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Journal : VALENSI

Studi Metode Diffusive Gradient In Thin Film dengan Binding Gel Titanium Dioksida-Chelex untuk Penyerapan Logam Besi(II) dan Fosfat Secara Simultan Asep Saefumillah; Amalia Ekaputri Hidayat
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 3, No. 2, November 2017
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (795.242 KB) | DOI: 10.15408/jkv.v0i0.6078

Abstract

Tingginya konsentrasi fosfor sebagai fosfat ke dalam sistem akuatik mengakibatkan eutrofikasi yang berujung pada terjadinya algae blooming. Input fosfat dalam sistem akuatik ini dicurigai dipengaruhi oleh pelepasan fosfat yang terikat pada besi(III) hidroksida ketika tereduksi menjadi besi(II) di sedimen, sehingga diperlukan pengukuran fosfat dan besi(II) secara simultan. Teknik diffusive gradient in thin film (DGT) merupakan salah satu metode pengukuran in-situ yang dikembangkan untuk pengukuran fosfat dan logam.Teknik DGT diteliti menggunakan binding gel campuran TiO2-Chelex. Metode baru ini memperkenalkan penggunakan TiO2 hasil sintesis melalui metode sol-gel sebagai agen pengikat fosfat dan resin Chelex-100 sebagai agen pengikat logam Fe(II). DGT yang terdiri dari diffusive layer dan binding layer diuji kemampuannya dalam menyerap logam labil besi(II) dan fosfat secara terpisah, kemudian diuji homogenitasnya. DGT dengan binding gel TiO2-Chelex diuji pada sejumlah variasi waktu pengukuran, konsentrasi larutan, dan pH.Hasil analisis menggunakan spektrofotometer AAS untuk logam besi dan spektrofotometer UV-Vis untuk fosfat menunjukkan bahwa waktu optimum untuk pengukuran DGT adalah 24 jam. DGT dengan binding gel TiO2-Chelex optimum mengukur fosfat pada larutan dengan pH 5.2 dan pH 6 dan optimum mengukur besi(II) pada pH netral (pH 7). DGT TiO2-Chelex memiliki kapasitas pengukuran 5.86 mg/L untuk fosfat dan 53.41 mg/L untuk logam besi(II). Sehingga dapat disimpulkan bahwa, binding gel campuran TiO2-Chelex yang telah dibuat dalam sistem DGT dapat menyerap logam Fe(II) dan fosfat secara simultan dengan baik. The high phosphorus as phosphate input into aquatic systems causes eutrophication which leads to the occurrence of algae blooming. Phosphate input in aquatic systems is influenced by the release of suspected phosphate bound to iron(III) when reduced to iron(II) in the sediment. Diffusive gradients in thin films (DGT) technique is one of the in-situ measurement methods developed for the measurement of phosphate and metals. DGT technique was studied using gel bindings mixture of TiO2-Chelex. This new method introduces the use synthesis of TiO2 via sol-gel method and resin Chelex-100 as phosphate and iron(II) binding agents, respectively. DGT composed of diffusive and binding layer was tested for their ability to absorb iron(II) and phosphate separately, and homogeneity. DGT with bindings TiO2-Chelex gel was tested at various measurement time, solution concentration, and pH. The results of the analysis using AAS for iron and UV - Vis spectrophotometer for phosphate showed that the optimum time for DGT measurement is 24 hours. Optimum measurement of DGT with bindings gel TiO2-Chelex was reached at pH around pH 5.2 and 6 for phosphate, and neutral (pH 7) for iron(II). TiO2-Chelex DGT measurement capacity was 5.86mg/L and 53.41 mg/L for phosphate and iron (II), respectively. In conclusion, the TiO2-Chelex mixed binding gel that was made can absorb iron (II) and phosphate simultaneously.
Development Study of Binding Agent in Diffusive Gradient In Thin Films (DGT) Technique for Absorption of Phosphate Compounds using Nano-La2O3 Hanna Shafira; Rika Tri Yunarti; Asep Saefumillah
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 8, No. 2, November 2022
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v8i2.26952

Abstract

The abundance of phosphate is a concern because it causes problems in aquatic ecosystems. The diffusive gradient in thin films (DGT) technique is a promising method for phosphate absorption because it can be used in situ. The DGT device consists of a membrane filter, a diffusive gel, and a binding gel. The presence of a binding agent in the binding gel makes the specific analyte bound to the binding gel. One of the binding agents that can be used for phosphate absorption is La2O3. Binding gel La2O3 was successfully synthesized that proven by the similarity of FTIR peaks of the diffusive gel and binding gel. The typical absorption of La-O also proves it from the binding gel at 642 cm-1 and 423 cm-1. La2O3 binding gel was made of N,-N'-methylenebisacrylamide as a cross-linker with an elution factor of 97.4%. DGT-La2O3 proved capable of adsorption for 72 hours, with phosphate absorbed at 1.91 x 105 ng. DGT-La2O3 also has the optimum ability to absorb phosphate at pH 3 of 1.93 x 105 ng.
Zeolite from Zirconium-Modified Fly Ash Waste for Absorption of Phosphate Compounds in Waters Putri, Mu'izzah Irsyadi; Saefumillah, Asep; Bakri, Ridla
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 9, No. 1, May 2023
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v9i1.26951

Abstract

Eutrophication is a phenomenon of decreasing air quality caused by the very high amount of phosphate ions in the aquatic system. Thus, an effective and efficient adsorbent is needed for phosphate absorption in aquatic systems. In this study, zeolit from fly ash waste was modified with zirconium (Zr) as an adsorbent for phosphate absorption in aquatic systems. Fly ash was pretreated with acid and then synthesised using the hydrothermal method. And then, the results of the fly ash zeolit synthesis were continued using zirconium. The adsorption capacity was tested through several parameters, including the adsorbent concentration test, variations in pH,and contact time. Zirconium-modified zeolite (ZrMZ) adsorbent was the most effective adsorbent for phosphate adsorption, with an adsorption capacity of 3.015 mg-P/g at a 3 g/L adsorbent dosage and pH 7. The adsorption kinetics for the ZrMZ adsorbent followed pseudo-second-order kinetics. The best result of ZrMZ adsorbent to absorb phosphate in lake water was an adsorption capacity value of 0.186 mg-P/g and an adsorption efficiency of 81.137%.
Characterization Study of Dyes Photodegradation-Adsorption Products by TiO2-Chitosan Immobilized on Glass Beads using Flow System Mahadika, Bella Sukma; Saefumillah, Asep; Saepurahman, Saepurahman; Kurnia, Kiki Adi; Wellia, Diana Vanda
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 9, No. 1, May 2023
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v9i1.31855

Abstract

Dyes have a complex molecular structure that is difficult to degrade and can persist for a long time in water bodies. This study examines more thoroughly the effectiveness of photodegradation-adsorption of dyes, kinetic aspects, isotherms, thermodynamics, identification of the structure of photodegradation products, and changes in environmental quality parameter values whose results are quite satisfactory. The combination of photodegradation-adsorption of dyes by TiO2-chitosan modified glass beads using a flow system has never been accomplished before. Flowing of the dye resulted in a dye degradation efficiency of 99%. The FESEM-EDX analysis shows that TiO2-chitosan has been coated onto the surface of the glass beads. R2 of kinetics MB, MO, RB are 0.99234, 0.9889, 0.9971, which were pseudo-first order. Qm, KL, R2 are 6.4382, 0.70533, 0.99923; 16.7364, 1.42059, 0.98816; 6.0078, 1.06973, 0.99889, respectively. The ∆H, ∆S, ∆S of -9.388, -0.024, -1.979; -27.182, -0.078, -3.592; -4.819, -0.017, 0.464 indicate the exothermic and spontaneous reaction. COD, TOC, pH, turbidity values have reached the threshold required by the government. The degradation products formed during the photodegradation-adsorption process were identified using LC-MS that the structure of the dye has been degraded to become simpler so that it is safely disposed of into the environment.