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.

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.

A water treatment chemical for membranes, which contains a polymer compound having a carboxyl group and a sulfo group, preferably a polymer compound represented by formula (1). A membrane treatment method wherein this water treatment chemical for membranes is added to membrane feed water when water to be treated, which contains an organic compound having a phenolic hydroxy group, is subjected to a membrane separation treatment.

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In the formula, m and n represent molar percentages of respective structural units; (m+n) is 90-100%; and R represents an anionic group containing a sulfo group.

A method of inhibiting carbonate scale in an industrial water system includes the steps of dosing the industrial water system with a water treatment polymer comprising at least 60 mol % of carboxylic acid monomer and a quaternized naphthalimide fluorescent monomer as disclosed herein, and then monitoring the fluorescence of the water system. If both maleic acid and phosphino moieties are included in the water treatment polymer, then the maleic acid is present as no greater than 70 mol % of the water treatment polymer. If the polymer contains a sulfonic acid monomer, the polymer is a fluorescence efficient polymer.

Multiple chemical dosing levels of differing chemical dosages are set. When control is initiated, chemical dosing is started at the level with the highest chemical dosage. Each time a sampling period S passes, the rate of increase in the pressure difference of an RO system is compared with a threshold value A. When the rate of increase is at or below the threshold value A, the chemical dosage is reduced to the level that is one step lower. When the rate of increase is greater than the threshold value A, the chemical dosage is increased to the level that is one step higher.

The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

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.

The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

A water desalination system includes a first set of ultrafiltration membranes, a second set of ultrafiltration membranes, a first backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with brine generated by a reverse osmosis process, and a second backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with one or more chemicals and reverse osmosis permeate water.

A novel multi-stage reverse osmosis system is proposed that allows for following benefits a) reduction in pressure-loss while achieving optimum cross-flow velocities and therefore reducing energy consumption of 4-10%; b) increased flux balance between stages resulting in reduced fouling of the first stage; c) disruption of scale forming conditions resulting in reduced scaling of the last stage; d) reduction in scale potential of the concentrate valve; e) reduction in downtime for CIP by proactively disrupting scaling or fouling through several innovative methods; f) ease-of and effectiveness-of CIP with reduced number of valves and g) to keep system operational via isolation of the last stage for maintenance while the keeping remaining system in production mode. All the above improvements are achieved with process-flow and operational characteristics defined in the Specifications and Claims.