Cellulose-based materials and their adsorptive removal efficiency for dyes: A review

Dyes are emerging as harmful pollutants, which is one of major issues for the environmentalists and there is a urgent need for the removal of dyes from the effluents. In this context, the adsorption technology has been extensively used as an effective tool for the removal of dyes from the aqueous phase. This technique uses low-cost adsorbents and the cellulosic material is a biodegradable, cost-effective and renewable polymer, which is not soluble in the majority of solvents because of its crystalline nature and hydrogen bonding. Currently, the modified cellulosic materials for the removal of dyes from wastewater gained much attention. Moreover, the application of cellulose for water treatment can be utilized for controlling pollution and have high economic viability and availability. This review signifies the use of cellulose-based adsorbent for dyes adsorption from wastewater. The key advancement in the preparation and modification of cellulose-based adsorbents is discussed and their adsorption efficiencies are compared with other adsorbents for removal of dyes and adsorption conditions are also considered for the same. The studies reporting cellulose-based adsorption from 2003 to 2022 are included and their various properties are compared for the efficient removal of dyes. The modified cellulosic materials cellulose is a highly effective adsorbent for the remediation of effluents

REMOVAL OF CRYSTAL VIOLET BY BIOSORPTION ONTO DATE STONES

The biosorption has the advantage that it can be applied to effluent disposal and thus brings various responses to the regulatory requirements for environmental protection. This study presents the results obtained from the use of date stones (DS) for the elimination of crystal violet (CV) from aqueous medium. Several analysis techniques were used to determine the different characteristics of biosorbent studied (FTIR, TGA-DTA, SEM and pHzpc).The physico-chemical parameters influence of the biosorption such as biosorbent dosage, contact time, temperature, biosorbent particles size and initial dye pH were investigated under static conditions in order to evaluate the process system. The test results show that a gram of date stones may set a maximum amount adsorbed 90.89 mg·g-1 of CV at 50 °C according to the Langmuir isotherm with pseudo-second-order kinetic. Thermodynamic calculations performed shows also that sorption is spontaneous, endothermic and increased randomness in the solid / solution interface

STUDY OF REMOVAL OF CONGO RED BY LOCAL NATURAL CLAY

The adsorption behavior of anionic dye (Congo Red) from aqueous solutions onto natural clay originated from Agadir region (south Morocco) was examined in this work. Batch mode experiments were performed to describe the Influence of interacting parameters such as contact times (10 - 70 min), adsorbent dose (1 - 6 g·L-1), initial dye concentration (100 - 900 mg·L-1), temperature (22 - 50 °C) and pH values (2 - 12) on dye removal. According to the obtained results, the adsorption of CR onto clay natural was dependent on pH, initial dye concentration and temperature. Experimental data have been modeled according to both Langmuir and Freundlich models. Also, kinetic studies of CR onto clay were evaluated by pseudo-first order and pseudo-second order. It was found that the adsorption of the dye on the clay were well fitted by the Langmuir model with coefficient of correlation R2 = 0.98 and maximum adsorption capacity 74.62 mg·g-1. Adsorption kinetics indicated that the adsorption of CR was found to follow a pseudo second-order model (R2 = 0.999). The thermodynamic parameters were also calculated, which suggested that the adsorption of anionic dye onto clay is physiosorptive process, spontaneous, and endothermic in nature

Life Cycle Assessment (LCA) of Agricultural Residues (Cocoa Cortex, Sugarcane Bagasse and Oil Palm Fiber) for Power Generation in Boilers through Fuel Combustion

Abstract Among the renewable energy resources available is biomass from agricultural waste. Herein, we propose 3 agricultural waste products (cocoa cortex, oil palm fiber and sugarcane bagasse. The environmental and energy performance of agr icultural waste used as fuel to produce 1 kWh of electr icity each in Ivory Coast was studied using the Life Cycle Assessment method. LAM is a method of environmental evaluation. It evaluates the environmental impact of a product over its entire life cycle, the life cycle of each of these 3 agricultural wastes is made up of collection, transport to the electricity production site and combustion of these biomasses hi the boilers of the cogeneration units. The results are as follows: In terms of global wanning impacts, for these 3 waste products (cocoa cortex, oil palm fiber and sugarcane bagasse) respectively (0.12; 0.16 and 0.19) kg CO2 eq. / kWh. hi terms of impacts on the depletion of non-renewable resources for these 3 wastes (cocoa cortex, oil palm fiber and sugarcane bagasse) respectively (0.007; 0.010 and 0.012) MJ / kWh. hi terms of eutrophication-related impacts on global warming for these 3 wastes (cocoa cortex, oil palm fiber and sugarcane bagasse) respectively (0.38; 0.4 and 0.91) g PO43-/ kWh. According to the results of the 3 impacts taken into account hi tins LCA study, it is desirable to use these 3 agricultural wastes to produce electricity with very good energy and environmental performance, instead of fossil fuels (diesel, oil and coal). Finally, the objective of this research will be to provide credible information to decision-makers (governments, private and public companies, national and international organizations and the general public) in order to promote the installation of energy production units (heat and/or electricity) based on the combustion of these 3 agricultural residues hi rural and industrial areas