Tides Measurement and Tidal Analysis at Jakarta Bay

Tides observation conducted for these purposes such as real-time depth of water, determination mean sea level and other tidal datums to establish a system of tidal benchmarks and data for production of tide and tidal current predictions. Center for Marine and Coastal Mapping – Geospatial Information System used water level and tides data mainly to correct the water depth measurement to chart datum. This study uses sea level observation data conducted from 20th February 2018 until 4th April 2018 at Marina Batavia, Jakarta. This study found that tidal types at this location is mixed diurnal using formzahl number. Astronomical and shallow water possible constituent were derived from the harmonic analysis. Fourier analysis gives clearly visual interpretation in frequency perspective. Several constituents inseparable because of short duration records.

Iron in Well Water: Case Study in Dulalowo and Heledulaa Districts

This study aims to determine the iron content of water wells in Dulalowo and Heledulaa, Gorontalo City. Ten well water samples were taken randomly from five different wells in each district. Water samples at each well consist of top, middle, and bottom water. Determination of iron level using Atomic Absorption Spectrophotometer (AAS) at a wavelength of 248.33 nm. The results showed that the iron concentration of well water in Dulalowo was 0.030 (D1), 0.265 (D2), 0.224 (D3), 0.158 (D4), 0.149 ppm (D5). Meanwhile, iron levels in Heledulaa were 0.100 (H1), 0.039 (H2), 0.159 (H3), 0.198 (H4), and 0.235 ppm (H5). These results prove that the Fe content in the well water in the two districts is still fulfil the drinking water standard which is a maximum of 0.3 mg/L iron.

Influence of Different Carriers in Polymer Inclusion Membranes for Desalination of Seawater

Desalination of seawater using various polymer inclusion membranes was carried out. Polymer inclusion membrane (PIM) is known to have the highest stability, able to overcome liquid membrane instability and was placed in between two phases: the source phase is seawater and the receiving phase is the micro-filtered water. Determination of salinity levels in the feed phase and the receiving phase was carried out using a salinity meter, while membrane characterization was done using FTIR and SEM techniques. Polyvinyl chloride (PVC) based PIM membranes were prepared using different single and mixed synergtic carriers ratio of 1:1 viz. dibutyl ether, methyltrioctylammonium chloride (Aliquat 336), di-(2-ethylhexyl)-phosphate (D2EHPA), thenoyl trifluoroacetone (HTTA), tributyl phosphate (TBP) and eugenol (PE). The results showed the salinity value for single HTTA carriers had a greater salinity value in comparison to mixed carriers (HTTA:TBP; HTTA:Aliquat; D2EHPA:TBP; and D2EHPA:Aliquat) gave different salinity value towards the desalination process.