scholarly journals UPAYA PENURUNAN KADAR MERKURI DALAM MEDIA AIR MENGGUNAKAN ADSORBEN 2-MERCAPTOBENZOTHIAZOLE (MBT)–LEMPUNG AKTIF

Konversi ◽  
2012 ◽  
Vol 1 (1) ◽  
pp. 7
Author(s):  
Doni Rahmat Wicakso ◽  
Agus Mirwan ◽  
Abdullah Abdullah
Keyword(s):  
Final Stage ◽  
Mercury Content ◽  
Metal Reduction ◽  
Water Medium ◽  
Blue Solution ◽  
Active Clay

Tujuan penelitian ini adalah untuk membuat adsorben 2-Mercapto-benzothiazole (MBT) – Lempung Aktif yang akan digunakan dalam upaya menurunkan kadar merkuri dalam media air. Penelitian dimulai dengan melakukan proses demetalisasi pada lempung (bentonit) yang dilakukan dengan merendam bentonit dalam larutan HCl, larutan NH4NO3 dan kemudian dilanjutkan dengan pemanasan pada dua temperatur yang berbeda (120 oC dan 400 oC). Langkah berikutnya adalah proses pilarisasi yang dilakukan dengan merendam bentonit hasil demetalisasi selama 18 jam dalam larutan AlCl3 yang sebelumnya telah ditambah dengan NaOH 0,1 M. Pada tahap akhir proses pilarisasi, bentonit dipanaskan pada temperatur 120 oC dan 400 oC. Bentonit hasil pilarisasi kemudian diuji kemampuan adsorpsinya dengan larutan metilen blue. Hasil pengujian dengan metilen blue tersebut diambil sebagai dasar untuk menentukan tahap selanjutnya, yaitu proses impregnasi mercaptobenzothiazole (MBT) pada berbagai konsentrasi (6%, 8%, dan 10%). Adsorben hasil impregnasi selanjutnya digunakan dalam proses adsorpsi larutan Hg pada berbagai konsentrasi (0,1 – 0,5 ppm) guna mengetahui kemampuannya sebagai adsorben. Hasil penelitian menunjukkan bahwa perbedaan temperatur pemanasan pada lempung (bentonit) berpengaruh terhadap daya serapnya terhadap metilen blue. Perlakuan pada bentonit (demetalisasi, pilarisasi pada dua temperatur yang berbeda) berpengaruh pada pola difraksi sinar-X nya.  Kapasitas adsorpsi dari MBT-lempung aktif yang diamati melalui penelitian ini belum berhasil ditentukan, sehingga perlu upaya lanjutan untuk mengetahuinya. Kata kunci : mercury, MBT, activated clay, bentoniteAbstract-The objective of thus research was to make adsorbent 2-Mercapto-benzothiazole (MBT) – active clay used to reduce mercury content in water medium. Firstly, this research was run by soakingin a solution ofHClbentonite, NH4NO3solutionandthen followed byheating attwodifferent temperatures(120° Cand 400° C). The next step was pillarization process by soakingthe bentonitefor 18hoursin solution ofAlCl3that have previously beenaddedwith 0.1 M NaOHAtthe final stage ofthe pillarization process, bentonitewas heatedat a temperature of120 oCand 400oC. After that, the bentonite was analyzed ability of adsorption by metilen blue solution. The test resultswith methylenebluewas takenas a basisfor determiningthe next stage, which wasthe process ofimpregnation MBT at various concentrations(6%, 8%, and 10%). The adsorbentof impregnationwas usedto adsorb Hgat various concentrations(0.1 to 0.5 ppm) for determininghis ability asadsorbent. The results showedthat thedifference inthe heating temperatureonclay(bentonite) affect theabsorbanceof themethyleneblue. Treatment ofbentonite(metal reduction, pillarizationon twodifferent temperatures) effected onX-ray diffractionpattern. MBT-adsorption capacityof theactivatedclaysobservedthroughthis studyhas not beensuccessfullydetermined,so we needfurthereffortsto find out. Keywords:mercury, MBT, activated clay, bentonite 

At the final stage of the global crisis: Economic tasksin 2017-2019

2018 ◽  
pp. 5-29 ◽  
Author(s):  
V. A. Mau
Keyword(s):  
Economic Growth ◽  
Final Stage ◽  
Government Regulation ◽  
Inflation Targeting ◽  
Social Dynamics ◽  
Growth Stimulation ◽  
Central Banks ◽  
Economic Area ◽  
National Trends

The paper deals with the global and national trends of economic and social development at the final stage of the global structural crisis. Special attention is paid to intellectual challenges economists will face with in the post-crisis world: prospects of growth without inflation, new global currencies and the role of cryptocurrencies, central banks independence and their role in economic growth stimulation, new tasks and patterns of government regulation, inequality and growth. Special features of Russian post-crisis development are also under consideration. Among them: prospects of macroeconomic support of growth, inflation targeting, new fiscal rule, social dynamics and new challenges to welfare state. The paper concludes that the main obstacles for economic growth in Russia are concentrated in the non-economic area.

Light Dramaturgy as an Element of an Integrated Approach to the Creation of Museum Expositions and Exhibition Projects

2019 ◽  
pp. 108-114
Author(s):  
Nicolay R. Vorobyov
Keyword(s):  
Final Stage ◽  
Historical Development ◽  
Integrated Approach ◽  
Lighting Design ◽  
Lighting System ◽  
Scientific Concepts ◽  
Hands On ◽  
Artistic Styles ◽  
The Creation

Architectural and artistic construction of museum is one of the most complex genres in environment development and design, with its inherent qualities, means of expressiveness, principles of environment and image development, scientific concepts, in the context of historical development, artistic styles and trends. The author of the article considers the artistic lighting design in isolation from the integral dramaturgy of the project to be deeply flawed, and the setting of accent lighting at the final stage Ц to be simple, but not outstanding. Based on extensive hands-on experience in the construction of museum expositions, the author of the article reveals some peculiarities, especially significant to the participants of the lighting system setting for museums and other cultural facilities.

The final stage of granitoid magmatism in the Dniester-Bug megablocks Ukrainian shield

2016 ◽  
Vol 36 ◽  
pp. 72-81 ◽  
Author(s):  
L.M. Stepaniuk ◽  
◽  
T.Y. Dovbush ◽  
S.Y. Kurylo ◽  
Y.M. Lesnaya ◽  
...  
Keyword(s):  
Final Stage ◽  
Ukrainian Shield ◽  
Granitoid Magmatism

Room Temperature Alkali Metal Reduction of Carbon Dioxide

2020 ◽  
Author(s):  
Lucas A. Freeman ◽  
Akachukwu D. Obi ◽  
Haleigh R. Machost ◽  
Andrew Molino ◽  
Asa W. Nichols ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Alkali Metals ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Bond Cleavage ◽  
Open Shell ◽  
Metal Reduction ◽  
One Pot ◽  
Earth Abundant ◽  
Electron Reduction

The reduction of the relatively inert carbon–oxygen bonds of CO<sub>2</sub> to access useful CO<sub>2</sub>-derived organic products is one of the most important fundamental challenges in synthetic chemistry. Facilitating this bond-cleavage using earth-abundant, non-toxic main group elements (MGEs) is especially arduous because of the difficulty in achieving strong inner-sphere interactions between CO<sub>2</sub> and the MGE. Herein we report the first successful chemical reduction of CO<sub>2</sub> at room temperature by alkali metals, promoted by a cyclic(alkyl)(amino) carbene (CAAC). One-electron reduction of CAAC-CO<sub>2</sub> adduct (<b>1</b>) with lithium, sodium or potassium metal yields stable monoanionic radicals clusters [M(CAAC–CO<sub>2</sub>)]<sub>n</sub>(M = Li, Na, K, <b> 2</b>-<b>4</b>) and two-electron alkali metal reduction affords open-shell, dianionic clusters of the general formula [M<sub>2</sub>(CAAC–CO<sub>2</sub>)]<sub>n </sub>(<b>5</b>-<b>8</b>). It is notable that these crystalline clusters of reduced CO<sub>2</sub> may also be isolated via the “one-pot” reaction of free CO<sub>2</sub> with free CAAC followed by the addition of alkali metals – a reductive process which does not occur in the absence of carbene. Each of the products <b>2</b>-<b>8</b> were investigated using a combination of experimental and theoretical methods.<br>

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

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