The biosorption of reactive red dye onto orange peel waste: a study on the isotherm and kinetic processes and sensitivity analysis using the artificial neural network approach

Environmental Science and Pollution Research - The agricultural waste of orange peels (OPs) was utilized as a cheap biosorbent and then tested for its ability to treat the reactive red (RR) dye...     

Competitive biosorption of lead, cadmium, copper, and arsenic ions using algae

The present study aims to evaluate the competitive biosorption of lead, cadmium, copper, and arsenic ions by using native algae. A series of experiments were carried out in a batch reactor to obtain equilibrium data for adsorption of single, binary, ternary, and quaternary metal solutions. The biosorption of these metals is based on ion exchange mechanism accompanied by the release of light metals such as calcium, magnesium, and sodium. Experimental parameters such as pH, initial metal concentrations, and temperature were studied. The optimum pH found for removal were 5 for Cd²⁺ and As³⁺ and 3 and 4 for Pb²⁺ and Cu²⁺, respectively. Fourier transformation infrared spectroscopy analysis was used to find the effects of functional groups of algae in biosorption process. The results showed that Pb²⁺ made a greater change in the functional groups of algal biomass due to high affinity to this metal. An ion exchange model was found suitable for describing the biosorption process. The affinity constants sequence calculated for single system was K _Pb > K _Cu > K _Cd > K _As; these values reduced in binary, ternary, and quaternary systems. In addition, the experimental data showed that the biosorption of the four metals fitted well the pseudo-second-order kinetics model.     

Capacity and Modeling of Acid Blue 113 Dye Adsorption onto Chitosan Magnetized by Fe2O3 Nanoparticles

Journal of Polymers and the Environment - A chitosan polymer was magnetized by coating with magnetite Fe2O3 nanoparticles, and the resultant material (C-Fe2O3) was first characterized through...