Organic Dyes versus Adsorption Processing

Abstract

Even in the first quarter of the XXI century, the presence of organic dyes in wastewaters was a normal occurrence in a series of countries. As these compounds are toxic, their removal from these waters is a necessity. Among the separation technologies, adsorption processing appeared as one of the most widely used to reach this goal. The present work reviewed the most recent approaches (first half of the 2021 year) regarding the use of a variety of adsorbents in the removal of a variety of organic dyes of different natures.

C.I. Basic Red 46 Removal from Sewage by Carbon and Silica Based Composite: Equilibrium, Kinetic and Electrokinetic Studies

“…Therefore, it is becoming increasingly important to find an effective and economical way of removing dyes from the industrial effluents. There is a lot of information available in the literature about the methods of their removal [ 4 , 5 , 6 , 7 , 8 ]. These methods can be divided into chemical and physical ones.…”

“…Among the abovementioned techniques for the removal of dyes from wastewater, adsorption is very popular. This is a simple technique in terms of technology and is very efficient and economical, because it allows the use of sorbents of both natural and synthetic origin, as well as industrial waste materials [ 1 , 2 , 3 , 4 , 5 , 8 ]. At present, the most popular adsorbents are materials based on activated carbon due to its developed specific surface area and high porosity, as well as high efficiency in the removal of dyes from wastewater [ 9 ].…”

Removal of Anionic and Cationic Dyes Present in Solution Using Biomass of Eichhornia crassipes as Bioadsorbent

“…On the other hand, biological treatment is not effective for this type of contaminant due to the low biodegradation of dyes [ 2 , 13 , 19 , 20 , 21 , 22 ]. Adsorption has shown to have some advantages over the mentioned methods due to its high efficiency in the removal of dyes from wastewater including dilute solutions, and the absence of sediment produced in its operation [ 4 , 12 , 19 , 23 , 24 , 25 , 26 ]. Different adsorbents have been synthesized for the removal of dyes from clays such as SBA-15, Bentonite, and other materials [ 2 , 4 , 17 , 27 , 28 , 29 ], up to the manufacture of activated carbon from different sources, however, there are large losses and high operating costs due to the possibility of pore blockage, hydroscoping, and incineration when using high temperatures [ 5 , 19 , 22 , 24 , 27 , 28 , 29 ].…”

“…Different adsorbents have been synthesized for the removal of dyes from clays such as SBA-15, Bentonite, and other materials [ 2 , 4 , 17 , 27 , 28 , 29 ], up to the manufacture of activated carbon from different sources, however, there are large losses and high operating costs due to the possibility of pore blockage, hydroscoping, and incineration when using high temperatures [ 5 , 19 , 22 , 24 , 27 , 28 , 29 ]. These drawbacks have encouraged several researchers to study other cheap, abundant materials that have similar efficiency to materials synthesized by chemical processes, therefore the use of agro-industrial residues was considered, which are cheap and, easily available materials that only need a simple pretreatment and are materials with properties that can be exploited in another industry as well as being good candidates for the adsorption of various contaminants [ 8 , 12 , 14 , 19 , 22 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. These materials are mainly constituted by lignocellulosic groups, peels of various fruits and vegetables furthermore, these materials have been used as adsorbents of various dyes including PR and GV with good results [ 4 , 5 , 11 , 12 , 13 , 18 , 22 , 23 , 24 , 25 , 26 , 33 , 35 , 36 ].…”

“…These drawbacks have encouraged several researchers to study other cheap, abundant materials that have similar efficiency to materials synthesized by chemical processes, therefore the use of agro-industrial residues was considered, which are cheap and, easily available materials that only need a simple pretreatment and are materials with properties that can be exploited in another industry as well as being good candidates for the adsorption of various contaminants [ 8 , 12 , 14 , 19 , 22 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. These materials are mainly constituted by lignocellulosic groups, peels of various fruits and vegetables furthermore, these materials have been used as adsorbents of various dyes including PR and GV with good results [ 4 , 5 , 11 , 12 , 13 , 18 , 22 , 23 , 24 , 25 , 26 , 33 , 35 , 36 ].…”