Doni Prakasa Eka Putra

REMOVAL OF SELENIUM (Se) AND ZINC (Zn) IN WATER BY USING NATURAL ZEOLITIC TUFF AS ADSORBENT FROM TEGALREJO AREA, GEDANGSARI DISTRICT, GUNUNGKIDUL REGENCY, SPECIAL PROVINCE YOGYAKARTA, INDONESIA.

Heavy metals are one of the most hazardous pollutant in the water. There are many methods for heavy metals remediation such as precipitation, oxidation, reverse osmosis, ion exchange and sorption by reactive materials. Zeolite is one of reactive materials have been used for water remediation. Therefero, in this the capability of zeolite from Gedangsari District, Gunung Kidul Regency, Special Province of Yogyakarta, Indonesia, will be invetigated to remidiate contaminated water by selenium (Se) and Zinc (Zn). To answer this objective, several samples of natural zeolitic tuff were taken and charaterized. Laboratory experiment was done by batch test. The results showed that natural zeolitic tuff is an effective adsorbent of Se and Zn and holds great potential material to remove heavy metals in water. The sorption isotherms of Se and Zn confirmed to type of Langmuir or Freundlich isotherms.

Determination of Lead Contamination in Urban Soil, Yogyakarta City, Indonesia

Lead (Pb) is one of common heavy metal that has been shown to be very useful tracers of environmental pollution. The consequences of urbanization process can cause not only economic growth but also negatively impact on the quality of water and soil. Therefore the objective of this research is to know the potential contamination of lead in soil of urban area. The soil samples were conducted by batch leaching experiment. In surface soil, lead in soil of Pakem area varies from 2.01ppm to 5.13 ppm with average value of 3.02 ppm and Merapi area ranges from 1.84 ppm to 3.41ppm with average value of 2.42 ppm. In urban area, lead varies from 4.18 to 14.88 ppm with average of 9.93 ppm. Lead in urban soil is higher than Pakem and Merapi soil. The potential contamination of lead in urban soil is occurred with respect to urbanization and human activities. The value of lead is shown with the average of 3 ppm for Caturtunggal, Depok District, 6.53 ppm in Mantrijeron District and 9.82 ppm for Kotagede District in Yogyakarta city. The result of lead distribution in Kotagede District is the highest concentrated and it is followed by Mantrijeron District and Caturtunggal, Depok District.

Geochemical fractionation and risk assessment of copper in urban soil, Yogyakarta city, Indonesia

Copper (Cu) is one of the most pollutants that impact the soil of urban environment. Urbanization in Yogyakarta city with its human activities causes asoil contamination. The objective of this study was to determine the geochemical fraction of copper and the risk assessment in urban territory. The study area, Kotagede district, is located in the southeastern part of Yogyakarta Special Province, and it is the oldest urban area. The soil sampling was drilled by hand auger until 7 meters and sampled for each 1 m depth from the surface. Six steps of sequential extraction procedures were carried out to assess the geochemical fraction of copper and risk assessment of copper. The highest amount of copper was found in amorphous iron oxide with the average of 81.72%. Exchangeable of copper in the geochemical fraction was shown in anegligible amount. Because of high concentration copper in amorphous iron oxide fraction, copper seems to occur as poor mobilization, bioavailability, and low-risk assessment in the stud...

Engineering geology evaluation for predicting the collapse susceptibility of Sidoarjo hot mud earth levees: A hazard assessment

Since May 29, 2006, a sea of hot mud has been gushing from the ground in Sidoarjo, East Java, 35 kilometres south of Indonesia’s second largest city, Surabaya. Due to this disaster, approximately thousand of peoples have been forced from their homes because 600 ha of land and villages were submerged, farmland was ruined, businesses and schools closed as the mud inundated the surrounding area. The authorities response was to build containment ‘basins’ or ‘ponds’ by enclosing areas of land within earth dams, or levees. During the heavy rain on the rainy season, the earth dams and ringdykes have overflown and broken regularly, causing the flooding of more land and damaging infrastructures. However, not only in the rainy season, the levees had also collapses during the dry season. Therefore, an engineering geology study was conducted in order to evaluate the geological factors which causes this phenomena. The parameters used for the evaluation are the heterogeniety of lithology under the dams, geological discontinuity which indicated by the occuring of surface cracks and bubbles, and subsidence phenomena which indicated by the vertical displacement. Overlying method was used to build homogeniety zone of engineering geology based on those parameters, and the resulted map was once again overlay with the location of dams collapses. Result of this evaluation shows that the earth dams collapses were highly correlated with the existing geological discontinuities and subsidences, respectively. Based on this study, the susceptible location of earth dams collapses can be predicted and allow engineers to prepare and plan better engineering solution for the high probable collapses points in order to protect land and infrastructures from the damaging hot mud overflown. Keywords: Hot mud disaster, geological factors, homogeniety zone, earth levee failure points, Sidoarjo-Indonesia

SELECTING RELOCATION OF LAND USE IN HOT MUD DISASTER AREA BY APPLYING GEO-ENVIRONMENTAL EVALUATION. CASE STUDY: SIDOARJO, EAST JAVA, INDONESIA

Since May 29, 2006, a sea of hot mud has been gushing from the ground in Sidoarjo, East Java, 35 kilometers south of Indonesia’s second largest city, Surabaya. Due to this disaster, approximately thousand of people have been forced from their homes because 600 ha of land and villages were submerged, farmland was ruined, businesses and schools closed as the mud inundated the surrounding area. Relocation of the land uses and supporting infrastructures are become important to support the human survivability and environmental sustainability in this disaster area. In order to select the suitable location for land uses and infrastructures, aspect of environmental geology must be concerned. Geo-Environmental parameters such as geological hazards and geological resources are used to select the suitable relocation area. Evaluation of the suitable land uses is conducted by applying simple overlay rating method. Result of this evaluation shows that the relocation of the land uses can be differentiated into three categories; (i) high risk land use/infrastructure, moderate risk land use/infrastructure and low risk land use/infrastructure. Each of these categories have difference map of relocation suitability, however all maps indicate that the suitable relocation area is in the west-part from the hot mud disaster area. Keywords: Hot mud blast, relocation of land uses, geo-environmental evaluation