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All Journal Jurnal Sains Teknologi dan Lingkungan (JSTL) Hydrogen: Jurnal Kependidikan Kimia Lombok Journal of Science
Leny Fitriah
Universitas Nahdlatul Wathan Mataram
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemistry Computer Science & IT Education Immunology & microbiology Public Health

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Serbuk Biji Asam Jawa (Tamarin Dusindica L) untuk Pengelolaan Limbah Industri Cair Tempe (Studi Kasus Mataram): Tamarind Seed Powder (Tamarindusindica, L) to Treatment the Liquid Waste Industrial of Tempe (Mataram case study) Dwi Agustini; Leny Fitriah
JURNAL SAINS TEKNOLOGI & LINGKUNGAN Vol. 7 No. 2 (2021): JURNAL SAINS TEKNOLOGI & LINGKUNGAN
Publisher : LPPM Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jstl.v7i2.193

Abstract

Most of the tempe industry have not been equipped with a waste water treatment unit. It is usually a water soaked soybeans and soybean excess water is still discharged directly in the into the environment. Liquid waste industrial of tempeh contain high organic materials. One of the process for wastewater treatment is coagulation with the addition of a positively charged polyelectrolyte in tempeh wastewater as negatively charged. One of plants in Indonesia that can be used as an alternative coagulant is tamarind seeds (Tamarindus indica, L).it can be used for wastewater treatment is more economical. The aims of this experiment is to determine the optimum stirring time, optimum pH of the waste and optimum coagulant dosage for treatment of the tempeh wastewater with coagulant tamarind seed powder. The experiment studied were stirring time, the pH of thetempeh wastewater and coagulant dosage to the percentage decrease in turbidity and COD (Chemical Oxygen Demand). The variables in the experiment were stirring time (10,15, 20, 25 and 30 minutes), the pH of the waste (3; 3.5; 4; 4 and 5) and the dosage of tamarind seed powder (100, 300, 500, 700, and 900 mg / L). COD testing methods is closed reflux method by spectrophotometry and turbidity testing using Turbidimeter. The results showed that the with coagulant tamarind seed powder effectively lowered cod levels and the dryness of tempeh liquid industrial waste. The optimum pH obtained is pH 4, optimum stirring time is 25 minutes and the increase in optimum coagulant dose is 500 mg with a percentage decrease in COD levels and noise by 90.57% and 78.94%.  Key words: liquid waste; sour power; turbidity; COD
PEMBELAJARAN INKUIRI TERBIMBING BERBANTUAN SIMULASI KOMPUTER TERHADAP HASIL BELAJAR MATERI KESETIMBANGAN KIMIA Leny Fitriah
Hydrogen: Jurnal Kependidikan Kimia Vol 5, No 2 (2017): Hydrogen: Jurnal Kependidikan Kimia
Publisher : Universitas Pendidikan Mandalika Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (492.858 KB) | DOI: 10.33394/hjkk.v5i2.1592

Abstract

This research uses factorial design 2 x 2. The sample in this research is thestudents of IKIP Kimia Mataram Chemistry study program that follow theBasic Chemistry 2 course in the even semester of academic year 2013/2014with 2 homogenously distributed classes. The sample was taken by clusterrandom sampling technique. One class consists of 21 students who weretaught inquiry led by using computer simulation and other class consists of 22students with guided Inquiry. The research data are low learning result andhigh level learning result on chemical equilibrium material measured by usingtest instrument choice and essay test with content validation each 80,6% and91,7%. The measurement of the reliability of questions was obtained fromCronbach's Alpha formula with a value of 0.73 for multiple choice tests and0.914 for the essay test. Data analysis using ANOVA Two Ways test. Theresult of the research shows that: (1) Low learning result of under guidedclass students in using computer simulation is higher than guided inquiryclass without computer simulation; (2) Higher student learning result inguided inquiry class using computer simulation higher than guided inquiryclass without computer simulation. So it can be concluded that guided inquirylearning using computer learning can student improve learning outcomes inchemical equilibrium material.
Pemodelan Matematika pada Sistem Korosi Logam Dwi Agustini; Leny Fitriah; Fahrurrozi Fahrurrozi
LOMBOK JOURNAL OF SCIENCE Vol 5 No 1 (2023): Lombok Journal of Science
Publisher : LOMBOK JOURNAL OF SCIENCE

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Logam merupakan bahan yang banyak digunakan untuk berbagai keperluan. Dalam udara terbukalogam mudah teroksidasi yang menimbulkan korosi sehingga dapat menurunkan kualitas dank ekuatannya. Korosi berasal dari bahasa latin “Corrodere” yang artinya perusakan logam atau berkarat akibat lingkungannya. Korosi umumnya memberikan dampak negatif bagi lingkungan. Dalam penelitianini akan dibahas 2 Model, Model 1 membahas model matematika mekanisme korosi logam sebelum penambahan inhibitor. Model 2 membahas model matematika mekanisme korosi logam dengan penambahan inhibitor. Tujuan dari penelitian ini adalah menentukan model matematika mekanisme korosi logam dan perilaku selesaiannya. Model tersebut diselesaikan dengan ditentukkan nilai parameter–parameter yang membuat sistem stabil. Selanjutnya akan dianalisa perilaku selesaiannya dengan menggunakkan nilai eigen dan sifat-sifat kestabilan titik kesetimbangan. Setelah itu dilakukan simulasi numerik dan interpretasi hasil yang diperoleh. Kata kunci : Korosi, nilai eigen, titik kesetimbangan, sifat kestabilan.
Co-Authors Dwi Agustini Fahrurrozi Fahrurrozi