Analysis of mercury (Hg) in water and sediment samples from Krueng Sabee (KS), Panga (P) and Teunom (T) rivers have been carried out. Water and sediment samples were collected at three different sampling points. Concentration of mercury was determined by using Atomic Absorption Spectrophotometer (AAS). Measurement of temperature, pH and salinity of the water samples was carried out in situ method. The results of in situ measurements showed a temperature ranges of 24 to 32°C, pH of 6 - 8 and salinity of 0.1 - 0.3. Based on the analysis of samples, the concentration of mercury in water and sediment samples during March 2019 (sunny condition) were 0.3328 and 6.2330 μg/L, respectively and April 2019 (rainy condition) were 0.0560 and 0.2778 μg/L, respectively. Evaluation of the pattern of Hg distribution in water and sediment samples was conducted by the Principal Component Analysis (PCA) method. The result of PCA analysis in sediment samples showed a strong correlation between Hg concentration at the KS1 and KS2 sampling points. Meanwhile, the concentration of Hg in water samples showed a strong correlation at sampling points of T2 and T3.
Anthocyanin from the flower Ruelila tuberosa L was successfully extracted by maceration using methanol. The total extract obtained was 19.22% with a concentration of 1.503 mg/L correspondingly. Retention time was analyzed using Thin Layer Chromatography and an Rf value of 0.43 was achieved. The analytical determination of functional groups was conducted using FTIR. The sensitivity of anthocyanin towards phosphate buffer pH is 0.222 at the range of pH 6 - 8 with R2 = 0.996 at maximum wavelength of 635 nm. On the other hand, its sensitivity towards citrate buffer is 0.022 at pH range 6 - 8 with a linearity of R2 = 0.999 at 625 nm maximum wavelength. The anthocyanin showed good in sensitivity and dynamic range in 0.1 M Phosphate buffer solution.
Neat chitosan membranes have shortcomings in their application owing to weak mechanical properties, thus, requiring modification. In this study, a chitosan membrane was modified utilizing starch and cross-linking agent (citric acid) addition. The characterization of chitosan-starch membranes using Universal Testing Machine, Scanning Electron Microscope (SEM), Fourier Transform Infra-Red (FTIR), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA) had proven the cross-linking formation. The cross-linked membrane had better tensile strength (11.07 kgf/mm2) than the uncross-linked membrane (66.07kgf/mm2). The DSC thermogram of uncross-linked and cross-linked membranes showed endothermic and exothermic peaks at different temperatures. In addition to the membranes’ thermal characteristics, the DTA thermogram showed the decomposition process on the uncross-linked membrane uncross-linking occurred at a temperature range of 277.74-363.27 °C, while the decomposition of the cross-linked membrane was observed at a range of 287.83-356.38 °C. The FT-IR spectra confirmed a decrease in the intensity of the absorption peak associated with cross-linking formation within the membrane.
Copper-doped hematite (Cu-doped α-Fe2O3) nanoparticles have been synthesized by the impregnation method using iron ore as the hematite source. The structural and morphological properties of the prepared samples were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption-desorption. The XRD results showed that the hematite extracted from iron ore was in the hematite phase. The average crystallite size of copper-doped hematite was slightly smaller than that of hematite. The copper-doped hematite nanoparticles exhibited high photocatalytic activity on degradation of indigo carmine (IC) dye with the degradation percentage of 98.21 % and 99.78%, respectively under UV and solar light irradiation. The highest photocatalytic activity was obtained at the experimental condition namely initial pH of IC solution 1.0, photocatalyst mass of 400 mg, initial concentration dye solution of 15 mg/L, and 90 minutes of irradiation times. The copper-doped hematite nanoparticles could also remove dyes found in batik wastewater with a percentage of the degradation up to 77.56 % and 97.83% under UV and solar light irradiation, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.