Saltwater Salinity Research Articles

Numerical investigation of saline gravity currents with different water depth and salinity based on the lattice Boltzmann method

In this paper, we used Lattice Boltzmann Method (LBM) to simulate the motion of saline gravity currents, considering different cases of water depth and salinity, aiming to evaluate the reliability of the LBM model and investigate the longitudinal properties of the gravity currents. The study in this paper was divided into two phases. The first phase explained the basic principles and the implementation process of the numerical model. By comparing the simulation results with laboratory experimental data, it was found that the simulation results were in good agreement with the laboratory experiments. The second phase of the study simulated the saline gravity currents with different water depths and salinities. It was observed that, due to the increasing density gradient, the front velocity of dense current increased with rising water depth and saltwater salinity, and the intensity of turbulence at the interface was enhanced.

Parallel dual‐cavity fiber‐optic F‐P salinity sensor based on hollow core fiber and ceramic ferrule

AbstractA parallel dual‐cavity fiber‐optic Fabry‐Perot (F‐P) salinity sensor based on hollow core fiber and a ceramic ferrule is proposed. The sensor is comprised of a F‐P reference cavity and a F‐P sensing cavity in parallel. The reference cavity is a closed cavity that is fusion spliced with a segment of single‐mode optical fiber (SMF) and a small piece of silica tube (ST). The sensing cavity is an open liquid cavity that is connected by a ferrule after inserting two single‐mode fibers into a ceramic core, facilitating the replacement of salt water. Variations in the salinity of salt water will affect the change in refractive index of optical path, and then change the output spectral structure. By precisely controlling the length of two cavities, the free spectral range (FSR) of the sensing cavity is approximately equal to the FSR of the reference cavity, resulting in the generation of the Vernier effect, which improves the sensitivity of the sensor to salinity greatly. From the experimental results, it can be seen that the sensor sensitivity to salinity reaches −0.78 nm/‰ (−3809.68 nm/RIU) in the salinity range from 35‰ to 20‰ at room temperature of 25°C, which is 10.8 times higher than the sensitivity of a single sensing cavity. The enhancement factor is generally consistent with theoretical analysis results.

Microbial Enhanced Oil Recovery (MEOR): Alternatif Peningkatan Produksi Migas di Indonesia

The need for petroleum is increasing along with the development of the industry, while the production results from the process of recovering oil from the reservoir by using primary recovery and secondary recovery are still very low so that it takes an advanced stage, namely tertiary recovery or, known as EOR. EOR is a method that produces oil production above 50%. EOR is an effort to increase oil production, so it is included in the IOR (Improved Oil Recovery) section. EOR consists of various applications, ranging from water injection, chemical injection, gases injection to microbiology injection. The stages in the injection of water and gas still leave oil trapped in the rocks in the reservoir. MEOR is one method that can be used to bring oil trapped in reservoir rocks to the surface. The effectiveness of the MEOR method is measured based on several parameters that is formation temperature, oil viscosity, permeability, saltwater salinity, water cut, API gravity crude oil, pH, pressure, residual oil saturation, porosity depth and bacterial content in the reservoir.

Study of the salinity effects on the cooling and desalination performance of an adsorption cooling cum desalination system with a novel composite adsorbent

Adsorption cooling cum desalination systems can produce cooling effect and fresh water simultaneously, powered by low-grade heat sources. This study aims to obtain the relationship between saltwater salinity and the cooling and desalination performance, and to develop a comprehensive numerical model that can accurately predict the cooling and desalination performance of an adsorption desalination system, with the use of a novel composite adsorbent having a high water uptake and thermal conductivity. A mathematical model has been developed, considering mass recovery process, preheating/precooling process and the effect of salinity on the physical properties of saltwater, which is verified by experiments on a prototype adsorption desalination system. It turns out that the simulation results match well with the corresponding experiment results. Under the operating conditions with the desorption temperature at 85 °C and evaporation temperature at 14 °C, experiment results show that the specific cooling power and specific daily water production values are 490 W/kg and 18 m3/tonne adsorbent/day for seawater. The trend of cooling and desalination performance change vs. saltwater salinity is clearly reported. Both experiment and simulation results demonstrate that the adsorption cooling cum desalination system adopting the composite adsorbent has a great potential to sustainably provide fresh water and cooling effect.

External Corrosion Of Pipe Riser API 5L X52 On Tidal Zone Of Offshore Production Platform

External corrosion on mature oil and gas field installation very challenging issues. External corrosion of pipeline riser on tidal zone is the most case for pipeline corrosion [2]. API 5L X52 is familiar pipeline for offshore oil and gas production facilities. Pipeline riser external corrosion on tidal zone have some consequences, time constrain related tidal cycle, production loss, oil spill impact to company reputation, costly maintenance. This research intended to find out effect of tidal cycle and salt water salinity to the rate and type of corrosion on API 5l X52 pipeline riser. Tidal cycle is modeling by wet and dry coupon on salt water. Corrosion rate measure by weight loss coupon. Corrosion product examine by XRD. Chloride contents and oxygen dissolve combination resulting maximum corrosion rate. Oxygen dissolve is main factor to corrosion on salt water. Maximum oxygen dissolve on salt water concentration 3.5% wt. On high salinity salt water corrosion rate depend oxygen dissolve [2]. Tidal cycle has impact to corrosion rate. General corrosion type happen on all coupon with corrosion product component Fe 2 O 3 , Fe 3 O 4 examined by XRD.

The Effect of Carbon and Zinc Electrodes Using Sea Water Electrolyte on Air Battery Power

The air-zinc battery uses oxygen from the atmosphere to produce electrochemical energy. After opening the battery into the air, oxygen diffuses into the cell and is used as cathode reagent. The air passes through the cathode to the active surface of the interior cathode in contact with the electrolyte liquid, namely sea water. On the active surface, the air cathode catalytically encourages the reduction of oxygen in the electrolyte liquid. This study aims to determine the effect of zinc anode on air batteries that are in direct contact with activated carbon as a source of electrical energy and find out the influence of electrolyte of seawater as an alternative source of electrical energy in air batteries. The research method uses Volta cells. Other advantages are safety and ecological benefits and low energy costs, as well as maximum power capability on environmentally friendly tolerance. In this study four salinity salinity was used, namely salinity of 3.56%, salinity of 3.99%, salinity 4.60% and salinity 5.02%. The results obtained are the highest voltage 1.144 Volt and the highest current of 4.85 mA is found in salt water salinity 5.02% .

Biofiltration Efficiency of Algae Spirogyra hyalina to Reduce Salinity of Sea Water

Algae Spyrogyra hyalina is one species of fresh water algae that is very easy to find in Indonesia. This species of algae known to have a lot of potential, which until now unknown. One potential that tried to explore in this research is the ability of these algae for decreasing the level of salt water salinity into fresh water. This research is an experiment with a completely randomized design (CRD), three treatments and three replications. Testing is done by performing algae arbsorbtion using three forms (powder, granule, and paper) with different biomass (1 g, 2 g, and 4gr). Preparations then coupled into a transparent pipe. The results showed the real effect of the decreased levels of salinity brine through the circuit. Filter with the powder forms with 4gr biomass has the highest salinity level reduction of 15%o, then the dosage form of granules with biomass 4gr with decreased 5.23%o and the third dosage form of paper with 1 gram of biomass with a decrease of 4.23%o.Forms with other biomass have a decrease in the salinity level of not more than 4%o. Preparations with powder form and 4gr biomass can be used to reduce the salinity level in the salt water.

Vertical leakage in sharp-interface seawater intrusion models of layered coastal aquifers

Summary Previous sharp-interface studies of seawater intrusion (SWI) adopt various approaches to the treatment of vertical fluxes in regions where alternating saltwater and freshwater are found in overlying aquifers. In this study, we compare dispersive modeling and sand-tank experiments to the results of sharp-interface models to evaluate assumptions regarding vertical fluxes in coastal multi-aquifer systems. The sand-tank experiments (one transient and two steady-state cases) consist of two coarse sand layers separated by a lower-permeability layer of fine sand. Vertical freshwater leakage in sharp-interface models is treated in one of three ways. Case 1: upward freshwater leakage flows only into freshwater in the aquifer above, bypassing any overlying saltwater; Case 2: no upward freshwater leakage occurs if there is overlying saltwater; Case 3: freshwater leaks into any overlying saltwater without modifying the saltwater salinity. Sharp-interface models over-predicted the toe position of the saltwater wedge in both the experiments and numerical models (regardless of the vertical leakage assumption), in agreement with previous studies. Nonetheless, Case 1 produced improved prediction of the sand-tank results relative to Cases 2 and 3. Freshwater leakage fluxes in areas where the interface was absent were reasonably well represented by all three sharp-interface leakage assumptions, compared to those of the dispersive model. In regions where saltwater overlies freshwater, the upward freshwater fluxes predicted by dispersive modeling were found to be consistently closest to the upward freshwater flux of Case 1, compared to Cases 2 and 3. Saltwater-to-saltwater leakages from the dispersive models were poorly represented by the sharp-interface models. Vertical flux assumptions were then evaluated for idealized field-scale situations, and Case 1 again best matched the dispersive modeling results. Streamlines from dispersive modeling show that upward freshwater leakage tends to flow around and bypass overlying saltwater. This matches optimally the assumption of Case 1. We conclude that Case 1 is the ideal approach to the treatment of upward freshwater fluxes in sharp-interface models of multiple-aquifer systems, whereas Cases 2 and 3 may create unrealistic SWI predictions, especially for situations where overlying aquifers are separated by a layer of low conductance.

주정을 이용한 멸치액젓의 탈염공정 및 품질특성

본 연구에서는 시판 멸치액젓에 주정을 일정한 비율로 첨가하여 소금의 용해도를 낮춤으로서 소금을 석출시키는 탈염방법을 활용하여 저염 멸치액젓의 제조공정을 확립하고자 하였다. 또한 시판 멸치액젓과 주정을 활용하여 탈염처리 한 저염 멸치액젓의 품질 특성을 비교하기 위해 일반성분, 총질소, 아미노태 질소, 대장균 및 아미노산 함량을 비교분석 하였다. 시판 멸치액젓에 대해 주정의 첨가량이 증가할수록 멸치액젓의 염도는 낮아지는 경향을 보였다. 즉, 멸치액젓 100 mL에 대해 주정을 각각 100% 및 300%(v/v)를 첨가한 경우에 멸치액젓의 염도는 14.3% 및 10.3%를 나타내었다. 이와 같은 현상은 염도 23%인 식염수 용액의 실험에서도 같은 경향을 보였다. 탈염처리 한 멸치 액젓의 총질소 함량은 1.20%이었고, 아미노태 질소 함량은 784.03 mg/100 g으로, 시판 멸치액젓보다 높은 함량을 나타내었다. 시판 멸치액젓과 탈염처리 한 저염 멸치액젓의 주요 총아미노산은 glutamic acid, alanine, lysine 및 leucine이었고, 필수아미노산의 함량은 탈염처리 한 멸치액젓에서 높게 나타났다. 또한, 시판 멸치액젓과 탈염처리 한 저염 멸치액젓의 주요 유리아미노산은 공통적으로 glutamic acid, leucine, alanine, valine, lysine 및 isoleucine 이었다. 이상의 결과에서 주정을 이용하여 소금을 원하는 농도만큼 특별한 장비없이 효과적으로 제거할 수 있는 멸치액젓의 탈염공정을 확립할 수 있었다. 또한 주정을 사용하여 멸치액젓을 탈염하는 방법은 총질소, 아미노태 질소 함량 및 아미노산 함량에 긍정적인 영향을 주어 맛을 향상시켜 줄 수 있을 것으로 기대되며, 본 연구의 결과로 저염 멸치액젓 상품화 연구의 기초자료로 활용 및 인류 보건향상에 크게 기여할 것으로 전망된다. To establish a new manufacturing process of low-salted fermented anchovy sauce, commercial fermented anchovy sauce with 23% NaCl was desalted using a spirit. The proximate composition, total nitrogen, amino nitrogen, Escherichia coli, and total and free amino acid contents were analyzed to evaluate the quality characteristics of commercial salted fermented anchovy sauce (CFAS) and low-salt fermented anchovy sauce by desalting processing (LFAS). The salinity of saltwater and fermented anchovy sauce decreased with an increase in the spirit added to 23% NaCl saltwater and 23% NaCl commercial fermented anchovy sauce. The total nitrogen and amino nitrogen contents were higher in LFAS than in CFAS. The major amino acids that were commonly found in CFAS and LFAS were glutamic acid, alanine, lysine and leucine. Basic data were provided for commodification research on low-salt fermented anchovy sauce, which is very important for the diet of humans.

Miniaturized multi-sensor for aquatic studies

We have developed and fabricated a multi-sensor chip for fisheries’ research and demonstrated the functionality under controlled conditions. The outer dimensions of the sensor chip are 3.0 × 7.4 × 0.8 mm3 and both sides of the chip are utilized for sensors. Hereby a more compact chip is achieved that allows for direct exposure to the seawater and thereby more accurate measurements. The chip contains a piezo-resistive pressure sensor, a pn-junction photodiode sensitive to visible light, a four-terminal platinum resistor for temperature measurement and four conductivity electrodes for the determination of the salinity of saltwater. Pressure, light intensity, temperature and salinity are all essential parameters when mapping the migration route of fish. The pressure sensor has a sensitivity of S = 1.44 × 10−7 Pa−1 and is optimized to 20 bar pressure; the light sensor has a quantum efficiency between 52% and 74% in the range of visible light. The temperature sensor responds linearly with temperature and has a temperature coefficient of resistance of 2.9 × 10−3 K−1. The conductivity sensor can measure the salinity with an accuracy of ±0.1 psu. This is all together the smallest and best functioning fully integrated MEMS-based multi-sensor made to date for this specific application. However, each single-sensor performance can be optimized by introducing a considerably more complicated process sequence. In this paper, a new simpler process for integrating the four sensors on one single chip is presented in details for the first time. Further, an optimized performance of the individual sensors is presented.

해안대수층에서 담수-염수 경계면 형성에 영향을 미치는 조건에 대한 실험적 연구

해안대수층의 염수침투에 의한 담수-염수 경계면 특성을, 가로 140 cm, 세로 70 cm, 두께 10 cm 의 직사각형 모래수조 모형을 이용하여 모의하였다. 대수층 모형의 특성과 염수의 염도에 따른 총 31가지의 실험을 수행하였으며, 위치흐름 해석법을 유도한 Glover (1959)의 이론식과 호도그래프를 이용한 Henry (1959) 해석식 및 위치흐름 해석법을 이용한 Strack (1976)의 해석해 결과와 비교하였다. 대수층의 수리전도도, 해수의 염도, 그리고 해안가 지표경사에 따른 담수-염수 경계면의 위치와 기울기를 모의하였다. 다공질매체의 수리전도도와 해수의 염도가 높을수록 평형을 이루려는 담수-염수의 수위비(<TEX>$H_F/H_S$</TEX>)가 높아지고, 이에 따라 경계면이 염수조 방향으로 이동하였다. 또한 염수조 방향의 모래사면의 경사가 급해질수록 경계면의 기울가가 완만하게 형성되었다. Saltwater intrusion in coastal aquifer was investigated using a laboratory model. Salt-wedge profiles were reproduced in a porous media tank 140 cm long, 70 cm high, and 10 cm wide. The experiments were performed with various conditions of porous media hydraulic conductivity, salinity, and ground surface slope to assess relationships on salt wedge location and inclination. Salt-wedge profiles induced by saltwater intrusion were observed in porous media equilibrium state, and compared with previously derived formulas of the Glover (1959), Henry (1959) and Strack (1976). It was found that salt-wedge shape and formations were affected by the water level ratio (<TEX>$H_F/H_S$</TEX>) due to high hydraulic conductivity, saltwater salinity and ground surface slope. High <TEX>$H_F/H_S$</TEX> of porous media having high hydraulic conductivity shifted the saltwater interface toward the saltwater reservoir. Increasing surface slope of the porous media caused the salt-wedge profile inclination to decrease. Saltwater salinity also contributed to the location of saltwater interface, yet the impact was not more significant than hydraulic conductivity.