Illegal gold mining carried out using amalgamation techniques produce mercury waste which can then damage the environment and damage the health of residents. The negative impact due to the use of mercury is dead fish, contaminated river water, water quality below environmental standard quality and spreading in the food chain. This has caused environmental damage, one of which is in terms of land and water. This condition is the basis for conducting deeper research on environmental damage by mercury waste, especially in terms of soil and water. The sampling method used is the Geochemical Method and Geoelectric Method. Geoelectric samples were taken using the superstring R8 tool. Geochemical samples used were soil and water samples which were subsequently tested by the Atomic Absorption Spectrophotometry (AAS) and X-ray Fluorescence (XRF) methods to see the mercury levels that had been scattered in the research location. The study aims to determine the distribution of mercury waste and its levels. This research includes sampling, sample testing, data processing and analysis, and making maps of the distribution of mercury waste through QGis software. From the study, it was found that the distance from the traditional gold mining processing location determines the concentration level (Hg). Analysis using AAS shows that there were 13 samples had mercury concentrations above the critical threshold. From the analysis, it is also known that AAS could not detect mercury levels in soil samples which is different from the results obtained using XRF.

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The metallurgical testings to treat the Kenyan artisanal gold mining samples were performed with several processes such as gravity concentration (i.e., Knelson Concentrator and panning), flotation, and cyanidation or leaching. These tests were conducted to find the best processing stages to improve the Kenyan artisanal mining recovery. From the three categories of samples treated, sample A, which was processed through gravity concentration and flotation, produced 95.64% of gold recovery. Meanwhile, sample B could produce 98.74% of gold recovery with the cyanidation test. The results from sample A and sample B confirmed that the combination of the Knelson concentrator and flotation, which the Processing Center should handle, was the perfect combination to reduce the use of cyanide during the leaching process. On the other hand, the study also showed that the tailing sample (sample C) could still be recovered through flotation. With the results obtained, the best scenario was proposed. The government played a critical role in facilitating both the artisanal miners and the Processing Center for both cases, in Kenya or Aceh.

E-waste, atau electronic waste, merupakan limbah listrik dan elektronik yang berupa kabel listrik, laptop, dan lain-lain. Smartphone merupakan salah satu alat elektronik yang memiliki banyak manfaat bagi manusia. Perkembangan yang pesat menyebabkan setiap tahunnya e-waste dari smartphone mengalami peningkatan di Indonesia terutama sekali di Bukittinggi. Karena setiap tahunnya mengalami peningkatan, penanggulangan e-waste mejadi sangat penting bagi lingkungan dan telah menjadi kewajiban bagi beberapa negara di dunia. Ekonomi sirkular merupakan salah pilihan yang tepat dengan konsep penggunaan kembali dan daur ulang produk. Hal ini berdampak pada berkurangnya permintaan bahan baku, menurunya konsumsi sumber daya alam, dan terciptanya lapangan pekerjaan yang baru. Urban mining dengan pemanfaatan e-waste berbasis ekonomi sirkular dapat menjadi salah satu solusi, terutama dalam mengganti proses pertambangan konvensional yang cenderung merusak lingkungan dengan menjadi alternatif penghasil komoditas pertambangan konvensional. Penelitian ini menggunakan metode Material Flow Analysis (MFA). Data penggunaan smartphone diperoleh dari Badan Pusat Statistik (BPS) Bukittinggi selama sepuluh tahun ke belakang. Hasil penelitian ini selanjutnya menjadi bahan pertimbangan bagi sektor perekonomian dan lingkungan.

Infrastructures in coastal area are mostly made of metal which is susceptible to corrosion due to direct contact with the seawater. The Seawater greatly affects the corrosion rate of metals because it contains chloride ions which can penetrate metal surface. The process of corrosion can be inhibited or slowed by decreasing the corrosion rate in one way, namely the addition of corrosion inhibitors derived from natural materials containing tannin compounds. This study proposed organic corrosion inhibitors which were derived from natural material extracts (coffee leaves and catappa leaves), the effect of time variations on the efficiency of organic inhibitors was investigated, and the efficiency of each inhibitor organic was compared. The corrosion rate with and without inhibitors was analysed by using the method of weight loss. The results showed that the corrosion rate can be reduced by adding the natural ingredients extract. The addition of 2% concentration coffee leaves extract resulted in the lowest corrosion rate with the addition of 0.00226 mmpy. The addition of catappa leaves extract concentration as much as 2% yield the lowest corrosion rate with the addition of 0.0012 mmpy. The highest efficiency of inhibition system was obtained by using 2% catappa leaves extract at 14 days soaking time at 69.23%, and the lowest by using 1% coffee leaves extract.