The present invention relates generally to stable percarboxylic acid compositions comprising, inter alia, at least two stabilizing agents, and various uses for water treatments, including water treatments in connection with oil- and gas-field operations. The present invention also relates to slick water compositions and gel based compositions that comprise stable percarboxylic acid compositions and the use thereof in oil- and gas-field operations.

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.

A method for degrading organic fractions in cooling circuits in industrial plants, in particular plants in the metallurgical industry, including the following steps: adding bacteria to the cooling circuit, wherein the bacteria are suitable for degrading the organic fractions in the cooling circuit, and disinfecting the aerosol generated in a cooling tower of the cooling circuit. A cooling circuit for an industrial plant is also disclosed.

The present invention provides a continuous mobile monitoring unit of a flow of cooling water comprising means to extract a flow of cooling water, means to analyze a plurality of parameters of the cooling water by means of diverse analytical techniques, generating results relating to each one of the parameters analyzed, and means to return the flow of cooling water to the cooling system (1). In addition, the invention furthermore provides a method of continuous monitoring of the flow of cooling water comprising the stages of: extracting a flow of cooling water, analyzing a plurality of parameters of the cooling water by means of diverse analytical techniques, generating results relating to each one of the parameters analyzed, and returning the cooling water to the cooling system (1).

Membrane filtration systems can be used to purify liquid streams for downstream use. In practice, foulant can build-up on the surface of a membrane within a filtration system over time. The effectiveness of the filtration system will deteriorate if the fouling is not properly controlled. In some examples, a method of controlling membrane fouling in a pressurized membrane system involves supplying a feed stream that is predominately air mixed with water to the membrane. In other words, the feed stream a greater volume of air than water, even though it is the water being processed by the membrane. Supplying the pressurized membrane system with a feed stream that contains a greater volume of air than water can yield significantly better performance than supplying the membrane with a feed stream that contains a greater volume of water than air.

A method of inhibiting scale in an industrial water system includes the steps of dosing the industrial water system with a water treatment polymer comprising at least 10 mol % of carboxylic acid monomer and a quaternized naphthalimide fluorescent monomer as disclosed herein, and then monitoring the fluorescence of the water system. The polymers are also useful for flocculation and coagulation in wastewater treatment.

In some embodiments, a method may include treating pulp in pulp and paper mills. The methods may include providing a peracetate oxidant solution and generating a reactive oxygen species. The peracetate solution may include peracetate anions and a peracid. In some embodiments, the peracetate solution may include a pH from about pH 10 to about pH 12. In some embodiments, the peracetate solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1. In some embodiments, the peracetate solution has a molar ratio of peracetate to hydrogen peroxide of greater than about 16:1. The peracetate oxidant solution may provide enhanced treatment methods of bleaching, brightening, and delignifying pulp fibers involving the use of peracetate oxidant solutions.

The cooling device for a power source for a ship propulsion device that pumps up cooling water, from which foreign matters with sizes that cause clogging of a cooling water route have been removed, supplies the cooling water to a cooling water passage (30), and discharges the cooling water to outside after cooling a power source (10) includes: a cartridge-type filtration device (40, 73) that is provided at a midpoint of a first water passage (36, 71) in the cooling water route and incorporates a filter (45, 46) for filtrating foreign matters remaining in the cooling water; and a second water passage (38, 72) that is branched from the first water passage and adapted such that a valve member (53) is opened to cause the cooling water to flow in a case in which clogging occurs in the filter.

A chiller water sampling device includes a pair of flow meters and a proportional valve to provide a constant flow rate of sample water containing peroxyacetic acid from a chiller to a mixing tank. Acid can be added to reduce the pH of sample water in the mixing tank to bring the pH within the operating range of a peroxyacetic acid sensor. The sensed level of peroxyacetic acid can be used to control further addition of peroxyacetic acid to the chiller.

A circulating water preparation system for cooling plants, a cooling system, in particular a recooling system, and a method for operating such a cooling system. In such a cooling system a surface of a heat exchanger is cooled by wetting with water, the water is collected in a collecting tank and returned by means of a water circuit for the renewed wetting of the surface of the heat exchanger. The method is characterised in that the water is purified by means of a filter, in particular a membrane filter. As a result considerably less biocide is needed to keep the water free of germs, in particular legionella, compared to conventional cooling systems or methods for operating such cooling systems.