Judul: Denitrifikasi air limbah industri amonium nitrat menggunakan reaktor berbahan isian batu belerang dan batu japur
Abstrak: Ammonium nitrate industry is one chemical industries that produce waste water with inorganic nitrogen compounds which has potency to pollute environment and threaten human’s health. Waste water treatment is needed to meet environmental quality standards in accordance with government regulations. The purpose of this study is to assess autotroph denitrification process by using a sulfur and limestone packed bed bioreactor in the wastewater with high concentrations of nitrate compounds as well as financial to asses feasibility. Data analysis is processed descriptively by using tables and graphs. The denitrification treatment was done in two stages of processing which is a high concentration (2000 mg-N/L) and low concentration (100 mg-N/L) of nitrate. The results showed that the concentration of nitrate in the outlet of bioreaktor decreased in rate the high and low nitrogen concentrations. For the highs concentration of nitrate, the concentration of nitrate in the outlet is 56,25 mg-N/L with removal efficiency 97,20% at four days hydraulic retention time (HRT). For the low concentration of nitrate, the concentration of nitrate in the outlet is 4,04 mg-N/L with a removal efficiency of 96,37% at one day hydraulic retention time (HRT). Each cost of sulfur materials for high and low concentrations, are Rp.1.100,-/m3 and Rp.200,-/m3 respectively.
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Judul: Penentuan konstanta kinetika reaksi denitrifikasi pada pengolahan limbah cair industri hasil perikanan dengan lumpur aktif
Abstrak: Limbah cair indushi hasil perikanan memiliki karakteristik dengan kandungan bahan organik khususnya nitrogen yang tinggi. Pada lingkungan perairan keberadaan nitrogen berlebih tersebut dapat menyebabkan turunnya oksigen terlarut, eutrofikasi, pendangkalan, penyebaran bau, keracunan ikan dan methemoglobinemia. Salah satu teknologi yang banyak dilakukan untuk mengurangi konsentrasi nitrat addah dengan pengolahan secara biologis menggunakan proses denitrifikasi. Prinsi~in i adalah memanfaatkan kegiatan mikroorga nisme dalam air untuk menguraikan dan memecahkan bahan-bahan organik yang terkandung dalam air limbah menjadi bentuk yang lebih sederhana.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology