Water Salt Concentration Research Articles

Response of Tomato Growth-Development and Soil Salinization to Irrigation Water Salt Contents and Na:Ca Concentration Ratios

Response of Tomato Growth-Development and Soil Salinization to Irrigation Water Salt Contents and Na:Ca Concentration Ratios

Desalination Plant Performance Prediction Model Using Grey Wolf Optimizer Based ANN Approach

The present era of advances in desalination plants revolves around the involvement of artificial intelligence techniques in ameliorating their modeling and operational performance. Among the two objectives, an accurate modeling of the plant&#x2019;s behavior may certainly help the design engineers to operate the plant in more stable and controlled operating conditions so as to achieve higher plant efficiency. Furthermore, this helps eliminate the risk to the operator&#x2019;s life and reduces production time, energy, and money. From the literature, it is observed that Artificial Neural Network (ANN) has been the most extensively used approach for modeling and simulation of the desalination plant. However, ANN has the concept of biases and weights updation for better prediction and accuracy of the predicted model, but the conventional methods do not yield desirable results. So, the updation of biases and weights using optimization algorithms is preferred in the literature. Therefore, this paper presents the Grey Wolf Optimizer based ANN (GWO-ANN) approach for desirable prediction and accuracy of models. Further, six models (GWO-ANN Model-1 to Model-6) are proposed to more accurately predict the Reverse Osmosis (RO) desalination plant&#x2019;s performance. For this investigation, we have considered four experimental inputs (feed water salt concentration, condenser inlet temperatures, evaporator inlet temperatures, and feed flow rate) and one output (permeate flux). The simulation results predict output performance in quite proximity to the experimental datasets. The simulated hybrid GWO-ANN models (best of best results of GWO-ANN Model-2: <inline-formula> <tex-math notation="LaTeX">$\text{R}^{2} \,\,=98.9$ </tex-math></inline-formula>&#x0025;, Error &#x003D; 0.007) show superior results than the reported results from the existing Response Surface Methodology (RSM) (<inline-formula> <tex-math notation="LaTeX">$\text{R}^{2} \,\,=98.5$ </tex-math></inline-formula>&#x0025;, Error &#x003D; 0.100) and ANN models (<inline-formula> <tex-math notation="LaTeX">$\text{R}^{2} =98.8$ </tex-math></inline-formula>&#x0025;, Error &#x003D; 0.060) and other PSO-ANN Model (<inline-formula> <tex-math notation="LaTeX">$\text{R}^{2} \,\,=96.3$ </tex-math></inline-formula>&#x0025;, Error &#x003D; 0.025) and GA-ANN model (<inline-formula> <tex-math notation="LaTeX">$\text{R}^{2} =98.7$ </tex-math></inline-formula>&#x0025;, Error &#x003D; 0.008). This research exemplifies the involvement of superior nature-inspired intelligent techniques in this modern era to further enhance the savings in production time, energy, and investment of desalination plants.

Organic fertigation system in saline‐sodic soils: A new paradigm for the restoration of soil health

AbstractA continuous decline in soil organic C (SOC) and an increase in salt‐affected areas are a challenge to future sustainability. We searched on the scientific databases of Web of Science, Scopus (Elsevier) database, and Google. We reviewed 101 studies of the last 25 yr with the following keywords: drip irrigation, fertigation system, liquid biochar, liquid organic, organic fertigation, saline‐sodic soils, and salinization. Our objectives were to identify knowledge gaps to direct future organic research and assess the effect of organic amendments on meeting the plant's N, P, and K requirements in saline‐sodic soils. The review showed that organic fertigation systems reduce salt concentration in irrigation water and inhibit glutamine synthetase by N‐fixing diazotrophs. The system increases photosynthetic activities in plants, microbial biomass C, bacterial colonization, plant–mycorrhizal association, and phospholipid‐derived fatty acids from microbes. It increases essential soil nutrients, including SOC; increases salt/water stress tolerance; and reduces Na+ ion toxicity in plants by regulating abscisic acid pathways in saline‐sodic soils. It creates a conducive environment for phosphatase, dehydrogenase, urease, protease, α‐amylase, and gibberellins. This review sketches the role of silicic acid, salicylic acid, and liquid organics in plant growth mechanisms: enhanced photosynthesis, increased salt/water tolerance, and reduced Na+ toxicity. It suggests novel strategies to develop a task force to promote a community–corporate farming system to adopt cost‐effective green technologies for bioresource regeneration, diverse market production, and social capital generation. We develop a synergy between organic fertigation system and community–corporate farming to bring much‐needed agricultural sustainability.

Statistical Model for Predicting Salinity of Water at Doho 1 Irrigation Scheme in Busia.

The concentration of salts in water or salt affects crop yields to a good extent. Irrigation salinity can be controlled by various methods including modelling. Therefore, this study aimed at designing a model for predicting the salinity of the water at the Doho Irrigation Scheme in Butaleja district, eastern Uganda for better rice growing. This study used the different water chemical parameters from the different sites of the scheme, where water samples were collected and measured in the laboratory. A multivariate regression method was used to model water salinity through the Electrical Conductivity as the dependent variable and other water chemical parameters like potassium (K), Sodium (Na), pH and Calcium (Ca) were used as independent variables. A non-linear statistical model was derived from the chemical results of the irrigation scheme, presented and validated by applying it on the water samples that were not used during the design of the model. The model measured salinity levels and can be used to determine which water chemical levels are good for rice growing in Doho and other similar situations. Hence, the model can be used to improve food quality and quantity as required in the food production goal

Growth and yield of beet irrigated with saline water in different types of vegetable mulching

ABSTRACT Vegetal mulching can mitigate the harmful effects of salts present in irrigation water. This study aimed to evaluate the effect of irrigation water salinity and mulching on the growth and yield of beet crops. The experiment was conducted in a greenhouse at Redenção, Ceará State. The experimental design was completely randomized in a 2 × 4 factorial scheme, with five replicates, composed of two levels of electrical conductivity of irrigation water - ECw: tap water - 0.3 dS m-1 and saline solution - 5.8 dS m-1; and four types of mulching (rice hulls, carnauba bagana, crop residues, and a control treatment without soil cover). The use of vegetal mulching, mitigated the effects of irrigation with saline water on the variables plant height, leaf area, stem diameter, and tuberous root. The increase of the salt concentration in irrigation water negatively affected the number of leaves, length of the tuberous root, and yield. But, it increased the soluble solids in the beet crop.

Chemical role of α-tocopherol in salt stress mitigation by improvement in morpho-physiological attributes of sunflower (Helianthus annuus L.)

Elevated concentrations of salts in soil and water represent abiotic stresses. It considerably restricts plant productivity. However, the use of alpha-tocopherol (α-toc) as foliar can overcome this problem. It can improve crop productivity grown under salinity stress. Limited literature is documented regarding its optimum foliar application on sunflower. That’s why the need for the time is to optimize α-toc foliar application rates for sunflower cultivated in salt-affected soil. A pot experiment was performed to select a better α-toc foliar application for mitigation of salt stress in different sunflower cultivars FH (572 and 621). There were 2 levels of salts, i.e., control (no salt stress) and sodium chloride (120 mM) and four α-toc foliar application (0, 100, 200, and 300 mg L−1). Results showed that foliar application of 100 mg/L- α-toc triggered the remarkable increase in fresh shoot weight, fresh root weight, shoot, and root lengths under salinity stress in FH-572 and FH-621 over 0 mg/L- α-toc. Foliar application of 200 mg/L- α-toc was most effective for improvement in chlorophyll a, chlorophyll b, total chlorophyll and carotenoids compared to 0 mg/L- α-toc. Furthermore, an increase in A was noted in FH-572 (17%) and FH-621 (22%) with α-toc (300 mg L−1) application under saline condition. In conclusion, the 100 and 200 mg/L- α-toc are the best application rates for the improvement in sunflower FH-572 and FH-621 growth, chlorophyll contents and gas exchange attributes. Further investigations are needed to select a better foliar application rate between 100 and 200 mg/L- α-toc at the field level under the different agro-climatic zone and soil types.

Laboratory and Numerical Study of Saltwater Upconing in Fractured Coastal Aquifers

This study investigated the saltwater upconing mechanism in fractured coastal aquifers. Head-induced saline intrusion was initiated into three narrow sandbox aquifers containing individual horizontal discontinuities placed on different positions. Subsequently, using a peristaltic pump, freshwater was abstracted from the aquifers’ center, triggering saltwater upconing. Progressively larger pumping rates were applied until critical conditions, resulting in the wells’ salinization, were achieved. Advanced image analysis algorithms were utilized to recreate the saltwater concentration fields and quantify the extent of the saline wedges with a high accuracy. A numerical model was successfully employed to simulate the laboratory results and conduct a comprehensive sensitivity analysis, further expanding the findings of this investigation. The impact of the fractures’ length, permeability and position on the upconing mechanism was identified. It was established that the presence of high permeability discontinuities significantly affected aquifer hydrodynamics. The conclusions of this study could constitute a contribution towards the successful management of real-world fractured coastal aquifers.

Gas exchange and leaf area of banana plants under salt stress inoculated with growth-promoting bacteria

ABSTRACT Banana orchards in arid and semiarid regions require the use of irrigation. However, the presence of high concentration of salts in water can impair the development of plants, requiring the evaluation of new technologies to mitigate the effects of stress. The objective of this study was to evaluate gas exchange and leaf area in banana seedlings of the cultivar Prata Catarina inoculated with strains of Bacillus spp. under different electrical conductivities of irrigation water. The experiment was carried out in a greenhouse at Embrapa Tropical Agroindustry, Fortaleza, Ceará state, Brazil. The design used was in randomized blocks, in a 4 × 4 factorial scheme, with the first factor being the inoculation treatments: without any application; slow-release fertilizer; Strain 186 and Strain 109, and the second factor being the electrical conductivity of irrigation water (0.5; 1.5; 3.0; 4.5 dS m-1), in five blocks and each plot consisting of three plants. The electrical conductivity of irrigation water negatively influenced the gas exchange of banana cv. Prata Catarina in the vegetative stage, during the 89 days of cultivation. The Bacillus spp. strains 186 and 109 did not improve the gas exchange and leaf area of plants under salinity conditions.

Exploring the Major Climate-smart Agricultural Practices for Dry Season Crop Production in Salinity Affected Fallow Land in the Coastal Areas of Bangladesh

The landmasses of the coastal areas of Bangladesh still remains under-utilized, thus cropping intensity is much less than the national average. Most areas remain fallow during dry (rabi) season from December to May due to presence of higher concentration of salts in soil and water, and scarcity of suitable irrigation water. Available adaptation options or technologies are not capable to solve these problems at all. Nevertheless, the areas receive a lot of water from monsoon rain, most of that rainwater is drain-out as surface runoff. The present study results suggest that the use of harvested rainwater and conservation agriculture either in combination or alone could mitigate the problem for bringing huge areas under crop cultivation. The public social safety net programmes such as cash-for-work, food-for-work etc. can be deployed for excavating or re-excavating the abandoned coastal ponds, ditches or canals for storing rainwater. Salt-, drought- and/or heat-tolerant crop varieties with short life span can also be cultivated to get the better results. Early plantation or growing crops with early-maturing varieties can ensure safer harvest in ahead of stress arrives. The avenues have immense potential as climate-smart practices for growing crops preferably non-rice crops during dry season in vast fallow land that will not only ensure food security for coastal people but could turn the entire southern Bangladesh as a food surplus zone. The findings refer the broad recommendation, therefore, specific research works based on the locations and resources available are necessary.

Analysis of Compositions of Flowback Water From Marcellus Shale Wells by Utilizing Data Mining Techniques

Abstract Volume and salt concentrations in Marcellus flowback water depend on geology, drilling and completions, stimulation and flowback operations. Recent studies include evaluations of geochemical origins based on the compostition concentrations, flowback sampling analysis and numerical studies. However, an in-depth understanding of chemical compositions as well as the changes of compositions is still needed. In this paper, we will first review the literature related to flowback water in Marcellus shale gas wells to fully understand the chemistry, geochemistry, and physics governing a fracture treatment, shut-in, and flowback. We will then gather all public and in-house flowback data, named as 3-week or 3-month flowback in this work, to build a data set of flowback water compositions. After data screening, we will then analyze this database using four different methods: geographical changes over time, linear regression, clustering, and multi-variable analysis. New understandings such as the magnitude and prevailing trends of concentrations for target constituents as well as the correlations among flowback compositions, the differentiation between early and late-time flowback water were obtained and explained on the basis of geochemistry and physics. This helps production companies and other stakeholders to better manage and reuse waste water for energy production.

PEMANFAATAN TEKNOLOGI THERMAL ENERGY STORAGE NON-MEKANIK SEBAGAI PENGERING BAHAN PANGAN SINGKONG

A drying machine is a machine that is used to dry some food or product. The process of heating can be used to preserve some products because drying reduces moisture content in the product and bacterial can’t live without water. Solar pond system will use for the machine which caught and trap the heat from the sun. The fluid in a pond of solar pond system is saltwater and the salinity will be varied. The variation of saltwater will be 3.5%, 5%, and 7%. In the solar pond system, some coils will circulate the water towards the cabin. The coil is made of copper pipe which has a length of 20.5 meters. This coil serves as a heat exchanger charged with the heat exchange process in the solar pond system. The water in this coil is circulated by a water pump. Water is circulated to the heat exchanger which is just below the cabin. The product used is 500 grams of cassava. Cassava is dried with the skin peeled and sliced about 2 mm thick. From the experiments that have been done obtained the best saltwater concentration is 7% with a tub temperature lower by 40 °C, the cabin temperature reaches 34.1 °C, and the water reduced of product weight by 210 grams. The COPactual heating average obtained by this machine is 1,15 and the COPcarnot heating average obtained by this machine is 29,80. The efficiency average that obtained by this machine is 3,77%.

Resistivity characteristics of soil saturated with variation of salt water-fresh water mixture

Peat soil has a specific physical character if compare with the other sediments. It has amount of organic matter and has relatively porosity and permeability. This preliminary research is to predict the salt water content in the soil and peat soil aquifer later on. This research is to investigate the resistivity characteristic of peat soil saturated with variation of salt water-fresh water mixture. Six undisturbed soil and peat soil samples were taken from difference sites in the coastal area. The soil and peat soil samples then saturated with difference amount of salt-fresh water mixture. The resistivity measurement then was measured to the soial and peat soil saturated with the salt-fresh water mixture. The result show that the resistivity decreases drastically as the increasing of a little amount of salt water in the salt-fresh water mixture.

Evaluating the impacts of saline water irrigation on soil water-salt and summer maize yield in subsurface drainage condition using coupled HYDRUS and EPIC model

Field experiment combined with numerical simulation is an efficient approach for evaluation the effects of saline water irrigation on soil water-salt movement, crop growth and water productivity. In this study, HYDRUS model was coupled with EPIC module to evaluate the effects of saline water irrigation on soil salinity and grain yield under subsurface drainage condition. Two years’ field experiment data collected in lysimeters of summer maize irrigated with water of two different levels of salinity under different subsurface drain depths was used to calibrate and validate the coupled model. The coupled model was then adopted to evaluate the effects of salinity stress on evaporation, transpiration and water productivity (WP) and of long-term saline water irrigation on soil salinity and grain yield under subsurface drainage. Results indicated that simulated values of soil water-salt content, subsurface drainage amount and concentration, grain yield and evapotranspiration (ET) were in good agreement with observed values. Transpiration and WP were reduced by salinity stress, while evaporation was sensitive to drain depth. Soil salinity evidently increased when irrigation water salinity was higher than 4.0 dS m−1 in each simulated year under drain depth of 80 cm. Grain yield maintained at around 7600 kg ha−1 when water salinity is 4.4 dS m−1 under drain depth of 80 cm, and decreased with higher water salinity across all simulated years. There were significant exponential relationships between soil salinity, grain yield and irrigation water salinity in the long-term simulation. Thus, the appropriate irrigation water salinity should be 4.0–4.4 dS m−1 under subsurface drain depth of 80 cm in the present study. The combined application of saline water irrigation and subsurface drainage should be given more attention for long-term soil salinity and grain yield management in the future.

The assessment of emerging data-intelligence technologies for modeling Mg+2 and SO4−2 surface water quality

The concentration of soluble salts in surface water and rivers such as sodium, sulfate, chloride, magnesium ions, etc., plays an important role in the water salinity. Therefore, accurate determination of the distribution pattern of these ions can improve better management of drinking water resources and human health. The main goal of this research is to establish two novel wavelet-complementary intelligence paradigms so-called wavelet least square support vector machine coupled with improved simulated annealing (W-LSSVM-ISA) and the wavelet extended Kalman filter integrated with artificial neural network (W-EKF- ANN) for accurate forecasting of the monthly), magnesium (Mg+2), and sulfate (SO4−2) indices at Maroon River, in Southwest of Iran. The monthly River flow (Q), electrical conductivity (EC), Mg+2, and SO4−2 data recorded at Tange-Takab station for the period 1980–2016. Some preprocessing procedures consisting of specifying the number of lag times and decomposition of the existing original signals into multi-resolution sub-series using three mother wavelets were performed to develop predictive models. In addition, the best subset regression analysis was designed to separately assess the best selective combinations for Mg+2 and SO4−2. The statistical metrics and authoritative validation approaches showed that both complementary paradigms yielded promising accuracy compared with standalone artificial intelligence (AI) models. Furthermore, the results demonstrated that W-LSSVM-ISA-C1 (correlation coefficient (R) = 0.9521, root mean square error (RMSE) = 0.2637 mg/l, and Kling-Gupta efficiency (KGE) = 0.9361) and W-LSSVM-ISA-C4 (R = 0.9673, RMSE = 0.5534 mg/l and KGE = 0.9437), using Dmey mother that outperformed the W-EKF-ANN for predicting Mg+2 and SO4−2, respectively.

Mixing in the Tyrrhenian Interior Due to Thermohaline Staircases

Thermohaline staircases are a well-known peculiar feature of the Tyrrhenian Sea. Generated by extensive double diffusion processes fueled by lateral intrusions, they are considered to be the most stable of all the staircases that have been detected in the world ocean, seeing their persistence of more than 40 years in the literature. Double diffusion leads to efficient vertical mixing, potentially playing a significant role in guiding the diapycnal mixing. The present study investigates this process of mixing in the case of the Tyrrhenian staircases by calculating the heat and salt fluxes in their gradient zones (interfaces) and the resulting net fluxes in adjacent layers using hydrological profiles collected from 2003 to 2016 at a station in the heart of the basin interior. The staircases favor downward fluxes of heat and salt, and the results of the calculations show that these are greater where temperature and salinity gradients are also high. This condition is more frequently encountered at thin and sharp interfaces, which sometimes appear as substructures of the thicker interfaces of the staircases. These substructures are hot spots where vertical fluxes are further accentuated. Due to the increasing salt and heat content of the Levantine Intermediate Water (LIW) during the observation period, a rise in the values of the fluxes was noted in the portion of the water column below it down to about 1800 m. The data furthermore show that internal gravity waves can modulate the structure of the staircases and very likely contribute to the mixing, too, but the sampling frequency of the time series is too large to permit a proper assessment of these processes. It is shown that, at least during the period of observation, the fluxes due to salt fingers do not reach the bottom layer but remain within the staircases.

Pathogenic and Spoilage Causing Microorganisms Associated with Traditional Seafood Product Jaadi Manufactured in Southern and Western Coastal Belt of Sri Lanka

Aims: The objective of this study was to investigate on microbial related food safety issues and microorganisms associated with the production of Sri Lankan traditional seafood Jaadi.&#x0D; Place and Duration of Study: Food Technology Section, Industrial Technology Institute, Colombo, Sri Lanka, between December 2013 to April 2016.&#x0D; Methodology: Seven Jaadi processing centers along the Southern and Western coastal belt of Sri Lanka were evaluated for its compliance to food safety, in terms of environment, processing techniques, hygiene and sanitation, physiochemical and microbiological quality of the final product. &#x0D; Samples drawn from all sites were analyzed for its water activity, salt content, pH and microbiological quality. Microorganisms associated with Jaadi production were isolated in selective media, followed by phenotypical, biochemical and molecular biological characterization.&#x0D; Results: The pH, water activity and salt content of Jaadi samples ranged between 3.60-5.85, 0.73-0.82 and 24.82-40.47%, respectively. Thirteen bacterial strains and one fungal strain detected were strains found to be responsible for human pathogenesis and food spoilage. These include, Bacillus cereus strain I (MN726935.1), Bacillus cereus strain II (MN901259.1), Bacillus haikouensis strain I (MN901262.1), Bacillus haikouensis strain II (MN726976.1), Bacillus licheniformis (MN726987.1), Acinetobacter baumannii (MN901499.1), Bacillus pumilus strain I (MN901264.1), Bacillus pumilus strain II (MN901263.1), Bacillus paralicheniformis (MN901167.1), Bacillus thuringiensis strain I (MN901165.1), Bacillus thuringiensis strain II (MN901257.1), Bacillus cereus (MN901161.1), Staphylococcus saprophyticus (MN901156.1) and Trichoderma longibrachiatum (MN907169.1). Presence of such organisms clearly proclaims the poor hygienic practices and risks related to food safety in this traditional processing technology.&#x0D; Conclusion: Jaadi processing facilities of Southern and Western coastal belt of Sri Lanka needs scientific and technical knowledge to upgrade their processing in order to assure food safety and product quality.

Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device.

Reverse electrodialysis (RED) is an effective way to generate power by mixing two different salt concentrations in water using cation-exchange membranes (CEM) and anion-exchange membranes (AEM). The RED stack is composed of an alternating arrangement of the cation-exchange membrane and anion-exchange membrane. The RED device acts as a potential candidate for fulfilling the universal demand for future energy crises. Here, in this article, we demonstrate a procedure to fabricate a reverse electrodialysis device using laboratory-scale CEM and AEM for power production. The active area of the ion-exchange membrane is 49 cm2. In this article, we provide a step-by-step procedure for synthesizing the membrane, followed by the stack's assembly and power measurement. The measurement conditions and net power output calculation have also been explained. Furthermore, we describe the fundamental parameters that are taken into consideration for obtaining a reliable outcome. We also provide a theoretical parameter that affects the overall cell performance relating to the membrane and the feed solution. In short, this experiment describes how to assemble and measure RED cells on the same platform. It also contains the working principle and calculation used for estimating the net power output of the RED stack using CEM and AEM membranes.

Effects of water content and salt content on electrical resistivity of loess

Effects of water content and salt content on electrical resistivity of loess

An Experimental Study on Investigating and Controlling Salt Wedge Propagation

This study aims to investigate the variation of profiles and propagation of salt wedge. It also aims to investigate the use of air and water curtains in controlling its propagation. A laboratory flume system was prepared to simulate the propagation of the salt wedge. Relations between the profiles and propagation of salt wedge and the discharge of fresh water, longitudinal slope of bed of flume, the concentration of the salt, and the depth of salt water were obtained and analysed. Seventy-seven experiment runs were carried out to investigate the propagation of salt wedge. Moreover, a set of sixteen experimental runs were conducted to investigate controlling the salt wedge using air or water curtains. It was found that by increasing the discharge of fresh water or the slope of the flume bed leads to a reduction in the length of the salt wedge. This reduction reached a maximum percentage of 95%. The propagation of the salt wedge varies proportionally and linearly with the concentration of salt water and its variation with depth of salt water follows a power function. Furthermore, a maximum reduction of 87% was achieved in the salt wedge propagation when the EC is reduced by about 49%. The salt wedge propagation was reduced by 95.3%% when the salt water depth reduced by 40%. It was found that both of the air and water curtains are efficient methods in controlling the propagation of salt wedge. A minimum discharge of air or water curtains to prevent the propagation of the salt wedge was obtained.

The effect of soaking in salt and atung (Parinarium glaberium, Hassk) on the quality of dried salted tongkol (Auxis thazard).

The study on the effect of soaking in salt and atung (Parinarium glaberimum, Hassk) has been conducted to investigate the quality of dried salted frigate tuna (Auxis thazard). There were 4 treatments of soaking in salt and atung applied in this study and a single soaking treatment in 25% salt concentration as control. Qualities parameter tested consists of objective tests i.e. the yield, water content, protein content, salt content, peroxide number, and TPC (Total Plate Count), and subjective tests consist of: appearance, smell, taste, and texture. The result of the research showed the yield of dried salted frigate tuna obtained through gradual soaking in salt and atung was ranged from 44.66% – 45.35%, while the yield obtained through single soaking salt treatment was 50.20%. Quality of dried salted frigate tuna objectively obtained through gradual soaking in salt and atung for water content, protein content, salt content, peroxide number and TPC (Total Plate Count), were 30.29 – 32.53%, 59.82 – 63.16%, 3.62 – 5.28%, 0,00 – 0,12 mg.eq./g, and 2.17 – 2.95 (Log X) or 1.48 – 8.91 × 102 CFU respectively, while for single soaking in salt 25% were 36.13%, 55.92%, 7.87, 0.27 mg eq./g and 2.21 (Log X) or 1.62 x 102 CFU respectively. Quality of dried salted frigate tuna subjectively obtained through gradual soaking in salt and atung for appearance, smells, taste and texture were 7.1–7.9, 7.0–7.7, 7,0– 7.9, and 7.0 – 7.7 respectively, while single soaking in salt were 7.2, 6.8, 6.9 and 7.0 respectively.