Elektrolisis Senyawa Organik dalam Limbah Cair Industri Tempe Menggunakan Elektroda PbO2/Pb dengan Rangkaian Seri

Limbah cair industri tempe memiliki nilai BOD dan COD yang tinggi, apabila dibuang ke badan perairan akan menyebabkan pencemaran lingkungan dan menurunkan kualitas air. Oleh karena itu, perlu dilakukan penurunan nilai BOD dan COD limbah cair tempe sebelum dibuang ke badan perairan. Penurunan nilai BOD dan COD limbah cair industri tempe dapat dilakukan menggunakan metode elektrokimia. Elektrokimia merupakan salah satu metode pengolahan limbah cair yang mudah dilakukan dan efektif. Penelitian ini bertujuan untuk mengetahui pengaruh voltase, arus dan waktu elektrolisis terhadap penurunan nilai BOD dan COD limbah cair industri tempe menggunakan anoda PbO2 dan katoda Pb. Analisis sampel setelah elektrolisis menggunakan metode Winkler untuk analisis BOD dan metode titrasi Iodometri untuk analisis COD. Hasil penelitian menunjukkan bahwa penurunan terbesar nilai BOD dan COD terjadi pada voltase 12 V, arus 10 A, pada waktu 180 menit, persentase penurunan BOD dan COD mencapai 100%

Hydrazine-Fueled Solution Combustion Method: Fuel/Oxidizer Ratio Effects on Photocatalytic Performance of Bismuth Oxide

Bismuth oxide nanoparticles were synthesized through the solution combustion method with a variation of fuel: oxidizer (hydrazine: bismuth nitrate) ratios (ϕ) of ϕ 1. Bismuth oxide nanoparticles were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and UV-Visible Diffuse Reflectance Spectroscopy (UV-DRS). The FTIR spectra obtained implies that the bismuth oxide nanoparticles of the three ratios contain Bi-O-Bi and Bi-O groups indicating its successful formation. XRD diffractogram suggests that the synthesized bismuth oxide nanoparticles form the α-Bi2O3 crystalline phase for ϕ1; meanwhile a mixture of α-/β- Bi2O3 phases for ϕ=1. The SEM image illustrates that bismuth oxide nanoparticles form pebble shapes with the ratios in the order of increasing particle sizes of ϕ>1, ϕ=1, and ϕ1 have respective band gap energies of 2.76 eV, 2.72 eV, and 2.78 eV. The evaluation of the photocatalytic activity of the three bismuth oxide samples shows bismuth oxide with ϕ=1 has the highest photocatalytic activity in remazol black B and methyl orange dyes with rate constants 6.744 x 10-5 s-1 and 7.369 x 10-5 s-1, respectively. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)