Judul: Efektivitas Ampas Teh Sebagai Adsorben  Alternatif Limbah Cair Industri Tekstil
Abstrak: Colored wastewater from textile industries treated by activated carbons requires relatively high costs. To overcome this disadvantages relatively cheap materials are used as alternative adsorbent, such as teawaste that has been used in this study. The teawaste powder was washed by deionized water (TA biosorbent), then washed by HNO3 0.6 M (AA), NaOH 0.6 M (AB), or ethanol (AE). The highest adsorption for amaranth and methylene blue was obtained from AE and TA biosorbent, i.e. 90.51% and 94.93%. The required time for 0.1 g AE biosorbent to adsorp amaranth solution was 6 hours. The amount of 0.2 g TA biosorbent was the best in adsorbing methylene blue solution at 2 hours contact time. The change of ionic strength and pH influenced adsorption capac ity of teawaste. The adsorption capacity of AA biosorbent to amaranth was increasing by adding KNO3 1.00 M. Addition of 0.10 KNO3 to methylene blue solution increased the capacity of all biosorbent . Adjusting to pH 4 increased AB biosorbent capacity of methylene blue solution and pH 6 increased AA biosorbent adsorption capacity to the same solution. According to the pattern of isotherm adsorption from teawaste, biosorbent was selective to methylene blue rather than to amaranth.
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Judul: Penjerapan zat warna rreaktif cibacron red menggunakan adsorben sekam padi
Abstrak: Textile wastewater containing dyes can pollute aquatic environment. This study utilized rice husk as adsorbent for Cibacron Red reactive dyes which are widely used in textile industries. Husks were made into adsorbent without modification (ATM) and acid modified adsorbent (AMA). The optimum condition was obtained under adsorption time of 30 minutes, 1.0 g of adsorbent, and initial concentration of dye solution was 150 ppm. The optimum condition for AMA was obtained under adsorption time of 60 minutes, 2.0 g of adsorbent, and 150 ppm initial concentration of dye solution. The optimum condition of activated charcoal (AA) as a comparison was 30 minute time of adsorption, 3.0 g of adsorbent, and 150 ppm initial concentration dye solution. Adsorption capacity of ATM, AMA, and AA at the optimum conditions was 2879.00, 6898.30, and 2470.00 μg/g, respectively. Adsorption efficiency of ATM, AMA, and AA at the optimum conditions was 19.86, 91.71, and 40.51%, respectively. All three types of adsorbent followed the Freundlich isotherm. Application of the adsorbent on waste of textile manufacture showed a decrease in colour after adsorption by ATM, AMA, and AA, up to 52.05, 98.86 and 48.69%, respectively, with the initial colour intensity of 1485 Pt-Co. Starting with COD of the wastewater which was 7372.0 mg/L, the values decreased after the adsorption with ATM, AMA, and AA were 43.30, 98.56 and 52.58%, respectively. Starting with BOD of 149.09 mg/L, the values decreased after adsorption by ATM, AMA, and AA were 63.41, 76.09, and 72.46%, respectively. Based on these results, rice husk is potentially used as an adsorbent of dyes, thereby reducing the level of pollution of aquatic environment.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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