· Iron-reducing agents. The most common iron-reducing agent is erythorbic acid—a cousin to vitamin C. Erythorbic acid is added to the acid to reduce any ferric ion to ferrous iron before it enters the formation. The use of a reducing agent does …
More DetailsSilicon is the most abundant element on earth after oxygen.Large amounts of silicon can be found in various minerals and it is abundant in oceans and nearly all other waters as silicic acid. In the surface layers of oceans silicon concentrations are 30 ppb, whereas deeper water layers may contain 2 ppm silicon.
More DetailsWater-reducing admixtures usually reduce the required water content for a concrete mixture by about 5 to 10 percent. Consequently, concrete containing a water-reducing admixture needs less water to reach a required slump than untreated concrete. The treated concrete can have a lower water-cement ratio.
More Details· Several techniques are available for minimizing sand production from wells. The choices range from simple changes in operating practices to expensive completions, such as sand consolidation or gravel packing. The sand control method selected depends on site-specific conditions, operating practices and economic considerations.
More DetailsHydraulic fracturing fluids: A wide variety of chemical additives are used in hydraulic fracturing fluids. They include: dilute acids, biocides, breakers, corrosion inhibitors, crosslinkers, friction reducers, gels, potassium chloride, oxygen scavengers, pH adjusting agents, scale inhibitors, and surfactants. These chemical additives typically ...
More Details· Depositional environments. Sedimentary rocks are formed by 5 processes, there are erosion, weathering, transport, deposition, and diagenesis process (Boggs, 1991). These 5 processes with 4 types of rocks make up a cycle that is known as sedimentary cycle. The properties of sedimentary rocks such as sediment textures and structures, are formed ...
More Details· A material other than water, aggregates, or cement that is used as an ingredient of concrete or mortar to control setting and early hardening, workability, or to provide additional cementing properties. Admixtures of concrete are generally used to alter the properties of concrete (such as increased workability or reduced water content, acceleration or retardation of setting time, …
More DetailsSoil compaction, low organic matter, loss of soil structure, poor internal drainage, salinisation and soil acidity problems are other serious soil degradation conditions that can accelerate the soil erosion process. This Factsheet looks at the causes and effects of water, wind and tillage erosion …
More DetailsWater Filtration. Water filtration is the process of removing or reducing the concentration of particulate matter, including suspended particles, parasites, bacteria, algae, viruses, and fungi, as well as other undesirable chemical and biological contaminants from contaminated water to produce safe and clean water for a specific purpose, such as drinking, medical, and pharmaceutical applications.
More Details· Figure 1: Sand filtration systems can provide a lower-cost solution in some circumstances, as part of a traditional water treatment system. Figure 2: Approximate size ranges of major pathogen groups as compared to approximate exclusion ranges typically expected from filtration and membrane technology.
More DetailsCoagulation-flocculation is a chemical water treatment technique typically applied prior to sedimentation and filtration (e.g. rapid sand filtration) to enhance the ability of a treatment process to remove particles. Coagulation is a process used to neutralise charges and form a gelatinous mass to trap (or bridge) particles thus forming a mass large enough to settle or be trapped in the filter.
More Details· Engineering activities can lead to serious soil erosion problems in red bed areas. To overcome their loose structure, low strength and poor water retention, the red bed weathered soil needs to be modified with adhesives and water-retaining agents. At present, on the premise of applying adhesive, there are few studies on the mechanism of water retention agent to improve soil, and the …
More Details· Gypsum is called the retarding agent of cement which is mainly used for regulating the setting time of cement and is an indispensable component. Without gypsum, cement clinker can condense immediately by mixing with water and release heat. ... which will destroy the normal use of cement. The retardation mechanism of gypsum is: when cement is ...
More DetailsThis experiment involves the use of a reducing agent (sodium borohydride) for converting a ketone (camphor) to a secondary ... The reduction mechanism is often shown with a hydride (H:-) ion attacking the carbonyl carbon. Why might one assign a ... of the flask on a sand bath for 15 minutes.
More DetailsThe stabilization mechanism of surfactant-like dispersing agents is electrostatic: the polar groups forming an electrical double layer around the pigments particles. Due to the Brownian movement the pigment particles frequently encounter each other in the liquid medium thus having a strong tendency to re-flocculate on the let down stage.
More DetailsThe mechanism by which water reducing admixture operate is to deflocculated or to disperse the cement agglomerates into primary particles or atleast into much smaller fragments. This deflocculating is believing to be a physio chemical effect whereby the admixture is first of all adsorbed on to the surface of the hydrating cement, forming a ...
More DetailsEffect on concrete by using Water Reducing Agent B. Water-Reducing Admixtures Usually reduce the required water content for a concrete mixture by about 5 to 10 percent. Consequently, concrete containing a water-reducing admixture needs less water to reach a required slump than untreated concrete. The treated
More Details· Pathogen removal from water – technologies and techniques. 23 March 2009 | Antony Bennett, Clarity. Figure 1: Sand filtration systems can provide a lower-cost solution in some circumstances, as part of a traditional water treatment system. Figure 2: Approximate size ranges of major pathogen groups as compared to approximate exclusion ranges ...
More Details· When the water-reducing agent is added to the mortar, the water-cement ratio can be significantly reduced, and the mortar''s good fluidity can be maintained. Generally speaking, the water reduction rate of high-efficiency water reducing agent can reach about 20%, while the water reduction rate of ordinary water reducing agents is about 10%.
More Detailsabsorption fields, ground water, streams and lakes by reducing levels of oxygen in the water. ★Organic solvents from cleaning agents and fuels may not be degraded or removed through treatment and can pass along with the wastewater back into the water supply. ★Nutrient contaminants are composed mainly of nitrogen from human wastes,
More Details· Water reducing agents reduce the water-cement ratio, resulting in higher strengths. Retarders are primarily intended to counteract the harmful results of heat on the concrete mix; they lower the water/cement ratio only as a side effect. Just remember, don''t use retarders in cold weather.
More DetailsOur mechanism must account for the formation of a carbon-bromine bond and an oxygen-hydrogen bond (in water) and the cleavage of a carbon-hydrogen bond (alpha) and a bromine-bromine bond. It must also suggest a role for the OH - . so let''s begin by speculating that the hydroxide ion acting as a base makes a bond to the alpha-hydrogen.
More Details· Their efficiency is measured by intensity, capacity and velocity can greatly vary from one solvent to the other. Capacity refers to the maximum numbers of moles of water that the drying agent can bind (n). Another parameter of importance is the efficiency, which refers to the amount of water left in the organic solution after the drying process is completed (e).
More DetailsIn metallurgy, a flux (derived from Latin fluxus meaning "flow") is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining. Some of the earliest known fluxes were sodium carbonate, potash, charcoal, coke, borax, lime, lead sulfide and certain minerals containing phosphorus.
More Details· The actual mechanisms by which drying shrinkage occurs are complex, but it is generally agreed upon that they involve the loss of adsorbed water from the hydrated cement paste [3-5]. When concrete is initially exposed to a drying condition—one in which there is a difference between the relative humidity of the environment and that of the ...
More Detailsthe bridging agent does occur, an acceptable stimulation technique is available to remove the bridging agent without damaging the formation. Another potential mechanism of permeability impairment associated with solids entrainment can occur during water injection or water …
More Details· Water is the main agent of degradation of solid materials, however it is essential in the production of concrete and responsible for the cement hydration reactions . The water and other fluids permeability in concrete can result in degradation, thus reducing the concrete structures service life.
More DetailsSentinel ™ Dust Suppressant. Hexion''s Sentinel dust suppressant mitigates the respirable silica dust generated by uncoated sand. This economical solution is designed to reduce the amount of respirable silica to levels below the new OSHA action level of 25 µg/m 3.The unique chemical system traps fine dust particles and remains on the proppant during transportation and transfer.
More DetailsHeat therapy is the application of heat to the body to relieve pain. It can take the form of a hot cloth, hot water, ultrasound, heating pad, hydrocollator packs, whirlpool baths, infrared (IR) heat therapy, and whatsoever. Heat is beneficial to those with soft tissue injury, noninfectious arthritis.
More DetailsAlireza Kashani, Tuan Ngo, in Self-Compacting Concrete: Materials, Properties and Applications, 2020. 3.1.1 Chemical admixtures. Chemical admixtures such as high-range water reducers or superplasticizers, viscosity modifying agents, shrinkage reducing and air-entraining admixtures, accelerators, retardants and mineral admixtures have been used in SCC (Şahmaran et al., 2006; Huang et al., 2018 ...
More DetailsFiltration through porous granular media, typically sand or successive layers of anthracite coal and sand, is the most widely used physical method for water treatment at the community level, and it has been used extensively for on-site treatment of both community and water since ancient times (Oza and Chaudhuri, 1975;
More DetailsMaterial for this article was largely taken from reference 1. Coagulation and flocculation are essential processes in various disciplines. In potable water treatment, clarification of water using coagulating agents has been practiced from ancient times. As early as 2000 BC the Egyptians used almonds smeared around vessels to clarify river water.
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