PENGARUH RASIO MASSA KITIN/NaOH DAN WAKTU REAKSI TERHADAP KARAKTERISTIK KITOSAN YANG DISINTESIS DARI LIMBAH INDUSTRI UDANG KERING. Kitosan merupakan polimer yang dapat dibuat dari kitin menggunakan proses deasetilasi. Tujuan penelitian ini untuk mempelajari pengaruh rasio massa kitin dengan volume NaOH dan waktu reaksi terhadap karakteristik kitosan yang disintesis dari limbah industri udang kering. Kitin diisolasi dari cangkang udang dengan metode deproteinasi dan demineralisasi. Deasetilasi kitin dilakukan pada suhu 120°C, kecepatan pengadukan 150 rpm, rasio massa kitin dengan volume NaOH 1:15, 1:20, 1:25 (w/v), dan waktu reaksi 0,5-3 jam. Hasil penelitian menunjukkan bahwa peningkatan nilai rasio massa kitin dengan volume NaOH terhadap waktu reaksi mengakibatkan peningkatan derajat deasetilasi dan penyusutan kadar abu dan rendemen kitosan, sedangkan kadar air tidak memiliki efek yang signifikan. Derajat deasetilasi kitosan adalah 85,7% pada rasio massa kitin

AbstrakBiodiesel merupakan sumber bahan bakar alternatif yang bisa dihasilkan dari minyak nabati melalui transesterifikasi dengan metanol. Sawit Off-grade merupakan salah satu sumber minyak nabati yang mempunyai potensi untuk digunakan sebagai bahan dasar produksi biodiesel. Reaksi transesterifikasi dilangsungkan dengan bantuan katalis CaO dari cangkang telur yang dikalsinasi pada suhu 900ºC selama 2 jam. Tujuan dari penelitian ini adalah untuk memproduksi biodiesel dari minyak sawit off-grade melalui reaksi dua-tahap, melihat performa katalis Cao terhadap reaksi transesterifikasi, serta mempelajari pengaruh temperatur reaksi, rasio mol minyak:metanol dan konsentrasi katalis terhadap yield biodiesel pada reaksi transesterifikasi. Esterifikasi dilakukan pada suhu 60°C dengan perbandingan mol minyak:metanol 1:12 menggunakan 1%wt katalis H2SO4. Asam lemak bebas (ALB) tereduksi dari 16,18% menjadi 0,6%. Reaksi transesterifikasi dilakukan dengan variasi perbandingan mol minyak:metanol 1:7, 1:9, 1:11, konsentrasi katalis 2%wt, 4%wt, 6%wt, serta suhu reaksi pada 50ºC, 60ºC, 70ºC selama 2 jam. Data yang diperoleh diproses dengan menggunakan response surface methodology (RSM), sedangkan jumlah eksperimen ditentukan dengan central composite design (CCD). Yield yang diperoleh pada penelitian ini yaitu sebanyak 62,30%-87,41%. Yield optimum dihasilkan pada reaksi dengan suhu 70ºC menggunakan minyak:metanol dengan perbandingan 1:11 dan katalis CaO 2%wt. Kondisi proses yang berpengaruh terhadap yield biodiesel adalah suhu reaksi, perbandingan mol minyak:metanol, serta interaksi antara suhu dengan perbandingan mol minyak:metanol. Akan tetapi tidak ditemukan adanya pengaruh signifikan konsentrasi katalis terhadap yield biodiesel.Kata kunci: biodiesel, CaO, minyak sawit off-grade, rsm, transesterifikasi AbstractBiodiesel is an alternative fuel which can be generated from transesterification of vegetable oil with methanol. Off-grade palm is one of vegetable oil sources which can potentially be used as a raw material in biodiesel production. Transesterification was conducted by using CaO catalyst produced from eggshell calcined at a temperature of 900ºC for 2 hours. This research was aimed to produce biodiesel from off-grade palm by means of two-stage reaction, to observe the performance of CaO catalyst from calcined eggshell on the transesterification reaction, and to determine the effect of reaction temperature, mole ratio of oil:methanol, and catalyst concentration on the yield of biodiesel. Esterification was carried out at a temperature of 60°C with mole ratio of oil:methanol 1:12 and 1%wt of catalyst H2SO4. Free fatty acid (FFA) managed to be disminished from 16.18% to 0.6%. Transesterification was run for 2 hours with variations of oil:methanol mole ratio of 1:7, 1:9, 1:11, CaO catalyst concentrations of 2%wt, 4%wt, 6%wt, at reaction temperatures of 50ºC, 60ºC, 70ºC. Processing of the data was done by response surface methodology (RSM) method, while the number of experiments was determined by central composite design (CCD). ...

Pencemaran logam berat kadmium (Cd2+) di perairan mengakibatkan kerusakan yang besar bagi kehidupan manusia. Salah satu cara untuk menghilangkan dan mengurangi logam cadmium adalah menggunakan proses adsorpsi. Larutan kadmium (Cd2+) 3mg/L sebanyak 200 mL ditambahkan HAp 0,5 gr dan diaduk dengan kecepatan 100, 200 dan 300 rpm pada suhu 30°C, 40°C dan 50°C. Larutan kemudian dianalisa menggunakan Atomic Adsorption Spectroscopy (AAS) untuk mengetahui konsentrasi kadmium. Semakin besar suhu adsorpsi maka kapasitas penjerapan adsorben HAp (Qe) semakin kecil. Semakin besar kecepatan pengadukan adsorpsi, maka semakin besar pula kapasitas penjerapan adsorben HAp (Qe). Mekanisme adsorpsi logam kadmium (Cd2+) menggunakan HAp memiliki kecocokan dengan model isotherm Freundlich yang mewakili adsorpsi fisika dengan kapasitas panas adsorpsi (ΔH) sebesar -1,665304 kcal/mol.K dan perubahan entropi (ΔS) didapatkan sebesar 15,76 J/mol.K.

Doughnuts are one of the most popular sweet foods for people of all ages around the world. Although made from simple ingredients such as flour, sugar, eggs, yeast, milk powder, salt, water, and margarine, however producing doughnuts requires special techniques to produce good-quality doughnuts. It needs more energy, even physically and electrical equipment. A workshop on doughnut production with autolyze method for Dharma Women Association, Faculty of Engineering, University of Riau, was conducted to increase the knowledge and skills of members of the organization in making healthy dishes for the family. In this workshop, doughnuts were made using the autolysis method, which is mixing bread flour with water and then keeping the dough until gluten was formed. The formation of gluten is one indicator of the formation of smooth, soft, and elastic dough. The workshop results showed high interest among the Dharma Women Association members in making doughnuts with this alternative method.

Brick is a building material that is often used for residential walls. The bricks in this study were bricks with the addition of palm frond charcoal in the manufacturing process. The aims of this study were (1) to determine the effect of adding palm stem charcoal on the manufacture of red bricks in terms of compressive strength, water absorption (Suction rate) and apparent density (apparent density). (2) Comparing the test results with the SNI 15-2094-2000 standard. The manufacture of experimental bricks begins with adding clay with pulverized palm frond charcoal in a ratio of 100:0, 95:5, 90:10, 85:15 and 80:20, then molded, dried, burned and tested for new mechanical properties. brick. In this study, the compressive strength of bricks that enter class 100 is a ratio of 100:0 and 95:5 namely 11.75 Mpa and 10.10 Mpa, then bricks grade 50 is a ratio of 90:10 and 85:15 which is 8.08 Mpa and 6.27 Mpa. The water absorption capacity of bricks that meet the requirements of SNI 15-2094-2000 is a ratio of 100:0 and 95:5, namely 18.65% and 19.74%. The apparent density of bricks that meet the requirements of SNI 15-2094-2000 are the ratios of 100:0, 95:5, 90:10 and 85:15, which are 1.63 g/cm3, 1.54 g/cm3, 1,37 g/cm3 and 1.24 g/cm3. Bricks that meet the standards and are recommended as masonry bricks are bricks with a ratio of 95:5.