Adsorption ofβ-carotene on mesoporous carbon coated monolith (MCCM) from methyl ester as a solvent was investigated. Kinetics and thermodynamics parameters have been evaluated. Maximumβ-carotene adsorption capacity was 22.37 mg/g at 50 °C. Process followed Langmuir isotherm. The adsorption was endothermic and spontaneous. Contact time studies showed increase in adsorption capacity with increase inβ-carotene initial concentration and temperature. Pseudo-second-order model was applicable to the experimental data. The value of activation energy confirmed physical adsorption process.

The biosorption of Cd(II) and Cr(VI) ions from aqueous solutions using Pensi (Corbicula moltkiana) shell activated with HNO 3 0,01 M was studied in batch method. The optimum conditions were reached at concentration 100 mg/L, particle size 32 µm, and biosorbent mass 0.1 gram for both Cd(II) and Cr(VI) ions. At pH 6 and contact time 120 minutes, biosorbent was warmed at 28 o C with the sorption capacity of 6.073 mg/g for Cd(II), while at pH 3, contact time 15 minutes, biosorbent was warmed at 80 o C with the sorption capacity of 1.286 mg/g. The adsorption of Cd(II) and Cr(VI) ions follows the Langmuir isotherm models with R 2 0.9389 for Cd(II) ions and 0.9972 for Cr(VI) ions. The Langmuir Isotherm Method indicates an adsorption process occurrs as chemicals formed monolayer. This result showed that Pensi shell can be used to overcome Cd(II) and Cr(VI) content in wastewater.

The increasing types of people needs along with the times have resulted in the need for energy increasing so that the supply of energy, especially energy that cannot be renewed (unrenewable energy) is decreasing. Currently, almost 80% of the world's energy needs are met by fossil fuels. In fact, the use of fossil fuels can cause global warming. To reduce dependence on fossil fuels as an energy source, it is necessary to search for energy sources that can be used as alternative fuels that are environmentally friendly. Indonesia is an agricultural country that is overgrown with plantation crops that produce various kinds of waste such as rubber seeds which contain oil. This plant produces a lot of wasted seeds that are not useful. Therefore, researchers want to research the oil from rubber seeds to be a biodiesel product and in order to get high quality results. This study regulates several independent variables, namely the alcoholysis temperatures: 650C, 700C and 750C and the alcohol volume: 200 ml, 250 ml and 300 ml. The process is carried out by extraction using the alkolysis method. The best yield yielded 60.5%, with the best yield of biodiesel from alcoholysis obtained at a volume of 250 ml of ethanol and a temperature of 75oC with a density of 09 kg/m3 and a viscosity of 3,285 mm2/s (cSt), fulfilling the requirements of SNI 7182:2015. Based on the results of GC analysis, the main fatty acid components in the sample were at peak 1, namely saturated fatty acids in the form of palmitic acid at 44,28% and peak 4, namely unsaturated fatty acids in the form of oleic acid at 31.99%.

The textile industry is a sub-industry that contributes to our country’s economy, and as a result, it is expanding on a daily basis. The processes that are involved in the textile industry are fibre production, spinning, twisting, weaving, knitting, scorching and dyeing, which involve colours or dyes. The combination of processes and products causes waste from the textile industry to contain a wide range of pollutants.The presence of even trace amounts of dye in water (less than 1 ppm) is highly visible and will affect water transparency and gas (carbon dioxide, oxygen) solubility in water bodies where waste is discharged. Dyes are usually resistant to conventional biodegradation. Therefore, adsorption is an effective alternative for dye removal treatment. Therefore, a study has been conducted to find a low-cost raw material for an alternative method of treating textile wastewater. In this study, the capability of activated carbon derived from coconut shells to remove malachite green dye was investigated. Three parameters were studied, such as activated carbon with different chemical impregnation and carbonization time, contact time and initial concentrations of dye. From the results acquired, 99.9% of malachite green dye was removed by the activated carbon impregnated with phosphoric acid solution of 5 minutes carbonization time. The optimum contact time and initial concentration of dye were 1 hour and 10 mg/L, respectively. Therefore, this result can contribute to some knowledge of using low-cost raw material impregnation with some chemicals to remediate textile wastewater.