No abstract

Curcuma xanthorrhiza Roxb. (giant curcuma) is one of herbal plants which is easily found in tropical region such as in Indonesia and has been widely used for medical purposes. This plant has been intensively used as the main ingredients of traditional medicines due to its potent healing power. Giant curcuma is generally dried using a conventional way under the sun prior to use. This method was less controlled, thus leading to poorer quality of products. Drying in a controlled batch dryer could improve product quality in overall. This experiment aimed to study the drying kinetics of giant curcuma using a laboratory designed batch dryer. Drying temperatures were varied between 40 ∘ C to 60 ∘ C. Samples were also dried in the oven at corresponding temperatures as the control. The drying was conducted until approximately 11 % dry basis moisture content inside the samples was achieved. In general, the drying time of giant curcuma were shorter when the temperatures were increased. This was also confirmed by Page's Model whereby drying rate constants increased four times both in the batch dryer as well as in the oven when the drying temperatures were increased from 40 ∘ C to 60 ∘ C.

Katuk (Sauropus androgynus) leaves have been traditionally used in Indonesia for increasing human breast milk production. In the previous research, katuk leaves have high moisture content, therefore katuk leaves extract were being prepared as spray dried S. androgynus extract. The freeze dried leaves were extracted with ultrasonic assisted extraction method using ethanol 80% as a solvent. Then, katuk extract was dried with spray drying method using maltodextrin as a drying aid. To improve the physical characteristics of this extract, it was mixed with mannitol, spray dried lactose, and crospovidone into S. androgynus extract powder. The results showed better physical characteristics, especially on moisture content and flow properties of powders. Metabolic profiles of all samples were analysed by thin layer chromatography (TLC) densitometry method, while the dried extract was dissolved in a suitable solvent and then spotted on GF254 and the plate was developed using a mixture of n-butanol:acetic acid:water (60:22:1.2). Based on TLC profiles, there are three different spots can be seen clearly at 366 nm on chromatogram of S. androgynus leaves, freeze dried leaves, spray dried leaves extract, and leaves extract powder. There is one spot (S3) at Rf 0.80 which is a stable chemical compound that is not affected by all factors in the entire process in S. androgynus extract powder formulations from extraction, drying, to formulation.

Solar thermal collectors generally convert sunlight into heat solely. However, if photovoltaic solar panels are used as collectors, the dryer system will get electricity in addition to the heat. The objectives of the present are to review the development of PV-T collectors and their use for solar drying. In addition, design and test a small scale solar dryer is carried out in this study by utilizing amorphous type photovoltaic-thermal (PV-T) as a collector. The heat obtained is used directly as a drying medium, while electrical energy is used for power supply for air circulating devices. The solar collector consists of 40 Wp amorphous solar panel, and covered with double glass at the top, while at the bottom and both sides are insulated to minimize heat loss. Heated air in the collector is then flowed to a chamber where the product to be dried the outlet. With the fixed position, it is found that the temperature of the outlet air from the collector varies from 35-50 o C during the day with solar Irradiation of 300-1000 W/m 2. At the same time, the electric power output from the PV panel varies from 4-25 Watt.

Simulation of Colored Waste Water Treatment Using Photo Fenton in Continuous System Waste water from coffee processing was treated by the Photo Fenton method. Experiments were carried out in a 2 liter batch reactor equipped with ultraviolet lamp for 4 hours. The synthetic waste water was made by dissolving 300 mg instant coffee in 1 liter water. Reagents used are 700 ppm H2O2 prepared from 30 % H2O2, and 15 ppm FeSO4.7H2O. The experiment was carried out at pH= 3. Prior to treatment, the color of the waste water was brownish yellow. After adding the fenton reagent under UV light exposure, the color of waste water changed to pale yellow, and finally became colorless. Absorbance and Total Organic Carbon (TOC) of the sample were measured periodically. The kinetics of organic carbon degradation followed first order reaction towards the TOC concentration. Based batch experiment data, organic degradation was simulated for a single CSTR and four CSTRs in series. The single CSTR with a residence time of 1100 minutes can reduce the organic content from 108 ppm to 10.8 ppm, whereas for the serial CSTR reactors, the residence time was only 100 minutes in each reactor to get the same reduction percentage. Keywords: photo fenton, colored waste water, continuous, residence timeAbstrakPengolahan limbah cair industri pengolahan kopi dilakukan dengan metode Foto Fenton. Kajian menggunakan limbah sintetis berwarna coklat, mengandung kopi 300 ppm. Percobaan dilakukan dalam sebuah reaktor gelas dua liter yang dilengkapi dengan lampu ultra violet. Reagen yang digunakan adalah hidrogen peroksida dengan konsentrasi 700 ppm yang dibuat dari H2O2 30%, dan besi sulfat 15 ppm. Pengolahan limbah dilakukan pada pH=3. Dengan penambahan reagen fenton dan bantuan lampu ultra violet, warna limbah cair berubah secara perlahan dari coklat menjadi kuning dan akhirnya tidak berwarna. Perubahan absorbansi relatif zat warna, kandungan bahan organik total diukur terhadap waktu. Berdasarkan data percobaan secara batch, kinetika degradasi karbon mengikuti orde satu terhadap konsentrasi bahan organik total. Aplikasi untuk sistem kontinyu dibuat menggunakan model simulasi penurunan kandungan organik dalam sebuah reaktor berpengaduk dan 4 buah reaktor berpengaduk yang dihubungkan secara seri. Dengan laju alir umpan tetap, peningkatan volume reaktor akan memperbesar waktu tinggal reaktan dalam reaktor. Hasil simulasi reaktor tunggal menunjukkan bahwa semakin lama waktu tinggal maka semakin tinggi persentase penurunan bahan organik total. Untuk mendegradasi 90% kandungan organik dalam limbah, sebuah reaktor kontinyu seharusnya dirancang dengan waktu tinggal 1100 menit sedangkan empat buah reaktor dirancang dengan waktu tinggal 100 menit.Kata kunci: foto fenton, limbah cair berwarna, kontinyu, waktu tinggal