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This study focused on assessing the impact of using a variety of Al3+ and Fe3+ combinations to prepare modified bentonite adsorbents to remove phosphorous from water. Eight adsorbents with various Al3+ and Fe3+ combinations were used; four where prepared by adding Al3+ then Fe3+ to the bentonite, and four were prepared by adding Fe3+ then Al3+ to the bentonite. The adsorption capacities and kinetics of the eight adsorbents were experimentally assessed and compared. The experimental results best fitted the Langmuir adsorption isotherm model and the kinetic data best fitted the pseudo-second-order kinetic model. The Langmuir maximum adsorption capacities of the various adsorbents were in the range of 5.6–11.3 mg P/g adsorbent. The results suggested that combining Al3+ and Fe3+ in preparing the adsorbents improved the adsorption capacity and adsorption rate compared to using Al3+ alone or Fe3+ alone. Furthermore, equal amounts of Al3+ and Fe3+ resulted in the maximum phosphorous adsorption capacities...

Experiments were carried out using granular activated carbon (GAC) adsorption techniques to treat wastewater contaminated with organic compounds caused by diverse human activities. Two techniques were assessed: adsorbent GAC prepared from coconut shell (GACC) and adsorbent GAC from palm shell (GACP). A comparison of these two techniques was undertaken to identify ways to improve the efficiency of the treatment process. Analysis of the processed wastewater showed that with GACC the removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and total dissolved solids (TDS) was 65, 60, 82, 82 and 8.7%, respectively, while in the case of GACP, the removal efficiency was 55, 60, 81, 91 and 22%, respectively. It can therefore be concluded that GACC is more effective than GACP for BOD removal, while GACP is better than GACC for TSS and TDS removal. It was also found that for COD and turbidity almost the same results were achieved by the two techniques. In addition, it was observed that both GACC and GACP reduced pH value to 7.9 after 24 hrs. Moreover, the optimal time period for removal of BOD and TDS was 1 hr and 3 hrs, respectively, for both techniques.