scholarly journals Mechanisms and adsorption capacities of biochar for the removal of organic and inorganic pollutants from industrial wastewater

2020 ◽  
Author(s):  
T. G. Ambaye ◽  
M. Vaccari ◽  
E. D. van Hullebusch ◽  
A. Amrane ◽  
S. Rtimi
Keyword(s):  
Organic Contaminants ◽  
Pyrolysis Temperature ◽  
Low Cost ◽  
Industrial Effluents ◽  
Economic Benefits ◽  
Inorganic Pollutants ◽  
Solution Ph ◽  
Adsorption Mechanisms ◽  
Adsorption Capacities ◽  
Temperature Solution

AbstractCurrently, due to the rapid growth of urbanization and industrialization in developing countries, a large volume of wastewater is produced from industries that contain chemicals generating high environmental risks affecting human health and the economy if not treated properly. Consequently, the development of a sustainable low-cost wastewater treatment approach has attracted more attention of policymakers and scientists. The present review highlights the recent applications of biochar in removing organic and inorganic pollutants present in industrial effluents. The recent modes of preparation, physicochemical properties and adsorption mechanisms of biochar in removing organic and inorganic industrial pollutants are also reviewed comprehensively. Biochar showed high adsorption of industrial dyes up to 80%. It also discusses the recent application and mechanism of biochar-supported photocatalytic materials for the degradation of organic contaminants in wastewater. We reviewed also the possible optimizations (such as the pyrolysis temperature, solution pH) allowing the increase of the adsorption capabilities of biochar leading to organic contaminants removal. Besides, increasing the pyrolysis temperature of the biochar was seen to lead to an increase in its surface area, while it decreases their amount of oxygen-containing functional groups, consequently leading to a decrease in the adsorption of metal (loid) ions present in the medium. Finally, the review suggests that more research should be carried out to optimize the main parameters involved in biochar production and its regeneration methods. Future efforts should be also carried out towards process engineering to improve its adsorption capacity to increase the economic benefits of its implementation.

SURFACE ALTERATION OF ACTIVATED CARBON FOR DETOXIFICATION OF COPPER (II) FROM INDUSTRIAL EFFLUENTS

2013 ◽  
Vol 20 (02) ◽  
pp. 1350021
Author(s):  
SADAF BHUTTO ◽  
M. NASIRUDDIN KHAN
Keyword(s):  
Activated Carbons ◽  
Selective Adsorption ◽  
Low Cost ◽  
Industrial Effluents ◽  
Copper Adsorption ◽  
Adsorption Capacities ◽  
Surface Alteration ◽  
Equilibrium Data ◽  
Modified Activated Carbons ◽  
Acetic Acids

The low-cost modified activated carbons were prepared from Thar and Lakhra (Pakistan) coals by activation with sulfuric acid and further modified with citric, tartaric and acetic acids for the selective adsorption of Cu(II) from aqueous solution. The original carbon obtained from activated Thar and Lakhra coals at pH 3.0 displayed significant adsorption capacity for lead and insignificant capacity values (0.880 and 0.830 mg⋅g-1) for copper. However, after modification with citric, tartaric and acetic acid the copper adsorption capacities enhanced in the range of 5.56–21.85 and 6.05–44.61 times, respectively. The Langmuir, Freundlich and Temkin adsorption isotherms were used to elucidate the observed sorption phenomena. The isotherm equilibrium data was well fitted by the Langmuir and sufficiently fitted to the Freundlich models. The calculated thermodynamic parameters such as change in Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) inferred that the investigated adsorption was spontaneous and endothermic in nature. Based on the results, it was concluded that the surface alteration with citric and tartaric acid, Thar and Lakhra activated carbons had significant potential for selective removal of copper(II) from industrial wastewater.

scholarly journals Nanoengineered Polysaccharide-Based Adsorbents as Green Alternatives for Dye Removal from Wastewater

2021 ◽  
Author(s):  
Hugues Kamdem Paumo ◽  
Lebogang Katata-Seru ◽  
Tshepiso Moremedi ◽  
Mpitloane Joseph Hato ◽  
Soumen Sardar ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Dye Removal ◽  
Organic Dyes ◽  
Low Cost ◽  
Industrial Effluents ◽  
Critical Discussion ◽  
Inorganic Nanoparticles ◽  
Living Organisms ◽  
Health Organization ◽  
Kappa Carrageenan

Water represents one of the essential resources on earth, and all living organisms rely on it for survival. However, freshwater systems are directly under serious threat by human activities. A recent World Health Organization report has estimated that 2 billion people use contaminated water sources. The major organic contaminants in water bodies include organic dyes. These are directly related to the spread of diseases owing to their allergenic, mutagenic, and carcinogenic characteristics. Dyes occur in the environment through untreated industrial effluents. Also, the advancement in human civilisation cannot be considered without the development of modern industries. However, an attempt to limit the resulting impacts of coloured effluents on global freshwater quality has become the focus of recent research. For this reason, the use of efficient, simple, and low-cost methods for the treatment of dyes-containing industrial wastewater could serve as a useful tool. An effort to meet the demand for “green chemistry” and sustainable development has led to several investigations on polysaccharide-based adsorbents. This chapter exposes a critical discussion on the literature concerning the biopolymeric xanthan gum and kappa-carrageenan polysaccharides as adsorbents for dye removal in an aqueous medium. Functionalisation of these biopolymers through graft copolymerisation and inclusion of inorganic nanoparticles for improved adsorption performance is systematically elaborated.

Copper(II) removal by natural siderite (FeCO3) from surface and groundwaters

2020 ◽  
Author(s):  
Lisa C. Füllenbach ◽  
Jeffrey Paolo H. Perez ◽  
Helen M. Freeman ◽  
Andrew N. Thomas ◽  
Liane G. Benning ◽  
...  
Keyword(s):  
Ferrous Iron ◽  
Groundwater Remediation ◽  
Low Cost ◽  
Reaction Products ◽  
Solution Ph ◽  
Anoxic Conditions ◽  
Adsorption Mechanisms ◽  
Reducing Conditions ◽  
Reaction Processes

<p>Anthropological use of land and resources releases vast amounts of waste into surface waters and aquifers. Copper(II) is one of the most widely occurring heavy metal contaminants, introduced into the environment from industrial discharge, landfill leakage, agricultural and mining sources. Common remediation strategies for redox-sensitive Cu(II) are based on adsorption or phytoremediation methods. To experimentally test the efficiency of Cu(II) retention by inorganic redox reaction processes suitable for in situ surface- and groundwater remediation applications, we used siderite (FeCO<sub>3</sub>), which is abundant in anoxic sediments and soils and as a carbonate highly soluble in acidic environments. Its dissolution increases alkalinity and releases highly reactive, redox sensitive Fe(II). This aqueous ferrous iron can act as 1) a precursor for Fe(III) (hydr)oxides in oxic conditions, which are effective sorbents of heavy metals, and 2) a reducing agent under reducing conditions, where it can form a strong redox couple with Cu(II). We investigated the long term (1008 h) removal of aqueous Cu(II) through siderite dissolution batch experiments under oxic and anoxic conditions and monitored changes in the aqueous concentrations of Cu and Fe, pH and the reacted solids morphology over time. Cu adsorption and speciation on the reaction products was determined by X-ray absorption and photoelectron spectroscopies.</p><p>Under oxic conditions, increasing alkalinity led to a rapid increase in solution pH and the precipitation of nanoparticulate goethite and hematite from the released ferrous iron. After 1008 h of reaction, 80 % of the dissolved Cu(II) were removed from solution by sorption, whereby up to >30 % of this sorbed Cu(II) was reduced to Cu(I). Under anoxic conditions, the solution pH increased abruptly and copper uptake occurred more than twice as fast as under oxic conditions. Notably, the released Fe(II) was oxidized by Cu(II) leading to the precipitation of lepidocrocite, while all copper was removed from solution with >70 % of Cu(II) being reduced to Cu(0).</p><p>Our results suggest that 1) redox reactions between aqueous Cu(II) and Fe(II) promote coupled dissolution-precipitation and adsorption mechanisms responsible for Cu(II) removal, and that 2) siderite is a low-cost and effective material that is potentially useful for in situ remediation in either oxygenated or reduced environments.</p>

scholarly journals Removal of Hydrophobic Contaminants from the Soil by Adsorption onto Carbon Materials and Microbial Degradation

2021 ◽  
Vol 7 (4) ◽  
pp. 83
Author(s):  
Shippi Dewangan ◽  
Amarpreet K. Bhatia ◽  
Ajaya Kumar Singh ◽  
Sónia A. C. Carabineiro
Keyword(s):  
Microbial Degradation ◽  
Organic Contaminants ◽  
Raw Materials ◽  
Low Cost ◽  
Environmental Safety ◽  
Hydrophobic Organic Contaminants ◽  
Adsorption Mechanisms ◽  
Environmental Treatment ◽  
Sufficient Food ◽  
Practicable Method

The pollution of soil is a worldwide concern as it has harmful consequences on the environment and human health. With the continuous expansion of industry and agriculture, the content of hydrophobic organic pollutants in the soil has been increasing, which has caused serious pollution to the soil. The removal of hydrophobic organic contaminants from soil, aiming to recover environmental safety, is an urgent matter to guarantee sufficient food and water for populations. Adsorption has proven to be an effective and economically practicable method for removing organic contaminants. This paper summarizes the use of low-cost adsorbents, such as biochar and activated carbon, for removing hydrophobic organic contaminants from soil. Biochar is usually appropriate for the adsorption of organic contaminants via the adsorption mechanisms of electrostatic interaction, precipitation, and ion exchange. Biochar also has numerous benefits, such as being obtained from several kinds of raw materials, having low costs, recyclability, and potential for environmental treatment. This paper illustrates biochar’s adsorption mechanism for organic contaminants and discusses the microbial degradation of hydrophobic organic contaminants.

scholarly journals Preparation of Cotton Fibers Modified With Aromatic Heterocyclic Compounds and Study of Cr(VI) Adsorption Performance

2021 ◽  
Author(s):  
Zhiyu Huang ◽  
Peng Wu ◽  
Yankun Yin ◽  
Xiang Zhou ◽  
Lu Fu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Low Cost ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract In order to prepare low-cost and environmentally friendly adsorbent materials for adsorption of heavy metal ion, two kinds of novel modified cottons (C-4-APD and C-2-APZ) were obtained by introducing 4-aminopyridin and 2-aminopyrazine into the surface of degreasing cotton, respectively, and used for the removal of Cr(VI) ions from aqueous solution. The two modified cottons were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed the amino groups, pyridine groups and pyrazine groups grafted onto the surface of modified cottons. The maximum adsorption capacities of C-4-APD and C-2-APZ were 73.78 mg/g and 61.34 mg/g, respectively, at the optimum pH of 6 and an initial concentration of 200 mg/g. Kinetic and isotherm studies were carried out to investigate the adsorption behavior of the modified cottons on Cr(VI) ions. The results showed that the adsorption of Cr(VI) ions by modified cottons followed a pseudo-second-order kinetic model, the equilibrium data were in good agreement with the Langmuir isotherm model, and electrostatic and chemisorption may be the main adsorption mechanisms. The recovery and reuse of modified cotton were achieved by washing with 2 wt% thiourea-hydrochloric acid solution (0.5 mol/L concentration of HCl), and the adsorption capacities of C-4-APD and C-2-APZ were maintained above 90% and 80%, respectively, after six cycles.

Adsorption of Zn2+ and Ni2+ in a binary aqueous solution by biosorbents derived from sawdust and water hyacinth (Eichhornia crassipes)

2014 ◽  
Vol 70 (8) ◽  
pp. 1419-1427 ◽  
Author(s):  
Willis Gwenzi ◽  
Tinashe Musarurwa ◽  
Phillip Nyamugafata ◽  
Nhamo Chaukura ◽  
Allen Chaparadza ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Water Hyacinth ◽  
Metal Ion ◽  
Eichhornia Crassipes ◽  
Low Cost ◽  
Initial Solution ◽  
Solution Ph ◽  
Water And Wastewater Treatment ◽  
Adsorption Capacities ◽  
The Relationship

The Zn2+ and Ni2+ adsorption capacities of six biosorbents derived from water hyacinth (Eichhornia crassipes) (WH) and sawdust (SD) were investigated, with activated carbon as the control. The biosorbents were raw biomass (WH, SD), charred WH (BWH) and SD and sulphonated bio-chars of WH and SD. The effect of the initial solution pH and Zn2+ and Ni2+ concentrations on adsorption capacity was studied, and adsorption isotherms for Zn2+ and Ni2+ evaluated. The initial solution pH significantly influenced adsorption (p < 0.05) but the relationship was generally nonlinear. Zn2+ suppressed Ni2+ adsorption on all biosorbents. The adsorption capacities of the biosorbents were statistically (p ≤ 0.05) similar to or higher than that of activated carbon. The effects of pyrolysis and bio-char sulphonation on adsorption were inconsistent and dependent on biomass type; in most cases bio-char was a better biosorbent than the original biomass, while sulphonation resulted in less or comparable adsorption. Adsorption data obeyed at least one of three isotherms (linear, Langmuir and Freundlich) (r2 = 0.90-0.995, p < 0.05). The study revealed that low-cost biosorbents may be used as alternatives to activated carbon in applications including selective separation of Zn2+ from multi-metal ion solutions containing Ni2+, and water and wastewater treatment.

scholarly journals Comparison of methylene blue adsorption from aqueous solution using spent tea dust and raw coir pith

2013 ◽  
Vol 16 (1) ◽  
pp. 146-159 ◽  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Rate Constant ◽  
Low Cost ◽  
Order Rate Constant ◽  
Solution Ph ◽  
Coir Pith ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Diffusion Rate Constant

<div> <p>The purpose of the present work is to test the possibility of using the spent tea dust and raw coir pith for the removal of methylene blue (MB) from aqueous solution. The effects of the contact time, adsorbent dosage and solution pH were studied in batch experiments at 27 &deg;C. Results showed that a pH of 7 is favourable for the adsorption of dye. The isothermal data could be well described by the Langmuir equations. Kinetic parameters of adsorption such as the Langergen pseudo-first-order, pseudo-second-order rate constant and the intraparticle diffusion rate constant were determined. The adsorption capacities of Spent Tea Dust (STD) and Raw Coir Pith (RCP) were found to be 86.21 mg and 142.86 mg g<sup>-1</sup> of the adsorbent respectively. The results indicate that STD and RCP could be employed as low-cost alternatives to commercial activated carbon for the removal of dyes from aqueous solution.</p> </div> <p>&nbsp;</p>

scholarly journals Various Adsorbents for Removal of Rhodamine B Dye: A Review

2021 ◽  
Vol 21 (4) ◽  
pp. 1039
Author(s):  
Zainab Mohammad Saigl
Keyword(s):  
Rhodamine B ◽  
Low Cost ◽  
Dye Adsorption ◽  
Industrial Effluents ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Waste Biomass ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Wide Range

Lately, there has been an increase in dye manufacturing, resulting in increased environmental pollution. Recent studies show a wide availability of usage adsorbents, including banana peels, potatoes, algae, etc. Food and Drug Administration prohibited the use of Rhodamine B (RhB) for its toxicity and harmful effects. Therefore, this study presents a wide range of non-conventional low-cost alternative adsorbents to remove RhB dye from wastewater. It has been observed that the mechanism of the dye adsorption is focused on kinetics, isotherm, and thermodynamics models, which depend on the chemical nature of the materials and various physicochemical experimental conditions such as solution pH, initial dye concentration, adsorbent dosage, and temperature of the system. The kinetic data of adsorption of RhB dye usually follow the pseudo-first-order and pseudo-second-order kinetic models. Several studies revealed that Langmuir and Freundlich adsorption isotherm models are frequently used to evaluate the adsorption capacity of the adsorbents. Furthermore, thermodynamic examination showed that RhB adsorption was endothermic and unconstrained in nature. Thus, both photocatalytic degradation and adsorption methods offer good potential to remove RhB dye from industrial effluents. The work is in progress to evaluate the possibility of using other modified waste biomass for industrial pollution control.

scholarly journals Adsorption of Chromium(VI) onto Freshwater Snail Shell-Derived Biosorbent from Aqueous Solutions: Equilibrium, Kinetics, and Thermodynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xuan Hoa Vu ◽  
Lan Huong Nguyen ◽  
Huu Tap Van ◽  
Dinh Vinh Nguyen ◽  
Thu Huong Nguyen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Freshwater Snail ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Adsorption Mechanisms

In this study, freshwater snail shells (FSSs) containing CaCO3 were used as a low-cost biosorbent for removing Cr(VI) from aqueous solutions. The characteristics of FSS and mechanism of Cr(VI) adsorption onto FSS were investigated. The FSS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The adsorption mechanism was determined by conducting various batch adsorption experiments along with fitting experimental data with various adsorption models. Batch adsorption experiments were conducted as a function of solution pH, contact time, biosorbent dose, and initial Cr(VI) concentration. Results indicated that pH = 2, a contact time of 120 min, and an initial Cr(VI) concentration of 30 mg/L at 20°C were the best conditions for adsorption of Cr(VI) onto FSS. The Cr(VI) adsorption onto FSS decreased with an increase in temperature from 20 to 40°C. The obtained maximum adsorption capacity was 8.85 mg/g for 2 g/L of FSS dose with 30 mg/L of initial Cr(VI) at 20°C. The adsorption equilibrium data fit well with the Sips and Langmuir isotherm models at 20°C with a high R2 of 0.981 and 0.975, respectively. Also, a good correlation between the experimental data and the pseudo-second-order model was achieved, with the highest R2 of 0.995 at 20°C. The adsorption mechanisms were electrostatic interaction and ion exchange. Simultaneously, this mechanism was also controlled by film diffusion. The Cr(VI) adsorption process was irreversible, spontaneous (−∆G°), exothermic (∆H° is negative), and less random (∆S° is negative). In conclusion, freshwater snail shells have the potential as a renewable adsorbent to remove toxic metals from wastewater.

scholarly journals Advances in metal-based vanadate compound photocatalysts: synthesis, properties and applications

2021 ◽  
Vol 1 (3) ◽  
pp. 151-168
Author(s):  
Asieh Akhoondi ◽  
Usisipho Feleni ◽  
Bhaskar Bethi ◽  
Azeez Olayiwola Idris ◽  
Akbar Hojjati-Najafabadi
Keyword(s):  
Visible Light ◽  
Low Cost ◽  
Synthesis Temperature ◽  
Solution Ph ◽  
Electron Hole ◽  
Preparation Methods ◽  
Ongoing Research ◽  
Synthesis Properties ◽  
Electron Hole Pair ◽  
Temperature Solution

Among the ongoing research on photocatalysis under visible-light, it has been shown that doped or hybrid catalysts are more active than a single catalyst alone. However, problems including visible light absorption, a low quantity of energetic sites on surfaces, and rapid recombination of the photo-electron hole pair produced by light have prohibited photocatalysts from being used in a practical and widespread manner. To overcome these problems, synthesis of nanostructure hybrid catalyst using several methods has attracted much attention. Several procedures have been suggested for the preparation of photocatalysts with the desired structure and morphology. Preparation methods similar to partial modification may lead to diverse structures and qualities. In this regard, the development of efficient, low-cost photocatalysts and rapid synthesis is the most important issues that should be considered. This review discusses various methods and mechanisms that work with the modification of vanadium compounds as photocatalysts to progress their photocatalytic efficiency. In addition, the effects of synthesis temperature, solution pH and concentration on the photocatalytic performance are also described in detail.

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