ABSTRAKTinta pemilu digunakan untuk identifikasi pada jari tangan pada waktu pemilihan umum atau kegiatan sejenis lainnya guna mencegah terjadinya kecurangan. Pada tinta pemilu saat ini digunakan bahan perak nitrat agar lebih tahan lama, namun penggunaan perak nitrat dapat merusak kulit dan bersifat racun. Untuk itu telah dilakukan penelitian pengaruh jenis bahan senyawa pengomplek dan bahan tambahan terhadap mutu tinta pemilu dari ekstrak gambir. Penelitian ini bertujuan untuk mendapatkan tinta dari ekstrak gambir yang secara teknis dapat memenuhi persyaratan kualitas tinta pemilu. Dalam penelitian ini gambir diolah menjadi cube black gambir melalui proses penghalusan, pemanasan dalam air mendidih, pengadukan, pendinginan, penyaringan, pencetakan, dan pengeringan. Selanjutnya cube black gambir dilarutkan dalam etanol teknis, ditambahkan senyawa pengomplek, FeSO atau FeNO 4 3 tergantung formula yang digunakan. Komposisi tinta terbaik adalah 70 bagian ekstrak gambir dalam etanol, 22 bagian larutan jenuh FeSO dalam etanol, 5 bagian ektrak kunyit serta 3 bagian 4 larutan kristal violet 4%. Tinta lebih homogen dengan warna yang dihasilkan violet, pH 3,86, tahan gosok terhadap air dan sabun. Daya tahan tinta dapat tahan sampai tiga hari, kandungan logam Pb, Cd, Hg tidak terdeteksi dan kandungan Cu sebesar 65,04 ppm, tinta memenuhi persyaratan Peraturan Komisi Pemilihan Umum nomor 16 tahun 2013. Kata Kunci: Tinta, pemilu, ekstrak gambir ABSTRACTElection ink is applied to the forefinger of voters during election in order to prevent electoral frauds such as double voting. The current election inks contain silver nitrate solutions to make it more durable which stains the skin on exposure to ultraviolet light, leaving a mark that is impossible to wash off and is only removed as external skin cells are replaced. But the silver nitrate solution may damage the human skins and is poisonous to the environment. This research was carried out to investigate the use of gambier extracts for election inks as environment-friendly raw materials. The aim of this study was to obtain the optimal ink from gambier extract which technically could meet quality requirements of the election ink. In this study, gambier was extracted through the following refinement process; heating in boiling water, stirring, cooling, filtering, molding, and drying. The cube black then was dissolved in technical ethanol, added the complexing compounds FeSO or FeNO depending on the formula used. 4 3 The best ink composition was 70% gambier extract in ethanol, 22% of FeSO saturated solution 4 in ethanol, 5% of turmeric extract, and 3% of crystal violet solution 4%. This ink was more homogenous with violet color at pH 3.86 which gave rub resistant to water and soap. The ink stains could stay on finger skin for 3 days. Analytical results showed that the ink did not contain Pb, Cd, and Hg while Cu was 65.04 ppm and met the requirement of General Election Comitee Number 16 year 2013.

This study aims to determine the amount of chrome that come out together with tannery waste in a tanned combination process of chrome-gambier and chrome-mimosa. the process research st was performed by 2 stages. The 1 stage used chrome with 5 concentration, they were 2,4,6 nd and 8 %. Then it was followed by the 2 stage tanning process by using nature tanning, gambier and mimosa, with each 7% and 9% concentration. The results showed that the combination of chrome-gambier tanned at the same concentration disposed chromium waste less than the combination of chrome-mimosa tanned. The lowest total chrome waste on the chrome-gambier tanning combination was 3.9 ppm at 2% chromium and 7% gambier concentration and the highest was 146.6 ppm at 8% chromium and 9% gambier concentration. The lowest total chrome waste on the combination of chrome-mimosa tanning was 2.2 ppm at 2% chromium and 7% mimosa concentration and the highest was 170.4 ppm at 8 % chromium nd and 9% mimosa concentration. The 2 stage tanning, was combination tanning process, chrome-gambier was able to reduce chromium levels more than the chrome-mimosa tanning.

Bahan baku potensial pembentukan biogas melalui pengolahan anaerobik yang tersedia di Kampus Universitas Andalas (Unand) Padang yakni sampah makanan kantin dan feses sapi. Studi ini bertujuan untuk melihat pengaruh penambahan feses sapi dalam pembentukan biogas dari sampah makanan menggunakan floating drum digester yang dikondisikan duplo. Waktu retensi 20 hari dan pH bahan isian dikondisikan dengan menambahkan batu kapur. Variasi rasio komposisi bahan isian berupa sampah makanan dan feses sapi yakni 100:0 (digester kontrol), 75:25 (digester uji 1 dengan rasio C/N 30) dan 50:50 (digester uji 2 dengan rasio C/N 25). Hasil penelitian menunjukkan volume kumulatif biogas digester kontrol yakni 0,927 liter dengan estimasi gas metana 591,885 mg/L serta tidak menyala saat dibakar. Volume kumulatif biogas digester uji 1 yakni 13,715 liter dengan estimasi konsentrasi gas metana 15502,61 mg/L serta warna nyala biru kemerahan. Volume kumulatif biogas digester uji 2 yakni 10,18 liter dengan estimasi konsentrasi gas metana 23297,59 mg/L serta warna nyala biru.

In this research, leather tanning using gambir processing liquid waste has been done. The research was done by varying the percentage of adding alum as mordant, respectively 0%, 2%, 4%, and 6% into the waste of gambier processing. The addition of alum crystal was done in step II of the tanning process. The observation was done by investigating several parameters, such as the skin color, physical and chemical properties of the tanned leather-based on SNI 06-0463. 1989 A. The results show that the use of alum crystal as a mordant made the skin color became yellowish, lower solubility of tannin in the water, smaller raw leather content, higher bonded tannin to the leather, higher tanning degree, higher tensile strength, and higher flexural strength. The alum crystal concentration affected the physical properties, i.e., tensile strength and flexural strength. Increasing the alum crystal concentration increases the tensile strength but decreases the tanned leather's flexural strength.

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