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"Separation and purification of yttrium from several rare earth elements available in rare earth mineral xenotime employing combined separation methods. In this study, rare earth mixtures and reagent grade synthetic materials were used instead of actual origin xenotime mineral samples. The concentration ration of each rare earth in the mixture was proportional to that of the rare earth mineral xenotime found on Bangka Island. Crystals of yytrium with a purity of 99,9% were obtained which indicates a successful separation of yttrium from the rare earth elements."

"ABSTRAKKrisis air bersih di daerah berair payau belakangan ini semakin memprihatinkan. Teknologi yang banyak digunakan saat ini yaitu distilasi dan Reverse Osmosis RO tidak bekerja secara maksimal karena kebutuhan energi dan biaya yang relatif besar. Teknologi capacitive deionization CDI yang ditemukan untuk menggantikan teknologi RO dan distilasi juga belum menjadi solusi yang baik, karena berdasarkan penelitian yang dilakukan sebelumnya tentang pemurnian air payau, didapatkan tingkat penurunan kadar garam hanya sebesar 13,1 . Hal tersebut mendorong pengembangan penelitian pemurnian air lebih lanjut dengan menggunakan teknologi membrane capacitive deionization MCDI agar dapat membantu mengatasi masalah krisis air bersih daerah air payau secara aplikatif. Prinsip dasar MCDI adalah dengan mengionisasi ion yang kemudian akan teradsorp ada elektroda. Hal yang membedakan MCDI dan CDI adalah penambahan membran yang diletakan di depan tiap elektroda dengan kutub yang berlawanan, sehingga dapat menghalangi ion yang sejenis dengan elektroda memenuhi pori elektroda, sehingga meningkatkan kemurnian dari produk. Pada penelitian ini didapatkan hasil penurunan kadar garam sebesar 23,9 , untuk 2 sel MCDI, dan 18 untuk 1 sel MCDI. Selain meningkatkan kemampuan penyerapan ion, pada 2 sel MCDI juga mengalami penyerapan ion yang lebih cepat jika dibandingkan dengan 1 sel MCDI, dari 50 menjadi 30 menit.

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ABSTRACTRecently, clean water crisis in brackish water area is increasing, particularly during the dry season. Technology that widely used today which are distillation and reverse osmosis RO do not work optimally because energy requierments and costs are relatively large. Capacitive deionization CDI , which is projected to replace RO and distillation is not a good solution, based on previous research using CDI to purify the brackish water, it can provide only 13,1 decrease in salinity level, encourages the study of water purification using membrane capacitive deionization MCDI in order to overcome the water crisis problem. The base principle of MCDI is by ionizing the brackish water, and electrodes will adsorp ion. Membrane capacitive deionization is different from capacitive deionization because the membrane capacitive deionization using membrane to help the counter ion filling the electrodes to increase the purity of the product. In this research, salinity reduction are 23,9 for 2 cells of MCDI, and 18 for 1 MCDI cell. In addition to improving the ability of ion adsorption, in 2 MCDI cells also experience faster ion adsorption compared with 1 cell of MCDI, 30 minutes in 2 MCDI cells and 50 minutes in 1 cell of MCDI."

"Furfural adalah senyawa yang bernilai jual tinggi dapat dihasil dari konversi selulosa dan hemiselulosa dan tingkat kebutuhan di Indonesia masih tinggi. Riset ini meneliti perancangan proses dan perhitungan ekonomi produksi furfural berbahan baku TKS dengan memvariasikan metode purifikasi dengan metode distilasi dan metode ekstraksi toluene menggunakan software Superpro Designer 9.5. Purifikasi furfural menggunakan dua cara yaitu pemurnian furfural menggunakan skema ekstraksi toluene dan skema distilasi. Terdapat dua rekomendasi lokasi pabrik yang dapat dipilih berdasarkan letak pabrik yang dekat dengan pembeli yaitu di Cilacap dan letak pabrik dekat dengan supplier yaitu Banten. Berdasarkan hasil perhitungan keekonomian, Skema pemurnian ekstraksi toluene dengan IRR bernilai 26.02% lebih menguntungkan walaupun kemurniannya 99,95% dibanding dengan skema pemurnian distilasi dengan IRR yaitu 25.86% walaupun kemurnianya mencapai 99,96%. Dengan kedua rekomendasi lokasi perhitungan keekonomian payback period yang dimiliki oleh kedua lokasi hampir sama maka Cilacap yang memiliki nilai NPV 89,739,000$ lebih menguntungkan dibanding dengan Banten yang memiliki NPV 87,430,000$.

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Furfural is a high-selling compound that can be produced from cellulose and hemicellulose conversion and the level of demand in Indonesia is still high. This research examines the economic process design and calculation of furfural production made from TKS by varying the purification method with the distillation method and the toluene extraction method using Superpro Designer 9.5 software. Furfural purification uses two methods, namely furfural purification using toluene extraction scheme and distillation scheme. There are two plant location recommendations that can be chosen based on the location of the factory that is close to the buyer, namely in Cilacap and the location of the plant close to the supplier, namely Banten. Based on the economic calculation results, the toluene extraction purification scheme with an IRR value of 26.02% is more profitable even though its purity is 99.95% compared to the distillation purification scheme with an IRR of 25.86% even though its purity reaches 99.96%. With the two recommendations for the location of the calculation of the economic payback period owned by the two locations almost the same, Cilacap which has a value of NPV 89,739,000$ is more profitable than Banten which has a NPV of 87,430,000 $."

"Pencemaran udara ruang dan maraknya berbagai bakteri serta virus di udara memerlukan perhatian. Salah satu upaya untuk meningkatkan kualitas udara adalah dengan menggunakan alat purifikasi udara. Untuk mendapatkan unit purifikasi udara terbaik yang dapat mengurangi berbagai polutan seperti gas toksik dan polutan biologi, maka dibutuhkan kombinasi dari beberapa teknologi, yaitu teknologi fotokatalisis, UVC, dan plasma ion. Protipe alat purifikasi udara ruang terdiri dari bagian-bagian utamanya yaitu blower untuk mensirkulasi udara masuk- keluar alat, komposit fotokatalis berbasis TiO2 yang dilengkapi sinar UVC germisidal untuk mendegradasi bakteri dan virus, dan generator plasma ion negative untuk menetralkan oksigen aktif berbahaya, membersihkan partikulat serta disinfeksi bakteri dan virus yang masih tersisa. Fotokatalisis TiO2 dilapiskan pada penyangga alumunium honeycomb dan karbon. Hasil karakterisasi SEM-EDX dan XRD menunjukkan persebaran TiO2 lebih baik dengan penyangga karbon. Pada degradasi polutan gas toksik (Formaldehida, Total Volatile Organic Compounds (TVOC), dan CO) digunakan formaldehyde detector dan Gas Analyzer, dilakukan perbandingan pada kondisi alat, dan didapatkan kombinasi dari ketiga teknologi dengan penyangga karbon yang terbaik yaitu dapat menurunkan 92% konsentrasi formaldehida dan TVOC dalam waktu 15 menit dan 100% CO dalam waktu 13 menit. Uji kinerja alat untuk disinfeksi polutan biologi dilakukan dengan sampling angka kuman di udara indoor dengan Microbiology Air Sampler menunjukkan pengurangan total angka kuman hingga 73% setelah unit purifikasi udara dinyalakan selama 30 menit.

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Indoor air pollution and various bacteria and viruses in the air require attention. One of the efforts to improve air quality is to use an air purifier. To get the best air purification unit that can reduce various pollutants such as toxic gases and biological pollutants, a combination of several technologies is needed, namely photocatalysis technology, UVC, and ion plasma. The prototype room air purifier consists of the main parts, namely a blower to circulate air in and out of the device, a TiO2-based photocatalyst composite equipped with germicidal UVC light to degrade bacteria and viruses, and a negative ion plasma generator to neutralize harmful active oxygen, clean particulates and disinfection of remaining bacteria and viruses. Photocatalyst TiO2 superimposed on aluminum honeycomb and carbon supports. The results of SEM-EDX and XRD characterization showed better TiO2 distribution with carbon buffer. In the degradation of toxic gas pollutants (Formaldehyde, Total Volatile Organic Compounds (TVOC), and CO) a formaldehyde detector and a Gas Analyzer were used, a comparison was made on the condition of the equipment, and the combination of the three technologies with the best carbon buffer was able to reduce 92% of the formaldehyde concentration. and TVOC within 15 minutes and 100% CO within 13 minutes. The performance test of the instrument for disinfection of biological pollutants was carried out by sampling the number of germs in the indoor air with the Microbiology Air Sampler, which showed a reduction in the total number of germs up to 73% after the air purification unit was turned on for 30 minutes."

"This book provides researchers and graduate students with an overview of the latest developments in and applications of adsorption processes for water treatment and purification. In particular, it covers current topics in connection with the modeling and design of adsorption processes, and the synthesis and application of cost-effective adsorbents for the removal of relevant aquatic pollutants. The book describes recent advances and alternatives to improve the performance and efficacy of this water purification technique. In addition, selected chapters are devoted to discussing the reliable modeling and analysis of adsorption data, which are relevant for real-life applications to industrial effluents and groundwater. Overall, the book equips readers with a general perspective of the potential that adsorption processes hold for the removal of emerging water pollutants. It can readily be adopted as part of special courses on environmental engineering, adsorption and water treatment for upper undergraduate and graduate students. Furthermore, the book offers a valuable resource for researchers in water production control, as well as for practitioners interested in applying adsorption processes to real-world problems in water treatment and related areas."