Nyoman Suwartha

Chitosan-praseodymium complex for adsorption of fluoride ions from water

Abstract Engineering of chitosan by praseodymium has been investigated to improve the adsorption properties as well as physical characteristics of chitosan. Modification of chitosan changes the original properties of chitosan so that it can be more suitable for adsorption of fluoride ions. In this study, chitosan-praseodymium (Chi-Pr) was synthesized by impregnation method. The Chi-Pr complex was characterized by scanning electron microscopic-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared (FTIR) and employed as an adsorbent for removal of fluorides ions from water in the batch system. The variables such as contact time, concentration of Pr, adsorbent dose, initial concentration of fluoride ions, and competitor anions were studied. The adsorption efficiency of fluoride ions (η) with increasing Pr loading into chitosan (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.% and 25 wt.%) were 35.5%, 56.1%, 72.0%, 68.5% and 62.5%, respectively. The Chi-Pr (15 wt.%) complex had the highest fluoride removal efficiency (72.0%). The experimental data fitted well to the Langmuir isotherm with maximum adsorption capacity (qmax) of 15.87 mg/g and an equilibrium constant (kL) of 0.15 mg. Kinetic study revealed that the adsorption of fluoride ions from water followed pseudo-second-order model with a maximum adsorption capacity (q2) of 8.20 mg/g and a rate constant (k2) of 0.01 g/mg·min. Adsorption efficiency of fluoride ions in the simulated drinking water was diminished with the changes in pH levels. The presence of Pr3+ in chitosan increased chitosans performance as an adsorbent for adsorption of fluoride ions.

Methane enrichment on biogas generated from anaerobic digester using coconut shell-based activated carbon

This study evaluates methane enrichment on biogas generated from Anaerobic Digester (AD) through CO2 adsorption process so that biogas can be used as fuel for vehicle engines, power plants, and natural gas substitutes. The experiment was observed by passing biogas synthesis (45% CH4 + 55% CO2) and biogas from cattle manure ±59.7% CH4, ± 37.1% CO2 and ±3.2% other gases) in spontaneously pressurized adsorption column. In addition, observation of CO2 adsorption capacity at various pressure and fixed temperature (27oC) was performed using pure CO2 (±98%). Methane in biogas has been successfully purified to 92% at 0.5 L/min flowrate and 79.6 seconds retention time. The adsorbent will be saturated after gas flowing for 60 and 80 minutes for synthesis biogas and biogas from AD on the amount of adsorbent of 266 grams. A change of surface area of activated carbon (AC) after thermal regeneration at 160oC for 2 hours was 7.51% and regeneration efficiency was 67%. The adsorption process followed Freundlich isothermal. This process can be feasible alternative technology to meet the need for biogas with high levels of methane in small-scale AD.This study evaluates methane enrichment on biogas generated from Anaerobic Digester (AD) through CO 2 adsorption process so that biogas can be used as fuel for vehicle engines, power plants, and natural gas substitutes. The experiment was observed by passing biogas synthesis (45% CH4 + 55% CO 2 ) and biogas from cattle manure ±59.7% CH 4 , ± 37.1% CO 2 and ±3.2% other gases) in spontaneously pressurized adsorption column. In addition, observation of CO 2 adsorption capacity at various pressure and fixed temperature (27°C) was performed using pure CO 2 (±98%). Methane in biogas has been successfully purified to 92% at 0.5 L/min flowrate and 79.6 seconds retention time. The adsorbent will be saturated after gas flowing for 60 and 80 minutes for synthesis biogas and biogas from AD on the amount of adsorbent of 266 grams. A change of surface area of activated carbon (AC) after thermal regeneration at 160°C for 2 hours was 7.51% and regeneration efficiency was 67%. The adsorption process followed Freundlich isothermal. This process can be feasible alternative technology to meet the need for biogas with high levels of methane in small-scale AD.

Accelerating Technology Development: Engaging Stakeholders and International Networking

Technology partnerships become a network model that is formed by stakeholders who share linked knowledge, activities, and resources, which lead to future strategic options and alternative product solutions that are efficient, effective, and sustainable. Technology results from inventors and researchers in various laboratories and companies translating ideas into prototypes, which can then serve various needs and purposes through transformation into value added products and/or projects. Technology transfer is conducted firstly via provider collaboration and secondly to customers. Both the governments and private investors that provide financial support to fund technology development and transfer make significant contributions by supporting development strategies and policies as well as creating sufficient market incentives.