified introduction of manganese oxides (MnOOH and MnO₂) successfully, improvement of surface microstructure and nature of single-layer adsorption, which enhanced the adsorption ability. In a short period of adsorption, the MAA maximum capacity increased from 38% to 67%. Then, batch-scale kinetic and thermodynamic adsorption investigations were performed. The high correlation coefficients R² (close to 1) of the quasi-second-order model, Langmuir kinetic model, and Langmuir isotherm model confirmed a better fit to the adsorption experimental data, further indicating that the diffusion of adsorbate was primarily governed by adsorption onto the active sites and the adsorption of fluoride on MAA was single-layer physical adsorption. This paper provides an approach to modifying activated alumina as a groundwater fluoride adsorbent. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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19 pages, 7518 KiB

Open AccessFeature PaperArticle

Fabrication of Polyethyleneimine-Modified Nanocellulose/Magnetic Bentonite Composite as a Functional Biosorbent for Efficient Removal of Cu(Ⅱ)

by Xiaoyin Sun, Xintian Lv, Caohui Han, Lu Bai, Tingting Wang and Yongchang Sun

Water 2022, 14(17), 2656; https://doi.org/10.3390/w14172656 - 28 Aug 2022

Cited by 11 | Viewed by 2346

Abstract

A novel inorganic–organic biosorbent, polyethyleneimine (PEI)-modified nanocellulose cross-linked with magnetic bentonite, was prepared for the removal of Cu(Ⅱ) from water. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) showed that the amino and carboxyl groups were successfully grafted onto the nanocellulose structure. [...] Read more.

A novel inorganic–organic biosorbent, polyethyleneimine (PEI)-modified nanocellulose cross-linked with magnetic bentonite, was prepared for the removal of Cu(Ⅱ) from water. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) showed that the amino and carboxyl groups were successfully grafted onto the nanocellulose structure. The adsorption performance of Cu(Ⅱ) with various factors, using the biosorbent, was investigated. The results show that the adsorption equilibrium could be reached within a short time (10 min), and the adsorption capacity of Cu(Ⅱ) reached up to 757.45 mg/g. The adsorption kinetics and adsorption isotherms were well-fitted with the pseudo-second-order and the Freundlich isotherm models, respectively. The adsorption process of the composite is mainly controlled by chemisorption, and functional group chelation and electrostatic force were the adsorption mechanisms; pore filling also has a great influence on the adsorption of Cu(Ⅱ). It was found that the prepared modified nanocellulose composite has great potential for the removal of heavy metals from water. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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24 pages, 1656 KiB

Open AccessFeature PaperArticle

Coupling of Advanced Oxidation Technologies and Biochar for the Removal of Dyes in Water

by Carolina Gallego-Ramírez, Edwin Chica and Ainhoa Rubio-Clemente

Water 2022, 14(16), 2531; https://doi.org/10.3390/w14162531 - 17 Aug 2022

Cited by 17 | Viewed by 2928

Abstract

When dyes are discharged in water bodies, mutagenic, carcinogenic and teratogenic effects may be caused in both aquatic organisms and human beings. The use of biochar and the implementation of advanced oxidation processes (AOPs) are alternative treatments that have been used individually in [...] Read more.

When dyes are discharged in water bodies, mutagenic, carcinogenic and teratogenic effects may be caused in both aquatic organisms and human beings. The use of biochar and the implementation of advanced oxidation processes (AOPs) are alternative treatments that have been used individually in the removal of dyes in wastewater. Besides being effective processes acting separately, biochar and AOPs can be coupled, exhibiting synergetic effects in the treatment of dyes contained in water. This work deals with the methods implemented to produce biochar from biomass, its mechanism in the removal of dyes and associated sustainability issues. Additionally, the main AOPs that have been utilized for the removal of dyes from water are covered, as well as the biochar-AOP combined processes. The future prospects for the removal of dyes from water have been also addressed. The coupling of biochar to AOPs has been proven to be more effective in the removal and mineralization of dyes than the individual treatments. In this regard and considering the scarce studies in the field, new horizons are opened on the treatment of water polluted with dyes. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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13 pages, 3722 KiB

Open AccessArticle

Remediation of PO₄³⁻ in Water Using Biodegradable Materials Embedded with Lanthanum Oxide Nanoparticles

by Kai Guo, Zirui Song and Chengchun Tang

Water 2022, 14(10), 1656; https://doi.org/10.3390/w14101656 - 23 May 2022

Cited by 2 | Viewed by 1983

Abstract

Eutrophication, a process in which algae grow inordinately, adversely affects aqueous fauna. Phosphorous at levels above 0.1 mg/L is adequate to cause eutrophication. In this study, we aimed to reduce the amount of PO₄³⁻ in water using biodegradable and ecofriendly sorbents. [...] Read more.

Eutrophication, a process in which algae grow inordinately, adversely affects aqueous fauna. Phosphorous at levels above 0.1 mg/L is adequate to cause eutrophication. In this study, we aimed to reduce the amount of PO₄³⁻ in water using biodegradable and ecofriendly sorbents. Lanthanum oxide nanoparticles were doped in agar and cellulose sponge to produce two new sorbents, agar–La and sponge–La, respectively. Both sorbents showed high efficacy in remediating up to 10 mg/L PO₄³⁻ in water. Sponge–La was found to be more proficient in terms of adsorption than agar–La because it required just 1 h to achieve 80% adsorption when the initial concentration of PO₄³⁻ was 10 mg/L. Sponge–La was effective at pH levels ranging from 4 to 8, with a removal rate of 80–100%. Although agar–La displayed a slow sorption process, it presented a high adsorption capacity (156 mg/g); moreover, the cake-shaped agar–La could be easily manufactured and separated from an aqueous matrix or any water-based solutions. These two sorbents could effectively remove high concentrations of PO₄³⁻, and their preparation requires a simple step. Agar–La was easier to manufacture, whereas the adsorption process using sponge–La was more rapid. In addition, both sorbents can be easily separated from the matrix after sorption. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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17 pages, 3681 KiB

Open AccessArticle

pH-Responsive Eco-Friendly Chitosan–Chlorella Hydrogel Beads for Water Retention and Controlled Release of Humic Acid

by Hao Li, Jin Wang, Yu Luo, Bo Bai and Fangli Cao

Water 2022, 14(8), 1190; https://doi.org/10.3390/w14081190 - 8 Apr 2022

Cited by 21 | Viewed by 4078

Abstract

For improving the mechanical strength of controlled release fertilizer (CRF) hydrogels, a novel material of Chlorella was employed as a bio-based filler to prepare chitosan–chlorella hydrogel beads with physical crosslink method. Here, the synthesis mechanism was investigated, and the chitosan–chlorella hydrogel beads exhibited [...] Read more.

For improving the mechanical strength of controlled release fertilizer (CRF) hydrogels, a novel material of Chlorella was employed as a bio-based filler to prepare chitosan–chlorella hydrogel beads with physical crosslink method. Here, the synthesis mechanism was investigated, and the chitosan–chlorella hydrogel beads exhibited enhanced mechanical stability under centrifugation and sonication than pure chitosan hydrogel beads. Chlorella brought more abundant functional groups to original chitosan hydrogel, hence, chitosan–chlorella hydrogel beads represented greater sensitivity and controllable response to external factors including pH, salt solution, temperature. In distilled water, the hydrogel beads with 40 wt% Chlorella reached the largest water absorption ratio of 42.92 g/g. Moreover, the mechanism and kinetics process of swelling behavior of the chitosan–chlorella hydrogel beads were evaluated, and the loading and releasing of humic acid by the hydrogel beads as a carrier material were pH-dependent and adjustable, which exhibit the potential of chitosan–chlorella hydrogel beads in the field of controlled release carrier biomaterials. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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16 pages, 2647 KiB

Open AccessArticle

Adsorption of Arsenic on Fe-Modified Biochar and Monitoring Using Spectral Induced Polarization

by Panagiotis Kirmizakis, Bassam Tawabini, Omer Muhammad Siddiq, Dimitrios Kalderis, Dimitrios Ntarlagiannis and Pantelis Soupios

Water 2022, 14(4), 563; https://doi.org/10.3390/w14040563 - 13 Feb 2022

Cited by 13 | Viewed by 3465

Abstract

This work demonstrates the potential of Fe-modified biochar for the treatment of arsenic (As) simulated wastewater and the monitoring of adsorption in real-time. Specifically, we propose the utilization of date-palm leaves for the production of biochar, further modified with Fe in order to [...] Read more.

This work demonstrates the potential of Fe-modified biochar for the treatment of arsenic (As) simulated wastewater and the monitoring of adsorption in real-time. Specifically, we propose the utilization of date-palm leaves for the production of biochar, further modified with Fe in order to improve its adsorption function against inorganic pollutants, such as As. Both the original biochar and the Fe-modified biochar were used for adsorption of As in laboratory batch and column experiments. The monitoring of the biochar(s) performance and As treatment was also enhanced by using the spectral induced polarization (SIP) method, offering real-time monitoring, in addition to standard chemical monitoring. Both the original and the Fe-modified biochar achieved high removal rates with Fe-modified biochar achieving up to 98% removal of As compared to the 17% by sand only (control). In addition, a correlation was found between post-adsorption measurements and SIP measurements. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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14 pages, 34119 KiB

Open AccessArticle

Rice Straw Biochar and Magnetic Rice Straw Biochar for Safranin O Adsorption from Aqueous Solution

by Do Thi My Phuong and Nguyen Xuan Loc

Water 2022, 14(2), 186; https://doi.org/10.3390/w14020186 - 10 Jan 2022

Cited by 28 | Viewed by 5309

Abstract

This study investigates the adsorption of Safranin O (SO) from aqueous solution by both biochar and magnetic biochar derived from rice straw. Rice straw biochar (RSB) was made by pyrolysis in a furnace at 500 °C, using a heating rate of 10 °C·min [...] Read more.

This study investigates the adsorption of Safranin O (SO) from aqueous solution by both biochar and magnetic biochar derived from rice straw. Rice straw biochar (RSB) was made by pyrolysis in a furnace at 500 °C, using a heating rate of 10 °C·min⁻¹ for 2 h in an oxygen-limited environment, whilst the magnetic rice straw biochar (MRSB) was produced via the chemical precipitation of Fe²⁺ and Fe³⁺. The physicochemical properties of the synthesized biochars were characterized using SEM, SEM- EDX, XRD, FTIR techniques, and N₂ adsorption (77 K) and pH_pzc measurements. Batch adsorption experiments were used to explore the effect of pH, biochar dosage, kinetics, and isotherms on the adsorption of SO. Experimental data of RSB and MRSB fit well into both Langmuir and Freundlich isotherm models, and were also well-explained by the Lagergren pseudo-second-order kinetic model. The maximum SO adsorption capacity of MRSB was found to be 41.59 mg/g, while for RSB the figure was 31.06 mg/g. The intra-particle diffusion model indicated that the intra-particle diffusion may not be the only rate-limiting step. The collective physical and chemical forces account for the adsorption mechanism of SO molecules by both RSB and MRSB adsorbents. The obtained results demonstrated that the magnetic biochar can partially enhance the SO adsorption capacity of its precursor biochar and also be easily separated from the solution by using an external magnet. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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Review

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36 pages, 9545 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Research Progress on Adsorption of Arsenic from Water by Modified Biochar and Its Mechanism: A Review

by Yongchang Sun, Fangxin Yu, Caohui Han, Chouarfa Houda, Mingge Hao and Qiongyao Wang

Water 2022, 14(11), 1691; https://doi.org/10.3390/w14111691 - 25 May 2022

Cited by 26 | Viewed by 5295

Abstract

Arsenic (As) is a non-metallic element, which is widely distributed in nature. Due to its toxicity, arsenic is seriously harmful to human health and the environment. Therefore, it is particularly important to effectively remove arsenic from water. Biochar is a carbon-rich adsorption material [...] Read more.

Arsenic (As) is a non-metallic element, which is widely distributed in nature. Due to its toxicity, arsenic is seriously harmful to human health and the environment. Therefore, it is particularly important to effectively remove arsenic from water. Biochar is a carbon-rich adsorption material with advantages such as large specific surface area, high porosity, and abundant functional groups, but the original biochar has limitations in application, such as limited adsorption capacity and adsorption range. The modified biochar materials have largely enhanced the adsorption capacity of As in water due to their improved physicochemical properties. In this review, the changes in the physicochemical properties of biochar before and after modification were compared by SEM, XRD, XPS, FT-IR, TG, and other characterization techniques. Through the analysis, it was found that the adsorbent dosage and pH are the major factors that influence the As adsorption capacity of the modified biochar. The adsorption process of As by biochar is endothermic, and increasing the reaction temperature is conducive to the progress of adsorption. Results showed that the main mechanisms include complexation, electrostatic interaction, and precipitation for the As removal by the modified biochar. Research in the field of biochar is progressing rapidly, with numerous achievements and new types of biochar-based materials prepared with super-strong adsorption capacity for As. There is still much space for in-depth research in this field. Therefore, the future research interests and applications are put forward in this review. Full article

(This article belongs to the Special Issue Application of Biochar, Adsorbent and Nanomaterials in Wastewater Treatment)

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