The purpose of this study is to analyze the impact of waste on the environmental conditions of the community, and to find out the proper management of waste due to massive population growth and development, as well as population activities that have an impact on domestic waste. This research belongs to the type of descriptive qualitative research, with data collection techniques by interviewing the Cipare Village, observation of research locations with assessment instruments that have been prepared, as well as secondary data obtained from Serang City in numbers. The conclusion of this research is population growth and development development have a very detrimental impact, especially on the environment around us, namely: garbage, excessive accumulation of garbage can cause various diseases, ecosystem imbalances, flood disasters because the flow of sewers is blocked by garbage, and inconvenience. in doing activities. Therefore, proper waste management must be carried out immediately to create a healthy environment. For this reason, local community participation is needed to carry out waste management properly and correctly, starting to sort out organic and inorganic waste, and also not to throw garbage indiscriminately.

ABSTRAKMasalah timbul ketika dilakukan pengelasan pada lambung kapal berbahan material Baja SS400. Proses pengelasan dilakukan di lingkungan pantai. Pengelasan dengan menggunakan metoda flux core arc welding ini menghasilkan porositas lasan yang berukuran relatif besar diatas 20% tebal sampel. Pada penelitian ini mencoba memvariasikan arus dan gas pelindung dengan tujuan menjaga busur agar busur las lebih stabil dan porositas dapat diminimalisasi. Arus pengelasan yang digunakan pada penelitian ini adalah 230, 250 dan 270 A dan dengan laju gas pelindung 12, 18, dan 24 liter/menit. Untuk mengamati cacat porositas di dalam lasan digunakan metoda radiografi. Struktur yang terbentuk akan diamati dengan mikroskop optik. Hasil Pengamatan menunjukkan porositas terjadi pada kuat arus 230 dan 250 A dengan aliran gas pelindung berturut-turut 12 dan 18 liter/menit, tetapi kondisi kedua menghasilkan porositas yang berukuran >1 mm diluar kriteria diterima. Pengamatan metalografi menunjukkan daerah las atas didominasi oleh fasa acicular ferrite dan daerah las tengah didominasi ferrite dan perlite, sedangkan HAZ yang dibagi dua daerah yaitu, coarse grain (CG) dan fine grain (FG) yang masing-masing didominasi oleh bainite, perlite, dan ferrite, sedangkan FG HAZ memiliki fasa ferrite dan perlite. Pengaruh kuat arus menunjukkan peningkatan fasa AF dari 45,002% menjadi 50,534% terhadap matriks. Pengaruh laju alir gas terhadap struktur mikro terlihat pada peningkatan inklusi yang semakin banyak dengan semakin meningkatnya laju gas.Kata kunci: Flux core arc welding, lambung kapal, arus pengelasan YENI MURIANI ZULAIDA, M ICHSAN KUSUMA, TIARA TRIANA Jurnal TEKNIKA -120 ABSTRACT Problems arise when welding on a hull made from SS400 Steel material. The welding process is carried out in the coastal environment. Welding using the arc welding flux core method produces relatively large weld porosity above 20% of the sample thickness. In this study try to vary the protective current and gas in order to maintain the arc so that the welding arc is more stable and the porosity can be minimized. The welding currents used in this study were 230, 250 and 270 A and with protective gas rates 12, 18, and 24 liters / minute. To observe porosity defects in welds, radiographic methods are used. The structure formed will be observed with an optical microscope. Observation results showed porosity occurred at 230 and 250 A currents with protective gas flow 12 and 18 liters/minute respectively, but the second condition produced porosity measuring>1 mm excluding acceptable criteria. Metallographic observations show that the upper weld area is dominated by the acicular ferrite phase and the middle weld area is dominated by ferrite and perlite, while the HAZ is divided into two regions, namely coarse grain (CG) and fine grain (FG), each of which is dominated by bainite, perlite, and ferrite, while FG HAZ has ferrite and perlite phases. The effect of current strength shows an increase in AF phase from 45.002% to 50.534% of the matrix. The effect of the gas flow r...

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Gold adsorption from dissolution of gold ore concentrate at Tanggamus mine using activated carbon from thiocyanate leached solution was investigated in this research. As the pollution of the environment has been raising accordingly with the increasing of cyanidation, thiocyanate is becoming current alternative and less toxic reagent in terms of gold dissolution. However, the research was still limited. The development and implementation of thiocyanate in gold extraction is the core of this research. Solvent and oxidizer concentrations (KSCN and FeCl3) were used in this study with 0.3 M and 0.1 M of concentration, respectively. Adsorption process was carried out for 4 hours using 100 ml of filtrate with activated carbon addition. Adsorption of thiocyanate complex gold compounds was studied by varying the size of activated carbon, the concentration of activated carbon, and the rotary speed of bottle roll. At-10+20# of activated carbon size, the %-adsorption obtained was 93.65%. Meanwhile, 94.31% of gold adsorption was achieved with the concentration of activated carbon at 1500 mg/l and 93.37% of gold adsorption was reached with the rotary speed of 150 rpm. Pseudo second order was applied to calculate the kinetics of gold adsorption with the R2 value obtained was 0.9999.

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