Experimental Study on Single Factor, Orthogonal and Characteristics of SRB Particles Fixed by Biologically Activated Lignite

Abstract Aiming at the problems of insufficient supply of carbon source and toxic effect of heavy metal ions in the treatment of acid mine wastewater (AMD) by sulfate reducing bacteria (SRB), immobilized particles were prepared with Rhodopseudomonas spheroides, SRB and lignite as the main raw materials, and the optimal ratio of immobilized particles was determined based on single factor test and orthogonal test. The adsorption experiment of immobilized particles was carried out under the optimal ratio, the reaction kinetic process and adsorption capacity of immobilized particles for different ions were analyzed, and the action mechanism was studied. The results show that lignite not only has good adsorption performance, but also can be used as the carbon source of SRB after degradation by Rhodopseudomonas spheroides, so as to solve the problems of low removal efficiency of AMD by SRB and insufficient supply of carbon source. When the dosage of lignite, Rhodopseudomonas spheroides and SRB is 3%, 10% and 10% respectively, and the particle size of lignite is 200 mesh, the overall treatment effect is the best. The removal rates of SO42-, Zn2+ and Cu2+ are 83.21%, 99.59% and 99.93% respectively, the pH is increased to 7.43, the release of COD is 523 mg/L, and the ORP number is -134 mV. The reduction process of SO42- by immobilized particles conforms to the pseudo first-order kinetics, the isothermal adsorption of Zn2+ more conforms to the Freundlich isothermal adsorption equation, and the adsorption kinetics of Zn2+ more conforms to the pseudo second-order kinetic model.

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Performance of poly-o-phenylenediamine and its carbon dot composite electrode in the removal of Cu2+ from its aqueous solution

Functional Materials Letters ◽

10.1142/s1793604721510371 ◽

2021 ◽

pp. 2151037

Author(s):

Yu Meng ◽

Qing Zhong ◽

Arzugul Muslim

Keyword(s):

Aqueous Solution ◽

Electrochemical Reduction ◽

Composite Electrode ◽

Reduction Process ◽

Order Kinetic ◽

Carbon Dot ◽

First Order ◽

Oxidation Reduction ◽

Order Kinetic Model ◽

Optimal Ph

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.

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Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽

10.15376/biores.16.2.3575-3595 ◽

2021 ◽

Vol 16 (2) ◽

pp. 3575-3595

Author(s):

Wanting Li ◽

Ruifeng Shan ◽

Yuna Fan ◽

Xiaoyin Sun

Keyword(s):

Tall Fescue ◽

Adsorption Process ◽

Exothermic Reaction ◽

Equilibrium Concentration ◽

Black Soil ◽

Adsorption Behavior ◽

Order Kinetic ◽

Isothermal Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

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Adsorption characteristics of Pb(II) using biochar derived from spent mushroom substrate

Scientific Reports ◽

10.1038/s41598-019-52554-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Qianlan Wu ◽

Yang Xian ◽

Zilin He ◽

Qi Zhang ◽

Jun Wu ◽

...

Keyword(s):

Physicochemical Properties ◽

Raw Materials ◽

Edible Mushroom ◽

Bet Surface Area ◽

Order Kinetic ◽

The Sustainable Development ◽

Adsorption Capacities ◽

Small Pore ◽

Order Kinetic Model ◽

Pseudo Second Order

Abstract As a multifunctional material, biochar is considered a potential adsorbent for removing heavy metals from wastewater. Most biochars with high adsorption capacities have been modified, but this modification is uneconomical, and modifying biochar may cause secondary pollution. Thus, it is necessary to develop an efficient biochar without modification. In this study, spent P. ostreatus substrate and spent shiitake substrate were used as the raw materials to prepare biochar. Then, the physicochemical properties of the biochars and their removal efficiencies for Pb(II) were investigated. The results showed that the physicochemical properties (e.g., large BET surface area, small pore structure and abundant functional groups) contributed to the large adsorption capacity for Pb(II); the maximum adsorption capacities were 326 mg g−1 (spent P. ostreatus substrate-derived biochar) and 398 mg g−1 (spent shiitake substrate-derived biochar), which are 1.6–10 times larger than those of other modified biochars. The Pb(II) adsorption data could be well described by the pseudo-second-order kinetic model and the Langmuir model. This study provides a new method to comprehensively utilize spent mushroom substrates for the sustainable development of the edible mushroom industry.

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Preparation and Adsorption Properties of Biochar/g-C3N4 Composites for Methylene Blue in Aqueous Solution

Journal of Nanomaterials ◽

10.1155/2019/2394184 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Xiaodong Li

Keyword(s):

Methylene Blue ◽

Thermodynamic Parameters ◽

Raw Materials ◽

Order Kinetic ◽

Adsorption Effect ◽

Freundlich Model ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Ft Ir ◽

Doping Ratio

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.

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Adsorption removal of Cr(VI) by isomeric FeOOH

Water Science & Technology ◽

10.2166/wst.2019.273 ◽

2019 ◽

Vol 80 (2) ◽

pp. 300-307

Author(s):

Di Zhang ◽

Jiaxin Liu ◽

Shibei Zhu ◽

Huixin Xiong ◽

Yiqun Xu

Keyword(s):

Active Sites ◽

Correlation Coefficients ◽

Order Kinetic ◽

Isothermal Adsorption ◽

Adsorption Mechanisms ◽

Ph Values ◽

Adsorption Removal ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Theoretical Evidence

Abstract The aim of this work is to study the performances of isomeric α-, β-, and γ-FeOOH (goethite, akaganéite and lepidocrocite, including five samples named as Gth1 and Gth2, Aka1 and Aka2, and Lep, respectively) for removing hexavalent chromium (Cr(VI)) from aqueous solutions. The adsorption mechanisms were explored by kinetic and isothermal experiments. Adsorption efficiencies under the different pH values, anions, and the levels of adsorbate and adsorbent were also measured. Results showed that the Cr(VI) adsorption by isomeric FeOOH could be best described by pseudo-second-order kinetic model. The processes of Cr(VI) isothermal adsorption could be greatly fitted by the Langmuir and Freundlich equations with the high correlation coefficients of R2 (>0.92). Also, there were the optimum pH values of 3.0–8.0 for FeOOH to adsorb Cr(VI), and their adsorption capacities were tightly related with the active sites of adsorbents. Cr(VI) adsorptions by these adsorbents were easily influenced by H2PO4–, and then SO42–, while there were little effects by Cl–, CO32– and NO3–. These obtained results could provide a potentially theoretical evidence for isomeric FeOOH materials applied in the engineering treatment of the polluted chromate-rich waters.

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Preparation and Adsorption Properties of Rod MgNiAl-LDH

Materials Science Forum ◽

10.4028/www.scientific.net/msf.956.294 ◽

2019 ◽

Vol 956 ◽

pp. 294-304

Author(s):

Guo Jun Ke ◽

Hong Jun Tan ◽

Peng Fei Yang ◽

Pin Yu Zou

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Raw Materials ◽

Magnesium Nitrate ◽

Chloride Ions ◽

Adsorption Properties ◽

Order Kinetic ◽

Nickel Aluminum ◽

Order Kinetic Model

Using magnesium nitrate, nickel nitrate and aluminum nitrate as raw materials and urea as precipitant, magnesium nickel aluminum ternary hydrotalcites with large specific surface area were prepared by hydrothermal method. The prepared samples were characterized by SEM、XRD、BET and EDS etc., respectively. The adsorption properties of MgNiAl-LDHs, MgAl-LDHs and their calcined products (MgNiAl-LDOs, MgAl-LDOs) for chloride ions in solution were investigated. The results show that MgNiAl-LDHs are cubic with rod-like structure, with a specific surface area of 197.62 m2/g, which is much larger than that of MgAl-LDHs (102.82 m2/g). Under the same adsorption conditions, the saturated adsorption capacities of MgNiAl-LDHs and MgAl-LDHs for chloride ions are 130.06mg/g and 110.02 mg/g respectively. MgNiAl-LDOs showed better adsorption ability for chloride ions. By simulating the adsorption data, the results show that the adsorption kinetics and the adsorption isotherm are in accordance with the quasi-second-order kinetic model and the Langmuir isotherm model, respectively.

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Studies on Kinetics, Isotherms, Thermodynamics and Adsorption Mechanism of Methylene Blue by N and S Co-Doped Porous Carbon Spheres

Nanomaterials ◽

10.3390/nano11071819 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1819

Author(s):

Yongpeng Ren ◽

Feng Chen ◽

Kunming Pan ◽

Yang Zhao ◽

Lulu Ma ◽

...

Keyword(s):

Methylene Blue ◽

Porous Carbon ◽

Adsorption Mechanism ◽

Order Kinetic ◽

Carbon Spheres ◽

Single Factor ◽

Isothermal Adsorption ◽

Porous Carbon Spheres ◽

Co Doped ◽

Mb Adsorption

Heteroatom-doped carbon is widely used in the fields of adsorbents, electrode materials and catalysts due to its excellent physicochemical properties. N and S co-doped porous carbon spheres (N,S-PCSs) were synthesized using glucose and L-cysteine as carbon and heteroatom sources using a combined hydrothermal and KOH activation process. The physicochemical structures and single-factor methylene blue (MB) adsorption properties of the N,S-PCSs were then studied. The optimized N,S-PCSs-1 possessed a perfect spherical morphology with a 2–8-μm diameter and a large specific area of 1769.41 m2 g−1, in which the N and S contents were 2.97 at% and 0.88 at%, respectively. In the single-factor adsorption experiment for MB, the MB adsorption rate increased with an increase in carbon dosage and MB initial concentration, and the adsorption reached equilibrium within 2–3 h. The pseudo-second-order kinetic model could excellently fit the experimental data with a high R2 (0.9999). The Langmuir isothermal adsorption equation fitted well with the experimental results with an R2 value of 0.9618, and the MB maximum adsorption quantity was 909.10 mg g−1. The adsorption of MB by N,S-PCSs-1 was a spontaneous, endothermic, and random process based on the thermodynamics analyses. The adsorption mechanism mainly involved Van der Waals force adsorption, π-π stacking, hydrogen bonds and Lewis acid–base interactions.

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Comparison and Analysis of Denitrification Effect and Kinetics Regarding Several New Type Carbon Sources

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.2695 ◽

2011 ◽

Vol 255-260 ◽

pp. 2695-2699

Author(s):

Hao Yan Li ◽

Dian Hai Yang ◽

Hai Yan Wu ◽

Qin Lu ◽

Xiang Zheng

Keyword(s):

Carbon Source ◽

Nitrate Removal ◽

Carbon Sources ◽

Batch Reactors ◽

Order Kinetic ◽

Starch Solution ◽

Primary Sludge ◽

Carbon Decomposition ◽

Order Kinetic Model ◽

Denitrification Kinetics

Three typical external carbon sources (i.e. leachate, hydrolysates from primary sludge and starch solution) with regard to the denitrification process were investigated respectively in sequencing batch reactors (SBR) and their denitrification properties were compared to provide the optimum substrate suited for nitrogen removal processes. The variations of nitrogen were examined and nitrate utility ratio as well as carbon consumption rate was exhibited, denitrification kinetics regarding leachate was also analyzed by use of zero-order kinetic model. The experimental results indicated that the similar denitrification trend was achieved between hydrolysates from primary sludge and starch solution other than leachate as carbon source in denitrification system. The nitrate was not entirely degraded and the nitrite generated permanent accumulation. Compared with other carbon sources, leachate in steady operation showed the highest nitrate removal concentration and rate in phase I with an average of 13 mg/L and 86%, respectively. In phase II, the maximum nitrate and carbon decomposition rates were 0.088 g N/g VSS•d and 0.848 g TOC/g VSS•d respectively occurring at leachate as substrate. Thus, stable leachate was considered as the most suitable carbon source in comparison with other substrates.

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Isothermal adsorption characteristics of bioretention media for fecal Escherichia coli

Thermal Science ◽

10.2298/tsci2004427m ◽

2020 ◽

Vol 24 (4) ◽

pp. 2427-2436

Author(s):

Ying Mei ◽

Hang Zhou ◽

Xiao-Han Zhu ◽

Peng Zhang ◽

Xiao-Fei Li ◽

...

Keyword(s):

Escherichia Coli ◽

Fly Ash ◽

Sandy Soil ◽

Pathogenic Bacteria ◽

Order Kinetic ◽

Rainfall Runoff ◽

Huge Number ◽

Isothermal Adsorption ◽

Isotherm Adsorption ◽

Order Kinetic Model

Rainfall runoff contains a huge number of pathogenic bacteria that seriously deteriorate water quality. Bioretention is an effective approach to removal of pathogenic bacteria from rainwater. This study uses sandy soil, fly ash, slag, sandy soil+5% fly ash, and sandy soil+5% slag as media to evaluate the adsorption of fecal Escherichia coli. The mechanisms of the five media conform to the Langmuir?s isotherm adsorption equation, and a pseudo-first-order kinetic model is adopted to reveal the absorption kinetics.

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Minerals as Potential Catalysts in Heterogeneous Catalytic Ozonation: A Kinetic Study of p-CBA Degradation in Aqueous Solutions at pH 7

Materials Proceedings ◽

10.3390/materproc2021005005 ◽

2021 ◽

Vol 5 (1) ◽

pp. 5

Author(s):

Savvina Psaltou ◽

Efthimia Kaprara ◽

Manassis Mitrakas ◽

Anastasios Zouboulis

Keyword(s):

Kinetic Model ◽

Kinetic Study ◽

Raw Materials ◽

Catalytic Ozonation ◽

Second Order ◽

Order Kinetic ◽

First Order ◽

Heterogeneous Catalytic ◽

Order Kinetic Model ◽

Pseudo Second Order

This study examines the removal of p-CBA via the application of heterogeneous catalytic ozonation in the presence of 13 minerals. The solids were used as raw materials or after hydrophilic/hydrophobic modification. The optimal minerals were zeolite, calcite, dolomite, and thermally treated talc. The kinetic study showed that the decomposition of ozone followed a first-order kinetic model for all ozonation systems, whereas the kinetic model of p-CBA removal depended on the materials that were applied. The catalytic degradation of p-CBA followed a second-order kinetic model, while in the presence of non-catalytic materials; the p-CBA abatement was in best agreement with the pseudo-second-order kinetic model, as single ozonation.

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