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Chemistry is one of the subjects taught in State Senior High Schools (SMAN), especially in Natural Sciences (IPA). The problem with chemistry subjects is that it is difficult to practice in the laboratory because laboratory facilities such as space, equipment and chemicals are expensive. As a result, chemical laboratory practices were only sometimes carried out. Several lecturers and students from the Department of Chemistry, FMIPA Unand Kimia Unand, carried out service activities at SMAN 16 Padang through laboratory practice using materials and equipment that were cheap and readily available in the surrounding environment. This community service aims to train teachers and students to carry out chemistry practicums using simple materials and equipment available around them. The training was given to chemistry subject teachers and students in the science laboratory at SMAN 16 on 17 and 21 November 2022. The material was practised in oxidation and reduction (redox) and electrolysis reactions. The activity went smoothly; the students enthusiastically carried out the practicum. Through the results of this simple chemistry practicum, students can design and carry out chemical experiments using simple tools and materials, conduct direct observations of chemical processes, practice scientific thinking, attitude and work skills and analyze and solve various scientific processes using scientific methods. SMAN 16 hopes that this activity will continue with different topics.

The purpose of this study was to improve the mechanical and physical properties, degradation performance, and water absorption of a thermoplastic mixture of sago starch with the addition of Linear Low-Density Polyethylene (LLDPE). The method used is the grafting method where polyethylene is grafted onto Maleic Anhydride (LLDPE-g-MA). In this research, Thermoplastics Sago Starch (TPSS) was made with a mixture of Sago Starch (65%) and Glycerol (35%), added with water as a solution. Compatibilizer (PE-g-MA) was made by reacting LLDPE (88%) and Maleate Anhydride (9%) with an additional initiator of Benzoyl Peroxide (3%). The concentration of LLDPE varied from 10,15, 20, 25, and 30%. Substances were mixed into an internal mixer Thermo Haake Polydrive with a speed of 100 mm/minute, for 15 minutes. The concentration of 30% LLDPE produced the highest tensile strength and elongation at a break of 4.30 N/mm2 and 2.15%, respectively. Simultaneously, as LLDPE concentration increased, Young's Modulus decreased. This was powered by the morphology of the sampling surface, with the occurred reaction of adhesion interface or dispersion of LLDPE toward the whole surface with the assistance of compatibilizer as connecting substance between hydrophilic polymer and a hydrophobic polymer, which could improve the properties of mechanical. The formation of ester groups from the reaction of inter groups of hydroxyls derived from the starch with the groups of anhydride derived from the mixture of compatibilizer was visibly seen at the peak of 1693 cm-1. The degradation performance of the TPSS: LLDPE mixture with a ratio of 70:30 showed good performance where the degradation continued to increase up to 42% on the 30th day of degradation in freshwater, 18% in seawater, and 17% in soil burial. While the water absorption test showed that the higher concentration of LLDPE, the lower speed of water absorption.

In this paper, we report that the compatibility of polymer blends between linear low-density polyethylene (LLDPE) and cyclic natural rubber (CNR) can be increased by the addition of oleic acid-grafted linear low-density polyethylene. The research aims to investigate the effect of LLDPE-g-OA compatibilizer in LLDPE/CNR blends on improving the mechanical properties and characteristics of the blends. The LLDPE/CNR/LLDPE-g-OA blends (compatible blends) were prepared by blending methods in the molten phase using an internal mixer set at a temperature of 160oC with a rotation speed of 100 rpm. The LLDPE pellets were inserted into it until melts and followed with an addition of CNR and LLDPE-g-OA. The tensile strength test results have shown an increase in mechanical properties after the addition of the compatibilizer with a maximum content of 4 wt%. The difference in FTIR spectra of compatible blends is indicated by the presence of C=C bonds from CNR, which appear at 1654.9 cm-1, indicating the occurrence of physical bonds in the blends. The existence of the LLDPE-g-OA compatibilizer has increased the thermal stability of the polymer blends and changes in the melting point temperature of 1240C. Compatible blends showed that the surface morphology was smoother, and there were significant microstructural changes compared to incompatible blends.

The Community Service Team of the Chemistry Department has worked closely with the Taman Pendidikan Qur'an (TPQ) and Rumah Tahzhul Qur'an (RTQ) Raudhatul Adzkia Jorong Dalam Koto Nagari Koto Tangah in solving problems faced by partners. The pond catfish farming business supports smooth operational costs and has been running for over a year, but these results still need to be improved for TPQ and RTQ. This activity aims to develop a catfish farming business accompanied by an aquaponic cultivation business to increase income from TPQ and RTQ. The benefit of this activity is that the partners have an Aquaponics business which is cultivating catfish and vegetable plants in the fish pond. The Community Service Team transferred knowledge to partners, especially in cultivating aquaponic plants through entrepreneurship. The activities of the Community Service Team in helping partners are a form of the Andalas University Higher Education Tri Dharma. The method applied to support the realization of this community service program was through supervision, program socialization, and implementation of activities. The result of this activity was that partners could run an aquaponics business to increase income to meet the operational costs of education and teacher salaries.

This study reports that Precipitated Calcium Carbonate (PCC) nanoparticles from limestone can be modified with oleic acid (OA), which was applied to LLDPE/CNR blends in the presence of the LLDPE-g-OA coupling agent. This study investigates PCC characteristics from limestone that has been modified with OA and its implications of increasing impact strength, thermal properties, and morphology changes in LLDPE/LLDPE-g-OA/CNR/O-PCC composites. Organo-PCC (O-PCC) was prepared by mixing the PCC with OA in n-hexane solvent. The polymer composites were made by mixing LLDPE, LLDPE-g-OA, and CNR simultaneously in an internal mixer at 160 °C with speed rotation of 100 rpm, followed by O-PCC. The characterization results of O-PCC obtained CaO compounds of 97.9%, crystallinity degree of 61.6%, crystals size of 48.6 nm, and scalenohedral-shaped crystals. The results of the impact strength test on LLDPE/LLDPE-g-OA/CNR/O-PCC composites with an O-PCC concentration of 5 wt% showed an increase of 21.5% compared to no fillers. The presence of O-PCC resulted in the thermal properties of polymer composites with a melting point of 125.5 °C and a decomposition temperature of 468.7 °C. The morphology did not result in significant differences in the surface structure after adding O-PCC nanoparticles.

Karbon aktif dari ampas biji kopi dimanfaatkan sebagai bahan dasar elektroda superkapasitor. Pembuatan karbon aktif ini diaktivasi dengan NaOH menggunakan gas N2, meliputi variasi konsentrasi 0,2 M, 0,3 M dan 0,4 M. Sifat fisis dari karbon aktif ampas biji kopi robusta telah dilakukan meliputi analisa densitas, penurunan densitas setelah karbonisasi- aktivasi berkisar antara 9% - 35%.Kapasitansi spesifik elektroda karbon ampas biji kopi robusta berdasarkan hasil pengujian menggunakan metode Cyclic voltammetry (CV) diperoleh kapasitansi spesifik tertinggi dengan elektrolit 1 M H2SO4 adalah 130 F/g-1 pada konsentrasi 0,3 M, dan pada pengujian menggunakan metode Galvanostatic charge discharge (GCD) diperoleh kapasitansi spesifik tertinggi dengan elektrolit 1 M H2SO4 adalah 198,53 F/g-1 pada konsentrasi 0,3 M. Luas permukaan spesifik elektroda 0,3 M adalah 739,911 m2 g -1, kandungan unsur elektroda karbon 0,3 M berdasarkan karakterisasi EDX didominasi oleh unsur karbon yaitu 49,37%. Kurva isotherm adsorpsi karbon aktif ampas biji kopi robusta 0,3 M adalah tipe IV yang menunjukkan bahwa struktur mesopore yang mendominan. Dengan nilai kapasitansi dan luas permukaan spesifik yang besar, karbon aktif dari ampas biji kopi robusta bisa dimanfaatkan sebagai elektroda superkapasitor yang murah dan ramah lingkungan.

Karbon aktif dari ampas biji kopi robusta yang diaktivasi menggunakan variasi konsentrasi KOH sebesar 0,2 M, 0,3 M, dan 0,5 M telah digunakan sebagai bahan dasar elektroda superkapasitor. Sintesis elektroda karbon aktif di awali dengan proses aktivasi kimia dan dilanjutkan dengan proses karbonisasi. Sampel di karbonisasi pada suhu 8000C dengan laju pemanasan 50C/menit dalam kondisi gas inert (N2). Pada penelitian ini, karbon aktif ampas biji kopi robusta dikarakterisasi menggunakan SEM EDX (Scanning Electron Microscopy–Energy Dispersive X-Ray) dan SAA (Surface Area Analyzer) sedangkan sifat elektrokimia sel superkapasitor diukur menggunakan metoda Cyclic Voltammetry (CV) dan Galvanostatic Charge-Discharge (GCD). Kurva isotherm adsorpsi karbon aktif ampas biji kopi robusta yang didapatkan pada karakterisasi SAA merupakan tipe IV yang menunjukkan bahwa struktur mesopori lebih dominan. Pada pengukuran sifat elekrokimia menggunakan metoda CV dan GCD, elektroda karbon aktif menggunakan konsentrasi KOH 0,3 M menghasilkan nilai kapasitansi spesifik tertinggi yaitu sebesar 123 Fg- 1 dan 192 Fg-1 dengan persentase unsur C sebesar 73.36 % dan luas permukaan spesifik sebesar 795,687 m2g-1. Karbon aktif dari ampas biji kopi robusta yang diaktivasi menggunakan aktivator KOH memiliki performance yang baik dan dapat dijadikan sebagai bahan dasar elektroda superkapasitor yang ramah lingkungan

The addition of LLDPE-g-MA into the compound of sago starch/LLDPE was studied to improve its mechanical, morphology, degradation performance, and water absorption properties. Thermoplastic Sago Starch was composed of a mixture of sago starch and glycerol. LLDPE-g-MA was prepared in varied concentrations based on the weight of TPSS (0, 6, 8, 10, and 14 wt.%) by reacting LLDPE, maleic anhydride, and benzoyl peroxide using an internal mixer. The results showed an increase in values obtained from mechanical tests, i.e., tensile strength was improved from 0.6902 to 3.6187 N/mm2 with the addition of LLDPE-g-MA at 10 wt.%. The addition also resulted in a 1.44% increment in elongation at break and 251 N/mm2 for Young's Modulus. The surface morphology of the sample demonstrated an excellent interfacial adhesion reaction or LLDPE dispersion over the entire surface of the matrix (starch). The water absorption test continued to decrease with the increase in the LLDPE-g-MA concentration from 53 wt.% (without LLDPE-g-MA) to 14 wt.% at 10 wt.% LLDPE-g-MA concentration. The degradation performance showed that the sample could be degraded under all three conditions for up to 30 days.

This study investigates the improvement of the mechanical, thermal, and morphological properties of linear low-density polyethylene (LLDPE)/cyclic natural rubber (CNR) after the addition of organo-precipitated calcium carbonate (O-PCC). The impact on the properties of the LLDPE/CNR/LLDPE-g-OA/O-PCC composites was investigated by a series of empirical experiments. First, the polymer composite was blended in the molten state using an internal mixer with a heating temperature of 160 °C and a rotation speed of 100 rpm. The LLDPE was placed in a chamber of internal mixer until melted, followed by CNR, LLDPE-g-OA, and O-PCC. The polymer composites with an O-PCC concentration of 5% obtained the optimal mechanical properties compared to other variations, with a tensile strength of 17.17 MPa and Young's modulus of 252.68 MPa. The presence of O-PCC resulted in better thermal stability and a change in the melting point temperature of 124 °C. The FTIR spectra of the polymer composite showed the specific characteristics of O-PCC at 872.1 cm–1. The morphology of the polymer composite indicates that the O-PCC is evenly dispersed in the polymer composite.

The insecticide imidacloprid (C9H10ClN5O2) common used by farmers to control pests on red tomato plants, is a dangerous substance classified as a Class II toxic. The imidacloprid residue in red tomatoes enters the body, it will lead to health problems. The purpose of this study was to determine the percentage of imidacloprid residue that can be degraded using the Advanced Oxidation Processes (AOPs) method, which includes sonolysis, sonozolysis, ozonolysis, ozone water, and the effect of various parameters. Processing time, water volume, and red tomato mass were the test parameters studied. The change in imidacloprid residue concentration during the degradation process was measured using a UV/Vis spectrophotometer (double beam) with a wavelength of 200-400 nm and HPLC with mobile phase composition used was acetonitrile/water (65:35 v/v). With a processing time of 10 minutes, the imidacloprid residue in red tomatoes can be degraded 57.38% by sonozonolysis, 63.51 % by sonolysis, 85.17 % by ozonolysis, and 88.76 % by ozone water. The imidacloprid residue in 75 g of red tomatoes could be removed as much as 91.65% by treating with ozone water for 15 minutes. HPLC analysis showed that no intermediate compounds were detected in the imidacloprid residue degradation process in red tomatoes.

Seberang Padang Village, South Padang District, is next to Padang City, which has approximately 200 families. This location is a crossing area between Padang-Painan, in West Sumatra. The community consists of two existing traditional markets that sell daily necessities. Besides that, there is also one elementary school, two junior high schools, and one high school. The global Covid-19 pandemic certainly affects the community's daily activities and learning activities, including children, elementary school students, middle and high school students, and the village community to fulfil their basic needs. Furthermore, the main problem of Covid-19 is not only about the effects caused by the virus on sufferers but also about its high-speed transmission. Therefore, to educate the community around the Seberang Padang village, several Chemistry Lecturers and students at the Faculty of Mathematics and Natural Sciences at Andalas University did a community engagement. They taught the community about making disinfectants and hand sanitizers without alcohol that can overcome the occurrence of Covid-19 transmission. In addition, face masks were provided for the community, and the alms of food for underprivileged residents to push down the negative impact of Covid-19.

The aim of this study is to utilize fly ash from various sources on chemical and physical properties of cement type I (OPC). Utilization of fly ash can improve the strengthness of the cement. It can reduce the waste of fly ash by utilization into cement process. The procedure has been carried out on cement type I (OPC) with the addition of fly ash additives from various sources with concentration variations such as 10% and 20%. Utilization of fly ash as additives substance in cement works to improve the quality of cement. The main parameter in determining the quality of cement is determined by the compressive strength. The results of the compressive strength test showed that the addition of fly ash with a concentration of 10% had a higher effect on the compressive strength than the addition of a concentration of 20%. 5 types fly ash from various sources, fly ash from PT Sinar Mas gives greater compressive strength at 28 days. the addition of fly ash additives to OPC cement mixture has chemical and physical properties which are not much different from properties of PCC cement.

Karbon aktif dari ampas teh telah disintesis dan telah diuji sebagai elektroda superkapasitor. Pembuatan karbon aktif berdasarkan variasi rasio massa karbon dan aktivator NaOH yaitu 1:4, 1;5 % b/b yang diberi kode AC-4 dan AC-5. Sintesis elektroda karbon aktif di awali dengan proses pra-karbonisasi dan dilanjutkan dengan proses aktivasi kimia. Sampel di karbonisasi pada suhu 800 oC dengan laju kenaikan 50C/menit dalam kondisi gas inert (N2). Karbon aktif ampas teh dikarakterisasi dengan SAA (Surface Area Assessment). Sifat elektrokimia dan kinerja elektroda karbon aktif yang disintesis diukur menggunakan metode voltametri siklik dalam larutan elektrolit H2SO4 1M. Elektroda karbon aktif menunjukkan kapasitansi spesifik tertinggi pada sampel AC-4 yaitu 67 F/g dengan scan rate 1 mV/s dan luas permukaan spesifik 473 m2/g. Mengingat sifat elekrokimia yang menarik tersebut, dan banyaknya ampas teh yang mudah ditemukan disekitar kita maka elektroda karbon aktif ini berpotensi untuk bahan pembuatan superkapasitor elektrokimia skala besar di masa depan. Activated carbon from tea waste has been synthesized and has been tested as a supercapacitor electrode. Making activated carbon based on variations in the ratio of carbon mass and activator NaOH that is 1: 4, 1; 5%wt coded AC-4 and AC-5. Synthesis of activated carbon electrodes begins with the pre-carbonization process and is followed by a chemical activation process. Samples are carbonized at 800 oC with a rate of increase of 50C / min under inert gas (N2) conditions. Activated carbon of tea waste is characterized by SAA (Surface Area Assessment). The electrochemical properties and performance of the activated carbon electrode were measured using the cyclic voltammetry method in a H2SO41 M electrolyte solution. The activated carbon electrode showed the highspecific capacitance in the AC-4 sample of 67 F / g with a scan rate of 1 mV / s and surface area Specifically 473 m2 / g. Considering these interesting electrochemical properties, and the abundance of tea dregs that are easily found around us, this activated carbon electrode has the potential to be a material for making large-scale electrochemical supercapacitors in the future. Keywords:Limbah ampas teh, Aktivator, Kapasitansi spesifik, NaOH, Supekapasitor

The Modified Phenanthroline Method (MPM) has been validated for determination of antioxidant content in herb samples. Validation was done using Relative Standard Deviation (RSD) and percentage of recovery. The RSD and percentage of recovery for herb samples are 3.13% and 98.6%, respectively. Based on these values, MPM method is valid for determining antioxidant content in herb samples. T test shows no significant differences of antioxidant content using any of these methods, MPM, PM, FRAP or DPPH, at a 95% confidence level. MPM method shows a very strong correlation with PM and FRAP method. While with DPPH and TPC shows is strong.

Studi karakteristik karbon aktif dari cangkang buah ketaping (Terminalia Catappa) sebagai elektroda superkapasitor telah diteliti. Karbon aktif dari cangkang buah ketaping (CBK) disiapkan dengan proses karbonisasi pada suhu 400oC dan Proses aktivasi KOH pada suhu 800oC di bawah aliran gas N2. Karbon aktif CBK memiliki kandungan karbon dengan massa atomik sebesar 97,52%. Karbon aktif CBK memiliki struktur amorf dengan dua buah puncak yang lebar pada sudut 2θ yaitu 24,93o dan 42,93o yang bersesuaian dengan bidang (002) dan (100). Karbon aktif CBK yang dihasilkan memiliki pola serapan dengan jenis ikatan OH, C-H, C=O, dan C=C. Adanya ikatan OH dan C=O menunjukkan bahwa arang aktif yang dihasilkan cenderung bersifat lebih polar. Morfologi permukaan karbon aktif CBK menunjukan distribusi ukuran pori yang merata dan luas permukaan yang besar. Luas permukaan spesifik karbon aktif dari CBK adalah 799,892 m2×g-1 dengan volume total pori 0,080 cm3×g-1 dan jari-jari pori rata-rata 1,9072 nm. Kapasitansi spesifik dari karbon aktif dari CBK adalah sebesar 125,446 F×g-1. Studies on the characteristics of activated carbon from ketaping fruit shells (Terminalia Catappa) as supercapacitor electrodes have been studied. Activated carbon from ketaping fruit shells (KFS) prepared by carbonization process at 400oC and the KOH activation process is carried out at 800oC under N2 gas flow. Activated carbon KFS has a carbon content with 97.52% of atomic mass. Activated carbon KFS has an amorphous structure with two wide peaks at an angle of 2θ 24.93ᵒ and 42.93ᵒ corresponding to the plane (002) and (100). Activated carbon KFS produced has an absorption pattern with OH, C-H, C = O, and C = C bond types. The presence of OH and C = O bonds indicates that the activated charcoal produced tends to be more polar. The surface morphology of activated carbon KFS shows an even distribution of pore size and large surface area. The specific surface area of activated carbon KFS is 799.892 m2×g-1 with a total pore volume 0.080 cm3×g-1 and an average pore radius of 1.9072 nm. The specific capacitance value of activated carbon KFS is 125.444 F×g-1. Keywords: Ketaping, Activated Carbon, Supercapacitor, Activator, Capacitance.

Penelitian cangkang pensi (Corbicula moltkiana) sebagai penyerap zat warna metanil yellow telah dilakukan dengan sistem batch. Kondisi optimum penyerapan terjadi pada pH 4 dan konsentrasi awal 100 mg/L. Proses adsorpsi terjadi mengikuti model isoterm Langmuir dengan nilai R2 adalah 0,886 pada monolayer dengan kapasitas adsorpsi maksimum (qmax) diperoleh 2,591 mg/g. Hasil analisis gugus fungsi cangkang pensi dengan FTIR menunjukkan adanya interaksi antara molekul zat warna metanil yellow dan gugus fungsi. Analisis morfologi permukaan cangkang pensi menggunakan SEM menunjukkan bahwa pori-pori cangkang pensi telah diisi oleh molekul zat warna metanil yellow. Cangkang pensi dapat digunakan sebagai bahan penyerap zat warna metanil yellow di dalam larutan. ABSTRACTThe study of the Pensi Shell (Corbicula moltkiana) to adsorb metanil yellow (MY)dyes has been investigated. This study was determined by batch system. The optimum conditions of metanil yellow dyes adsorption occurred at pH 4 and initial concentration 100 mg/L. The adsorption process was properly described by Langmuir isotherm model which was indicated by the value of R2=0,886. This confirmed that the adsorption process was monolayer with maximum adsorption capacity (qmax) was 2,591 mg/g. Functional groups analysis by FTIR showed the interactions MY molecule on pensi shell functional groups. Analysis of morphology surface of pensi shell by SEM indicated that the pore was filled by MY molecules. Pensi shell could be used as adsorbent of metanil yellow dyes in aqueous solution.

The corrosion of steel and its alloys is an important problem in industry, especially in acidic environments. Mild steel is one of the important alloys of iron which has many industrial applications because of its excellent mechanical properties, but mild steel is susceptible to corrosion. Corrosion problems need to be a concern and must be handled properly. Hydrochloric acid is widely used for pickling, cleansing, decomposition and metal etching, on the other hand also contributes to corrosion of metal surfaces. Plant extracts investigated the properties, mechanisms of adsorption and efficiency of inhibition as environmentally friendly corrosion inhibitors for various steel materials in different acidic media. The efficiency of corrosion inhibition of steel from plant extracts analyzed ranged from 72-98% and generally as a mixed-type inhibitor. Most of the inhibitors are adsorbed on the steel surface through a physisorption mechanism.

Abstrak Kesadaran terhadap ancaman krisis energi karena kebutuhan yang sangat besar dan pencemaran lingkungan yang terjadi, maka perlu dilakukan penelitian untuk menghasilkan sumber energi alternatif. Hidrogen merupakan energi alternatif yang dapat digunakan sebagai bahan bakar, ramah lingkungan, dan dihasilkan dari sumber yang melimpah di bumi yaitu air. Salah satu metode yang dipakai untuk memproduksi gas hidrogen adalah metode fotolisis. Katalis yang digunakan adalah TiO2 yang didoping N, tujuannya mempelajari pengaruh variasi perbandingan TiO2/N terhadap aktifitas fotokatalitik pembentukan hidrogen. Hasil penelitian memperlihatkan produksi gas menggunakan TiO2/N pada kondisi optimum terjadi pada perbandingan 4:6 yang menghasilkan gas 2.2 mL. Dari hasil penelitian dapat disimpulkan bahwa TiO2 doping N dapat membantu pembentukan gas secara fotokatalitik. Kata kunci : Fotolisis, katalis, doping, fotokatalitik Abstract The awareness about energy crisis is rising quickly. Consider to the very fast growing need of energy and the environmental impact caused by the conventional energy, so that the research about renewable energy as an alternative energy resource is very urgent. Therefore, the research to produce hydrogen as an alternative energy resourse was conducted. Hydrogen can be used as a green fuel which can be extracted from water, a huge amount of resource on the earth. In this research, the photolysis method was used. Nitrogen-doped TiO2 catalyst was used in order to analyse the influence of variational ratio of TiO2/N to the photocatalytic process of hydrogen production. The result shows that the optimum condition in producing gas using TiO2/N occured at the ratio 4:3 which produced as much as 2.2 ml gas. From this result can be concluded that Nitrogen-doped TiO2 supports the extraction of gas in photocatalytic process. Keywords: Photolysis, catalys, doped, photocatalytic DOI: http://dx.doi.org/10.15408/jkv.v0i0.3077

Dye alami dari daun pandan, akar kunyit dan biji black rice telah dipreparasi dalam larutan etanol sebagai sensitiser pada dye sensitized solar cells (DSSC). Dye campuran dipreparasi dengan perbandingan volume 1 : 1 juga diteliti sebagai sensitiser pada DSSC. Metoda doctor blade dipakai untuk menumbuhkan lapisan tipis TiO2. Karakterisasi spektrofotometer UV-Vis dilakukan pada larutan dye untuk mengamati panjang gelombang yang diserap dye dan menghitung energi gap dye. Dari perhitungan diperoleh energi gap dye 1,387- 1,777 eV. Sedangkan dari karakterisasi arus tegangan (I-V), diperoleh efisiensi terbesar dye tunggal 0,056% dari dye kunyit dan efisiensi terbesar dye campuran 0,207% dari dye campuran black rice dan kunyit. Penggunaan dye campuran dapat meningkatkan performa dan efisiensi DSSC secara signifikan.

This research aims to obtain reactor design photocells that can convert light energy into electrical energy space. Room light energy derived from sunlight that comes into the room and fluorescent light irradiation. Photocells reactor using a panel of copper oxide (Cu2O/CuO) of calcined Cu plate and filler electrolyte Na2SO4 0.5 N. The design of the geometry of the reactor photocells covering thickness of the glass pane, the distance between the electrodes, the interface layer, layer and coating reflector panels, and junction type np used. Reactor photocells 1 (R1) and 2 (R2) is identical in geometry to the thickness of the glass panel 3 mm thick reactor 15 mm without anti reflector, but the difference at the junction of type n, (R1 = plate Cu; R2 = plate Aluminum) generate 182.82 mW/m2 and 21119644.3 NW/m2. Design R3 (junction-type n = plate Cu) and R4 (junction-type n = plate Al), a panel thickness of 15 cm and has a layer anti reflector provide power 214.95 mW/m2 and 24163298.3 NW/m2. Design Reactor 5 (R5 = Cu) and R6 (Al), thickness of 9 mm, the distance between the electrodes 0:30 mm, using anti reflector carbon, giving each the power of 277.36 mW/m2 and 31258420.91 NW/m2. The most optimum reactor design is the design of R6 with 2:14% conversion capabilities (Intensity = 90.21 foot candles) for the sunlight into the room.

ABSTRACT Determination of kinetic analysis of Co(II) ion transport through bulk liquid membranes by consecutive method have been study. The optimum condition was obtained at pH 4 for the intermediate phase and receiving phase at pH near zero, while the source phase at pH 7, oxine concentration in chloroform at source phase is 2.10 M, methyl red concentration in chloroform at receiving phase is 3.10 M. It was found that Co(II) ion receiving phase at optimum condition as 4.40%. Evaluation of Co(II) ion kinetic transport shows k1 as 0.0116 minutes-1 and k4 0.0113 minutes-1. Kinetic transport process of Co(I1) ion through bulk liquid membranes by consecutive method followed first order consecutive irreversible reaction rate low. Consecutive method can used as an alternative method in determination the optimum condition of metals ion transport and kinetic evaluation of mentioned transport metals ion. Keywords : bulk liquid membranes, consecutive, cobalt

ABSTRACT A research aimed to study the influence of ZnO white powder on photodegradation of methylene blue using Merkuri lamp (l = 365 nm) as light source have been reached. A suspension of ZnO (40 mg) mixed with 25 mL of methylene blue solution (initial concentration of 0.015 mM) then was illuminated for 60 minutes showed degradation and quantum yield amounting 23.84% and 3.55 molecules photon-1, respectively. These results mean that by using ZnO as photocatalyst there is about four times efficiency than the one without ZnO either in case of time consumed or the number of photon applied. In kinetic study, it has been observed that such semiconductor-catalyzed photochemical reaction obeys the first order rule where rate constant and half time consecutively were 0.0029 minute-1 and 231 minutes. Keywords : photodegradation, photocatalyst, quantum yield, semiconductor, photochemical reaction.

ABSTRACT Peat water purification by filtration with perlite-cement-lime mixtures was preliminary studied. The filtration was realized under static condition without any pressure. From the experimental results obtained that perlite composition in the mixture plays an important role in the filtration processing. Otherwise the some physical properties of perlite-cement-lime mixture was also determined. Key words: peat water, perlite.

ABSTRACT Hydrogen is one of the promising alternative energy sources which is environmentally-friendly. Amongs several methods that have been used to produce hydrogen is a photolysis base on photochemical reaction which has been choosen and applied for this work. In this system where water was photolyzed in the present of TiO2 powder as photocatalyst and potassium iodide as sacrificial agent. The sample was prepared by addition various potassium iodide concentrations and then each sample was treated in the present and absent of air. The sample was placed in a quartz reactor which was then illuminated by a Philips low pressure vapoured mercury lamp (λ = 254 nm) as light source for 7 hours. Produced gas volume was measured by a method based on the movement of soap bubbles. The results showed that the maximum gas volume obtained at 0.006 g/L TiO2 and 0.1 g/L KI concentration (in the present and absent of air) were applied. Furthermore, the maximum volume of hydrogen gas was produced at the present of air. In the present of air, dissolved oxygen accelerated H2 gas productions which act as oxidation agent and electron carrier to H+. Keywords: Photolysis, Photocatalyst, Titania, Hydrogen, Sacrificial agent

ABSTRACT The research about bio-filtration of peat water using paddy chaff coated by carbon as filter biomaterial has been conducted. Iodimetry titration method was selected for determination of BOD and COD concentration, while gravimetry method and UV/Vis spectrophotometry is used to determinate TSS and humic acid containing in sample. The results of filtration with bio-filter lock up this paddy able to reduce organic compounds in peat water. The existence of coating carbon causing of BOD 22.37 mg/L (without carbon 27.73 mg/L), COD 54.30 mg/L (without carbon 86.02 mg/L), TSS 120 mg/L (without carbon 155 mg/L) concentration was decreasing, especially at the third step of filtration. Keywords : peat water, biofiltration, biomass

Vol 5 No 1 ABSTRACT The roselle flower and mangosteen pericarp dyes were applied as dye sensitizer for dye-sensitized solar cell. The solar cell was composed of a thin film TiO2 as working electrode, 2B pencil as controle electrode, and I-/I3- as electrode couple. The influence of dipping time of working electrode in dyes extract on the cell efficiency was investigated. The highest efficiency of roselle and mangosteen dye-sensitized solar cells was obtained at 60-minutes dipping, respectively as 0.017% and 0.032%. Characterization of both dyes extract by UV-Vis Spectrophotometry method showed that dyes adsorb in visible region. Keywords: Solar cell, sensitized, dyes, antosianin, TiO2

ABSTRACT Cacao beans contain many kinds of mineral, magnesium (Mg), calcium (Ca), Zinc (Zn), Phosphor (P) and etc. This study investigated magnesium (Mg) and calcium (Ca) in fermentation and non fermentation cacao beans by atomic absorption spectrophotometry. Mg and Ca, content in non fermentation cacao beans of green and red variety are 453 µg/g, 466 µg/g, and 491 µg/g, 445 µg/g. Mg and Ca, contents in fermentation cacao beans of green and red variety are, 596 µg/g, 528 µg/g, and 554 µg/g, 505 µg/g. Fermentation make magnesium (Mg) and calcium (Ca) content increase significantly. Keywords : Theobroma cacao Linn, fermentation, spectrophotometry.

ABSTRACT The selective transport of Ni(II) to Cd(II) through simultaneously liquid membrane technique has been investigated. The cell membrane was made by mixturing Ni(II) and Cd(II) ions at concentration as 3.41x10-4 M and 1.78x10-4 M respectively as source phase, oxine in chloroform as membrane phase and Na2EDTA solution as receiving phase. Concentration of recidual Ni(II) and Cd(II) ions in source phase transported to receiving phase was measured by Atomic Absortion Spectrofotometry (AAS). The results showed the at optimum condition of Ni(II) and Cd(II) transport occurred at source phase of pH 7, oxine concentration 0.001 M in chloroform and 0.04 M Na2EDTA solution pH 7. In this condition, Ni(II) and Cd(II) transport selectivity was found 80.89%. From the experiment, it was found that the transport rate constant from source phase to membrane phase (k1) for Ni(II) (0.7544 per hour) smaller than Cd(II) (1.3800 per hour ), on the other hand the transport rate constant from membrane phase to receiving phase (k2) Ni(II) (2.7580 per hour) greater than Cd(II) (1.3790 per hour). The phase-to-phase transport of Ni(II) and Cd(II) was consecutive first order reaction. Keywords : bulk liquid membrane, oxine, technique