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"Limbah fenol dan logam Cr(VI) merupakan dua jenis limbah industri yang seringditemukan sebagai kontaminan limbah cair yang berbahaya serta sulit untuk didegradasi.Melalui penelitian ini, fenol dan Cr(VI) didegradasi secara bersamaan menggunakanreaktor elektrolisis plasma yang dilengkapi dengan titanium sebagai plasma anoda olehspesies reaktif seperti radikal •OH, radikal •H dan molekul H2O2. Untuk efisiensi energi,injeksi udara diterapkan ke zona elektrolisis plasma, yang berkontribusi padapembentukan spesies radikal. Penelitian ini bertujuan untuk mengetahui pengaruh variasilaju aliran injeksi udara, daya dan tegangan yang berkorelasi dengan persentase degradasifenol-Cr(VI) serta konsumsi energi spesifiknya. Hasil penelitian menunjukkan kondisioperasi maksimum elektrolisis plasma dicapai pada laju injeksi udara 0,2 LPM; daya 330W; tegangan 600 V; konsentrasi elektrolit 0,02 M Na2SO4. Dalam waktu 30 menit, fenolterdegradasi sebanyak 54% dan Cr(VI) tereduksi seluruhnya dengan konsumsi energispesifik sebesar 100.888 kJ/mmol. Efek penambahan injeksi udara kedalam zona plasmaakan berdampak terhadap penambahan jenis spesi reaktif dan mengurangi konsumsienergi, sedangkan peningkatan tegangan operasi akan mempengaruhi rasio spesi reaktifyang dihasilkan, sementara efek terhadap peningkatan daya operasi akan menambahjumlah dari radikal •OH, radikal •H dan molekul H2O2. Temuan dalam penelitian ini akansangat membantu untuk menghilangkan polutan organik dan anorganik secara bersamaandalam air limbah yang kompleks.

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Phenols and Cr(VI) are hazardous organic and heavy metal wastes produced from various

industrial processes such as textile, paint, and electroplating. Through this research,

phenol and Cr(VI) were degraded simultaneously using the plasma electrolysis reactor

equipped with titanium as anode plasma by reactive species such as •OH radicals, •H

radicals and H2O2 molecules. For energy efficiency, air injection is applied into the

plasma electrolysis zone, which contributes to the formation of radical species. This

research aims to obtain the effect of variations in the flow rate of air injection volatge and

electrical power correlated with the percentage of phenol-Cr(VI) degradation and their

specific energy consumption. The results showed maximum operating conditions of

plasma electrolysis is achieved on the air injection rate of 0.2 LPM; 600 V; 330 W; and

the electrolyte solution 0.02 M Na2SO4. Phenol degraded to 54% and Cr(VI) was

degraded to 100% with a specific energy of 100.888 kJ/mmol within 30 minutes. The

effect of adding air injection into the plasma zone will have an impact on the addition of

reactive species and reduce energy consumption, while the increase in operating voltage

will affect the ratio of reactive species produced, and the effect on increasing operating

power will increase the number of radicals •OH, •H and H2O2. The findings in this

research would be helpful for removing organic and inorganic pollutants simultaneously

in complex wastewater."

"Limbah fenol dan logam Cr(VI) merupakan limbah organik dan logam berat berbahaya dan sulit didegradasi. Kedua jenis limbah tersebut dihasilkan dari berbagai macam proses industri seperti industri tekstil, cat, pewarna, dan lain lain. Maka, diperlukan teknologi pengolahan limbah yang efektif, salah satunya adalah dengan teknologi Contact Glow Discharge Electrolysis (CGDE). Metode Cathodic Contact Glow Discharge Electrolysis adalah bagian dari teknologi CGDE, dimana plasma terbentuk di katoda dengan pancaran sinar yang terang (glow discharge). Metode ini dapat menghasilkan spesi reaktif •OH dan H• dalam jumlah besar sehingga mampu mendegradasi limbah cair fenol dan Cr(VI) secara simultan. Kondisi optimum yang didapatkan adalah pada konsentrasi awal Cr(VI) 100 ppm, konsentrasi elektrolit Na2SO4 0,02 M, dan laju alir udara 0,2 L/menit. Untuk plasma anodik, didapatkan persentase degradasi untuk fenol sebesar 99,7% dan Cr(VI) sebesar 49%. Sedangkan untuk plasma katodik didapatkan persentase degradasi untuk fenol sebesar 70,98% dan Cr(VI) sebesar 44,77% selama 120 menit proses CGDE.

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Phenol waste and Cr(VI) metal are hazardous organic waste and heavy metals that are difficult to degrade. Both types of waste are generated from various industrial processes such as textile, paint, dye, and so on. Therefore, an effective waste treatment technology is needed, one of which is Contact Glow Discharge Electrolysis technology. Cathodic Contact Glow Discharge Electrolysis is a part of plasma electrolysis technology in which plasma is formed at cathode with a bright glow (glow discharge). This method produces large quantity of reactive species •OH and H• which can degrade phenol and Cr(VI) liquid waste simultaneously. The optimum conditions obtained were at the initial concentration of Cr (VI) 100 ppm, electrolyte Na2SO4 0.02 M, and air flow rate of 0.2 L/minute. For anodic CGDE, the percetage for phenol degradation was valued at 99.7% and Cr(VI) degradation was valued at 49%. Whereas for the cathodic CGDE, the percentage for phenol degradation was valued at 70.98% and Cr(VI) degradation was valued at 44.77% for 120 minutes of plasma electrolysis process."

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Industri pupuk dapat menjadi salah satu sektor strategis yang dapat memacu perekonomian Indonesia dikarenakan industri pupuk memegang peranan penting dalam mendorong peningkatan produksi pada sektor pertanian yang meningkat seiring dengan bertambahnya populasi di Indonesia. Oleh karena itu untuk memenuhi kapasitas produksi yang terus meningkat, PT. Pupuk Kujang menggunakan katalis nikel oksida dengan alumina yang berfungsi sebagai penyangga pada proses steam reforming. Namun dengan harga logam berharga yang terus meningkat, perlu adanya proses perolehan kembali logam berharga,  yaitu nikel, yang efektif sebagai upaya menurunkan biaya produksi dan mencegah pencemaran lingkungan yang disebabkan oleh limbah spent catalyst. Dalam penelitian ini, dilakukan upaya perolehan logam nikel pada limbah spent catalyst NiO/Al₂O₃ menggunakan asam asetat sebagai 3 M + 1% H₂O₂, rasio S/L 20 g/L, dengan temperatur 80 ^oC dalam waktu 120 menit, dan kecepatan agitasi sebesar 500 rpm berhasil mendapatkan efisiensi recovery logam nikel sebesar 74,63%. Studi kinetika yang dilakukan menggunakan Shrinking Core Model (SCM) menunjukan bahwa prosesnya dikendalikan oleh mekanisme reaksi kimia permukaan dengan energi aktivasi sebesar 23,28 kcal/mol. Kemudian dilanjutkan dengan ekstraksi pada Pregnant Leached Solution (PLS) menggunakan LIX 84-ICNS dengan konsentrasi 40% v/v selama 120 menit pada pH fase akutik 6 dengan kecepatan 500 rpm diperoleh efisiensi ekstraksi nikel sebesar 99,56%.

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The fertilizer industry can be one of the strategic sectors that can spur the Indonesian economy because the fertilizer industry plays an important role in encouraging increased production in the agricultural sector which increases along with the increasing population in Indonesia. Therefore, to meet the ever-increasing production capacity, PT. Pupuk Kujang uses a nickel oxide catalyst with alumina which functions as a buffer in the steam reforming process. However, with the price of precious metals continuing to increase, it is necessary to have an effective process for recovering precious metals, namely nickel, as an effort to reduce production costs and prevent environmental pollution caused by spent catalyst waste. In this research, efforts were made to recover nickel metal from spent catalyst NiO/Al2O3 waste using acetic acid as 3 M + 1% H2O2, S/L ratio of 20 g/L, with a temperature of 80 oC in 120 minutes, and an agitation speed of 500 rpm managed to get a nickel metal recovery efficiency of 74.63%. Kinetic studies conducted using the Shrinking Core Model (SCM) showed that the process was controlled by a surface chemical reaction mechanism with an activation energy of 23.28 kcal/mol. Then proceed with extraction in Pregnant Leached Solution (PLS) using LIX 84-ICNS with a concentration of 40% v/v for 120 minutes at pH aqueous phase 6 at a speed of 500 rpm to obtain a nickel extraction efficiency of 99.56%.

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"Thermo-hydrodynamic design of fluidized bed combustors : estimating metal wastage is a unique volume that finds that the most sensitive parameters affecting metal wastage are superficial fluidizing velocity, particle diameter, and particle sphericity. Gross consistencies between disparate data sources using different techniques were found when the erosion rates are compared on the same basis using the concept of renormalization. The simplified mechanistic models and correlations, when validated, can be used to renormalize any experimental data so they can be compared on a consistent basis using a master equation."