Performance of precipitation and electrocoagulation as pretreatment of silica removal in brackish water and seawater

2019 ◽  
Vol 126 ◽  
pp. 18-24 ◽  
Author(s):  
Xin Zhang ◽  
Mengjia Lu ◽  
Mohd Amzar Mohamed Idrus ◽  
Cameron Crombie ◽  
Veeriah Jegatheesan
Keyword(s):  
Brackish Water ◽  
Silica Removal

Silica pretreatment for a RO brackish water source with high magnesium

2006 ◽  
Vol 6 (4) ◽  
pp. 179-187 ◽  
Author(s):  
S. Chen ◽  
T. Chang ◽  
C. Lin
Keyword(s):  
Brackish Water ◽  
Water Source ◽  
Xrd Analysis ◽  
Electrostatic Attraction ◽  
Magnesium Concentration ◽  
X Ray Diffraction ◽  
Silica Removal ◽  
Pros And Cons ◽  
The Impact ◽  
Amphoteric Properties

A brackish water source containing high magnesium concentration (333 mg/L as CaCO3) for reverse osmosis (RO) was studied for silica scaling. Threshold limit for RO recovery and required silica removal were firstly determined by a removal–saturation–recovery curve. Three different ratios of lime/soda ash combination were used to test the efficiency of silica removal as well as the impact of calcium and magnesium. Higher pH was more effective for silica removal due to electrostatic attraction since H3SiO−4 and H2SiO−24 were dominant when pH >9.9. The precipitation of Mg(OH)2(s) has assisted more for silica removal than that of CaCO3(s) and the ratio of 0.044 mg SiO2/mg Mg(OH)2(s) and 0.027 mg SiO2/mg CaCO3(s) were statistically determined. Moreover, the presence of high magnesium causes Mg(OH)2(s) to precipitate at lower pH (9.41) instead of formation of forsterite (Mg2SiO4(s)), which typically occurs at pH >12.3. Therefore, no forsterite was observed and was verified by X-ray diffraction (XRD) analysis. Consequently, adsorption is more dominant than chemical reaction in this study. Silica removal was also enhanced by coagulation. With the addition of coagulant (PACl), highest silica removal was achieved at pH of 10, but was decreased when the pH was over 10, due to the amphoteric properties of aluminum hydroxide to reduce the electrostatic attraction to silica at higher pH. Since both softening and coagulation were effective for silica removal, seven decision-making criteria were developed to compare the pros and cons of these two processes.

Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

2018 ◽  
Vol 6 (6) ◽  
pp. 46
Author(s):  
Raveesha P ◽  
K. E. Prakash ◽  
B. T. Suresh Babu
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Salt Water ◽  
Construction Material ◽  
Salt Content ◽  
River Estuary ◽  
Sand Sample ◽  
River Sand ◽  
Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods.  It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

Metazoan Parasites and Health State of European Eel, Anguilla Anguilla (Anguilliformes, Anguillidae), From Tonga Lake and El Mellah Lagoon in the Northeast of Algeria

2018 ◽  
Vol 52 (4) ◽  
pp. 279-288 ◽  
Author(s):  
F. Bakaria ◽  
S. Belhaoues ◽  
N. Djebbari ◽  
M. Tahri ◽  
I. Ladjama ◽  
...  
Keyword(s):  
Brackish Water ◽  
Parasite Species ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Health State ◽  
Component Community ◽  
Metazoan Parasites ◽  
Parasite Communities ◽  
High Dominance ◽  
Argulus Foliaceus

Abstract The aim of the study was to examine metazoans parasite communities of European eels (Anguilla anguilla) in freshwater (Tonga Lake) and brackish water (El Mellah lagoon) in the northeast of Algeria. Six parasite taxa were collected: one monogenean, Pseudodactylogyrus sp.; two crustaceans, Ergasilus sp. and Argulus foliaceus; two nematodes, Cucullanus sp. and Anguillicola crassus; one cestode, Bothriocephalus claviceps. Th e most prevalent parasite taxa in freshwater were Pseudodactylogyrus sp., A. crassus and Bothriocephalus claviceps; whereas in the brackish water, eels were infected mainly with A. crassus. Th e characteristics of the parasite component community structure revealed low parasite species diversity and high dominance values in eels from the two localities. Both communities were dominated by a single parasite species: Tonga eels by the monogenean Pseudodactylogyrus sp. and El Mellah lagoon eels by the nematode A. crassus, verified by high Berger-Parker dominance values of 0.76 and 0.87 respectively.

Low-Resistance Monovalent-Selective Cation Exchange Membranes for Energy-Efficient Ion Separations

2020 ◽  
Author(s):  
Eyal Wormser ◽  
Oded Nir ◽  
Eran Edri
Keyword(s):  
Cation Exchange ◽  
Brackish Water ◽  
Molecular Layer ◽  
Water Desalination ◽  
Molecular Layer Deposition ◽  
Selective Layer ◽  
Trade Off ◽  
Membrane Selectivity ◽  
Layer Deposition ◽  
Water Energy Nexus

<div> <div> <div> <p>The desalination of brackish water provides water to tens of millions of people around the world, but current technologies deplete much needed nutrients from the water, which is detrimental to both public health and agriculture. A selective method for brackish water desalination, which retains the needed nutrients, is electrodialysis (ED) using monovalent-selective cation exchange membranes (MVS-CEMs). However, due to the trade-off between membrane selectivity and resistance, most MVS-CEMs demonstrate either high transport resistance or low selectivity, which increase energy consumption and hinder the use of such membranes for brackish water desalination by ED. Here, we used molecular layer deposition (MLD) to uniformly coat CEMs with ultrathin layers of alucone. The positive surface charge of the alucone instills monovalent selectivity in the CEM. Using MLD enabled us to precisely control and minimize the selective layer thickness, while the flexibility and nanoporosity of the alucone prevent cracking and delamination. Under conditions simulating brackish water desalination, this compound provides monovalent selectivity with negligible added resistance—the smallest reported resistance for a monovalent-selective layer, to date—thereby alleviating the selectivity–resistance trade-off. Addressing the water–energy nexus, we show that using these membranes in ED will cut at least half of the energy required for selective brackish water desalination with current MVS-CEMs. </p> </div> </div> </div>

SEA CURE

Alloy Digest ◽  
1979 ◽  
Vol 28 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Stainless Steel ◽  
High Resistance ◽  
Brackish Water ◽  
Crevice Corrosion ◽  
Heat Treating

Abstract SEA-CURE is a ferritic stainless steel designed to provide high resistance to pitting and crevice corrosion in condensers cooled by saline or brackish water. It is used for condenser tubes and has great potential for many other uses. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-364. Producer or source: Trent Tube.

CRONIFER 1713 LCN

Alloy Digest ◽  
1983 ◽  
Vol 32 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Brackish Water ◽  
Heat Treating ◽  
Nitrogen Addition ◽  
Chloride Ions ◽  
Low Carbon ◽  
Good Resistance ◽  
Temperature Performance ◽  
Aqueous Chloride

Abstract CRONIFER 1713 LCN is a fully austenitic low-carbon chromium-nickel-molybdenum stainless steel. It contains a nitrogen addition (0.10-0.20%) which helps to stabilize the austenite. Its molybdenum content (4.0-5.0%) provides good resistance to pitting attack by media containing chloride ions. Thus it has good resistance to brackish water and seawater. Typical applications are bleaching plants and equipment for handling aqueous chloride solutions. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-425. Producer or source: Vereingte Deutsche Metallwerke AG.

Stratigraphic Intervals for Oil and Tar Sand Deposits in the Uinta Basin, Utah

2017 ◽  
Vol 54 (4) ◽  
pp. 227-264
Author(s):  
Ronald Johnson ◽  
Justin Birdwell ◽  
Paul Lillis
Keyword(s):  
Brackish Water ◽  
Source Rocks ◽  
Uinta Basin ◽  
Green River ◽  
Reservoir Rocks ◽  
Stratigraphic Framework ◽  
Two Samples ◽  
The Rich ◽  
And Migration ◽  
Almost All

To better understand oil and bitumen generation and migration in the Paleogene lacustrine source rocks of the Uinta Basin, Utah, analyses of 182 oil samples and tar-impregnated intervals from 82 core holes were incorporated into a well-established stratigraphic framework for the basin. The oil samples are from the U.S. Geological Survey Energy Resources Program Geochemistry Laboratory Database; the tar-impregnated intervals are from core holes drilled at the Sunnyside and P.R. Spring-Hill Creek tar sands deposits. The stratigraphic framework includes transgressive and regressive phases of the early freshwater to near freshwater lacustrine interval of Lake Uinta and the rich and lean zone architecture developed for the later brackish-to-hypersaline stages of the lake. Two types of lacustrine-sourced oil are currently recognized in the Uinta Basin: (1) Green River A oils, with high wax and low β-carotane contents thought to be generated by source rocks in the fresh-to-brackish water lacustrine interval, and (2) much less common Green River B oils, an immature asphaltic oil with high β-carotane content thought to be generated by marginally mature to mature source rocks in the hypersaline lacustrine interval. Almost all oil samples from reservoir rocks in the fresh-to-brackish water interval are Green River A oils; however four samples of Green River A oils were present in the hypersaline interval, which likely indicates vertical migration. In addition, two samples of Green River B oil are from intervals that were assumed to contain only Green River A oil. Tar sand at the P.R. Spring-Hill Creek deposit are restricted to marginal lacustrine and fluvial sandstones deposited during the hypersaline phase of Lake Uinta, suggesting a genetic relationship to Green River B oils. Tar sand at the Sunnyside deposit, in contrast, occur in marginal lacustrine and alluvial sandstones deposited from the early fresh to nearly freshwater phase of Lake Uinta through the hypersaline phase. The Sunnyside deposit occurs in an area with structural dips that range from 7 to 14 degrees, and it is possible that some tar migrated stratigraphically down section.

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