Preliminary evaluation of a natural surfactant extracted from Myrtus communis plant for enhancing oil recovery from carbonate oil reservoirs

Surfactants are among the materials used to improve water properties for injection into oil reservoirs, and reduce injection phase and crude oil interfacial tension (IFT). Recently, the interest in the use of natural surfactants has increased and is constantly on the rise to solve some challenges of using chemical surfactants such as incompatibility with the environment and the high cost. In this study, we have used aqueous extract of powdered leaf of Myrtus communis as an available source of natural surfactant. The extracted surfactant was characterized by TGA, 1H NMR and FTIR techniques. The surfactant efficiency was demonstrated by performing some experiments including IFT and injection of chemical slug and surfactant into carbonate plugs. The surfactant adsorption on carbonate rock was also studied. It was observed that this natural surfactant can reduce IFT to 0.861 mN/m at surfactant critical micelle concentration (CMC) of 5000 ppm. This minimum IFT was further reduced at optimum salinity and alkali. Finally, an increase of 14.3% oil recovery by surfactant flooding and 16.4% oil recovery by ASP slug injection containing NaOH alkali and partially hydrolyzed polyacrylamide (PHPA) polymer with 0.5 PV volume from carbonate plugs was achieved.

Correlation between Phase Behavior and Interfacial Tension for Mixtures of Amphoteric and Nonionic Surfactant with Waxy Oil

Phase behavior tests in the surfactant screening process for EOR applications remain one of the relatively convenient ways to design an optimum surfactant formulation. However, phase behavior studies are unable to provide quantitative data for interfacial tension, which is one of the parameters that must be considered when selecting surfactants for EOR. Several studies related to the prediction of interfacial tension through phase behavior testing have been carried out. In this paper, the Huh correlation was used to estimate the interfacial tension value based on phase behavior tests. It was found that the current form of the Huh correlation may be applied for the below-to-optimum salinity condition. Furthermore, the constants of the equation vary depending on the surfactant type and mixtures.

ANALISIS KECEPATAN JATUH SEDIMEN PADA SUNGAI CIBEET, JAWA BARAT

Cibeet River is one of the branch of the Citarum river in West Java province with a length of 101 km. Cibeet River is one of the rivers supplying water and sediment to the West Tarum irrigation channel or known as the Kalimalang. In this research, the sample used was in the form of mud taken at the Cibeet River Estuary. This research is focused on settling velocity which is a parameter for sedimentation in order to improve numerical modeling and conceptual understanding of sediment dynamics, especially mud. Sediment research is carried out in the Soil Mechanics laboratory and Hydraulics laboratory. Bottom withdrawal tube experiments were carried out using 5 types of salinity and 6 kinds of sediment concentrations. The purpose of the study was to obtain settling velocity and compare laboratory results with the Stokes law approach and compare the relationship between settling velocity with sediment concentration and salinity. The optimum salinity is obtained at 15 ‰, and the optimum sediment concentration at 4700 ppm with an average fall speed of 37,28 mm / s. The results from the laboratory are not in accordance with the Stokes law due to the influence of flocculation from the cohesive nature of the mud sediment, so that using the Stokes law approach cannot calculate the velocity of falling sediment on the mud. Keywords: concentration; salinity; sediment; settling velocity AbstrakSungai Cibeet merupakan salah satu anak sungai dari sungai Citarum di provinsi Jawa Barat dengan panjang 101 km. Sungai Cibeet merupakan salah satu sungai pemasok air dan sedimen ke saluran irigasi Tarum Barat atau dikenal sebagai Kalimalang. Pada penelitian ini, sampel yang digunakan berupa lumpur yang diambil di Muara Sungai Cibeet. Penelitian ini difokuskan pada kecepatan jatuh sedimen yang merupakan parameter untuk sedimentasi demi meningkatkan permodelan numerik dan pemahaman konsep dari dinamika sedimen terutama lumpur. Penelitian ini dilakukan di laboratorium Mekanika Tanah dan laboratorium Hidrolika, memakai bottom withdrawal tube, dilakukan dengan menggunakan 5 macam jenis salinitas dan 6 macam konsentrasi sedimen. Penelitian ini membandingkan antara hasil laboratorium dengan pendekatan yaitu hukum Stokes serta membandingkan hubungan antara konsentrasi sedimen dengan salinitas. Untuk salinitas didapat optimum pada saat 15‰, dan konsentrasi sedimen yang optimum pada saat 4700 ppm dengan kecepatan jatuh rata-rata 37,28 mm/s. Hasil dari laboratorium tidak sesuai dengan pendekatan hukum stokes dikarenakan adanya pengaruh flokulasi dari sifat sedimen lumpur yang kohesif, sehingga menggunakan pendekatan hukum stokes tidak bisa untuk menghitung kecepatan jatuh sedimen pada lumpur.

Early Study on Embryogenesis O.woworae at Different Salinities

Oryzias woworae is an endemic fish of Sulawesi. This endemic fish naturally had faced endangered illegal and unlawful capture, therefore it is needed to be protected and conserved by a cultivation system. This research aims to provide basic information related to the cultivation of O. woworae to know the optimum salinity of hatching media and its influence on the hatchability of eggs and the length of time hatching O. woworae. This research was conducted using experimental methods and presented descriptively. The treatment used in this study is 0 ppt, 2-4 pt, 6-8 ppt, 10-12 ppt. The results showed that O. woworae eggs can hatch in salinity 0 ppt until 10-12 ppt and the best salinity for the length of hatching time is treatment of 2-4 ppt which is 7th day 14 hours 20 minutes. Treatment 0 ppt, 2-4 ppt and 6-8 ppt can reach 100%. This can be concluded that the optimum salinity of the hatching rate of Oryzias woworae until 6-8 ppt, but in treatment 10-12 ppt hatchability only gets 80% as some embryos become shrinking. Hatchability per day shows the treatment of 2-4 ppt is the best treatment, on the 7th day as much as 40% and on the 8th day as much as 40%. The optimal salinity for hatching O. woworae eggs is 2-4 ppt treatment, salinity that can expedite the length of hatching time and produce hatching rate by 100%.

Peer Review jurnal AACL 2017

Salinity and calcium affect the osmoregulation activity. In the optimum salinity and calciumconditions, the energy for osmoregulation will be minimal thus allowing for more available energyportion for growth. This study aimed to determine the values of optimum salinity and the optimum calcium content range at optimum salinity which can improve the survival and growth of Indonesianshortfin eel Anguilla bicolor. This research was conducted in two stages: determination of optimum salinity which was done for seven days and determination of optimum calcium content range atoptimum salinity which was carried out for 14 days. The research design used was complete randomized design (CRD)

Growth and metabolic responses of orange spotted grouper Epinephelus coioides (Hamilton, 1822) fingerlings at different salinity regimes

A feeding trial was conducted for 60 days to delineate the effect of different salinities on growth and metabolic responses in fingerlings of orange spotted grouper Epinephelus coioides (Hamilton, 1822). The grouper fingerlings (N=1050; Av. wt. 2.0±0.01 g) were distributed equally into seven treatments of varying salinities viz., 5±1‰ (T1), 10±1‰ (T2), 15±1‰ (T3), 20±1‰ (T4), 25±1‰ (T5), 30±1‰ (T6) and 35±1‰ (T7) in triplicates. Fingerlings were fed with commercial diet containing 45% crude protein and 10% lipid. Results from the experiment concluded that growth performance of fingerlings of T4 group was better with minimum metabolic enzyme activity. The liver glycogen was significantly lower (p<0.05) in T4 group. Oxygen consumption rate (OCR) was recorded maximum at 15±1‰ and was significantly reduced for the fingerlings maintained at high salinity (p<0.05) from 20±1 to 35±1‰. Orange spotted grouper fingerlings maintained at salinity of 20±1‰ confirmed that, the animal spent less metabolic energy for maintaining the ionic balance at this optimum salinity compared to other salinities and it was reflected in better growth performance with minimum OCR and metabolic enzyme activities.

Start-Up of Anammox SBR from Non-Specific Inoculum and Process Acceleration Methods by Hydrazine

Biological nutrient removal from wastewater to reach acceptable levels is needed to protect water resources and avoid eutrophication. The start-up of an anaerobic ammonium oxidation (anammox) process from scratch was investigated in a 20 L sequence batch reactor (SBR) inoculated with a mixture of aerobic and anaerobic sludge at 30 ± 0.5 °C with a hydraulic retention time (HRT) of 2–3 days. The use of NH4Cl, NaNO2, and reject water as nitrogen sources created different salinity periods, in which the anammox process performance was assessed: low (<0.2 g of Cl−/L), high (18.2 g of Cl−/L), or optimum salinity (0.5–2 g of Cl−/L). Reject water feeding gave the optimum salinity, with an average nitrogen removal efficiency of 80%, and a TNRR of 0.08 kg N/m3/d being achieved after 193 days. The main aim was to show the effect of a hydrazine addition on the specific anammox activity (SAA) and denitrification activity in the start-up process to boost the autotrophic nitrogen removal from scratch. The effect of the anammox intermediate hydrazine addition was tested to assess its concentration effect (range of 2–12.5 mg of N2H4/L) on diminishing denitrifier activity and accelerating anammox activity at the same time. Heterotrophic denitrifiers’ activity was diminished by all hydrazine additions compared to the control; 5 mg of N2H4/L added enhanced SAA compared to the control, achieving an SAA of 0.72 (±0.01) mg N/g MLSS/h, while the test with 7.5 mg of N2H4/L reached the highest overall SAA of 0.98 (±0.09) mg N g/MLSS/h. The addition of trace amounts of hydrazine for 6 h was also able to enhance SAA after inhibition by organic carbon source sodium acetate addition at a high C/N ratio of 10/1. The start-up of anammox bacteria from the aerobic–anaerobic suspended biomass was successful, with hydrazine significantly accelerating anammox activity and decreasing denitrifier activity, making the method applicable for side-stream as well as mainstream treatment.

Larval development of nypa palm worm Namalycastis rhodochorde (Polychaeta: Nereididae)

Junardi, Anggraeni T, Ridwan A, Yowono E. 2020. Larval development of nypa palm worm Namalycastis rhodochorde (Polychaeta: Nereididae). Nusantara Bioscience 12: 148-153. Namalycastis intensive culture is still facing problems in mass production due to limited information on reproduction, especially in fertilization and production of larvae. The present research was designated to find out optimum salinity for fertilization and the production of nypa palm worm larvae (Namalycastis rhodochorde). Gamete samples were collected using a capillary glass tube inserted into ventro-lateral part of a body segment of a mature worm. Artificial fertilization was done by mixing the sperms and oocytes in a fertilization dish containing sterilized seawater as the medium. The larval development was observed until the benthic phase larvae (3-setigers). Fertilization was performed in medium salinity of 7-21‰ and water temperature of 25-29°C. The cleavage and larva stage occurred respectively within 28.20 to 58.67 minutes and within 72 to 80 hours after fertilization. The fertilization and larval development of N. rhodochorde were highly influenced by the medium salinity and temperature.