A method of controlling a volatile fatty acid in an aqueous industrial system is provided in the present disclosure. The method includes determining a level of dissolved oxygen in process water in the aqueous industrial system and adding an effective amount of a control agent to the process water if the determined level of dissolved oxygen is above a predetermined level. The compositions and methods can lower the amount of VFA present in the aqueous industrial system.

A system for modifying pH in an aqueous environment comprises an aqueous salt solution feed stream having a first pH and an electrochemical device positioned proximate an aqueous restoration area. The electrochemical device is configured to receive the feed stream and convert the feed stream to an acid stream and a base stream having respective predetermined pH values. A first effluent stream comprises the base stream, wherein the first effluent stream has a second pH that is higher than the first pH. The first effluent stream is delivered proximate the aqueous restoration area. A second effluent stream comprises the acid stream, wherein the second effluent stream has a third pH that is lower than the second pH.

A system for modifying pH in an aqueous environment comprises an aqueous salt solution feed stream having a first pH and an electrochemical device positioned proximate an aqueous restoration area. The electrochemical device is configured to receive the feed stream and convert the feed stream to an acid stream and a base stream having respective predetermined pH values. A first effluent stream comprises the base stream, wherein the first effluent stream has a second pH that is higher than the first pH. The first effluent stream is delivered proximate the aqueous restoration area. A second effluent stream comprises the acid stream, wherein the second effluent stream has a third pH that is lower than the second pH.

A ground water contamination remediation process includes the steps of identifying a source and location of land-based ground water contamination and excavating the soil above and within the location of the contamination to create a void. The width and depth of the void is increased to a predetermined size until the contaminated ground water is exposed creating a man-made treatment lake by allowing the contaminated ground water to partially fill the void. In one embodiment, the water in the treatment lake is aerated to reduce the amounts of hydrogen sulfide, methane, and biodegradable compounds in the contaminated water. In another embodiment, an adsorbent material is added to the treatment lake so to isolate per- and poly-fluoroalkyl substances (PFAS). The adsorbent material is applied to or mixed into PFAS contaminated water, PFAS is adsorbed, and the solid adsorbent materials settle to the bottom of the lake for subsequent management or removal.

A method for producing modified sawdust sorbent that includes sulfonating sawdust with sulfuric acid and oxidizing the sulfonated sawdust with hydrogen peroxide. The method yields modified sawdust sorbent containing sulfonated and oxidized cellulose. The modified sawdust sorbent has a higher surface area, higher organic dye adsorption capacity, and more rapid organic dye adsorption rate than unmodified sawdust. A method of using the modified sawdust sorbent for organic dye removal from water includes contacting dye contaminated water with the modified sawdust sorbent and forming a dye-impregnated sorbent and decontaminated water.

A method for producing modified sawdust sorbent that includes sulfonating sawdust with sulfuric acid and oxidizing the sulfonated sawdust with hydrogen peroxide. The method yields modified sawdust sorbent containing sulfonated and oxidized cellulose. The modified sawdust sorbent has a higher surface area, higher organic dye adsorption capacity, and more rapid organic dye adsorption rate than unmodified sawdust. A method of using the modified sawdust sorbent for organic dye removal from water includes contacting dye contaminated water with the modified sawdust sorbent and forming a dye-impregnated sorbent and decontaminated water.

The present invention generally relates to a system and method for treating spent caustic effluent using chlorine dioxide solution. The system comprises a spent caustic storage tank for receiving spent caustic obtained from refinery operations; an acid storage container connected to the spent caustic storage tank for neutralizing free alkali content with a mineral acid to eliminate unwanted chemical reactions associated with free caustic present in spent caustic with ClO.sub.2; a heat exchanger unit engaged for reducing temperature of spent caustic to 35-45° C. from high temperature raised due to heat of neutralisation at least one of a cavitation (mixing) chamber or venturi mixing equipment mechanically connected downstream of the heat exchanger unit for adding CIO solution to the spent caustic solution to oxidize sulphide/thiols content for complete reduction of sulphide/mercaptane and reduction of 80-90% of COD.

The present invention generally relates to a system and method for treating spent caustic effluent using chlorine dioxide solution. The system comprises a spent caustic storage tank for receiving spent caustic obtained from refinery operations; an acid storage container connected to the spent caustic storage tank for neutralizing free alkali content with a mineral acid to eliminate unwanted chemical reactions associated with free caustic present in spent caustic with ClO.sub.2; a heat exchanger unit engaged for reducing temperature of spent caustic to 35-45° C. from high temperature raised due to heat of neutralisation at least one of a cavitation (mixing) chamber or venturi mixing equipment mechanically connected downstream of the heat exchanger unit for adding CIO solution to the spent caustic solution to oxidize sulphide/thiols content for complete reduction of sulphide/mercaptane and reduction of 80-90% of COD.

A method and apparatus for removing specific contaminants from an aqueous solution in a recirculating tank or linear treatment system is described. An aqueous solution is pumped into a reaction chamber. Measurements from the aqueous solution are collected, including one or more of Free Chlorine, Total Chlorine, Total Ammonia Nitrogen, pH, bacteria in the tank, and Oxidation Reduction Potential. In response to the measurements collected, one or more of pump speed, injection of pH precursors prior to the reaction chamber, reaction chamber electrode voltage, current, infusion rate of the chlorine, and contact time of the aqueous solution with the chlorine, are adjusted.

A method for the decontamination of water containing one or more PFAS, having the steps of generating colloidal gas aphrons (CGAs) by mixing a gas, water, and one or more surfactants together with high shear forces, introducing the CGAs and a PFAS-containing water in an enclosed space where the CGAs move upwards through the water due to their inherent buoyancy, allowing the plurality of CGAs to extract PFAS from the water, and separating the PFAS-containing CGAs from the surface of the water in the enclosed space for further treatment or disposal, leaving the water with lower PFAS concentrations in the vessel. The aphrons may be anionic or cationic and created by mixing speeds or surfactant concentration, and treatment may be with gas bubbles to remove PFAS from water gas bubbles or destruction of PFAS by plasma reactor or deployed in situ through wells into geologic ground formations.