cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Dina Kartika Maharani
Contact Email
dinakartika@unesa.ac.id
Phone
+628174140131
Journal Mail Official
dinakartika@unesa.ac.id
Editorial Address
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Surabaya State University, located at Jl Ketintang, Surabaya, East Java, Indonesia. 60231
Location
Kota surabaya,
Jawa timur
INDONESIA
Unesa Journal of Chemistry
  • unesa-journal-of-chemistry
  • Website
Published by Universitas Negeri Surabaya
ISSN : -     EISSN : 22528180     DOI : https://doi.org/10.26740/ujc.v11n2
Core Subject : Science, Engineering,
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Materials Science & Nanotechnology
UNESA Journal of Chemistry is online Journal covering all aspects of Chemistry. The journal publishes original research paper and review articles.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 104 Documents
 7   8   9   10   11 
UJI KUALITAS AIR SUNGAI GEMPOLSARI DI SEKITAR LUMPUR LAPINDO DENGAN PARAMETER FISIKA-KIMIA UNTUK MENENTUKAN STATUS MUTU LINGKUNGAN Izzy Eka Nur Rochmad; Naja Suad Suzainti; Abellya Syafira; Rizky Alicia Miranti; Rusmini
Unesa Journal of Chemistry Vol. 14 No. 2 (2025): Vol 14 No 2 (2025)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, Surabaya State University, located at Jl Ketintang, Surabaya, East Java, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/ujc.v14n2.p56-62

Abstract

Water is a resource that is vulnerable to quality degradation due to anthropogenic activities and environmental disasters. The Lapindo mudflow that has been occurring since 2006 in Sidoarjo has the potential to affect the condition of surrounding waters, including the Gempolsari River, which is located near the affected area. This study aims to analyze the water quality of the Gempolsari River using physical-chemical parameters as a basis for determining environmental quality status. The methods used included water sampling and analysis of selected parameters, namely pH, DO, TDS, nitrate (NO3-), ammonia (NH3), and heavy metals. The analysis was carried out using simple field test equipment and compared with river water quality standards based on Government Regulation No. 22 of 2021. The results showed that the nitrate level was 50 mg/L, which exceeded the threshold, indicating nutrient pollution. Other parameters such as ammonia (0 mg/L), most heavy metals (0 mg/L), pH (7.5), TDS (0.308 mg/L), and DO (10 mg/L) were still within the quality standards. However, the concentrations of magnesium (425 mg/L) and carbon (425 mg/L) were detected to exceed the standards. These findings indicate that the water quality of the Gempolsari River is relatively good for most parameters, but is lightly to moderately polluted due to nutrient loads, particularly nitrates, and certain mineral content. Overall, this study emphasizes the importance of continuous monitoring of water quality in the areas affected by the Lapindo mudflow. The results can be used as a basis for environmental management recommendations and pollution mitigation efforts for the sake of aquatic ecosystem sustainability and public health protection.
OPTIMASI VARIASI KONSENTRASI TWEEN 80 PADA FORMULASI NANOEMULSI KOMBINASI EKSTRAK DAUN PEGAGAN DAN DAUN KELOR devanus lahardo; yafet Pradikatama Prihantono
Unesa Journal of Chemistry Vol. 14 No. 3 (2025): Vol 14 No 3 (2025)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, Surabaya State University, located at Jl Ketintang, Surabaya, East Java, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/ujc.v14n3.p83-89

Abstract

Abstract. This study aims to optimize the nanoemulsion formulation of combined extracts of Centella asiatica and Moringa oleifera leaves using varying concentrations of Tween 80 as a surfactant. Three formulas were prepared with 8%, 10%, and 12% Tween 80. Physical evaluations included particle size, pH, and viscosity. Results showed that increasing Tween 80 concentration increased particle size and viscosity, while pH remained relatively stable. The 8% Tween 80 formula yielded the most optimal result with the smallest particle size and suitable viscosity for topical application. One-way ANOVA revealed significant differences in particle size and viscosity, but not in pH. These findings indicate that Tween 80 concentration affects the physical stability of the nanoemulsion Key words: kelor leaves, pegagan leaves, nanoemulsion, tween 80
Pengaruh Variasi Waktu Ekstraksi terhadap Rendemen dan Total Kurkuminoid Ekstrak Etanol 96% Temu Giring (Curcuma heyneana) menggunakan Metode Microwave-Assisted Extraction Nur Oktavia, Mutia; Hanif Rifqi Prasetyawan
Unesa Journal of Chemistry Vol. 14 No. 3 (2025): Vol 14 No 3 (2025)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, Surabaya State University, located at Jl Ketintang, Surabaya, East Java, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/ujc.v14n2.p63-69

Abstract

This study aimed to evaluate the effect of extraction time variations on the yield and total curcuminoids of 96% ethanol extract of temu giring (Curcuma heyneana) using the Microwave-Assisted Extraction (MAE) method. Extraction was performed at 20, 60, 120, and 150 seconds using an 800-watt microwave with a 1:10 (w/v) solvent ratio. Yield was calculated based on total solids, while total curcuminoids were quantified using UV-Vis spectrophotometry at 469 nm. The results showed an increase in yield from 2.40% (20 s) to 7.52% (150 s) and total curcuminoids from 2.3962 µg/mL to 5.9593 µg/mL. Statistical analysis indicated a significant difference between treatments (****p < 0, 0001). Based on the tested time range 150-second exteaction time was identified as optimum, maximizing cell rupture and solvent diffusion without compromising thermal stability of curcuminoids. Thus, extraction time plays a key role in optimizing green extraction of temu giring.
SINTESIS DAN KARAKTERISASI NANOKATALIS K2O/LUMPUR LAPINDO SEBAGAI KATALIS REAKSI TRANSESTERIFIKASI MINYAK JELANTAH MENJADI BIODIESEL Hamidatul Mubarokah; Samik
Unesa Journal of Chemistry Vol. 14 No. 3 (2025): Vol 14 No 3 (2025)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, Surabaya State University, located at Jl Ketintang, Surabaya, East Java, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/ujc.v14n3.p97-106

Abstract

Lapindo mud (LM) was explored as a low-cost base material for nanocatalyst development aimed at converting waste cooking oil (WCO) into biodiesel. This study evaluates the synthesis and characterization of K₂O/LM nanocatalysts through the impregnation of K₂CO₃ with variations of 10%, 20%, and 30% followed by calcination at 550 °C for 3 h and particle size reduction via ball milling. The catalysts were characterized using XRF, XRD, and PSA. XRF analysis confirmed a significant increase in K₂O content from 2.51% in Lapindo Mud to 13.5%, 23.7%, and 36.4% after impregnation. The presence of characteristic K₂O peaks in XRD patterns further verified successful incorporation of active species. PSA results showed average particle sizes of 556.8 nm for LM and 535.9 nm for the K₂O(30)/LM catalyst. Transesterification was carried out at 60 °C for 2 h using a methanol-to-oil molar ratio of 9:1 and 4 wt% catalyst. GC–MS analysis revealed that biodiesel produced using LM catalyst contained 99.28% methyl esters, whereas the K₂O(30)/LM catalyst yielded 19.74% methyl esters. The K2O/LM catalyst exhibited relatively low performance in the transesterification of WCO, which is attributed to the absence of a prior calcination step of the lapindo mud before impregnation.

Page 11 of 11 | Total Record : 104

 7   8   9   10   11 

Filter by Year

2020 2025


Reset
Filter By Issues
All Issue Vol. 14 No. 3 (2025): Vol 14 No 3 (2025) Vol. 14 No. 2 (2025): Vol 14 No 2 (2025) Vol. 14 No. 1 (2025): Vol 14 No 1 (2025) Vol. 13 No. 3 (2024): Vol 13 No 3 (2024) Vol. 13 No. 2 (2024): Vol 13 No 2 (2024) Vol. 13 No. 1 (2024): Vol 13 No 1 (2024) Vol. 12 No. 3 (2023): Vol 12 No 3 (2023) Vol. 12 No. 2 (2023): Vol 12 No 2 (2023) Vol 12 No 1 (2023) Vol 11 No 3 (2022) Vol 11 No 2 (2022) Vol 11 No 1 (2022) Vol 10 No 3 (2021) Vol 10 No 2 (2021) Vol 10 No 1 (2021) Vol 9 No 3 (2020) More Issue