Journal of Applied Geology
Not a member yet
197 research outputs found
Sort by
Evolution of groundwater chemistry on shallow aquifer of Yogyakarta City urban area
Get PDFSince 1980s, accelerated by urbanization, Yogyakarta City was shifting to many directions defined by main road networks and service centres. Urbanization has transformed rural dwellings to become urban settlements and generated urban agglomeration area. Until now, new business centres, education centres and tourism centres are growing hand in hand with new settlements (formal or informal) without proper provision of water supply and sanitation system. This condition increase the possibility of groundwater contamination from urban wastewater and a change of major chemistry of groundwater as shallow unconfined aquifer is lying under Yogyakarta City. To prove the evolution of groundwater chemistry, old data taken on 1980s were comparing with the recent groundwater chemistry data. The evaluation shows that nitrate content of groundwater in 1980s was a minor anion, but nowadays become a major anion, especially in the shallow groundwater in the centre of Yogyakarta City. This evidence shows that there is an evolution of groundwater chemistry in shallow groundwater below Yogyakarta City due to contamination from un-proper on-site sanitation system.
Keywords: Urbanization, Yogyakarta city, rural dwellings, settlements, agglomeration, contamination, groundwate
Removal Of Lead (Pb2+) From Aqueous Solutions By Natural Bentonite
Get PDFThe aim of the present work is to investigate the ability of natural bentonite (untreated) from Pacitan, East Java to remove lead ions from aqueous solution. The bentonite has specific surface area and cation exchange capacity of 27.52 m2 g−1 and 65.20 meq/100 gr of bentonite, respectively. Towards this aim, batch adsorption experiments were carried out and the effect of various parameters on this removal process has been investigated. The effects of pH, grain size of bentonite, adsorption time and lead ion concentration on the adsorption process were examined. The optimum pH for adsorption was found to be 9, with the finer grain size of bentonite is more effective. In adsorption studies, residual lead ions concentration reached equilibrium in a duration of 24 hours. Adsorption of lead on bentonite appeared to follow Freundlich isotherm. Our results demonstrate that the adsorption process was mostly dominated by ion exchange process. Keywords: Removal, lead, aqueous solution, natural bentonite, adsorption
Lead Contamination In Soil Of Yogyakarta City, Indonesia
Get PDFThis paper investigates on Pb concentrations and mobility in soil of overall Yogyakarta City, Indonesia. The objectives of this study include to investigate Pb concentrations in the surface soil throughout Yogyakarta and to study their possible sources and potential environmental impacts. The soil samples from 168 locations in Yogyakarta was obtained, representing different land use and traffic conditions. Spatial analysis and sequential extraction analysis were performed. Generally, contour pattern of Pb value clearly shows that high value is concentrated in the middle and few north part of the study area, confirmed by traffic condition in the study area. In general, the results of sequential extraction analysis shows that Pb was predominantly associated with exchangeable fraction. The presence of lead in the exchangeable fractions may pose a serious environmental concern since they are highly soluble and potentially bio-available in the soil of study area. Keywords: Soil, lead contamination, GIS, sequential extraction
FLUID INCLUSION STUDIES OF THE EPITHERMAL QUARTZ VEINS FROM SUALAN PROSPECT, WEST JAVA, INDONESIA
Get PDFSualan prospect is located at Talegong Sub-district of Garut Regency, West Java, Indonesia. The area constitutes calc-alkaline volcanic and volcaniclastic rocks of Tertiary age. The rocks have experienced regional propylitic and argillic alteration. Fluid inclusions from quartz veins were studied in order to constrain the nature, characteristics and evolution of fluids. Microthermometric measurements on fluid inclusion were carried out by freezing and heating experiment. Temperatures of homogenization (Th) and final melting of ice (Tm) were measured for primary, liquid-dominated, two-phase inclusions. The values of Th range from 160°C to 210°C and salinities range from 0.35 to 4.96 wt.% NaCl equiv. Formation temperature of the quartz veins are estimated at 180°C and 190°C and paleo-depth of formation are at 80m and 140m, respectively. Microthermometric data indicates that fluid mixing and dilution were important processes during the evolution of hydrothermal system. Based on fluid inclusion types, microthermometric data, trapping temperature, paleo-depth, texture of quartz and hydrothermal alteration types, quartz veins from prospect were developed under epithermal environment. Keywords: Quartz vein, fluid inclusions, microthermometry, salinities, formation temperature, paleo-depth, epithermal, Sualan prospect
ESTIMATION, REALITY AND TREND OF GROUNDWATER NITRATE CONCENTRATION UNDER UNSEWERED AREA OF YOGYAKARTA CITY – INDONESIA
Get PDFIn the last two decades, urbanization has transformed Yogyakarta City expanding beyond its administrative area with about one million inhabitants. The City sited on shallow unconfined aquifer has rapidly changed without appropriate access to sanitation and piped water supply. Until now, only 9% of the urban population is served by sewers system and less than 30% of urban population have access to clean water which supplied by the local public water-work. Most of the urban population depend on shallow groundwater for much of their water supply. Regards to the massive used of on-site sanitation systems in the city, contamination of nitrate in shallow groundwater is predicted to occur and surveys of domestic dug wells have revealed a widespread nitrate contamination of the groundwater. Comparison of groundwater nitrate and chloride concentration from several old data and the latest data shows clearly an evidence of the increasing of nitrate concentration and nitrate leaching in the shallow groundwater under Yogyakarta City overtime. Considering the trend, it is no doubt that most of nitrate concentration under urbanized area in the Yogyakarta City will be greater than 50 mg/L in the next several years, if appropriate management action to deal with the on-site sanitation system is not conducted
CHARACTERIZATION OF JULY 17, 2006 TSUNAMIITE AT SOUTH COAST OF WEST JAVA
Get PDFJuly 17, 2006 tsunami which occurred in Indian Ocean had swept most of the south coast of Java, especially at Pangandaran area, West Java. The tsunami wave transported and deposited sediment known as tsunamiite, with various compositions. Three different textural characteristics have been recognized on the tsunami sediment deposit. First type is on the tsunamiite found at West Pangandaran Beach, which is darker than the older beach sediment and separated by erosional surface. The sedimentary structures are parallel lamination and current ripple. The grains have no fining trend in vertical as well as lateral direction. Whereas the second type is found at East Pangandaran Beach, which is brighter than the older beach sediment and also separated by erosional surface. The sedimentary structures are cross lamination on the lower layer, parallel lamination on the middle layer and massif on the upper layer. The grains have no fining trend in vertical and lateral direction Benthic foraminifera is one of organism which is transported and deposited as tsunami deposit on the coast. Ammonia beccarii, Elphidium advenum, Amphistegina lessonii, Cibicides sp., Biginerina irregularis, Bolivina plicata, Bathysiphon sp., Nodosaria andQuinqueloculina were found in the recent tsunami deposit from Pangandaran. Based on the benthic foraminifera contents, it can be inferred that the sediments came from lagoonal until deep sea (abyssal) environment
COPPER (Cu2+) REMOVAL FROM WATER USING NATURAL ZEOLITE FROM GEDANGSARI, GUNUNGKIDUL, YOGYAKARTA
Get PDFDevelopment of indusrialization and urbanization not only increase economic growth but also contribute to the environmental degradation, especially contamination of heavy metals in water. In other side, there are many geological materials have capability to immobilize heavy metals. Therefore, the objective of this research is to know the maximum capacity of natural zeolite from Trembono area, Gunung Kidul regency to immobilize copper (Cu2+) from water and to understand their mechanism. This experiment was carry out by a batch test. The result showed that the maximum capacity of zeolite to immobilize Cu (qmax) is 63,69 mmolCu/kg Zeolite according to Langmuir adsorption equilibrium model. In addition, the capability to immobilize Cu will increases due to decreasing the grain size. The result of this research can be used as an alternative for waste water treatment, especially Cu.
Keywords: Removal, copper (Cu2+), natural zeolite, Langmuir isother
DETERMINATION OF NUCLEAR POWER PLANT SITE IN WEST BANGKA BASED ON ROCK MASS RATING AND GEOLOGICAL STRENGTH INDEX
Get PDFIndonesian government through the NationalAtomic Energy Agency has planned to build anuclear power plant. One of the proposed sitesis in West Bangka Regency, Bangka BelitungArchipelago Province. The engineering geologyof this area is, however, not fully understood andrequires further investigations. Engineering geology investigations were carried out by assessing therock mass quality and bearing capacity based onfield observation and drilling data. The assessmentwas conducted using Rock Mass Rating (RMR)and Geological Strength Index (GSI) classifications.The rock masses in the study area were dividedinto four units, namely units of sandstone, granite,mudstone and pebbly sandstone. The RMR andGSI values in the study area were influenced by theparameters of discontinuity space density, the slopeof discontinuity orientation, grade of weatheringand groundwater conditions. The assessment showsthat the granite unit had the best quality which wasshown by a 53 average RMR value and 66 GSIvalue. Based on the average RMR value, the graniteunit was estimated to have cohesion value between0.2 and 0.3 MPa, friction angle between 25° and35°, and allowable bearing pressure between 280and 135 T/m2. Based on the GSI value, the graniteunit was estimated to have uniaxial compressivestrength value between 1.0465 and 183.8 MPa, ten-sile strength between (-0.0122) and (-5.2625) MPa,rock mass strength values between 24.5244 and220.351 MPa, and modulus of deformation withina range of 1.73 - 86.68 GPa. The Granite Unit wasconsidered to be the most appropriate location forthe nuclear power plants
Regional Depositional Model Of South Makassar Basin Depocenter, Makassar Strait, Based On Seismic Facies
Get PDFSouth Makassar Basin Depocenter (SMBD) is located in Southern Makassar Strait which has petroleum potential by the presence of oil and gas indications within the area based on Airborne Laser Fluorescence survey. However, detail studies within this area are not developed well. One of the studies which can be utilized for further discoveries of oil and gas field in SMBD is a study of depositional model using seismic facies method to maximize limited seismic and well data. Interpretation of depositional model in Eocene (syn-rift phase) was varied from alluvial plain and alluvial fan complex, continued gradually to platform. In Oligocene time (post-rift phase), massive transgression caused a major deepening in entire SMBD where the depositional environment changed to basinal plain. In early Miocene – recent interval (syn-orogenic phase), SMBD was relatively in stable condition at basinal plain environment. Lower Tanjung Sequence will be the most prolific petroleum play in SMBD due to its adequate source rock, reservoir rock and seal rock as well. Keywords: South Makassar basin, depositional model, seismic facie
ASSESSMENT OF OPTIMUM YIELD OF GROUNDWATER WITHDRAWAL IN THE YOGYAKARTA CITY, INDONESIA
Get PDFThe high demand of clean water supply and groundwater usages in Yogyakarta City, Indonesia has caused the lowering of groundwater table of about 3 m in average since 1984. This condition is caused by the increase number of groundwater pumping in this city relate to the rising of the urban population, economics condition, education and cultural activities, change of land use and increase number of hotels on this famous tourism city in Indonesia. Therefore, it became necessary to assess the optimum yield from the groundwater system beneath this city which can still preserve the recent level of shallow groundwater. This is important because most of the people in this city depends their daily water supply from shallow dug well. In order to assess the safe yield, a groundwater modeling is conducted. The data used on this modeling was taken from previous research and also primary data collected during this research such as; aquifer geometry, aquifer characteristics, shallow groundwater level, water usage/pumping wells discharge, river discharge and surface water level, and climate data. Prediction of the impact of groundwater pumping was made by increasing the water usage/pumping wells discharge on several scenarios. The result of this modeling shows that the optimum yield of the aquifer beneath Yogyakarta City area is about 125,000 m3/day. Keywords: Optimum yield, groundwater usage, groundwater table, pumping, urban population, shallow dug well