The adsorption behavior of anionic dye congo red (CR) from aqueous solutions using an anion exchange membrane (EBTAC) has been investigated at room temperature. The effect of several factors including contact time, membrane dosage, ionic strength and temperature were studied. Kinetic models, namely pseudo-first-order and pseudo-second-order, liquid film diffusion and Elovich models as well as Bangham and modified freundlich Equations, were employed to evaluate the experimental results. Parameters such as adsorption capacities, rate constant and related correlation coefficients for every model were calculated and discussed. The adsorption of CR on anion exchange membranes followed pseudo-second-order Kinetics. Thermodynamic parameters, namely changes in Gibbs free energy (∆G°), enthalpy (∆H°) and entropy (∆S°) were calculated for the adsorption of congo red, indicating an exothermic process.

a b s t r a c tIn this research, batch adsorption of anionic dye Eosin-B (EB) onto anion exchange membrane (AEM) (BI) from aqueous solution has been investigated at room temperature. The effect of some operating conditions such as contact time, membrane dosage, initial dye concentration and temperature on the percentage removal of EB from aqueous solution has been investigated in detail. Moreover, adsorption kinetics has been analyzed using different models such as pseudo-first-order, pseudo-second-order, Elovich, liquid film diffusion, modified Freundlich and Bangham models. Results show that adsorption data fits to the pseudo-second order kinetics very well. Non-linear isotherms containing two parameters and three parameters isotherms have been applied on experimental data. Different thermodynamic parameters such as Gibb's free energy (DG°), enthalpy (DH°), and entropy (DS°) have been calculated, which shows that adsorption of EB onto anion exchange membrane (B1) is an exothermic process.

To reduce the environmental impact of acids present in various industrial wastes, improved and robust anion exchange membranes (AEMs) are highly desired. Moreover, they should exhibit high retention of salts, fast acid permeation and they should be able to operate with low energy input. In this work, AEMs are prepared using a facile solution-casting from brominated poly-(2,6-dimethyl-1,4-phenylene oxide) (BPPO) and increasing amounts of 2-phenylimidazole (PI). Neither quaternary ammonium salts, nor ionic liquids and silica-containing compounds are involved in the synthesis. The prepared membranes showed an ion exchange capacity of 1.1–1.8 mmol/g, a water uptake of 22%–47%, a linear expansion ratio of 1%–6% and a tensile strength of 0.83–10.20 MPa. These membranes have potential for recovering waste acid via diffusion dialysis, as the acid dialysis coefficient (UH) at room temperature for HCl is in the range of 0.006–0.018 m/h while the separation factor (S) is in the range of 16–28, which are higher than commercial DF-120B membranes (UH = 0.004 m/h, S = 24).

This manuscript describes the synthesis of dimethylethanolamine (DMEA)-grafted anion exchange membrane (AEM) by incorporating dimethylethanolamine as ion-exchange content into the polymer matrix via the solution casting method. The synthesis of the DMEA-grafted AEM was demonstrated by Fourier transform infrared (FTIR) spectroscopy. The prepared DMEA-grafted AEM exhibited higher thermal stability, homogeneous morphology, water uptake (WR) of 115%, and an ion exchange capacity (IEC) of 2.70 meq/g. It was used for the adsorptive removal of methyl orange (MO) from an aqueous solution via batch processing. The effect of several operating factors, including contact time, membrane dosage, initial concentration of aqueous dye solution, and temperature on the percentage discharge of MO and adsorption capacity, was evaluated. Experimental data for adsorption of MO onto the DMEA-grafted AEM was analyzed with two parameter and three parameter nonlinear adsorption isotherm models but fitted best using a nonlinear Freundlich isotherm. Adsorption kinetics were studied by using several models, and attained results showed that experimental data fitted well to pseudo-second-order kinetics. A thermodynamic study showed that adsorption of MO onto the prepared DMEA-grafted AEM was an endothermic process. Moreover, it was a feasible and spontaneous process.

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Being a developing economy, Pakistan is facing a severe energy crisis that limits its economic development. Pakistan relies heavily on energy resources like natural gas, oil, hydropower, nuclear, coal and liquefied petroleum gas (LPG) which contribute as 48.3, 32.1, 11.3, 7.6, and 0.6% of the primary energy supply, respectively. Because of the rapidly growing population and economy, Pakistan's energy needs are huge; to accomplish these energy necessities, Pakistan is continually spending $7-9 billion on the import of fossil fuels. To resolve the serious issues of energy availability, the Alternative Energy Development Board (AEDB) of Pakistan is currently exploring the development of renewable energy technologies in Pakistan that will be beneficial for the developing economy so that Pakistan might be able to minimize the growing energy crisis. Out of all the renewable energy resources, biomass is considered the best and most easily accessible source of energy with its unique environmentally friendly nature, constant supply, wider availability, and ease of integration into existing infrastructure. Despite the presence of an abundance of biomass energy resources, there is still a need for work on the use of these sources to produce energy. This literature review explores the availability of biomass resources in Pakistan and their potential for addressing rapidly growing energy demand in the country, which can assist in the stabilization of a Pakistan's energy demand for challenged economic development.

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