scholarly journals Assessing Pretreatment Effectiveness for Particulate, Organic and Biological Fouling in a Full-Scale SWRO Desalination Plant

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 167
Author(s):  
Almotasembellah Abushaban ◽  
Sergio G. Salinas-Rodriguez ◽  
Delia Pastorelli ◽  
Jan C. Schippers ◽  
Subhanjan Mondal ◽  
...  
Keyword(s):  
Full Scale ◽  
Growth Potential ◽  
Feed Water ◽  
Biological Degradation ◽  
Two Stage ◽  
Particulate Fouling ◽  
Desalination Plant ◽  
Organic Fouling ◽  
Two Stages ◽  
Pretreatment Processes

In this study, the removal of particulate, organic and biological fouling potential was investigated in the two-stage dual media filtration (DMF) pretreatment of a full-scale seawater reverse osmosis (SWRO) desalination plant. Moreover, the removal of fouling potential in two-stage DMF (DMF pretreatment) was compared with the removal in two-stage DMF installed after dissolved air floatation (DAF) (DAF-DMF pretreatment). For this purpose, the silt density index (SDI), modified fouling index (MFI), bacterial growth potential (BGP), organic fractions and microbial adenosine triphosphate (ATP) were monitored in the pretreatment processes of two full-scale SWRO plants. Particulate fouling potential was well controlled through the two stages of DMF with significant removal of SDI15 (>80%), MFI0.45 (94%) and microbial ATP (>95%). However, lower removal of biological/organic fouling potential (24–41%) was observed due to frequent chlorination (weekly) of the pretreatment, resulting in low biological activity in the DMFs. Therefore, neutralizing chlorine before media filtration is advised, rather than after, as is the current practice in many full-scale SWRO plants. Comparing overall removal in the DAF-DMF pretreatment to that of the DMF pretreatment showed that DAF improved the removal of biological/organic fouling potential, in which the removal of BGP and biopolymers increased by 40% and 16%, respectively. Overall, monitoring ATP and BGP during the pretreatment processes, particularly in DMF, would be beneficial to enhance biological degradation and lower biofouling potential in SWRO feed water.

scholarly journals Monitoring Biofouling Potential Using ATP-Based Bacterial Growth Potential in SWRO Pre-Treatment of a Full-Scale Plant

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 360
Author(s):  
Almotasembellah Abushaban ◽  
Sergio G. Salinas-Rodriguez ◽  
Moses Kapala ◽  
Delia Pastorelli ◽  
Jan C. Schippers ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Full Scale ◽  
Growth Potential ◽  
Feed Water ◽  
Potential Growth ◽  
Dissolved Air Flotation ◽  
Particulate Fouling ◽  
Seawater Reverse Osmosis ◽  
Pre Treatment ◽  
Modified Fouling Index

Several potential growth methods have been developed to monitor biological/organic fouling potential in seawater reverse osmosis (SWRO), but to date the correlation between these methods and biofouling of SWRO has not been demonstrated. In this research, the relation between a new adenosine triphosphate (ATP)-based bacterial growth potential (BGP) test of SWRO feed water and SWRO membrane performance is investigated. For this purpose, the pre-treatment of a full-scale SWRO plant including dissolved air flotation (DAF) and two stage dual media filtration (DMF) was monitored for 5 months using BGP, orthophosphate, organic fractions by liquid chromatography coupled with organic carbon detection (LC-OCD), silt density index (SDI), and modified fouling index (MFI). Results showed that particulate fouling potential was well controlled through the SWRO pre-treatment as the measured SDI and MFI in the SWRO feed water were below the recommended values. DAF in combination with coagulation (1–5 mg-Fe3+/L) consistently achieved 70% removal of orthophosphate, 50% removal of BGP, 25% removal of biopolymers, and 10% removal of humic substances. Higher BGP (100–950 µg-C/L) in the SWRO feed water corresponded to a higher normalized pressure drop in the SWRO, suggesting the applicability of using BGP as a biofouling indicator in SWRO systems. However, to validate this conclusion, more SWRO plants with different pre-treatment systems need to be monitored for longer periods of time.

scholarly journals PILOT TEST OF HIGH-EFFICIENCY MEMBRANES FOR OPTIMISATION OF THE MEMBRANE SYSTEM IN CARBONERAS DESALINATION PLANT

10.6036/9811 ◽  
2021 ◽  
Vol 96 (3) ◽  
pp. 260-263
Author(s):  
FEDERICO LEON ZERPA ◽  
ALEJANDRO RAMOS MARTIN ◽  
CARLOS ALBERTO MENDIETA PINO
Keyword(s):  
High Efficiency ◽  
Minimum Energy ◽  
Membrane System ◽  
Full Scale ◽  
Operating Conditions ◽  
Feed Water ◽  
Pilot Test ◽  
Desalination Plant ◽  
Minimum Energy Consumption ◽  
The Difference

The construction of the new seawater intake for the desalination plant in Las Carboneras (Almería, Spain) was completed in May 2011. Since then, the water intake increased from 14 m to 35 m in depth. A new scenario appeared with the lowest maximum temperatures, while the minimum temperatures remained constant. As a result, new designs and opportunities for operational improvements appeared to optimize the process. To improve the membrane system, a pilot test was developed. This test pilot compared different membranes, and the setup of making 3 different membranes. The test was carried out in high pressure tanks of the full-scale plant (7 elements per tank). The experiment was carried out in two phases: the aging phase and the testing phase. During the aging phase, the membranes of the three manufacturers were tested simultaneously using the same feed water and the same discharge conditions as the full-scale frame in order to achieve the membrane performance estimated by the manufacturer. The main operating parameters were controlled. During the test phase the membranes of each manufacturer were alternately tested in individual tanks with total control of the operating conditions (flow and pressure). The purpose of this test was to compare the performance of the different membranes and determine the optimal configuration of the membrane capable of achieving the necessary quality and quantity of water, with the minimum energy consumption with the new thermal scenario. The results showed the difference in performance between membranes. The study's conclusions could serve as a tool for the decision-making process, related to membrane replacement and plant modernization projects (whose designs are based on the configuration of new high-efficiency membranes). Keywords: Reverse osmosis, membranes, pilot test, energy efficiency, desalination.

scholarly journals Full-Scale Seawater Reverse Osmosis Desalination Plant Simulator

2020 ◽  
Vol 53 (2) ◽  
pp. 16561-16568
Author(s):  
Mariam Elnour ◽  
Nader Meskin ◽  
Khlaed M. Khan ◽  
Raj Jain ◽  
Syed Zaidi ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Full Scale ◽  
Desalination Plant ◽  
Seawater Reverse Osmosis ◽  
Reverse Osmosis Desalination

scholarly journals Novel Treatment of Sugar Mill Wastewater in a Coupled System of Aged Refuse Filled Bioreactors (ARFB): Full-Scale

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 516
Author(s):  
Rubén Fernando Gutiérrez-Hernández ◽  
Hugo Alejandro Nájera-Aguilar ◽  
Juan Antonio Araiza-Aguilar ◽  
Rebeca Isabel Martínez-Salinas ◽  
Carlos Manuel García-Lara ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Coupled System ◽  
Food Supplement ◽  
Full Scale ◽  
Sugar Mill ◽  
Daily Diet ◽  
Aged Refuse ◽  
International Regulations ◽  
Sugar Mills ◽  
Two Stages

Sugar is the most important food supplement of our daily diet. During the production, sugar mills use a large volume of water and produce a significant amount of wastewater polluted with high organic compounds. Therefore, it is necessary to treat the wastewater before their disposal. For this reason, this article presents the results obtained from the monitoring of a coupled system of aged refuse filled bioreactors (ARFB) in full scale to treat wastewater from a sugar mill. The coupled system consists of two bioreactors (a primary one -ARFB1- and a rectification one -ARFB2-) arranged in a series with identical geometries. The ARFB1-ARFB2 system was evaluated in two stages. The first stage (maintenance period) for 28 weeks, and second stage (Zafra season) for 29 weeks. The system was fed with sugar mill wastewater (SMW) with a chemical oxygen demand (COD) of 2787 ± 1552 mg/L and 2601 ± 722 mg/L, respectively. As results, we observed a rapid stabilization of the system over 2 months. In addition, we found the ARFB1-ARFB2 system achieved an average COD removal of 94.9%, with a final effluent (E2) concentration below the maximum permissible limits of Mexican and international regulations for all analyzed parameters. Finally, the results of this study show that the ARFB1-ARFB2 full-scale novel technology is an efficient process for removal of the main contaminants that affect the wastewater from the sugar mills.

scholarly journals Application of a Two-Stage Steam Jet Injector Unit for Latent Heat Recovery of a Marine Steam Turbine Propulsion Plant

2021 ◽  
Vol 11 (12) ◽  
pp. 5511
Author(s):  
Szymon Grzesiak ◽  
Andrzej Adamkiewicz
Keyword(s):  
Steam Turbine ◽  
Steam Pressure ◽  
Relative Increase ◽  
Parameters Optimization ◽  
Feed Water ◽  
Water Heating ◽  
Two Stage ◽  
Heating Systems ◽  
Heating Steam ◽  
Numerical Research

The paper presents the results of the numerical research of the steam jet injector applications for the regenerative feed water heating systems of marine steam turbine propulsion plants. The analysis shows that the use of a single injector for a single heat exchanger results in a relative increase in the thermal efficiency of the plant by 0.6–0.9%. The analysis also indicates the legitimacy of the usage of multistage feed water heating systems, which would enable the operating parameters optimization of the injectors. The obtained steam pressure up to the value of 1.8 barA allows for the heating of the feed water up to 110 °C. For higher degrees of feed water heating in the heat exchangers, it is necessary to supply heating steam of higher pressure. Therefore, the usage of two-stage steam jet injector units was considered advisable for the analyses.

scholarly journals Measuring Biofouling Potential in SWRO Plants with a Flow-Cytometry-Based Bacterial Growth Potential Method

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 76
Author(s):  
Nirajan Dhakal ◽  
Sergio G. Salinas-Rodriguez ◽  
Joshua Ampah ◽  
Jan C. Schippers ◽  
Maria D. Kennedy
Keyword(s):  
Flow Cytometry ◽  
Bacterial Growth ◽  
Potential Method ◽  
Absolute Number ◽  
Growth Potential ◽  
Added Value ◽  
Feed Water ◽  
Dissolved Air Flotation ◽  
Ultra Filtration ◽  
Pre Treatment

Measuring the bacterial growth potential of seawater reverse osmosis (SWRO) feed water is an issue that is receiving growing attention. This study developed and demonstrated the applicability of the flow-cytometry (FCM)-based bacterial growth potential (BGP) method to assess the biofouling potential in SWRO systems using natural microbial consortium. This method is relatively fast (2–3 days) compared to conventional bioassays. The effect of the potential introduction of nutrients during measurement has been studied thoroughly to achieve the lowest measure value of about 45,000 cells/mL, which is equivalent to about (10 µg-C glucose/L). The BGP method was applied in two full-scale SWRO plants that included (i) dissolved air flotation (DAF) and ultra-filtration (UF); (ii) dual-media filtration (DMF) and cartridge filter (CF), which were compared with the cleaning frequency of the plants. A significant reduction (54%) in BGP was observed through DAF–UF as pre-treatment (with 0.5 mg Fe3+/L), while there was a 40% reduction by DMF–CF (with 0.8 mg Fe3+/L). In terms of the absolute number, the SWRO feed water after DAF–UF supports 1.5 × 106 cells/mL, which is 1.25 times higher than after DMF–CF. This corresponds to the higher cleaning-in-place (CIP) frequency of SWRO with DAF–UF compared to DMF–CF as pre-treatment, indicating that the BGP method has an added value in monitoring the biofouling potential in SWRO systems.

A novel two-stage method of plant seedlings classification based on deep learning

2021 ◽  
pp. 1-11
Author(s):  
Tianhong Dai ◽  
Shijie Cong ◽  
Jianping Huang ◽  
Yanwen Zhang ◽  
Xinwang Huang ◽  
...  
Keyword(s):  
Deep Learning ◽  
Learning Technology ◽  
Two Stage ◽  
Second Stage ◽  
Stage Classification ◽  
Different Types ◽  
Two Stages ◽  
Plant Seedlings

In agricultural production, weed removal is an important part of crop cultivation, but inevitably, other plants compete with crops for nutrients. Only by identifying and removing weeds can the quality of the harvest be guaranteed. Therefore, the distinction between weeds and crops is particularly important. Recently, deep learning technology has also been applied to the field of botany, and achieved good results. Convolutional neural networks are widely used in deep learning because of their excellent classification effects. The purpose of this article is to find a new method of plant seedling classification. This method includes two stages: image segmentation and image classification. The first stage is to use the improved U-Net to segment the dataset, and the second stage is to use six classification networks to classify the seedlings of the segmented dataset. The dataset used for the experiment contained 12 different types of plants, namely, 3 crops and 9 weeds. The model was evaluated by the multi-class statistical analysis of accuracy, recall, precision, and F1-score. The results show that the two-stage classification method combining the improved U-Net segmentation network and the classification network was more conducive to the classification of plant seedlings, and the classification accuracy reaches 97.7%.

scholarly journals Simple Method of Approximate Calculation of Statically Indeterminate Trusses

2019 ◽  
Vol 16 (06) ◽  
pp. 1840026 ◽  
Author(s):  
Janusz Rębielak
Keyword(s):  
Approximate Calculation ◽  
Computer Software ◽  
Two Stage ◽  
Simple Method ◽  
Two Stages

The paper presents principles of the simple method which makes possible approximate calculations of statically indeterminate truss systems in two stages. The two-stage method applies rules of other methods used for calculations of statically determinate trusses. In each of the two stages, there are considered statically determinate trusses, patterns of which are obtained as results of suitable withdrawing of appropriate members from the pattern of the basic statically indeterminate truss. There are presented results of calculations carried out for two cases of load for selected type of plane truss together with comparison of outcomes obtained by means of using appropriate computer software.

scholarly journals Full-Scale Seawater Reverse Osmosis Desalination Plant Simulator

2020 ◽  
Author(s):  
Hammad Siddiqui ◽  
Mariam Elnour ◽  
Nader Meskin ◽  
Syed Zaidi
Keyword(s):  
Reverse Osmosis ◽  
Full Scale ◽  
Operating Conditions ◽  
Water Desalination ◽  
System Behavior ◽  
Desalination Plant ◽  
Local Plant ◽  
Seawater Reverse Osmosis ◽  
High Flexibility ◽  
Operational Data

Reverse Osmosis (RO) is an efficient and clean membrane-based technology for water desalination. This work presents a full-scale seawater reverse osmosis (SWRO) desalination plant simulator using MATLAB/Simulink that has been validated using the operational data from a local plant. It allows simulating the system behavior under different operating conditions with high flexibility and minimal cost.

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