BIOSORPTIONOF Cr(lII) ION ON ALGAE Eucheuma spinosum BIOMASSA Biosorpsi Ion Cr(lll)pada Biosorben RumputLaut Eucheuma Spinosum

ABSTRACT Studies on biosorption and desorption of Cr(lll) on algae (Eucheuma spinosum) adsorbent have been carried out. These studies included determination of biosorbent acidity, optimum pH, contact time of biosorption, isoterm and biosorption capacity, and mechanisms of interaction between Cr(lll) and algae (E. spinosum) biosorben. Mechanisms of interaction were evaluated by sequential desorption of Cr(lll) on algae biosorben by using aquadest, 1M HCI and 0.05 M NazEDTA. The result showed that the total acidity of algae biosorbent was 4.15:i: 0.33 mmollg, the optimum pH was 3, and the optimum contact time was 20 min. Biosorption capacity of algae (E. spinosum) toward chromium (III) was 57.33 mglg. The highest desorption of Cr(lll) achieved when 1 M HCI was used, i.e. 51,01%, wheareas desorptions using aquadest and 0.05 M NazEDTA were relatively low, i.e. 2.07% and 2.38% respectively. This result indicates that the main interaction mechanism of Cr(lll) on algae was electrostatic attraction. Keywords: Biosorption, Cr(lll), Eucheuma Spinosu

BIOSORPTION OF Cr(III) ION ON ALGAE <i>Eucheuma spinosum</i> BIOMASSA

Studies on biosorption and desorption of Cr(III) on algae (Eucheuma spinosum) adsorbent have been carried out. These studies included determination of biosorbent acidity, optimum pH, contact time of biosorption, isoterm and biosorption capacity, and mechanisms of interaction between Cr(III) and algae (E. spinosum) biosorben. Mechanisms of interaction were evaluated by sequential desorption of Cr(III) on algae biosorben by using aquadest, 1 M HCl and 0.05 M Na2EDTA. The result showed that the total acidity of algae biosorbent was 4.15 ± 0.33 mmol/g, the optimum pH was 3, and the optimum contact time was 20 min. Biosorption capacity of algae (E. spinosum) toward chromium (III) was 57.33 mg/g. The highest desorption of Cr(III) achieved when 1 M HCl was used, i.e. 51,01%, wheareas desorptions using aquadest and 0.05 M Na2EDTA were relatively low, i.e. 2.07% and 2.38% respectively. This result indicates that the main interaction mechanism of Cr(III) on algae was electrostatic attraction.   Keywords : Biosorption, Cr(III), Eucheuma Spinosu

TEKNIK PENAMPUNGAN DAN FERMENTASI AIR KENCING SAPI BALI DI DESA DAUH YEH CANI, BADUNG MENJADI PUPUK ORGANIK RAMAH LINGKUNGAN

ABSTRACT The activity was carried out to put to use of the urine cattle bali with fermented technology. The activity of community servece was ccaried out at Dauh Yeh Cani village, Badung regency, on Suturday, 4 August 2007. The participants from the farmers group at Dauh Yeh Cani village. The demo plots was carried out at KUBE KMM. The material of a demo plots i.e. a removal by product (urine) with feces and than its were fermented.. The products made from the activity were liquied fertilizer organic (clean governunt). The participants were curious to follow all the activities and hope for the team Unud be able to came again with a news information. </em

Penentuan Kandungan Logam Pb dan Cr pada Air dan Sedimen di Sungai Ao Desa Sam Sam Kabupaten Tabanan

Research on the heavy metal content, Pb and Cr in water and sediment of Ao River in Sam SamVillage, Tabanan Regency have been carried out. Sample of water taken at 8 location per week during 4weeks, while sample of sediment only taken once at 8 location. Determination of metal content of Pb and Crconducted using destruction method with mixture of HNO3 dan HCl (3:1) and analysed with AbsorptionAtomic Spectrophotometer.The result showed that mean metal content of Pb and Cr in water of Ao river at the location aftertextile industry (location 5 until 8) from four times intake of samples have passed enabled boundarythreshold that is 0,03 mg/L for Pb and 0,05 mg/L for Cr. Mean Pb content in sediment at location 1, 2, 3, 4and 5 still under natural content while location 6, 7 and 8 over the natural boundary threshold. Meanwhile forthe Cr metal only at location 8 over the natural boundary threshold. The highest metal content of Pb and Cr insediment and water found at location 8 that is each of 0,496 mg/L and 0,213 mg/L for Pb and Cr in water and141,844 mg/Kg and 33,489 mg/Kg for Pb and Cr in sediment respectively

Laboratory Wastewater Treatment Using a Combination of Anaerobic Bioaccumulation Systems and Plant Biofiltration

Laboratory waste that is disposed of into the environment will have an impact on environmental pollution and threaten human health. Efforts to treat laboratory wastewater must be carried out. This research aims to analyze the effectiveness of Anaerobic Bioaccumulation Systems with sulfate reducing bacteria (SRB) in reducing heavy metals and sulfate ions as well as the effectiveness of Plant Biofiltration (PB) in reducing Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and heavy metals in laboratory wastewater compared to quality standards. In this research a plant biosystem which uses the principle of phytoremediation is used to reduce the heavy metal content in wastewater. This anaerobic reactor is cylindrical with r of 0.23 m and t of 0.93 m and has a volume of 1.5 m3. In this tank there is a SRB initial growth column with a volume 6.7 L. SRB media in the form of 30% compost fermentation solution, Postgate B nutrients with 10% sulfate added to the column. It stimulated with SRB seeds that had been isolated previously, then laboratory waste is added until it fills the column. After being acclimatized for 15 days, the laboratory wastewater began to flow slowly into Anaerobic Bioaccumulation System. The next stage is a plant filtration system in sized of basin 3 m x 1 .0 m x 1.0 m with of 4 vertical layers. The bottom layer consists of 20% limestone, 30% coral and 50% sand. The plant used is Sansevieria trifasciata. The research results showed that the SRB Anaerobic Bioaccumulation was effective in reducing heavy metals and sulfate ions by up to 80.6% with a residence time of 24 hours after growing SRB for 15 days PB is effective in reducing BOD, COD and heavy metal content to meet the specified quality standards with a residence time of 30 hours after plant acclimatization for 15 days. The combination of the SRB Anaerobic Accumulation and PB system worked effectively with a total residence time of 2.25 days, which was marked by a decrease in all test parameters to below the specified quality standards

Enhancement of the photostability and visible photoactivity of ZnO photocatalyst used for reduction of Cr(VI) ions

In this present study, the enhancement of ZnO stability toward photo-corrosion was conducted by incorporating onto natural zeolite (NZ), followed by improvement of the photocatalytic activity under visible light through doping Ag into ZnO/NZ. The prepared photocatalysts were characterized by using X-ray diffraction, ultraviolet diffuse reflection, surface area analyzer, and transmission electron microscope machines. The modified ZnO photocatalyst was examined for photoreduction of Cr(VI) under visible light through batch experiments. The research results reveal that ZnO was successfully incorporated in the zeolite, generating a larger surface area and higher photostability, thereby increasing its activity in the photoreduction of Cr(VI) under UV light. Furthermore, the doping Ag into the ZnO/NZ photocatalyst can narrow the band gap to 2.85 eV, greatly increasing the activity undervisible light. The enhancement of the ZnO–Ag/NZ activity under visible light in the photoreduction of Cr(VI) was controlled by Ag content, ZnO–Ag/NZ with medium Ag content (⁓10 mg g−1) showed the highest activity. The best photoreduction of Cr(VI) 10 mg L−1 in 20 mL of the solution, under visible light over ZnO–Ag/NZ containing 10 mg g−1 of Ag, could be reached within 10 h by 40 mg of the photocatalyst mass at pH 3.0, which is around ⁓60%