Brine

About: Brine is a research topic. Over the lifetime, 6542 publications have been published within this topic receiving 76741 citations.

Two-stage Sequential Electrochemical Treatment of Nitrate Brine Wastes

Abstract: Nitrates in concentrated brines can be electrochemically reduced in the cathodic chamber of a split-cell electrochemical reactor with formation of ammonium (and small amounts of nitrite). Fortunately, ammonium may be electrochemically oxidized to nitrogen gas in the anodic reaction chamber if a coupled sequential process is used. The presence of chloride in the brine waste is an important consideration in oxidative electrochemical processes, however, because it cycles through oxidized and reduced states at the electrode surfaces and in the bulk solution. Electrochemical oxidation converts chloride ions to “active chlorine” species with additional oxidizing capability (chlorine, hypochlorous acid and hypochlorite – essentially bleach), as well as to chlorates, depending on the reaction conditions. The production of these active species improves treatment performance in the ammonium oxidation phase since oxidation is no longer limited to the electrode surface. However, the process must be engineered to minimize loss of process efficiency due to parasitic side reactions (chloramines and chlorate). In this study, two-stage batch electrolysis was conducted using a three-electrode (copper anode, platinum-coated titanium cathode, silver/silver chloride reference) electrochemical cell, with the anodic and cathodic chambers separated by a Nafion 117 membrane. Treatment of nitrate and ammonium was tested with and without the presence of chloride in the waste. No significant difference was observed in cathodic nitrate reduction with chloride present or absent. However, the presence of chloride in the solution favored overall soluble nitrogen elimination upon oxidation. Increasing applied current increased production of undesirable byproducts (especially chlorate).

Composition and method for thickening heavy aqueous brines

Abstract: A process of preparing a well servicing fluid comprising viscosifying a heavy brine by contacting with a cationic polysaccharide and a composition thereof.

Method for preparing lithium carbonate by using salt lake brine with high magnesium-to-lithium ratio

Abstract: The invention provides a method for preparing industrial lithium carbonate by using salt lake brine with a high magnesium-to-lithium ratio In the method, a TBP-CON-KS+FeCl3 is used as an extraction system to extract and back-extract impurity-free salt lake brine with a high magnesium-to-lithium ratio, the residual liquid obtained after back-extraction is converted by alkaline liquor for precipitation, the precipitate is washed to form an industrial lithium carbonate product and the lithium carbonate content is more than or equal to 990 percent and is in accordance with the requirements of GB/T 11 075-2003 standards The method has the advantages that: liquid-liquid extraction with an organic solvent is adopted to realize the separation of lithium from magnesium, the lithium carbonate is precipitated by inorganic slats, the lithium carbonate is extracted from the salt lake brine with a high magnesium-to-lithium ratio, the process is simple, the control is easy, the operational reliability is high and the application range is wide; a process of calcination and diluted lithium solution evaporation and concentration is saved, the energy consumption is only 30 to 50 percent of that of the conventional process for producing lithium carbonate by using lithium-containing brine; initial raw material consumption comparison show that the production cost of the method is only about 8 percent of that of the prior art; and the raw material brine can return to a storage pool after the extraction of the lithium carbonate, so no by production disposal problem is involved, environmental pollution is relatively low and lithium yield in the whole process is more than or equal to 70 percent

Reduction of by-product formation in alkali chloride membrane electrolysis

Abstract: To obtain higher chlorine purity hydrochloric acid can be added to the feed brine of membrane cells in alkali chloride electrolysis. During the electrolytic process hydroxide ions migrate from the cathode compartment into the anode compartment. Hydrochloric acid neutralizes these hydroxide ions and, hence, formation of the by-products (oxygen in the anode gas and sodium chlorate in the anolyte) is reduced. With laboratory membrane cells the effects of varied amounts of hydrochloric acid on concentrations and current efficiencies of these by-products have been studied. Under normal operating conditions (with pH of feed brine between 2 and 11) the formation of by-products is not influenced by the addition of acid. Effects can only be observed at brine pH values<1. Maximum effects occur if the brine pH is 0.1 and the anolyte pH is 2. The latter value is the limiting pH given by the membrane suppliers. At this point 6.3 dm3 hydrochloric acid (37% HCl) per 1 m3 of the feed brine have to be added in order to obtain an anode gas with 0.4% oxygen by volume. The formation of sodium chlorate is completely suppressed. Problems connected with this process and its application to industrial electrolysis are discussed.

Direct asymmetric aldol reactions in water with a β-aminosulfonamide organocatalyst

Abstract: Organocatalyst 4 promoted the direct asymmetric aldol reactions of aldehydes with ketones in brine or in the presence of water to afford the corresponding anti-aldol products in moderate to excellent yields with up to 97% ee.