A system is provided for removing arsenic from water to safe levels at or below the EPA standards. The system is a hybrid spouted vessel/fixed bed filter system that significantly enhances/improves arsenic removal for drinking water using zero-valent iron (ZVI) particles. Movement of the circulating, iron-containing particles in a dense moving bed that forms on the spouted vessel bottom creates an abrasive “self-polishing” action among them that continuously generates colloidal iron corrosion products. This material then circulates with the water in the vessel and is removed and concentrated in a fixed bed filter. The colloidal material captured and immobilized in the filter has been shown to remove arsenic from contaminated water at very rapid rates.

A batch reactor includes a first portion, a second portion, a first drainage tank, a second drainage tank, and a first flow control mechanism. The first portion includes a first chamber, a second chamber, and a third chamber in fluid communication with one another configured for a flow of at least one biomaterial therethrough. The second portion includes a first chamber and a second chamber in fluid communication with one another configured for a flow of the least one biomaterial therethrough. The first drainage chamber is in fluid communication with the first and second chambers. The second drainage chamber is in fluid communication with the third chamber of the first portion and the second chamber of the second portion. The first flow control mechanism is disposed between the third chamber of the first portion and the first chamber of the second portion.

A scale suppression apparatus capable of suppressing in a low-priced manner the generation of silica-based scale and calcium-based scale in the influent water containing at least a silica component and a calcium component, a geothermal power generation system using the same, and a scale suppression method are provided. The scale suppression apparatus includes a chelating agent and alkaline agent addition unit injecting liquid containing a chelating agent and an alkaline agent into a pipe arrangement through which influent water such as geothermal water or the like flows, and a controller controlling a pump and a valve of the chelating agent and alkaline agent addition unit. The controller controls the injection of the chelating agent and the alkaline agent and stops of the injection based on the signal output from a scale detection unit for detecting a precipitation state of the scale.

Disclosed are magnetic nanoparticles and methods of using magnetic nanoparticles for selectively removing biologics, small molecules, analytes, ions, or other molecules of interest from liquids.

Disclosed herein is a method for inhibiting scale comprising adding to a fluid that causes scale formation a polycarboxylic acid having a polymer backbone and a plurality of branches from the polymer backbone.

Iron contaminants are removed from hydrocarbon oils, and from produced water or flowback water by-products of oil and gas production, by treatment of such liquids with a composition comprising a two-tail lipid compound. The lipid binds iron to form a lipid/iron phase in the liquid, which is then removed to provide a liquid with a reduced iron level.

A treatment process for preparing a remediated liquid from a contaminated liquid originally containing more than 5 ppm hydrogen sulfide (H.sub.2S) and substantially without formation of precipitate, includes steps of steps of adding an aqueous solution containing at least one hydroxide compound at a collective concentration of 35-55 wt % to the contaminated liquid to achieve a concentration of 125-5000 ppm of the hydroxide compounds in the contaminated liquid, adding a fulvic acid and/or a humic acid to the contaminated liquid to achieve a concentration of 0.01-10 ppm of the acid(s) in the contaminated liquid, and dispersing the aqueous solution and the at least one organic acid in the contaminated liquid and allowing the aqueous solution and the at least one organic acid to react with the contaminated liquid for a period of time until a concentration of hydrogen sulfide in the contaminated liquid is reduced to ≤5 ppm.

The object is to provide a wastewater treatment method and a wastewater treatment system that reduce the total selenium concentration of treated water while reducing cost compared to conventional methods of removing selenium by oxidation. In the wastewater treatment method according to the present disclosure, an iron agent is added to waste water containing selenium and cyanogen to form a first coagulated substance, the first coagulated substance is removed by solid-liquid separation to obtain first treated water, a second iron agent is added to the first treated water, an acid is added to the first treated water to obtain acidic water, an oxidizing agent is added to the acidic water to oxidize the selenium, a coagulant is then added to form a second coagulated substance, and the second coagulated substance is removed by solid-liquid separation to obtain second treated water.

An organic polymer composition (OPC) comprising guanidinium-containing A units interconnected with B units of the formula *—R*).sub.r, wherein each asterisk (*) in A units denotes a connection point with an asterisk in B units; R is a hydrocarbon linking group containing at least one carbon atom; r is an integer of 1, 2, or 3; and the composition necessarily includes an anionic species X.sup.m− with a magnitude of charge m of at least 1, wherein the sum of negative charge provided by anionic species X.sup.m− counterbalances the total positive charge provided by the A units. Also described herein is a method for removing one or more oxoanions from an aqueous source by (i) contacting the aqueous source with the above described OPC to result in absorption of the oxoanion into the OPC to produce an oxoanion-containing OPC; and (ii) removing the oxoanion-containing OPC from the aqueous source.

The present embodiments generally relate to the treatment of produced water comprising one or more water soluble polymers, wherein such treatment comprises: adding to the produced water at least one iron complex; and degrading at least a portion of the one or more water soluble polymers. This treatment may result in a reduction of the viscosity of said produced water and/or the degradation of the water soluble polymers which are contained therein.