Isothermal adsorption characteristics of bioretention media for fecal Escherichia coli

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.

Download Full-text

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.

Download Full-text

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

10.21203/rs.3.rs-956144/v1 ◽

2021 ◽

Author(s):

Junzhen Di ◽

Yangyang Jiang ◽

Mingjia Wang ◽

Yanrong Dong

Keyword(s):

Carbon Source ◽

Raw Materials ◽

Reduction Process ◽

Order Kinetic ◽

Single Factor ◽

Isothermal Adsorption ◽

Optimal Ratio ◽

Mine Wastewater ◽

Order Kinetic Model ◽

Rhodopseudomonas Spheroides

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.

Download Full-text

Adsorption of Pb(II) from Aqueous Solutions on Dithizone-Immobilized Coal Fly Ash

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.840.57 ◽

2020 ◽

Vol 840 ◽

pp. 57-63

Author(s):

Dina Fitriana ◽

Mudasir Mudasir ◽

Dwi Siswanta

Keyword(s):

Fly Ash ◽

Adsorption Isotherm ◽

Contact Time ◽

Coal Fly Ash ◽

Order Kinetic ◽

Adsorbent Dosage ◽

Activated Coal ◽

Concentration Of Ions ◽

Order Kinetic Model ◽

Pseudo Second Order

Adsorption of Pb(II) ions onto selective adsorbent of dithizone-immobilized coal fly ash (DCFA) from Holcim, Cilacap, Indonesia has been investigated in batch experiments. Prepared coal fly ash (CFA) modified by immobilization of dithizone previously were characterized by FT-IR and XRD. Several parameters influencing the adsorption of Pb(II) ions such as effect of pH, adsorbent dosage, contact time and initial concentration of ions on the efficiency of the adsorption were studied. The optimum condition of Pb(II) adsorption was found at pH 5, adsorbent dosage 0.1 g, contact time 60 min and initial Pb(II) ions concentration of 60 mg L–1. The adsorption kinetics of Pb(II) ions on DCFA was found to follow a pseudo-second-order kinetic model. The adsorption isotherm data were fitted to the Langmuir model. Kinetics and adsorption isotherm studies suggest that the capacity and affinity of the DCFA in adsorbing Pb(II) ions is significantly improved compared to those of non-immobilized activated coal fly ash (ACFA).

Download Full-text

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.

Download Full-text

Bagasse Fly Ash as an Effective Adsorbent: Evaluation of Adsorptive Characteristics for 4-Nitroaniline Removal

International Journal for Modern Trends in Science and Technology - RTT2020 ◽

10.46501/ijmtst0705026 ◽

2021 ◽

Vol 7 (05) ◽

pp. 155-161

Author(s):

Amarnath P.C & Shashikala K. J. Praveen Kumar D. G., Kalleshappa C.M.,

Keyword(s):

Fly Ash ◽

Contact Time ◽

Order Kinetic ◽

Batch Experiments ◽

Bagasse Fly Ash ◽

Initial Ph ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Adsorbent Dose ◽

Maximum Removal

In the present study we explored the adsorptive characteristics of 4-nitroaniline from synthetic aqueous solution onto bagasse fly ash (BFA). Batch experiments were carried out to determine the influence of parameters like initial pH (pH0), adsorbent dose (m), contact time (t) and initial concentration (C0) on the removal of 4-nitroaniline. The maximum removal of 4-nitroaniline was determined to be 98% at lower concentrations (50 mg/L) and 41% at higher concentrations (300 mg/L), using a BFA dosage of 10 g/L at 303K. Kinetic study of 4-nitroaniline removal by BFA was well represented by pseudo second-order kinetic model. The 4-nitroaniline desorption from 4-nitroaniline loaded BFA shows that only 27% and 36% of 4-nitroaniline could be recovered using ethyl alcohol and acetone respectively.

Download Full-text

Preparation and Characterization of a Novel Amidoxime-Modified Polyacrylonitrile/Fly Ash Composite Adsorbent and Its Application to Metal Wastewater Treatment

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph19020856 ◽

2022 ◽

Vol 19 (2) ◽

pp. 856

Author(s):

Yan Sun ◽

Xiaojun Song ◽

Jing Ma ◽

Haochen Yu ◽

Gangjun Liu ◽

...

Keyword(s):

Fly Ash ◽

Adsorption Process ◽

Single Layer ◽

Nitrogen Adsorption ◽

Order Kinetic ◽

X Ray Diffraction ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

High Degree

The polyacrylonitrile/fly ash composite was synthesized through solution polymerization and was modified with NH2OH·HCl. The amidoxime-modified polyacrylonitrile/fly ash composite demonstrated excellent adsorption capacity for Zn2+ in an aqueous medium. Fourier transform-Infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption, X-ray diffraction, and scanning electron microscopy were used to characterize the prepared materials. The results showed that the resulting amidoxime-modified polyacrylonitrile/fly ash composite was able to effectively remove Zn2+ at pH 4–6. Adsorption of Zn2+ was hindered by the coexisting cations. The adsorption kinetics of Zn2+ by Zn2+ followed the pseudo-second order kinetic model. The adsorption process also satisfactorily fit the Langmuir model, and the adsorption process was mainly single layer. The Gibbs free energy ΔG0, ΔH0, and ΔS0 were negative, indicating the adsorption was a spontaneous, exothermic, and high degree of order in solution system.

Download Full-text

Lead and cadmium removal by adsorption process using hydroxyapatite porous materials

Water Practice & Technology ◽

10.2166/wpt.2020.003 ◽

2020 ◽

Vol 15 (1) ◽

pp. 130-141 ◽

Cited By ~ 7

Author(s):

Amina Ramdani ◽

Abdelkader Kadeche ◽

Mehdi Adjdir ◽

Zoubida Taleb ◽

Djamila Ikhou ◽

...

Keyword(s):

Porous Materials ◽

Adsorption Process ◽

Industrial Effluents ◽

Order Kinetic ◽

Cadmium Removal ◽

Lead And Cadmium ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Removal Efficiencies ◽

Time Required

Abstract This contribution is a comparison study between synthetic hydroxyapatite (Sy-HAP) and commercial hydroxyapatite (C-HAP) for the removal of Pb2+ and Cd2+ ions present in wastewater from industrial effluents. The obtained results show that the equilibrium time required for complete adsorption of Pb2+ and Cd2+ ions on C-HAP and Sy-HAP is 15 min for both. The obtained removal efficiencies for Sy-HAP are 95.52% and 90.91% for Pb2+ and Cd2+ ions, respectively. Whereas, C-Hap presents lower removal efficiencies of 86.53% and 81.43% for Pb2+ and Cd2+ ions, respectively. Maximum adsorption was observed at pH 5; at lower pH levels adsorption was less. The experimental kinetic data fitted with the second order kinetic model. Thermodynamically, the adsorption process was endothermic and spontaneous in nature. Isotherm adsorption studies indicated that Langmuir, Freundlich and Temkin are the most valid models to describe and evaluate the adsorption process. The EDX results also confirmed the presence of lead and cadmium in adsorbents after adsorption. Finally, the HAP porous materials possess great potential for the removal of Pb2+ and Cd2+ ions from aqueous solutions and wastewater from industrial effluents.

Download Full-text

A renewable, sustainable and low-cost adsorbent for ibuprofen removal

Water Science & Technology ◽

10.2166/wst.2020.551 ◽

2020 ◽

Author(s):

Olugbenga Solomon Bello ◽

Oluwakemi Christiana Alao ◽

Temitope Chris Alagbada ◽

Oluwatobi Samuel Agboola ◽

Omotoyosi Toheeb Omotoba ◽

...

Keyword(s):

Low Cost ◽

Ph Effect ◽

Aqueous Media ◽

Solution Temperature ◽

Order Kinetic ◽

Operational Parameters ◽

Adsorption Parameters ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Best Fit

Abstract Adsorption efficiency of acid-modified kola nut husk (KNHA) as a non-conventional adsorbent for the sorption of Ibuprofen from aqueous media was investigated in this study. The raw and modified samples were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, electron dispersive X-ray spectroscopy pH, and Boehm titration techniques respectively. Adsorption parameters such as pH effect, adsorbate concentration, contact time, and solution temperature were studied. The amount of Ibuprofen uptake was observed to increase with a corresponding increase in adsorption operational parameters. The kinetic data was found to best fit the pseudo-second-order kinetic model. Isotherm adsorption models of Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich were utilized to analyze the adsorption data. The Langmuir isotherm model showed the best fit for experimental data with a maximum monolayer adsorption capacity of 39.22 mg/g. The values of Gibbs free energy change were negative (−164.48 to −64.045.4 kJ/mol) suggesting that the process of ibuprofen adsorption onto KNHA was spontaneous. The positive value of standard enthalpy change (+34.203 kJ/mol) suggests that the process of ibuprofen adsorption was endothermic. KNHA adsorbent was found to be efficient and viable for the uptake of ibuprofen from aqueous medium. Hence, adsorbent prepared from kola nut husk waste has proved to be effective for the adsorptive uptake of Ibuprofen from aqueous media.

Download Full-text

Synthesis of carbon dots-assisted MgAl-LDH hollow microspheres with hierarchical structure for the effective removal of Congo red from wastewater

E3S Web of Conferences ◽

10.1051/e3sconf/202126902003 ◽

2021 ◽

Vol 269 ◽

pp. 02003

Author(s):

Zhigang Jia ◽

Cong Han ◽

Rui Chang ◽

Daqing Zhang

Keyword(s):

Congo Red ◽

Carbon Dots ◽

Ostwald Ripening ◽

Order Kinetic ◽

Effective Removal ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Ft Ir ◽

Double Hydroxide

Hierarchical hollow Mg-Al layered double hydroxide microspheres (HHMs) are successfully prepared by hydrothermal treatment in the presence of carbon dots (CDs). Morphology and structure of the as-prepared samples are characterized using XRD, SEM, FT-IR, and TEM techniques. The growth process of HHMs has been investigated in detail, and Ostwald ripening mechanism is suggested for the hierarchical growth of HHMs. Adsorption isotherms and adsorption kinetics of HHMs for congo red (CR) are investigated. Langmuir and Temkin model are more fitted to the experimental data of CR isotherm adsorption. Adsorption kinetic data obeys the pseudo-second-order kinetic model. Moreover, thermodynamic parameters (ΔGo, ΔHo and ΔSo) show that the CR adsorption onto HHMs is an endothermic and spontaneous process. The as-prepared HHMs could be a potential adsorbent for wastewater treatment containing anion dyes.

Download Full-text

Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

Indonesian Journal of Chemistry ◽

10.22146/ijc.21175 ◽

2018 ◽

Vol 16 (1) ◽

pp. 36 ◽

Cited By ~ 6

Author(s):

Idha Yulia Ikhsani ◽

Sri Juari Santosa ◽

Bambang Rusdiarso

Keyword(s):

Adsorption Capacity ◽

Freundlich Isotherm ◽

Second Order ◽

Isotherm Models ◽

Disperse Dyes ◽

Order Kinetic ◽

Initial Ph ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

Download Full-text