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Oil palm empty fruit bunch (EFB) was chemically activated by phosphoric acid and heat treatment to produce porous activated carbon (AC) for adsorption of copper ions from synthetic wastewater using static batch test. Copper adsorption process was optimized using Response Surface Method (RSM) by varying four operating parameters i.e. pH (A), initial concentration (B), adsorbent dosage (C) and contact time (D) through a quadratic model developed based on Central Composite Design (CCD) approach. Within the tested parameter range, copper adsorption was found to be at optimum condition at pH 5, initial concentration of 200 mg/L, adsorbent dosage of 0.55 g per 200 mL copper solution and contact time of 2.5 hours, yielding 52.5% of copper removal. A good agreement was achieved by comparing the predicted model with experimental data (R2=0.9618). All four operating parameters tested are significant in affecting the adsorption process, with pH being the most significant with an F-value of 171.70. The interaction between pH and initial concentration (AB) has the most significant interacting effects (F-value of 18.30), while quadratic effects of pH (A2) and adsorbent dosage (C2) are most significant with F-values of 62.80 and 42.58 respectively.

Emission of hazardous SO2 into the atmosphere due to the burning of fossil fuels in various industries is detrimental not only to the environment but also to human beings. Various mitigation techniques have been implemented to overcome this problem, with flue gas desulfurization (FGD) method being the most commonly used. Dry FGD does not typically perform as good as wet method and requires new type of sorbent to be tested. Mesoporous silica (MS), a sorbent with porosity in the range of 2-50 nm is considered as attractive alternative due to its high specific surface area, ordered pore structures and wide array of morphologies. Due to relatively weak interaction between MS and SO2 adsorbate during dry FGD process, additives are introduced to overcome this problem. These MS are modified with basic additives which are deemed more favorable for SO2 adsorption. Metal and amine-based additives are commonly employed where the latter are reported to obtain higher adsorption capacity. Increasing additive loading is beneficial up to an optimal value depending on the types of additives.