Application of modified clays as an adsorbent for the removal of Basic Red 46 and Reactive Yellow 181 from aqueous solution

Abstract

The valorization of a low-cost and an abundant material is a significant work for environmental protection. The objective of this work was to investigate the adsorption of two dyes: Basic Red 46 (BR46) and Reactive Yellow 181 (RY181) onto raw (S1) and modified clays. These modifications were carried out by calcination at different temperature (S2, S3, ..., S9), acidic activation, and acetylation. The surface properties of the adsorbents were characterized by the cation exchange capacity, Fourier transform infrared, and X-ray diffraction analyses. Batch studies were performed to evaluate the effect of the contact time and initial dye concentrations on the removal capacities of adsorbents. Among the kinetic models tested, the adsorption kinetics was best described by the pseudo-second-order equation. The isotherm data fitted well with Langmuir model. The maximum adsorption capacities onto the raw clay (S1), calcined clay at 600˚C (S5), acidic activated clay (AC), and acetylated clay (MC) were 2.805, 4.232, 1.968, and 2.756 mmol/g for CI Basic Red 46 and 0.031, 0.030, 0.046, and 0.050 mmol/g for CI Reactive Yellow 181, respectively.

Catalytic degradation of real-textile azo-dyes in aqueous solutions by using Cu–Co/halloysite

“…According to the literature, it is estimated that about 10-25% of dyes used in textile factories are lost during the dyeing process, and between 2 and 20% is directly discharged as aqueous effluents in different ecosystems [2,3]. Some textile dyes dissolved in water, e.g., azo-compounds are toxic, mutagenic and carcinogenic [5][6][7][8], causing serious environmental problems. Besides, all dyes give highly coloured appearance to water sources, causing a variation in their natural aesthetic perception, blocking sunlight transmission and decreasing photosynthesis [8,9].…”

“…Great endeavours have been performed to achieve removal, decolourization or total degradation of azodyes in wastewaters. Several methods, such as adsorption [6,17], biosorption [18], biological treatments by bacterial culture and fungal species [11,19], microwave irradiation [16], photocatalytic oxidation [2,10,20], wet oxidation [21], catalytic wet ozonation [22] and catalytic wet peroxide oxidation (CWPO) [23,24] have been employed to eliminate these textile dyes. Typically, azo-dyes are toxic compounds, non-biodegradable or difficult to be biodegraded.…”

Uso dos resíduos de maracujá como adsorvente alternativo para a adsorção de corante

“…Esta classe de corantes é solúvel em água e produz cátions coloridos e também são chamados de corantes catiônicos. Suas principais classes são cianina, tiazina, acridina, oxazina, hemicianina e diazahemicianina, ou seja, vermelho básico 46, verde malaquita, amarelo básico 28, violeta cristal, azul de metileno, o castanho básico e o vermelho básico 9 (Bouatay, Dridi-Dhaouadi, Drira, & Farouk Mhenni, 2016).…”

Superior adsorption of cationic dye on novel bentonite/carbon composites

“…In recent years, environmental pollution problems and water shortage have attracted increasing public concern due to the development of industrialization and urbanization in the developing countries. Organic pollutants existing in the wastewater from the paper, textile, leather, electroplating, cosmetic manufacturing, and photographic industries are one of the most common problems 1–5 . Although there are many wastewater treatment technologies, adsorption is the most widely adopted one due to its simplicity and low cost 5–10 .…”

“…Physical and chemical treatments on clays were carried out to increase their adsorption capacity toward pollutants such as cations (e.g., Pb, 13 Co and Zn, 14 Cr (VI), 15,16 and U (VI) 17 ), phenols, and dyes 1–10 . For example, modification routes by means of cation exchange, thermal treatment, acid or alkali reaction, and chemicals addition (e.g., surfactants, polymers, and pillaring agents) were found to cause considerable alterations in clay surface properties 1–6 . As a result of such amendments, some important factors such as porosity, surface charge, and functional groups were changed.…”