Potential of Cogon Grass as an Oil Sorbent

Experiments on the potential of Cogon grass (lmperata cylindrica), a weed harmful to other plants, for use as a low-cost and biodegradable oil sorbent were carried out under various spill conditions. Flowers of Cogon grass adsorbed much larger amount of high-viscosity lubricating oil (57.9 g-oil/g-sorbent) than that adsorbed by Peat Sorb (7.7 g-oil/g-sorbent), a commercial oilsorbent based on peat. However, the flowers adsorbed only 27.9 g of low-viscosity crude oillgsorbent. In an oil-water system, the mount of oil adsorbed was influenced by the level with which the two were mixed: vigorous stirring reduced the sorption capacity by 36%. The high sorptive capacity of the flowers can be attributed to their hydrophobic nature and good oil-wettability. The flowers showed good buoyancy even after 24 hours of shaking under conditions that simulated water ripple (gentle wary motion) in sea, which suggests their potential in combating oil spills both on land and in water

Effect of Combining Electron Beam Irradiation and Alkaline Pretreatments of OPEFB for Enzymatic Hydrolysis and Fermentation of Ethanol

The effect of pretreatment process from the combination of electron beam irradiation and alkaline to Oil Palm Empty Fruit Bunch (OPEFB) was studied. The combination of pretreatment method was considered as an alternative way to increase glucose yield. In this study, OPEFB was pretreated using Electron Beam Irradiation (EBI) at 100 kGy and 300 kGy and followed by chemical pretreatment. In chemical pretreatment, irradiated OPEFB was reacted with sodium hydroxide 6% and 10% in stirred vessel at 4 bars and 150 oC for 30 min. The effectiveness of pretreatment was evaluated by calculating the composition of chemical component using National Renewable Energy Laboratory (NREL) Method. The samples which were hydrolyzed using enzymes with the addition of 30 FPU of Cellic®CTec2 per gram of pretreated biomass resulted high glucose in the amount of 9.86%. The fermentation process using Saccharomyces cereviceae obtained the highest ethanol concentration for 5.36% at 72h. The combination of the two pretreatment methods gave an effect on the weight loss, chemical composition, structure, and enzymatic hydrolysis produc

Karakterisasi Pasir Berlapis Oksida Besi sebagai Adsorben untuk Penyisihan Besi dalam Air Tanah

Air tanah merupakan sumber air minum utama bagi masyarakat yang berdomisili di daerah yang belum terjangkau layanan air bersih dari PDAM. Salah satu masalah pada kualitas air tanah adalah kandungan besi dalam air tanah di atas 0,3 mg/l, melebihi standar baku mutu PP nomor 82 tahun 2001. Sebagai contoh kandungan besi pada air tanah di Bandung mencapai 3-4 mg/l dan di Medan sebesar 4-5 mg/l. Pada penelitian sebelumnya telah diketahui bahwa adsorben dari pasir kuarsa yang dilapisi oksida besi (goethite) mampu menyisihkan kandungan besi dalam air tanah hingga 74,20%. Makalah ini melaporkan karakteristik dan potensi pasir sungai dan pasir pantai yang dilapisi oksida besi sebagai adsorben untuk menyisihkan kandungan besi dalam air tanah. Hasil percobaan mengindikasikan terbentuknya senyawa lepidocrocite pada permukaan pasir pantai. Uji kinerja yang dilakukan terhadap adsorben ini menunjukkan efisiensi penyisihan besi dalam air tanah sebesar 61,65%