An automated produced water treatment system that injects ozone or an ozone-oxygen mixture upstream of produced water separators, with the dose rate changing dynamically as the produced water quality changes, as determined by continuous monitoring of the produced water quality by a plurality of sensors that detect water quality parameters in real time. The system may operate as a “slipstream” injection system, that draws a portion of produced water from the produced water pipeline and injects ozone or an ozone-oxygen mixture back into the pipeline with disrupting or slowing normal operations. Disinfectants or other additives may also be injected.

Methods for removing a soluble heavy metal-sulfur complex from a process solution comprise contacting the process solution with an oxidant to oxidize the heavy metal-sulfur complex and form an oxidized complex precipitate, or with an acid to acidify the heavy metal-sulfur complex and form an acidified complex precipitate, and removing the precipitate from the process solution to provide a heavy metal-reduced solution. The method is advantageous for removing heavy metals such as mercury, cadmium, barium, iron, vanadium and/or manganese from process solutions, for example originating from natural gas production, petroleum production, water treatment or mining.

Methods for removing anions from an aqueous solution include contacting the aqueous solution with an initial organic phase composition in a primary stage to form a first mixture, the initial organic phase composition including a quaternary amine and a weak organic acid; separating a nitrate-depleted raffinate from the first mixture; mixing the remaining organic phase (now containing nitrate) with a first basic solution to obtain a second mixture; separating an aqueous phase sulfate-containing scrub solution from the second mixture; mixing the remaining organic phase with a second basic solution to form a third mixture; and separating the third mixture into an aqueous phase nitrate-rich solution and a secondary organic phase composition. The secondary organic phase composition can be recycled. The raffinate, the sulfate-containing scrub solution, and the nitrate-rich solution can then be further processed.

A method is provided herein for using produced water (PW), for example, for use in a fracturing fluid. The method includes performing ultrafiltration on the PW to form filtered PW, filtering seawater (SW) to form filtered SW, and blending the filtered PW with the filtered SW to form an aqueous blend.

The use of ferric sulphate or polyferric sulphate to treat liquid animal effluent to reduce methane emissions therefrom.

Disclosed herewith is a method of providing N-hydroxycarboxamide compound-based metabolic inhibitor composition, which has demonstrated efficacy for inhibiting sulfide production, under anaerobic conditions. This composition is suitable for use in downhole, drilling and exploration application environments and other harsh environment applications, including mining, industrial extraction of metals and sewage treatment, as well as non-harsh environment applications.

The present invention relates to an apparatus for reducing greenhouse gas emission in a vessel, and a vessel including the same, which are capable of satisfying IMO greenhouse gas emission regulations by separating and discharging NO.sub.x, SO.sub.x, and CO.sub.2 from exhaust gas exhausted from a vessel engine and increasing CO.sub.2 solubility and CO.sub.2 removal efficiency by removing CO.sub.2 after removing SO.sub.x.

A process for the treatment of contaminated water includes contacting the contaminated water with a cryptocrystalline magnesite-bentonite clay composite thereby to remove one or more contaminants from the water. The invention extends to a method for the manufacture of a cryptocrystalline magnesite-bentonite clay composite wherein an admixture of cryptocrystalline magnesite and bentonite clay is milled to a desired particle size with amorphization of the magnesite and bentonite clay in the resultant cryptocrystalline magnesite-bentonite clay composite, and to a cryptocrystalline magnesite-bentonite clay composite.

Provided are a system and a method of treating wastewater. The system includes a wastewater chamber, positive and negative electrode chambers, acid and basic solution chambers and a buffer chamber. The wastewater chamber receives wastewater containing a first ion. The positive and the negative electrode chambers are respectively on opposite sides of the wastewater chamber. The acid chamber is between the wastewater chamber and the positive electrode chamber. The basic chamber is between the wastewater chamber and the negative electrode chamber. The buffer chamber is between one of the acid and the basic chambers and the wastewater chamber, and receives the buffer solution containing the first ion. The interfaces between the wastewater chamber and the buffer chamber and between the one of the acid and the basic chambers and the buffer chamber are ion exchange membranes having the same electrical properties.

A method of reducing hydrogen sulfide content in a medium is disclosed. The method may include the steps of contacting a medium containing hydrogen sulfide with an effective amount of hydrogen peroxide, contacting the medium with an oxidizing agent, converting the hydrogen sulfide to sulfate, and reducing the hydrogen sulfide content in the medium. The medium may be a gas or a liquid.