PREPARASI, KARAKTERISASI DAN APLIKASI TiO2(ET)/RESIN SEBAGAI FOTOKATALIS PADA FOTOREDUKSI ION Cu(II)

To increase photocatalitic activity of TiO2, the preparation and characterization of TiO2 photocatalyst on resin accompanied with photoactivity test for Cu(II) ion photoreduction, have been carried out. The dispersion of TiO2 on resin was carried out by mixing TiO2 that had been suspensed in ethanol (TiO2(et)) with resin, then continued with the ethanol evaporation at temperature 60-70 oC. The characterizations were carried out by using X-Ray diffraction (XRD), FTIR and Diffuse Reflactance UV (DR-UV) methods. Photoreduction process was executed in batch system, by irradiating mixture of Cu(II) solution and TiO2(et)/resin photocatalyst. The influences of photocatalyst mass, Cu(II) ion concentration, andirradiating time towards photoreduction result were also evaluated. The research results showed that TiO2(et)/resin dried at 60-70 oC does not destroy resin and TiO2 structure. Result of activity examination showed that TiO2(et)/resin photocatalyst has highest activity (94.52%) on Cu(II) ion photoreduction followed by TiO2/resin (91.44%) and TiO2 (67.58%). The increase of photocatalyst mass (5-50 mg), could improve the effectivness of the photoreduction, but further increase of mass (50-100 mg) could reduce it. A low Cu(II) concentration (10 mg/L) yielded effective photoreduction (93.44%), but for higher concentration (15-100 mg/L) decreased photoreduction effectivity (89.24- 86.41%). The irradiating time of 1-24 hours increased effectivness of Cu(II) ion photoreduction, but for longer irradiating than 24 hours, photoreduction effectivity was decreased

PENGARUH PENGKOMPOSAN LIMBAH ORGANIK SEBAGAI BAHAN PEMBUATAN PUPUK TERHADAP KANDUNGAN C, N, P DAN K DALAM PUPUK CAIR YANG TERBENTUK

Composting of organic waste including tofu wastewater, banana skins and goat rumen as raw materials for production liquid organic fertilizer has been carried out. The research consists of composting a single organic waste and as a mixture with or without of molasses addition. In this study the effect of adding molasses and composting time on the content of C, N, P and K in the liquid fertilizer produced were also studied. The results of this study indicate that the industrial tofu wastewater, banana skins and goat rumen contain C, N, P, K and ratio C/N that are lower than the standard requirements of organic fertilizer, so it can not be used directly as fertilizer, but has potential as materials for liquid fertilizer. Composting tofu wastewater, banana skins and goat rumen separately can reduce the content of C and N, but gives same P and K content, and results in C / N = 1-5, so the mixture has not been qualified as a fertilizer. Composting the mixture of tofu wasterwater, banana skins and goat rumen gives a product with C / N = 12.6, which qualifies as organic fertilizer. However, K content in the product is higher while the content of C, N, and P are lower than required, so that the liquid composting results are not qualified as a fertilizer. The addition of molasses on organic waste wether single and mixture can increase the effectiveness of composting which is marked with a C/N ratio of 10-25 and the increase of C, N, P and K content, so it qualifies as a fertilizer. The composting time longer than 21 days shows efective process that results in liquid which has ratio C / N = 10-20 that qualifies as a fertilizer

METHOD DEVELOPMENT FOR THE DETERMINATION OF IMAZALIL AND ITS METABOLITES IN WATER SAMPLES USING SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY � TANDEM MASS SPECTROMETRY

In this work, a sensitive and selective method for the determination of imazalil and its 5 selected metabolites in water samples using solid phase extraction (SPE) and liquid chromatography � tandem mass spectrometry (LC-MS/MS) has been developed. Three water matrices were used, i.e., deionised, surface and waste water. The extraction efficiencies of OASIS HLB, OASIS MCX, Strata X, C18 and C18 polar plus cartridges were checked in acidic condition. OASIS HLB was then chosen for further experiments due to the highest recoveries for all target compounds, yielded 97% to 101%. The performance of analytical instruments, i.e., high performance liquid chromatography-diode array detector (HPLC-DAD) and LC-MS/MS, to determine the target compounds were compared as well using fortification experiments. Results showed that LC-MS/MS detection gave higher sensitivity and selectivity for all target compounds in comparison with HPLC-DAD. The value of method detection limit (MDL) and method quantification limit (MQL) for both methods are at concentration of µg L -1 and ng L -1 for HPLC-DAD and LC-MS/MS, respectively. The evaluation of matrix effects from surface water samples analysed by SPE and LC- MS/MS showed there was an ion suppression phenomenon at low values, -1% to -7%, and thus, it could be neglected. The validation results of SPE and LC-MS/MS method consistently demonstrated the accuracy and precision to meet the acceptance criteria, the accuracy range, -30% to +20%, and the precision value � 20%. In addition, the applicability of SPE and LC-MS/MS method for screening analysis or identification of the target compounds was achieved in this work. Imazalil was found in all investigated waste water samples from waste water treatment plant (WWTP) Weddel and Steinhof, Germany, both influent and effluent at very low concentration, below the MQL of imazalil

INVESTIGATION OF ALTERNATIVE CHEMICAL OXIDATION METHODS FOR COD DETERMINATION AVOIDING DICHROMATE AND MERCURY

In chemical oxygen demand (COD) determination, according to the standard methods, K2Cr2O7 is used as an oxidant and Hg is used in order to inhibit interference of Cl-. K2Cr2O7 and Hg are characterized as toxic substances. In this study, Na2S2O8 and Mn(III) were used as oxidants and in order to inhibit Cl- interference, precipitation using Ag2SO4, removal using anion exchanger and oxidation using bismuthate were investigated. As reference substances for the COD method development, potassium hydrogen phthalate (PHP), glycine, glutamic acid, L-cystein, sodium acetate, and cellulose were used. Oxidation was conducted in the open and closed reflux system followed by COD determination using spectrophotometry or titrimetry. The results showed that precipitation with Ag2SO4 and oxidation with bismuthate could basically be applied in order to inhibit up to a concentration of 1000 mg Cl-/L. Anion exchanger as an alternative method for Cl- removal and Na2S2O8 as an alternative oxidant were found to be inappropriate for the COD test. Mn(III) was found to work in principle as an alternative oxidant to K2Cr2O7. Efficiency of the oxidation for some samples using Mn(III) was comparable to DIN 38409-41. In case of glycine, Mn(III) gave 103% oxidation recovery which was better than DIN 38409- 41 (34%). Combination between oxidation using Mn (III) and Cl- elimination with bismuthate showed a better oxidation method (average recovery rates for PHP COD of 99%) than with precipitation using Ag2SO4 (average recovery rates for PHP COD of <65%)

DISTRIBUTION AND TRANSLOCATION OF HEAVY METALS IN SOIL IRRIGATED WITH TREATED WASTEWATER IN BRAUNSCHWEIG

The study to investigate the distribution and translocation of heavy metals in the wastewater irrigated soils in Braunschweig has been carried out. The wastewater used for irrigation was the previously treated domestic and industrial wastewater from Braunschweig. The soil samples were taken from the Steinhof wastewater treatment plant (WWTP) area in the northwest of Braunschweig, Germany. The non-irrigated soil was also analyzed as a comparison. The soil fraction > 2 mm was excluded from analysis through sieving. All soil samples were analyzed for the pH values in 0.01M CaCl2 solution, grain size distribution (using wet sieving and settling methods), and the concentration of their aqua regia (3:1, v/v, HCl 32% to HNO3 65%) extractable elements. The concentration of aqua regia extractable elements was analyzed using ICP/OES instrument. The pH values of soil samples ranged from 4.9 to 6.8. The soil samples are dominated by sand fraction with the content in the range of 75 � 97%. The concentrations of heavy metals in the top soils of irrigated areas are generally higher than the concentrations of heavy metal in the reference areas, indicating the heavy metals enrichment on top soils due to the long term application of wastewater. There is a linear correlation between heavy metals (Al, Fe and Zn) and silt fraction. A second-order correlation was found between aqua regia extractable elements (Cd, Cu, Pb and Zn) and the organic content of the soil. There is also a linear correlation between inter-element such as Fe versus Al, Al versus Zn, Zn versus Pb, Sr, P and Ca and for P versus Ca and Pb. The enrichment factors (EFs) of some heavy metals calculated using Al as the normalizing element revealed that the EFs of heavy metal in soil samples are higher than those of the references. This indicated that the long-term application of wastewater has elevated the concentration of heavy metals in the soil

OPTIMASI WAKTU PEMANASAN DALAM ANALISIS ASPARTAM SECARA SPEKTROFOTOMETRI VISIBEL DAN PENERAPANNYA UNTUK PRODUK MINUMAN SERBUK BERKARBONASI

In this research, optimization of heating time on the aspartame analysis using ninhydrin reagent by means of Visible Spectrophotometry has been done. This method was applied to determine aspartame content in carbonated beverage powder product. The analysis was based on the reaction between aspartame with ninhydrin at pH 5, then heated and rested for 5.5 hours. The absorbance of resulting solution was measured at λ 570 nm. The result of this research showed that optimum heating time is 5 minutes. Calibration curve was linear in concentration range of 0- 0.019 M with regression equation y = 20.42x � 0.005 with a regression coefficient of 0.994 and limit of detection (LOD) and limit of quantification (LOQ) of 2.297�10-3 M and 0.008 M, respectively. Statistically, it could be stated that analytical method of aspartame could be applied to determine aspartame content in carbonated beverage powder sample and showed that the sample positively contained aspartame of 546 mg/g sample. Key words: Aspartame, ninhydrin, heating time, spectrophotometer