Simulation of Contaminants Transport in Groundwater From Nickel Mining Waste Dump Southeast Sulawesi

The irregularities of nickel resource mining in Indonesia cause many serious environmental problems. Piles of leftover rocks on nickel mining waste dumps have the potential to be a source of heavy metal seepage into the water. This study was conducted to assess the impact of nickel mining in the Langgikima Subdistrict of the North Konawe Regency of Southeast Sulawesi Province. The focus is to assess the migration of hexavalent chromium (Cr6+) and iron (Fe) using MT3DMS to model the transport of solutes. The study's goal was to identify cr6+ and Fe concentrations in waste dumps and predict the spread of contaminants over a 20-year period of time. XRF (X-Ray Fluorescence) is done to determine the content of elements and minerals in rocks. Toxicity Characteristics Leaching Procedure (TCLP) is performed to estimate the concentration of Cr6+ and Fe in waste dumps. AAS (Atomic Absorption Spectrophotometer) to find out the content of Cr6+ and Fe in surface water and land water samples. The results showed the highest concentrations of Cr6+ of 0.0462 mg/L and Feat 0.8709 mg/L. Simulations without compacted clay coatings, Cr6+ and Fe contaminants could be transported consecutively by 2.7 km and 2.42 km while simulations used compacted clay layers with a hydraulic conductivity of 1 × 10−9 m/s of Cr6+ and Fe contaminants could be transported consecutively by 0.412 km and 0.467 km. It can therefore be concluded that heavy metals in the remaining rock piles from the waste dump can be transported into groundwater, and the action of using a compacted layer of clay must be taken to prevent contaminant migration into groundwater.

PM2.5 Exposure Risk Analysis Around Mining Area Wolo District

Particulate measuring below 2.5 microns have a very large effect on the body and the atmospheric environment, and are harmful to the respiratory organs and can cause asthma and lung disorders. The objective of this study was to identify the risk of PM2.5 exposure to communities in residential areas around nickel mining in Wolo District, Kolaka Regency. This study uses a descriptive observational method with a total sample of 324 respondents. The results showed that the highest value of the PM2.5 concentration measurement was 68.8 g/Nm3. The measurement of PM2.5 concentration has normally distributed so that the mean value is used as the PM2.5 concentration value. The risk of health living in the vicinity of the PT. Ceria Nugraha Indotama due to PM2.5 exposure of 0.093 mg/kg/day for 5 years (RQ<1) and 3.59 mg/kg/day for 30 years (RQ>1). It is necessary to plant green trees around the mining area to reduce the concentration of particulates in the air and to control the distance of the population to at least 2 km from the industrial center.

SWOT Analysis in Determining Environmental Risk Management Strategy in Medium Scale Nickel Laterite Mining (Case Study in PT Rohul Energi Indonesia)

Nickel is an essential metal in modern infrastructure, with significant uses in the stainless-steel industry for less than 65%. Nearly 70% of the world’s nickel laterite production comes from Indonesia and the Philippines. The high demand for nickel-based materials globally and the availability of nickel laterite ore in Indonesia make laterite nickel mining in Indonesia inevitable. Medium and small mining companies are more likely to have a more significant impact on the environment than large companies. Therefore, it is necessary to evaluate the implementation of environmental risk and impact management, and develop a company strategy. The research was conducted by qualitative method, namely by descriptive analysis and SWOT analysis. The data was collected in interview text, questionnaire results, field notes, documentation, photos, and videos. SWOT is one of the methods to analyze the strategy of an organization by identifying and measuring strengths and weaknesses, and opportunities and threats of the organization. Result is obtained score 3.77 (the X-axis), and 0.34 (the Y-axis) and will be plotted into a quadrant graph of the SWOT analysis method. The research resulted in PT. REI is in quadrant I. Therefore, the strategy would be utilizing the strengths and opportunities of the organization.

Combining colour parameters and geochemical tracers to improve sediment source discrimination in a mining catchment (New Caledonia, South Pacific Islands)

Tracing the origin of sediment is needed to improve our knowledge of hydro-sedimentary dynamics at the catchment scale. Several fingerprinting approaches have been developed to provide this crucial information. In particular, spectroscopy provides a rapid, inexpensive and non-destructive alternative technique to the conventional analysis of the geochemical properties. Here, we investigated the performance of four multi-proxy approaches based on (1) colour parameters, (2) geochemical properties, (3) colour parameters coupled with geochemical properties and (4) the entire visible spectrum to discriminate sediment source contributions in a mining catchment of New Caledonia. This French archipelago located in the south-west Pacific Ocean is the world's sixth largest producer of nickel. Open-cast nickel mining increases soil degradation and the downstream transfer of sediments in river systems, leading to the river system siltation. The sediment sources considered in the current research were therefore sediment eroded from mining sub-catchments and non-mining sub-catchments. To this end, sediment deposited during two cyclonic events (i.e. 2015 and 2017) was collected following a tributary design approach in one of the first areas exploited for nickel mining on the archipelago, the Thio River catchment (397 km2). Source (n=24) and river sediment (n=19) samples were analysed by X-ray fluorescence and spectroscopy in the visible spectra (i.e. 365–735 nm). The results demonstrated that the individual sediment tracing methods based on spectroscopy measurements (i.e. (1) and (4)) were not able to discriminate sources. In contrast, the geochemical approach (2) did discriminate sources, with 83.1 % of variance in sources explained. However, it is the inclusion of colour properties in addition to geochemical parameters (3) which provides the strongest discrimination between sources, with 92.6 % of source variance explained. For each of these approaches ((2) and (3)), the associated fingerprinting properties were used in an optimized mixing model. The predictive performance of the models was validated through tests with artificial mixture samples, i.e. where the proportions of the sources were known beforehand. Although with a slightly lower discrimination potential, the “geochemistry” model (2) provided similar predictions of sediment contributions to those obtained with the coupled “colour + geochemistry” model (3). Indeed, the geochemistry model (2) showed that mining tributary contributions dominated the sediments inputs, with a mean contribution of 68 ± 25 % for the 2015 flood event, whereas the colour + geochemistry model (3) estimated that the mining tributaries contributed 65 ± 27 %. In a similar way, the contributions of mining tributaries were evaluated to 83 ± 8 % by the geochemistry model (2) versus 88 ± 8 % by the colour + geochemistry model (3) for the 2017 flood event. Therefore, the use of these approaches based on geochemical properties only (2) or of those coupled to colour parameters (3) was shown to improve source discrimination and to reduce uncertainties associated with sediment source apportionment. These techniques could be extended to other mining catchments of New Caledonia but also to other similar nickel mining areas around the world.

Fitting the variogram model of nickel laterite using root means square error in Morowali, Central Sulawesi

Abstract. The nickel commodity is getting popular due to its role as one of the raw materials for battery manufacture. It is estimated that this trend will continue for the next 2 - 3 years and reaching its peak when the factories that process the raw material for electric vehicle batteries are established. For this reason, the nickel mining companies are competing to explore new nickel deposits. The research location is a nickel mine in Sulawesi. The purpose of this study was to determine the most suitable Nickel variogram model based on root means square error (RMSE). To obtain an accurate number of resources, it is necessary to apply an accurate and validated estimation method to gain data that are in line with the actual conditions. Therefore, this study uses a geostatistical method that takes into account the spatial relationship of each data using a variogram which is validated by the cross-validation method and RMSE. From the results of the RSME analysis, the most suitable variogram model for nickel content in the limonite and saprolite layers is the exponential variogram model. In addition, the values of root mean square error for nickel content in the limonite and saprolite layers were 0.022 and 0.098 respectively.

Pemanfaatan Limbah Carsul Sebagai Koagulan untuk Menurunkan Konsentrasi Chrome Hexavalent Dalam Air Limbah Industri Nikel

Pertambangan merupakan suatu kegiatan yang berhubungan dengan lingkungan. Pertambangan nikel di Sorowako yang saat dipegang oleh PT. Vale Indonesia, Tbk, Salah satu limbah yang dihasilkan pada kegiatan penambangan bijih nikel berupa Carsulyang berasal dari sulphur melteryang merupakan sumber mineral yang dapat diolah kembali. Tujuan penelitian ini adalah untuk mengetahui besar kandungan Chrome Hexavalent dalam air limbah hasil produksi tambang nikel PT. Vale Indonesia, Tbk. dan menganalisis pengaruh massa koagulan (Carsul)serta lama waktu pengadukan terhadap efisiensi penyisihan Chrome Hexavalent dalam air limbah tambang nikep PT. Vale Indonesia. Tbk. Metodologi yang digunakan adalah kuantitatif eksperimen. Hasil penelitian menunjukkan kandungan air limbah hasil produksi PT. Vale Indonesia, Tbk 0,2 ppm, adapun massa koagulan yang paling efektif adalah 5gram dengan rata-rata efisiensi penyisihan Chrome Hexavalent sebesar 98,5%, dan lama waktu pengadukan optimum adalah 20 detik dengan rata-rata efisiensi penyisihan Chrome Hexavalent sebesar 97,2%. Berdasarkan nilai penyisihan kadarChrome Hexavalent oleh Carsul sebagai koagulan cukup memberikan pengaruh positif dan cukup efektif.Mining is an activity related to the environment. Nickel mining in Sorowako, which was currently held by PT. Vale Indonesia, Tbk, One of the wastes generated in nickel ore mining activities is Carsul which comes from sulfur melter which is a mineral source that can be reprocessed. The purpose of this study was to determine the content of Chrome Hexavalent in the waste water produced by the nickel mine of PT. Vale Indonesia, Tbk. and to analyze the effect of coagulant mass (Carsul) and the length of time of stirring on the removal efficiency of Chrome Hexavalent in PT. Vale Indonesia. Tbk. The methodology used is quantitative experiment. The results showed that the content of waste water produced by PT. Vale Indonesia, Tbk 0.2ppm, while the most effective coagulant mass is 5 grams with an averageremoval efficiency Chrome Hexavalent of 98.5%, and the optimum stirring time is 20 seconds with an averageremoval efficiency Chrome Hexavalent of 97.2. %. Based on the removal value oflevels Chrome Hexavalent by Carsul as a coagulant, it was quite positive and quite effective.

Unearthing conscious intent in women’s everyday resistance to mining in Indonesia

Resistance to nickel mining in Sorowako, Indonesia has existed since the operation started taking land from farmers in the 1970s. However, in Sorowako and beyond, little is known about the gendered nature of everyday resistance to mining. We conducted a photovoice study with women from two Indigenous communities affected by the same mine to uncover conscious intent in everyday resistance. Some scholars call for abandoning intent and consciousness in analytical frameworks for everyday resistance, but by pairing photovoice with a conjunctural exercise, we found women’s awareness of how dispossession and exploitation for mining affects them and their responses to mining as rural Indigenous women. The participants used photovoice to show that their everyday acts, such as accessing forbidden land, intend to lessen their domination and better their conditions, a kind of quiet encroachment of the ordinary theorized by Bayat.