La2O3 nanoparticles (NPs) have been formed using Nothopanax scutellarium leaf extract (NSE) and lanthanum precursor in two-phases system (n-hexane/water) with high-speed stirring method. Alkaloids as a secondary metabolite compound in NSE were used as a hydrolyzing agent and the other substances, namely saponin and tannin as a capping agent. All characterizations in this study were undertaken by Fourier transform infrared (FT-IR), UV-Vis DRS, X-Ray diffraction (XRD), scanning electron microscopy energy-dispersive X-Ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and UV-Vis spectrophotometer. UV-Vis DRS characterization showed that La2O3 NPs has a bandgap value of 5.59 eV. The particle size of La2O3 NPs was around 84.3 nm confirmed by TEM. UV-Vis spectrophotometer was utilized to analyze the photocatalytic activity of La2O3 NPs for the degradation of malachite green (MG) as a modelling of dye. The degradation percentage of MG using La2O3 NPs was 87.32 % for 120 min under UV light irradiation.

INTRODUCTIONLately introduced superabsorbent of graft copolymerization of vinyl monomers to natural polymers known as superabsorbent composites, such as chitosan 1 , starch 2 , cellulose 3 , montmorillonite 4 . Copolymerization conducted to get the desired properties, increase the absorption capacity. Natural polymers used to replace synthetic polymers is more difficult to decompose in the environment and the prices tend to be expensive 5 .The agricultural waste such as wheat straw, bagasse, rice straw, cassava dregs and others can be used as a more attractive alternative to get cellulose. Waste of rice straw utilization is not optimal, the farmers remove the rice straw by burning them, as the consequence of increase air pollution. Utilization of rice straw as a superabsorbent is expected to increase the economic value and overcome the environmental pollution. The rice straw including stems, leaves and stalks, at the time the crop was harvested, the straw is parts of plant discarded about 45 % of rice straw produced as the rest of the plant. Traditionally the use of straw is very limited for household and farming activities, such as, animal cage floor mats, animal feed, fuel in the industrial the manufacture of tiles, bricks and organic fertilizer. The use of superabsorbent in agriculture aims to reduce irrigation water consumption and plant mortality rates, increase the availability of water in the soil that allows plants to last longer, reducing the tendency of soil compaction,

ABSTRAKLimbah yang mengandung logam berat timbal (Pb) sangat berbahaya bagi lingkungan. Proses pengolahan telah diperkenalkan untuk mengolah limbah, dari proses pengendapan, hingga menggunakan resin penukar ion. Daun ketapang telah di gunakan sebagai media pengolahan air yang digunakan untuk akuarium. Para peneliti telah menunjukkan daun ketapang berpotensi sebagai pengolah air limbah. Penelitian ini bertujuan untuk mengetahui potensi biosorpsi daun ketapang pada limbah yang tercemar logam berbahaya, dengan mempelajari karakteristik biosorpsi, kesetimbangan, kinetika dan termodinamika. Kondisi optimum seperti pH, dosis daun ketapang, waktu kontak dan suhu akan diamati pada penelitian ini. Hasil Penelitian biomassa daun ketapang berpotensi sebagai biosorben, dengan perlakuan asam atau basa daun ketapang ini masih berpotensi sebagai biosorben. Penyerapan sangat dipengaruhi oleh pH, konsentrasi ion Pb, massa adsorben, waktu kontak dan suhu, yang berurutan nilai maksimum nya adalah pH 3, konsentrasi ion Pb 5 mg/L, massa adsorben 0,5 gram, waktu kontak 4 jam, dan suhu 40 ºC. Laju reaksi berjalan pada orde satu dan memenuhi kaidah isotermal Langmuir. Daun ketapang memiliki energi aktivasi yang rendah sehingga cocok untuk dijadikan adsorben alternatif penyerapan logam Pb dari limbah yang mengandung logam Pb.Kata kunci: Adsorpsi, daun ketapang, timbal (Pb) ABSTRACTWaste containing of lead (Pb) is very dangerous for the environment. However, waste treatment process has been introduced to minimize the waste, either by precipitation process or ionic exchange resin. In addition, researchers have shown that ketapang leaves (Terminalia catappa) can be potentially used in waste water treatment. It has been used as water treatment media for fresh water aquarium. Moreover, this research was aimed to find out the potential of ketapang leaves biosorption for waste treatment that has been polluted by heavy metal, such as lead, by investigating the characteristics of biosorption, kinetics and thermodynamics. Maximum conditions of pH, ketapang leaves dose, contact time, and temperature were also investigated in this research. The result showed that biomass of ketapang leaves has potential as biosorbent. Nevertheless, the absorbtion was highly affected by dependent to pH, Pb concentration, adsorbent mass, contact time, and temperature, in which the maximum limits are 3; 5 mg/L; 0.5 gram; 4 hours; 40 ºC; respectively. Reaction rate, moreover, was running

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One method of separating tripolyphosphate ion uses ion-imprinted polymer. Chitosan-succinate, tripolyphosphate and methylene bis akrilamida (MBA) were used as the complexing polymer, template, and crosslinker agent, respectively. In the first step, Fe(III)-chitosan-succinate-tripolyphospate was formed. In the second step, Fe(III)-chitosan-succinate-tripolyphospate was crosslinked by MBA and irradiated by gamma rays. Then, tripolyphosphate ion was removed with KOH solution to form a selective cavity for tripolyphosphate ion in the ion-imprinted polymer (IIP). Based on the results of this study, the optimum adsorption of tripolyphosphate ion was found at an MBA crosslinker concentration of 1%, pH 2, irradiation dose 20 kGy, and a tripolyphosphate ion concentration of 1 ppm. This study also included experimental adsorption of tripolyphosphate ion on non-imprinted polymer (NIP-MBA) and an evaluation of the effect of interference ions. The resulting adsorption of tripolyphosphate ion on IIP was found to be higher than those of non-imprinted polymer. The adsorption percentages were found to be 94 % for IIP and 14 % for NIP-MBA. Chloride ion (Cl-) provided greater interference in the adsorption process of tripolyphosphate ion compared to carbonate ions. The percent adsorptions of tripolyphosphates were estimated to be 57.71 % in the presence Cl- ion and 68.28 % in the presence CO3 2−ion.