Determinasi Arsen (AS) dan Merkuri (Hg) dalam Air dan Sedimen di Kolam Bekas Tambang Timah (Air Kolong) di Propinsi Bangka-belitung, Indonesia

Indonesia dikenal sebagai produsen timah terbesar kedua di dunia, di mana produksi timah sebagian besar berlokasi di Propinsi Bangka Belitung (Babel), yang termasuk dalam Sabuk Timah Asia Tenggara. Penambangan timah diperkirakan telah berdampak negatif pada lima belas sungai di Babel, sepuluh di antaranya berada di Pulau Bangka. Sebagian besar penduduk di Babel mengandalkan ketersediaan air bersih dari air sungai atau air kolong. Perusahaan Daerah Air Minum (PDAM) menggunakan beberapa kolam bekas penambangan (kolong) sebagai sumber air bakunya untuk diolah dan didistribusikan untuk kepentingan penduduk. Tujuan dari penelitian ini adalah menentukan konsentrasi logam berat arsen (As) dan merkuri (Hg) di dalam air dan sedimen dari beberapa kolong yang digunakan sebagai air baku PDAM. Pengambilan contoh uji dilakukan pada bulan kering dan bulan basah di 5(lima) lokasi dengan 15 titik sampling. Analisis meliputi parameter lapangan dan laboratorium, pengukuran logam Hg menggunakan cold vapor fumeless AAS Varian Spectro, AA 20plusVGA,1996; sedangkan logam As menggunakan AAS-VarianSpectro, AA-20 plus hydride, 1996 (SM 21st.,2005,APHA-AWWA-WEF, Part.No.3114). Hasil penentuan logam berat As dalam sedimen menunjukkan nilai konsentrasi di atas baku mutu sedimen WAC 173-204-320, terutama di Site I, yaitu di musim penghujan pada PDAM Pemali sebesar 84,84 +0,36 mg/L serta di musim kemarau pada air baku PLN Merawang sebesar 99,686+0,084 mg/L dan air baku PDAM Merawang sebesar 76,797+3,685 mg/L. Hasil penentuan logam berat Hg dalam sedimen menunjukkan nilai konsentrasi di atas baku mutu sedimen WAC 173-204-320, di Site I, yaitu di musim kemarau pada air baku PLN Merawang sebesar 0,679+0,001 mg/L, air baku PDAM Pemali sebesar 0,513+0,153 mg/L, Open Pit Pemali TB Timah 0,431+0,160 mg/L, Kolong Kenanga 0,658+0,070 mg/L, Site III Kolong Bikang 0,611+0,031 mg/L, Kolong Acam Rindik 0,444+0,077mg/L. Konsentrasi As dalam air memenuhi baku mutu air baku air minum Peraturan Pemerintah no.82 tahun 2001, sedangkan Hg melebihi bakumut

Optimization of Naoh Alkali Pretreatment of Oil Palm Empty Fruit Bunch for Bioethanol

Bioethanol from lignocellulosic waste as an alternative energy began to be developed. Pretreatment is an early stage of the process of lignocellulose conversion into bioethanol. Chemical pretreatment using NaOH was done by inserting 3 mm EFB and 10 % NaOH solution at the reactor in moderate temperature and 4 bars pressure. The effect of temperature and time on the pretreatment process was investigated. The variation of temperature process starts from 140, 150 and 160°C, during the time variation of the process starting from 20, 30 and 40 minutes. The highest of biomass recovery was obtained in the pretreatment process with temperature 140 oC, 20 minutes at 42.83 % (dba). The highest delignification at 160 oC temperature, 40 minutes was equal to 86.92 %. However, the optimal pretreatment conditions to produce the highest bioethanol from EFB obtained at 150 oC, 30 minutes were the biomass recovery reached 35.97 %, delignification reached 76.74 %, and ethanol yield from initial EFB reached 15,17 % (w/w)

The Effect of Pretreatment by using Electron Beam Irradiation on Oil Palm Empty Fruit Bunch

Oil palm empty fruit bunch (OPEFB) is a potential type of lignocellulosic biomass for second-generation bioethanol production. The pretreatment process is an important process in the series of processes to produce bioethanol. This research aims to study the effects of pretreatment process by using electron beam irradiation to OPEFB’s characterization as raw materials for the hydrolysis reaction to produce monomer sugars which will be fermented into ethanol. The untreated and treated OPEFB are characterized in terms of their physical and chemical properties. Analysis results of the compositional analysis by using NREL/TP-510-42618 method show that after pretreatment by using electron beam irradiation, OPEFB's total lignin content is changed little while its cellulose and hemicellulose contents tend to decrease with increasing irradiation dose. X-ray diffraction (XRD) analysis shows that there is a decrease of crystallinity compared to untreated OPEFB, except for 200-kGy irradiated OPEFB. The highest decrease of crystallinity was shown by 300-kGy irradiated OPEFB. Further, crystallite sizes of treated OPEFBs are not significantly different from the untreated, except for the 200-kGy irradiated OPEFB. Irradiation pretreatment also increases specific surface area, pore volume, and pore size. The IR spectra analysis show the absorption of cellulose, hemicellulose, and lignin.Received: 07 January 2015; Revised:15 May 2015; Accepted: 17 May 2015

Alkaline Pretreatment of Sweet Sorghum Bagasse for Bioethanol Production

Lignocellulosic material, which consist mainly of cellulose, hemicelluloses and lignin, are among the most promising renewable feedstocks for the production of energy and chemicals. The bagasse residue of sweet sorghum can be utilized as raw material for alternative energy such as bioethanol. Bioethanol production consists of pretreatment, saccharification, fermentation and purification process. The pretreatment process was of great importance to ethanol yield. In the present study, alkaline pretreatment was conducted using a steam explosion reactor at 1300C with concentrations of NaOH 6, and 10% (kg/L) for 10, and 30 min. For ethanol production separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) process were conducted with 30 FPU of Ctec2 and Htec2 enzyme and yeast of Saccharomyces cerevisiae. The results showed that maximum cellulose conversion to total glucose plus xylose were showed greatest with NaOH 10% for 30 min. The highest yield of ethanol is 96.26% and high concentration of ethanol 66.88 g/L were obtained at SSF condition during 48 h process. Using SSF process could increase yields and concentration of ethanol with less energy process. Article History: Received January 16th 2016; Received in revised form May 25th 2016; Accepted June 28th 2016; Available online How to Cite This Article: Sudiyani, Y., Triwahyuni, E., Muryanto, Burhani, D., Waluyo, J. Sulaswaty, A. and Abimanyu, H. (2016) Alkaline Pretreatment of Sweet Sorghum Bagasse for Bioethanol Production. Int. Journal of Renewable Energy Development, 5(2), 113-118. http://dx.doi.org/10.14710/ijred.5.2.113-11

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

Biological Pretreatment of Oil Palm Frond Fiber Using White-Rot Fungi for Enzymatic Saccharification

Oil palm frond is one type of lignocellulosic biomass abundantly and daily available in Indonesia. It contains cellulose which can be converted to glucose, and further processed to produce different kinds of value –added products. The aim of this research is to study the effects of biological pretreatment of oil palm frond (OPF) fiber using Phanerochaete chrysosporium and Trametes versicolor on the enzymatic saccharification of the biomass. The OPF fiber (40-60 mesh sizes) was inoculated with cultures of the two fungi and incubated at 27 °C for 4 weeks. The samples were taken after 1, 2, 3, and 4 weeks of incubation. Chemical components of the biomass after pretreatment were analyzed. The saccharification of the pretreated samples using cellulase and β-glucosidase was performed in a water bath shaker at 50 °C for 48 hours. The concentration of reducing sugar increased with increasing of incubation time, either in those pretreated with culture of P. chrysosporium or with T. versicolor. Pretreatment of OPF fiber using single culture of T. versicolor for 4 weeks gave the highest reducing sugar yield (12.61% of dry biomass)

Application of chemometric analysis to infrared spectroscopy for the identification of wood origin

Chemical characteristics of wood are used in this study for plant taxonomy classification based on the current Angiosperm Phylogeny Group classification (APG III System) for the division, class and subclass of woody plants. Infrared spectra contain information about the molecular structure and intermolecular interactions among the components in wood but the understanding of this information requires multivariate techniques for the analysis of highly dense datasets. This article is written with the purposes of specifying the chemical differences among taxonomic groups, and predicting the taxa of unknown samples with a mathematical model. Principal component analysis, t-test, stepwise discriminant analysis and linear discriminant analysis, were some of the chosen multivariate techniques. A procedure to determine the division, class, subclass and order of unknown samples was built with promising implications for future applications of Fourier Transform Infrared spectroscopy in wood taxonomy classification