Assessment of Arsenic Levels in Water, Sediment, and Human Hair around Ie Seu’um Geothermal Manifestation Area, Aceh, Indonesia

The concentration of arsenic in water, sediment, and resident hair in the Ie Seu’um geothermal manifestation area has been analyzed using the Atomic Graphite Furnace Atomic Absorption Spectrophotometry (GF-AAS) method. Sediment and hair samples were prepared by wet digestion using an acid solution. The measurement results were validated by linearity, Limit of Detection (LoD), Limit of Quantification (LoQ), Relative Standard Deviation (%RSD), and %Recovery. The validation test showed that this method is very linear, sensitive, accurate, and precise with a correlation coefficient of 0.9999, LoD of 0.009 μg/L, LoQ of 0.027 μg/L, recovery values of 89.117–101.027% for hair samples and 88.337–105.175% for sediment samples, and RSD of 1.067%. The sample test results showed that the hot springs contained the highest arsenic with levels of 166.73 ± 0.0081 μg/L (IS1). In comparison, the water samples with the lowest arsenic levels were in the rivers that had not been in direct contact with the hot water (IS2) flow, which is 0.80 ± 0.0036 μg/L. All the river water samples that had been in contact with hot water were boreholes, and the resident boreholes located around hot water streams/rivers contaminated with arsenic were above the threshold. Only the river water that had not been in contact with hot water, refill water, and borehole waters outside the hot water flow were detected to be below the threshold level. All the sediment samples showed arsenic contamination, with levels ranging from 2.56–6.86 mg/kg, and it was still within the normal limits recommended by the National Oceanic and Atmospheric Administration (NOAA). Arsenic exposures in communities living around the Ie Seu’um geothermal area, Mesjid Raya Sub-District, Aceh Besar District, Aceh Province, were very high, where 9 out of 10 respondents were positive for arsenic with levels ranging from 54.59–164.57 mg/kg, which was already above the threshold set by the researchers.

The Estimation of Subsurface Structure within Geothermal Manifestation Area as an Outflow Zone Using Geoelectrical Resistivity Method in Tegal, Jawa Tengah

<p class="TesisTextOneHalfSpace"><em>Indonesia is one of the country having a lot of geothermal fields potentially used as a source of energy. For example, Java island is noted to have almost 57 geothermal fields. One of those geothermal fields which is rarely studied is Guci geothermal field. Hence, there was conducted a research to investigate the subsurface image and geothermal system in Guci geothermal field based on resistivity data. </em><em>The research in Guci geothermal field was carried out using geoelectrical method. Resistivity geoelectrical research used two configurations, namely dipole-dipole and schlumberger. Data acquisitions for dipole-dipole configuration was done in two lines, 500 metres spread for each line. Whereas the acquisitions for schlumberger configuration was done in four points, 200-250 metres spread for each point. </em><em>Research result showed that the area of geothermal manifestation in Guci consist of top soil layer, sandstone, andesite, and a fluids-containing layer. A fluids-containing layer is estimated to be related to geothermal manifestation in Guci and is a fault zone. Fault is estimated to be a normal fault and lies in 20 metres depth. Fault within geothermal manifestation area in Guci has a role as the pathway of hot-fluid out to the surface which forms a manifestation.</em></p>

APLIKASI METODE GEOLISTRIK RESISTIVITAS KONFIGURASI WENNER- SCHLUMBERGER UNTUK MENGIDENTIFIKASI LITOLOGI BATUAN BAWAH PERMUKAAN DAN FLUIDA PANAS BUMI WAY RATAI DI AREA MANIFESTASI PADOK DI KECAMATAN PADANG CERMIN KABUPATEN PESAWARAN PROVINSI LAMPUNG

Research area is located in Padang Cermin Sun-District, Pesawaran Regency, Lampung Province. Manifestation in research area is hot water pool with surface temperatures reach 900C. Data acquisition has been done by Wenner-Schlumberger configuration with 5 acquisition line. Line 1, line 4 and line 5 have 280 meters length. Line 2 have 240 meters length and line 3 have 320 meters length with a spacing of each electrodes in each lines is every 5 meters. The objective of this research are (1)examining the geochemical contaminant and fluid types, (2)identifies the geothermal fluid based on 2D and 3D resistivity data analysis, also (3)identifies the layer of rock in Padok manifestation area based on 2D and 3D subsurface resistivity section. Subsurface lithology in research area generally divides into 4 parts. Which is hot water fluid with mean resistivity value between 1 Ωm into 3 Ωm and based on geochemistry data the fluid type is chloride water; surface sediment with resistivity value between 6 Ωm into 50 Ωm and identified as swamp sediment and alluvium sediment divides into gravels, pebbles, sands, clay and peat; Gravels, pebbles, sands, clay and peat with resistivity value between 50 Ωm into 100 Ωm; and igneous rock (andesite-basalt) with resistivity value more than 100 Ωm.

ANALISIS VEGETASI DAN KEANEKARAGAMAN TUMBUHAN DI KAWASAN MANIFESTASI GEOTERMAL IE SUUM KECAMATAN MESJID RAYA KABUPATEN ACEH BESAR

Ie Suum geothermal manifestation area is a hot sering resource in Ie Suum Village at Aceh Besar regency. Ie Suum hot spring is a stretch of Seulawah Agam mountain and is one of the most active volcanic mountains in Aceh. This area has higher temperature and soil pH compared to areas far from geothermal areas. Therefore, this study can be associated with the unique characteristics of vegetation of geothermal areas will be different from vegetation plants that exist in other vegetation types. This research was conducted by quadrat transect method by determining the location of the research by purposive sampling divided into four point (station) with size determined based on plant habitus that is: herb (1x1 m2), bush / shrub (2x2 m2), pole ( 5x5 m2), and trees (10x10 m2). Data analysis is done qualitatively and quantitatively. Quantitative analysis of data by using vegetation analysis are: density (Kr), Frequency (Fr), Dominance (Dr), and Diversity Index (Ĥ). The results of the study found 23 families consisting of 34 species with a total number of individuals as many as 534 scattered in 4 observation stations divided into herbaceous plants, shrubs, poles and trees. Important Value Index (INP) vegetation in geothermal manifestation area of Ie Suum in all stations was obtained by INP 225,86%. This value belongs to the high category. The species species that have the highest index of other species Axonopus compressus is 17.02%, while the lowest Importance Value Index is Clidemia hirta with a value of 1.32%. The high value of INP Axonopus compressus is due to this species living on dry soil moisture and high acidity. The biodiversity index (Ĥ) of geothermal area of Ies Suum of Mesjid Raya District of Aceh Besar is Ĥ = 3,508. Vegetation of plants in the geothermal area ie suum belong to the high category due to plants that can adapt to high environmental physical-chemical conditions.

Subsurface Structure and Fluid Flow Analysis Using Geophysical Methods in the Geothermal Manifestation Area of Paguyangan, Brebes, Central Java

The indication of an active geothermal system is shown by the presence of surface manifestations such as the hot spring in Kedungoleng, Paguyangan, Brebes, Central Java. The temperature of the largest hot spring reaches 74o C and there is an assumption that this is an outflow of Mount Slamet geothermal system. DC-resistivity, Spontaneous Potential (SP) and Shallow Surface Temperature surveys were conducted to determine the subsurface structure as well as its correlation with the distribution of thermal fluid flow and shallow surface temperature. The subsurface resistivity has been investigated using 5 points of the Schlumberger configuration with 400 m separation for each point. For the fluid and temperature pattern, a measurement using 15 m interval in 3 lines of conducting fixed electrode configuration has been carried out, along with a 75 cm of depth of temperature measurement around the manifestation area. The thermal fluid is assumed by the low resistivity of 0.756 to 6.91Ωm and this indicates sandstone that has permeable characteristic. The fluid flows in two layers of Sandstone at more than 10 meter from surface of the first layer. Accordingly, the SP values have a range between -11- 11 mV and a depth interval of 13.42- 28.75 m and the distribution of temperature is between 24o-70oC at a tilting range of 46.06o-12.60o. Hence it can be inferred that the thermal fluid moves in the Northwest direction and is controlled by a fault structure stretching from Northwest to Southeast.Article History: Received Feb 3, 2016; Received in revised form July 11, 2016; Accepted August 13, 2016; Available onlineHow to Cite This Article: Setyawan, A., Triahadini, A., Yuliananto, Y., Aribowo, Y., and Widiarso, D.A. (2016) Subsurface Structure and Fluid Flow Analyses Using Geophysical Methods in Geothermal Manifestation Area of Paguyangan, Brebes, Central Java. Int. Journal of Renewable Energy Development, 5(3), 171-177.http://dx.doi.org/10.14710/ijred.5.3.171-177

Doctrinal Approachs of the Land Operations at Tactical Level

The character of armed conflict will be further granted by the use of conventional military forces, of professionalized but high-tech armies - as it has been enshrined in recent finished confrontations as well as in the ones currently underway- the manifestation area and the intensity of the threats have extremely diversified and expanded in the context of the operational environment. This meant the need for new approaches of the specific operational framework for the conduct of military operations, with consequences for the structure of the operation of groupings of forces and the way of conducting actions.