Rev Chem Eng 2018; 34(3): 427–453
Kshitij Tewari, Gaurav Singhal and Raj Kumar Arya*
Adsorption removal of malachite green dye from aqueous solution DOI 10.1515/revce-2016-0041 Received September 20, 2016; accepted March 6, 2017; previously published online May 5, 2017
Abstract: In this review, the state of the art on the removal of malachite green dye from aqueous solution using adsorption technique is presented. The objective is to critically analyze different adsorbents available for malachite green dye removal. Hence, the available recent literature in the area is categorized according to the cost, feasibility, and availability of adsorbents. An extensive survey of the adsorbents, derived from various sources such as low cost biological materials, waste material from industry, agricultural waste, polymers, clays, nanomaterials, and magnetic materials, has been carried out. The review studies on different adsorption factors, such as pH, concentration, adsorbent dose, and temperature. The fitting of the adsorption data to various models, isotherms, and kinetic regimes is also reported. Keywords: adsorption; biological adsorbents; magnetic adsorbents; malachite green; nanomaterials; polymeric adsorbents.
1 Introduction
Malachite green dye is generally used in agriculture, food, health, textile, and other industries for several purposes. It is highly carcinogenic for species living on water like fishes, mammals, etc. It is highly toxic in nature, and its toxicity increases with exposure time, temperature, and concentration. It causes carcinogenesis, mutagenesis, chromosomal fractures, respiratory toxicity, etc. Hence, there is a need to review the various methods available for its separation and mitigation before discharging it into water bodies. In earlier days, malachite green was widely used in the fish farming industry because of its price and good efficiency in prevention and treatment of external fungal and parasitic infection in fish (Li et al. 2008, Pan and Zhang 2009). In earlier studies, the researchers found that it is a hazardous dye that is very harmful for human beings when inhaled or ingested by the body and creates irritation when contacted with skin. There are several techniques to remove malachite green dye from waste water. The dye can be removed by coagulation, flocculation, oxidation/advanced oxidation, precipitation, combined chemical and biochemical processes, ozonation, aerobic and anaerobic digestion, irradiation, adsorption, membrane treatment, katox treatment (Bekçi et al. 2009), biosorption, fungal decolonization, ion exchange, and photo degradation (Debrassi et al. 2012, Song et al. 2012, Pal and Deb 2013, Ghaedi et al. 2014, Zhang et al. 2016d). Each technique has its own merits and limitations. Among all the techniques, adsorption is the most effective technique as it is cheap, fast, and simple (Debrassi et al. 2012, Song et al. 2012, Pal and Deb 2013, Ghaedi et al. 2014, Zhang et al. 2016b,d).
Color is a visual pollutant and one of the most important hazardous species found in industrial effluents. There are more than 10,000 dyes that are extensively used in many process industries such as textile, paper, etc. Malachite green is a commonly used dye. It is an organic compound, and its molecular structure is shown in Figure 1 (Saha et al. 2010a). It is known by many other names as aniline green, Victoria green B, basic green 4, and diamond green B. It was first prepared by Fischer in 1877 by condensing benzaldehyde and dimethylaniline in a molecular ratio of 1:2 and in the presence of dehydrating agent.
1.1 M alachite green dye removal using adsorption
*Corresponding author: Raj Kumar Arya, Department of Chemical Engineering, Thapar University, Patiala, Patiala 147004, Punjab, India, e-mail:
[email protected],
[email protected]. http://orcid.org/0000-0003-1210-108X Kshitij Tewari and Gaurav Singhal: Department of Chemical Engineering, Jaypee University of Engineering & Technology, Guna, A. B. Road, Raghogarh, Guna 473226, M. P., India
Among the different types of dye removal methods, adsorption of a dye over a solid surface is now recognized as an effective and economical method for wastewater treatment. There is a great flexibility in design and operation in adsorption processes. In many cases, adsorption will produce high-quality treated effluent. Also, in some cases, recovery of the dye as well as the adsorbent is also Bereitgestellt von | De Gruyter / TCS Angemeldet Heruntergeladen am | 30.05.18 18:19
428 K. Tewari et al.: Removal of malachite green dye
2 M alachite green adsorption using various biological wastes HCL
OH
N CH3
N
CH3
CH3
CH3
Figure 1: Structure of malachite green.
possible. A wide variety of adsorbents have been used for the removal of malachite green dye from wastewater by various researchers. Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or solid to the surface. It is usually described by isotherm, which is the amount of adsorbate on the adsorbent as a function of pressure and concentration at constant temperature. The various adsorption isotherms used to explain the data are linear isotherm, Freundlich isotherm, Langmuir isotherm, BET isotherm, Kisliuk isotherm, Thomas isotherm, Temkin isotherm, Dubinin-Radushkevich isotherm, Dubinin Kaganer Radushkevich isotherm, Frumkin isotherm, Redlich-Peterson isotherm, Sips isotherm, and KobleCorrigan isotherm. The Langmuir and Freundlich models are most commonly used due to ease and better prediction capabilities of the adsorption data. Langmuir equation states that
θ=
αp 1 + αp
(1)
where α is Langmuir adsorption constant, θ is fractional coverage of the surface, and p is gas pressure or concentration. In Freundlich isotherm, the concentration of a solute on the surface of an adsorbent is plotted against the concentration of the solute in the liquid with which it is in contact. The Freundlich isotherm is mathematically shown as 1
x = kp n m
(2)
where x is mass of the adsorbate, m is mass of the adsorbent, p is equilibrium pressure of adsorbate, k is constant for a given adsorbate, and n is constant for adsorbent at given temperature.
Garg et al. (2004) prepared the adsorbent from Prosopis cineraria sawdust – an agro-industry waste – and used it to remove malachite green in a batch reactor. The prepared adsorbent was treated with formaldehyde and sulfuric acid. The percentage dye removal was 96%. An agro-industry waste contains P. cineraria, which is available in the northern states of India. Rahman et al. (2005) made similar studies with activated carbon derived from bamboo, rice husk, or by spent tea leaves. Rice husk treated with phosphoric acid, sodium hydroxide, and nitrogen was used to remove malachite green. They found that the maximum carbonization temperature for effective adsorption was 500°C and the corresponding adsorption capacity was 80 mg/g. The derived activated carbon also gave good removal efficiency. Kumar et al. (2006) proposed a method for the removal of malachite green using Pithophora sp., a fresh water algae. The maximum uptake of the dye was observed at pH 6. The adsorbent had an adsorption capacity 42.2 mg/g with a removal of 98.88% at 30°C. The data followed the first-order kinetics. The dye uptake decreased with increased adsorbent dosage. This process was found to be surface diffusion controlled. Papinutti et al. (2006) used wheat bran to remove the malachite green. The maximum dye removal was 90% at pH 7–9. Wheat bran is an inexpensive agricultural residue. It contains polysaccharides such as starch and cellulose and is a useful carbon source. This is the main advantage of wheat bran as compared to other lignocellulosic materials such as pine sawdust. The maximum dye adsorption capacity was 240 mg/g at 28°C. Hameed and El-Khaiary (2008a) used oil palm trunk fiber to remove malachite green from an aqueous solution. The palm trunk was left to dry naturally. The dried trunk was chopped to pieces 1 in3 in size, ground and sieved to obtain a particle size range of 0.5 mm. The prepared particles were washed with boiled water and then dried at 70°C for 24 h. The maximum dye removal was 82% at pH 10 and 30°C. The maximum adsorption capacity was 149.35 mg/g. The equilibrium was attained in 140 min. They found that dye adsorption was unfavorable at pH 603 m2 g−1,
