Optimum Salt Concentration Design of Low Salinity Water Injection in Tangai Structure at Sukananti Field

Enhanced Oil Recovery (EOR) come up with promising result to endure mature fields production performance and has been proven worldwide in many various methods. Recently, Low Salinity Water Injection evolves as a simply operation and relatively low cost EOR method with wide of research and implementation seem to be proved effective in the past decades. Some laboratory tests have indicated that injecting low salinity water can improve conventional waterflood performance by 5 – 20%. Hence, it introduces a promising idea that Low Salinity Water Injection should be implemented to mature fields in Indonesia for EOR activity. This paper will focus on determining the optimum salt concentration of injection water for low salinity water injection. Low salinity water injection in this study will be acted as a secondary recovery method. The production performance as a result of low salinity water injection was acquired by numerical simulation using tNavigatorTM Simulator. This simulation will be conducted in Tangai Structure at Sukananti Field, South Sumatera Basin, Indonesia with Talang Akar Formation reservoir target. The simulation is conduct with the constraint injection rate of 1,340 BWIPD. The low salinity water is designed by dilution of salt concentration from formation water with 18,000 ppm of concentration. In this case, the sensitivity of low salinity water, mainly amount of salt concentration design, will be conducted in the simulation consisting of using formation water as scenario’s base case and various low salinity water designs which will be limited until 10x of dilution (1,800 ppm). The result of this study concluded that Low Salinity Water Injection achieved more oil recovery than conventional waterflood did. This incremental is caused by wettability alteration due to of salt concentration changes which attract the clay minerals in reservoir through many complex mechanisms. The simulation result shows that injection water with 10x dilution (1,800 ppm) is chosen as an optimum salt concentration design, which gives the best result with gains additional oil recovery and recovery factor about of 118,8 MSTB and 4,9% respectively from a scenario by injecting formation water (18,000 ppm).

Seafood Processing Chitin Waste for Electricity Generation in a Microbial Fuel Cell Using Halotolerant Catalyst Oceanisphaera arctica YHY1

In this study, a newly isolated halotolerant strain Oceanisphaera arctica YHY1, capable of hydrolyzing seafood processing waste chitin biomass, is reported. Microbial fuel cells fed with 1% chitin and 40 g L−1 as the optimum salt concentration demonstrated stable electricity generation until 216 h (0.228 mA/cm2). N-acetyl-D-glucosamine (GlcNAc) was the main by-product in the chitin degradation, reaching a maximum concentration of 192.01 mg g−1 chitin at 120 h, whereas lactate, acetate, propionate, and butyrate were the major metabolites detected in the chitin degradation. O. arctica YHY1 utilized the produced GlcNAc, lactate, acetate, and propionate as the electron donors to generate the electric current. Cyclic voltammetry (CV) investigation revealed the participation of outer membrane-bound cytochromes, with extracellular redox mediators partly involved in the electron transfer mechanism. Furthermore, the changes in structural and functional groups in chitin after degradation were analyzed using FTIR and XRD. Therefore, the ability of O. arctica YHY1 to utilize waste chitin biomass under high salinities can be explored to treat seafood processing brine or high salt wastewater containing chitin with concurrent electricity generation.

Desulfotignum toluenicum sp. nov., a novel toluene-degrading, sulphate-reducing bacterium isolated from an oil-reservoir model column

A Gram-negative, sulphate-reducing bacterium (strain H3T) was isolated from an oil-reservoir model column. The new isolate was able to oxidize toluene coupled to hydrogen sulphide production. For growth, the optimum salt concentration was 1.5 % (w/v), the optimum pH was 7.2 and the optimum temperature was 34 °C. The cells were straight to slightly curved rods, 0.6–1.0 μm in diameter and 1.4–2.5 μm in length. The predominant fatty acids were C16 : 0, C16 : 1 ω7c and C17 : 0 cyclo, and the cells also contained dimethylacetals. Cloning and sequencing of a 1505 bp long fragment of the 16S rRNA gene showed that strain H3T is a member of the Deltaproteobacteria and is related closely to Desulfotignum balticum DSM 7044T. The G+C content of the DNA was 52.0 mol% and the DNA–DNA similarity to D. balticum DSM 7044T was 56.1 %. Based on differences in DNA sequence and the unique property of toluene degradation, it is proposed that strain H3T should be designated a member of a novel species within the genus Desulfotignum, for which the name Desulfotignum toluenicum sp. nov. is proposed. The type strain is H3T (=DSM 18732T=ATCC BAA-1460T).

Investigations on the Reduction of Molecular Oxygen on Polyphenol Oxidase-Modified Electrode

Polyphenol oxidase (PPO, E.C.1.10.3.1) from Nicotiana tobacum, PPO II, shows a different behavior from that of PPOs from other sources. A one-electron oxygen reduction on PPO II - Nafion modified glassy carbon electrode surface has been observed by square-wave voltammetry. The cathodic peak has been found to be proportional to the concentration of dissolved oxygen. The optimum salt concentration was 0.2 mol/l. The study of its dependence on pH (4-9) indicates that the reduction of oxygen is accompanied by a one-proton-transfer process. Temperature shows little influence on the cathodic peak. The electrode storage has also been studied to evaluate its stability.

Reduction by GA3 of Nacl-Induced Inhibition of Growth and Development in Suaeda ussuriensis

Seedlings of Suaeda ussuriensis were grown in soil with NaCl concentrations of 0.5, 1.0, 2.0 and 3.0% on a dry weight basis. The optimum salt concentration for growth and development was 1.0%. At 3.0% all seedlings died. Treatment with 10*5 �g/litre GA3 counteracted partly the growth inhibition, and the dry weight of plants increased 21.6, 2.2 and 19.4%, respectively, for soils with salt concentrations of 0.5, 1.0 and 2.0%. GA*3 increased the numbers of plants coming to flower in soil of salt concentration of 0.5 and 2.0%, by 40 and 20%, respectively, but had no effect on plant growth in a salt concentration of 1.0%.

THE FIRST TWO STEPS OF THE INVASION OF HOST CELLS BY BACTERIAL VIRUSES. II

At 37°C., the attachment of T1 virus to its host cell in solution containing 10–3 M CaCl2 or 10–2 M NaCl is extremely rapid (in the neighborhood of 100 per cent collision efficiency) and irreversible. At 1°C., the attachment rate is almost equally rapid but largely reversible. If a suboptimal concentration of the necessary ions is employed when T2 virus attaches to host cells, the resulting binding is largely reversible, even at 37°C. Reversible T2 attachment to host cells leaves the cell undamaged and capable of normal reproduction. Irreversible attachment results in death of the cell. Zn++ exercises a specific inhibitory action on the invasion of E. coli B by T1 virus. The virus can still attach to the host cell at a rate closely approximating the maximum value, but the reaction remains reversible and the cell is protected against permanent damage. The protective action of the Zn against T1 invasion is exerted through an action on the cell, rather than on the virus. Studies of the uptake of radioactive Zn65 show that cells become completely immune to T1 invasion when, on the average, 4 x 107 atoms of Zn have been taken up by each cell. Cells killed by ultraviolet irradiation still bind T1 at the maximum rate, but the reaction is reversible even when taking place at 37°C., in optimum salt concentration. The tryptophane-deficient mutant of T4 bacteriophage requires its specific cofactor for the initial step of attachment to the host cell. These experiments support the picture previously developed that virus invasion of host cells consists in an initial, reversible attachment whose properties are those to be expected from the operation of electrostatic binding forces. The step is followed by an enzymatic transformation which is irreversible, strongly temperature-dependent, and in the case of T1 virus, susceptible to inactivation by ultraviolet radiation. The resistance of mutant cells to specific bacteriophages is of two types, depending on whether the first or second of these steps is blocked.

Proteins in Fish Muscle.: I. Extraction of Protein Fractions in Fresh Fish

Methods for the extraction of protein from fish muscle have been studied. Using the Waring Blendor to obtain fine subdivision, up to 95 per cent of the fish muscle protein can be extracted with 5 per cent sodium chloride. Optimum pH for extraction was pH 7–9, and the optimum salt concentration 3 to 5 per cent. About 3 per cent stroma protein, collagen and elastin, was found in cod and haddock muscle. Myosin constituted about 75 to 80 per cent of the total protein. Globulin X, myogen, and myoalbumin made up about 20 per cent of the protein.

The Effects of Freezing on Marine Bacteria.: I. Quantitative Studies.

When marine bacteria were exposed to a moderate freezing temperature, −16 °C., for short periods, sea-water offered greater protection than broth media or distilled water. Reduction in number of bacteria was least severe in broth media of optimum salt-concentration and hydrogen ion concentration. During freezing in distilled water, transfer of bacteria from the crystallizing portion to the liquid part occurred. Old strains were more resistant to freezing, and previous cultivation at −3° produced more resistant strains. A higher percentage of cells were killed by freezing at lower freezing temperatures, by prolonged freezing, rapid freezing and repeated freezing. In truly super-cooled sea-water higher percentage reduction occurred than in frozen sea-water at −6.5° and −10°.