Inventor: Prof. Dr. Shahlaa Ismael Ibrahim/Department of Environmental Engineering, College of Engineering, University of Baghdad
Abstract
The use of a natural substance (cork stoppers particles), which are economical and abundant to remove lead ions from wastewater using adsorption process was studied. Adsorption is a process of connection and accumulation of heavy metals onto dead biomass by the forces of attraction. Cork stoppers particles are natural substances used as a substitution of manufactured expensive aerogel materials also called (nanogel). Nanogel are used in inverse fluidized bed reactors because they are lighter than water and hydrophobic, it will float on the bed although the flow of wastewater from top to bottom. Batch and continuous inverse fluidized bed systems where used. The results of the batch system show that the efficiency of the adsorption affects by the amount of the adsorbent and the pH. A removal efficiency of 97.32% produced at 50 mg/l initial lead ions concentration, pH=4, 1 g of cork stoppers particles, and 4 h contact time. Four equilibrium isotherm models where used to analyze the experimental data for batch system (Langmuir, Freundlich, BET, and Timken models). It was found that the isotherm relation was of favorable type and Langmuir model was the best fitted model to the experimental data. These correlations are empirical and can be used for heterogeneous surfaces and for one or multilayer adsorbent. Kinetic experiments results were used to analyze the layer around the cork particles. Elovich Kinetic model was best fit the experimental data where more that 95% of lead ions removed at 400 rpm and 4 h. Fourier Transform Infra Red (FTIR) test was used to study the physical and chemical characteristics of the cork particles and it was found that carboxylic and aromatic functional groups play an important rule in the adsorption process. Continuous experiments using inverse fluidized bed were studied at different operating conditions such as flow rate, initial adsorbate concentration, and bed depth of the adsorbent.