Ibuprofen, abbreviated to IBP, is a widely used non-steroidal anti-inflammatory drug that can find its way into the environment via hospital and medical wastes, municipal wastewater, and through veterinary usage. IBP is harmful to aquatic life with long lasting effects and as such its release can pose an environmental hazard. Therefore, this study focussed on determining the potential of modified biochar derived from a by-product of the food industry, namely grass jelly tree waste, as an effective adsorbent for removing IBP from aqueous solutions. The modified biochar could be prepared by pyrolysis at 700 °C for 1 hour, then phosphoric acid modification was achieved by soaking for 24 hours, followed by washing with water until neutral. This modified biochar exhibited a specific surface area (SSA) of 111 m²/g, a total pore volume of 0.097 cm³/g with an average pore diameter of 3.49 nm. Adsorption parameters such as contact time, solution pH, concentration and temperature were studied. Batch adsorption experiments indicate that the modified biochar is highly efficient in removing IBP, with equilibrium rapidly being reached after 2 hours. Kinetic studies demonstrated that the adsorption of IBP on modified biochar fitted better to the pseudo-second order kinetic model than the pseudo-first order model. The Sips isotherm model which is a combination of Langmuir and Freundlich models demonstrated a superior fit of adsorption behaviour with the maximum adsorption capacity for IBP being 200.73 mg/g at optimal pH (pH 2). The thermodynamic parameters show that the adsorption is spontaneous, exothermic, and results in increased disorder. Thus, the use of grass jelly tree waste in the production of biochar can be a sustainable and economical approach for converting this industrial waste into a useful adsorbent for the remediation of pharmaceutical contaminated water.

A tubular reactor filled with a granular catalyst (granular catalyst-filled reactor) and a tubular reactor (catalyst-coated reactor) in which the surface inside the reactor was porosized and catalyst-coated were the targets of analysis. The concentration of CO2, H2 and CH4 at the gas inlet and outlet of these reactors were analyzed, and the temperature distribution in the reactor in the gas flow direction was obtained, respectively. Based on the reported reaction rate equations, theoutlet gas concentration in the small region in the gas flow direction, considering the mass balance, was successively estimated using the measured value. Furthermore, various parameters were calculated so that the final estimated value was closest to the measured value after the reaction. As a result, it was found that, in the case of a granular catalytic reactor with a uniform temperature inside in order to achieve a CO₂ conversion rate of 93%, which is equivalent to the reactor with temperature distribution, the set temperature at the reactor inlet must be raised at 340 °C or higher. On the other hand, in the catalyst-coated reactor, where the reactor internal temperature is equalized, if the temperature, GHSV and pressure were within the measured range, all estimated values agree with the additional measurement values within 10%. Moreover, under the same gas conditions as the granular catalytic reactor, it was estimated that a CO2 conversion rate of 93% could be achieved by increasing the pressure to 1.4 MPa or higher at a set temperature of 340 °C.