Now showing 1 - 3 of 3
  • Publication
    Nitrate adsorption using spent coffee ground: kinetics, isotherm, and thermodynamic studies
    (Springer, 2023-09)
    Viga Rajiman
    ;
    ;
    Lian See Tan
    Excess amount of nitrate in water bodies can have harmful effects on humans and aquatic life. In this current study, the effectiveness of spent coffee grounds as adsorbents in nitrate adsorption from an aqueous solution was investigated. Spent coffee ground (SCG) was activated using hydrochloric acid (HCl) and used in the batch adsorption experiment. The removal performance was evaluated at different contact times ranging between 1 and 6 h. Removal efficiency was increased with the longest contact time of 6 h. Meanwhile, when nitrate concentration was increased from 100 to 500 mg/L, the removal efficiency was also increased from 39 to 78%. A temperature range of 298–328 K was applied in this study and the optimum operating temperature for nitrate adsorption was found to be at 308 K. Based on the experimental data, the Freundlich model showed R2 at 0.9802, which was the highest for the adsorption of nitrate using SCGs. In addition, the pseudo-first order kinetics model fitted the nitrate adsorption trend the best (R2 = 0.9652). The thermodynamic parameters obtained from this study described nitrate adsorption using SCG as endothermic in nature that required an external energy source for the interaction. This study has proven that spent coffee grounds activated by HCl have the potential of being an adsorbent for nitrate removal.
  • Publication
    Utilization of spent coffee ground as adsorbent for Nitrate removal
    (Springer, 2023)
    Viga Rajiman
    ;
    The annual rise in global coffee consumption has resulted in large amounts of discarded spent coffee ground following the brewing process. Spent coffee ground is a biomass waste that can be utilized in various applications. The present study aimed to assess the possibility of using spent coffee grounds as an alternative adsorbent to remove nitrate from aqueous solutions. Batch adsorption experiments were performed at 298 K and the spent coffee ground underwent a chemical pre-treatment using hydrochloric acid (HCl) at different concentrations. The results showed that the most suitable pre-treatment concentration was 0.4 M of HCl. Experiments were also conducted to study the effects of the solution pH (pH 3–9) and adsorbent dosage (0.2–1.0 g) in terms of nitrate removal efficiency. The experimental data showed that the highest nitrate removal efficiency occurred at pH 4 with 58 ± 0.69% removal efficiency. The adsorption performance was improved from 34% to 68 ± 0.58% as the adsorbent increased from 0.2 g to 1.0 g. These results showed that spent coffee ground could potentially be utilized as the adsorbent for removing nitrate from aqueous solutions.
  • Publication
    Activated carbon derived from Jackfruit seeds for oil adsorption
    Activated carbons (AC) are widely used as adsorbents for treating oily wastewater. An effective, cheap and environmental-friendly method for oil adsorption by using AC derived from jackfruit seeds (JS) was developed in this study. The JS were chemically activated with different concentrations (10 wt.% and 15 wt.%) of chemical activating agents (H3PO4 and ZnCl2) to produce activated carbon. The optimum conditions for developing AC from JS with the highest oil adsorption capacity was found using 15 wt.% ZnCl2, and carbonised at 500°C resulting in maximum adsorption capacity of 0.8621 g/g. Raw JS and jackfruit seed-derived activated carbon (JSAC) were characterized by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy analysis. The influence of process parameters such as contact times (0 – 240 minutes), adsorbent dosages (0.5 – 2.5 g) and adsorption temperatures (25 – 65 °C) for oil adsorption were investigated. The results showed that the optimum parameters for maximum adsorption capacity were as follows; 120 minutes of contact time, adsorbent dosage of 1.5 g and at 35 °C. At this condition, the highest oil adsorption capacity was achieved at 1.5674 g/g. The adsorption kinetic studies depicted that the oil adsorption mechanism was represented by pseudo-second-order kinetic model which implies that the adsorption is a chemisorption process. Jackfruit seeds had been proven to have the capability as an effective adsorbent for oil adsorption.
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