The present disclosure describes a process for the use of peracid compositions to eliminate and/or control the growth of undesirable bacteria, including contaminating bacteria, in water systems is disclosed. Beneficially, the peracid compositions and methods of use of the same are effective in reducing or eliminating both planktonic and sessile bacterial contamination.

The present invention relates to a system and a method for abating the presence of a selected chemical substance in wastewater flowing in a wastewater channel system from an upstream position to a downstream position. The method typically comprising dosing into the wastewater, at the upstream position, chemical agent(s) adapted to abate the presence of said selected chemical substance, wherein the dosing is in an amount set by a dosing set-point, and adjusting the dosing set-point based on determinations of the concentration of the selected chemical substance at the downstream position. The invention involves comparison between a determined concentration and a pre-selected fractile and adjusting a dosing set-point based thereon.

A multistage desalination process for treatment of seawater or salt wastewater. During initially processing the seawater or salt wastewater is treated to precipitate scaling minerals as phosphates including magnesium ammonium phosphate useful as a fertilizer. During the initial phase, ammonium phosphate and sodium phosphate are added to the seawater or salt wastewater followed by an addition of ammonia and a water-based charged solvent. After separating the precipitated solids, the cleaned seawater or salt wastewater is aerated and filtered to produce potable or otherwise usable water.

A water conditioning composition includes at least one gluconate compound; at least one carbonate compound; one or more compounds which form a phosphate buffer when dissolved in water; and a filler material, where the composition does not include a non-ionic preservative. For example, the composition can include 6 to 12 wt. % of the at least one gluconate compound; 35 to 50 wt. % of the at least one carbonate compound; 10 to 30 wt. % of the one or more compounds which form the phosphate buffer when dissolved in water; and 20 to 40 wt. % of the filler material.

A water purification system comprises a bioreaction subsystem receiving contaminated input effluent and having a gas-lift anaerobic membrane bioreactor removing urea and organic matter to create a first effluent. A light-treatment subsystem receives the first effluent and exposes the first effluent to UV light to create a second effluent free from microorganisms. A reactor subsystem fluidically connects an ammonia-reducing reactor to the UV output and receives UV-treated second effluent and has a struvite regenerator connected to the ammonia-reducing reactor output, separating ammonia from the second effluent in the ammonia-reducing reactor, and outputting the ammonia. A separation subsystem fluidically connects to the reactor output and receives the second effluent substantially free from ammonia and has a continuous electro-deionization device separating brine/salts from the second effluent to produce potable water. A closed-loop includes an ammonia-converting subsystem and a sequential fertilizer producer.

A process of treating nano-filtration membrane retentate comprises introducing seawater comprising a sulfate ion concentration of greater than or equal to 3000 mg/l to the NF membrane to produce a retentate stream and a permeate stream, wherein the retentate stream has a sulfate ion concentration greater than or equal to 10,000 mg/l, and mixing barium additives comprising barium chloride dehydrate (BaCl.sub.2.Math.2H.sub.2O), barium chloride (BaCl.sub.2), or both with the retentate stream to precipitate sulfate from the retentate stream to form barite (BaSO.sub.4) and reduce the sulfate ion concentration, wherein the barium additives are added into the retentate stream at a barium ion concentration of greater than 10,000 mg/l.

A process for extracting a surfactant from a mixture using a boronic acid modified material.

A multi-branched cationic phosphonium salt is provided. The multi-branched cationic phosphonium salt has a structure represented by formula (I):

{Z[P.sup.+(R.sup.1)(R.sup.2)(R.sup.3)].sub.n}(X.sup.).sub.n(I) wherein each of R.sup.1, R.sup.2, and R.sup.3 is independently a linear or branched C.sub.1C.sub.10 alkyl group, X.sup. is an organic or inorganic anion, and Z has a structure represented by Formula (IIb) or Formula (IIc):

##STR00001## wherein a is an integer of 115. In Formulas (IIb) and (IIc), Z is connected to [P.sup.+(R.sup.1)(R.sup.2)(R.sup.3)] at the position marked by an asterisk (*), and n is an integer of 34.

Selective scaling in water treatment systems in which desalination is performed is generally described. According to certain embodiments, the location of the formation of solid scale within a water treatment system is controlled by adjusting one or more system parameters, such as the temperature and/or flow velocity of a saline stream within the water treatment system.

The invention provides methods and compositions for utilizing encapsulated tracer dyes in difficult liquids such as wastewater or with highly reactive treatment chemicals such as aluminum-based coagulants. In difficult liquids or highly reactive treatment chemicals even so-called inert tracers end up reacting and their fluorescence changes. As a result they are inconsistent and cannot be used to measure the amount of treatment chemical present. But by encapsulating the tracer dyes, even non inert tracer dyes become inert and they can reliably be used to measure the amount of treatment chemical present even if highly reactive or in a difficult liquid.