A synergistic composition comprising a THP salt and a biopenetrant, in which the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being terminated by a mono- or diphosphonated unsaturated carboxylic acid group or having such monomers incorporated into the polymer backbone. This composition acts synergistically to enhance the biocidal efficacy of the THP salt against both planktonic (free-swimming) and sessile (attached) bacteria, and also acts synergistically to enhance the efficacy of the THP salt in the dissolution of iron sulphide scale.

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer, or salt thereof, to one or more stages of a wet process phosphoric acid production stream are provided herein, wherein the primary amine-containing polymer includes an A mer according to Formula (I): ##STR00001## where R is H, C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.6 alkenyl, halide, or carboxyl; R.sup.1 is H, C.sub.1-C.sub.6 alkyl, or C.sub.2-C.sub.6 alkenyl; R.sup.2 is H or an A mer according to Formula (I) as herein defined; R.sup.3 is chosen from a direct bond or a C.sub.1-C.sub.12 alkyl, C.sub.2-C.sub.12 alkenyl, or a C.sub.6-C.sub.12 aryl group; and n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and
wherein the percentage of primary amines in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer, or salt thereof, to one or more stages of a wet process phosphoric acid production stream are provided herein, wherein the primary amine-containing polymer includes an A mer according to Formula (I): ##STR00001## where R is H, C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.6 alkenyl, halide, or carboxyl; R.sup.1 is H, C.sub.1-C.sub.6 alkyl, or C.sub.2-C.sub.6 alkenyl; R.sup.2 is H or an A mer according to Formula (I) as herein defined; R.sup.3 is chosen from a direct bond or a C.sub.1-C.sub.12 alkyl, C.sub.2-C.sub.12 alkenyl, or a C.sub.6-C.sub.12 aryl group; and n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and
wherein the percentage of primary amines in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

The present invention addresses the problem of providing a technique for a metal corrosion protection treatment for a water system, whereby it becomes possible to achieve a satisfactory anticorrosive effect without using a phosphorus compound, which is a causative substance for eutrophication, as a metal anticorrosive agent and it also becomes possible to achieve a satisfactory anticorrosive effect in high-hardness water as well as low-hardness water. The present invention can provide: a metal corrosion protection treatment method for a water system, in which a component (A) and a component (B) as mentioned below are allowed to be present at a usage ratio of 1:9 to 7:3 by mass in the water system; and (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid monomer, and (B) a maleic acid-based polymer in which the carboxyl group content is 11.5 mmol/g or more.

A process for preventing the formation of white rust on a steel surface at least partially coated with zinc includes a) bringing said surface, preferably under thermal load, into contact with an aqueous composition, the pH of which is between 6.5 and 8.5 comprising at least one organic acid of formula:
RXOH(I) wherein X represents C(O) or S(O)2, and R represents an organic chain. A composition and also to a cooling tower treated by the process are provided.

A process for preventing the formation of white rust on a steel surface at least partially coated with zinc includes a) bringing said surface, preferably under thermal load, into contact with an aqueous composition, the pH of which is between 6.5 and 8.5 comprising at least one organic acid of formula:
RXOH(I) wherein X represents C(O) or S(O)2, and R represents an organic chain. A composition and also to a cooling tower treated by the process are provided.

Glycine is an organic compound that can be used in the making of a synthetic acid that obviates all the drawbacks of strong acids such as hydrochloric acid. The new compound is made by dissolving glycine in water, in a weight ratio of approximately 1:1 to 1:1.5. The solution is mixed until the glycine is essentially fully dissolved in the water. Once dissolution is complete, hydrogen chloride gas is dissolved in the solution to produce the new compound, which can be referred to as hydrogen glycine. Also disclosed is a method for adjusting the pH of a fluid, the method comprising adding an effective amount of a solution to the fluid for adjusting the pH thereof to a desired level, wherein the solution is prepared by mixing glycine in water to form a glycine solution; and adding hydrogen chloride to the glycine solution.

A phosphorus-free corrosion and scale inhibitor used in circulating cooling water of central air conditioning is provided, which contains tourmaline, green corrosion and scale inhibitor, zinc salt and the like, wherein the content of the tourmaline is 5-500 g/t (calculated based on solid form); the content of the green corrosion and scale inhibitor is 5-50 g/t (calculated based on liquid form); and the content of the zinc salt is 0.2-0.8 g/t (calculated based on solid form), wherein the tourmaline includes dravite, schorlite, elbaite, manganese tourmaline, uvite or the like. The green corrosion and scale inhibitor contains any one, or two or three of polyaspartic acid, polyepoxysuccinic acid and polymaleic acid. Copper corrosion can be effectively inhibited by adding 0.2-2 g/t of benzotriazole (calculated based on solid form) into copper-containing devices. Also disclosed is a method of preparing the phosphorous-free corrosion and scale inhibitor used in circulating cooling water of central air conditioning.

The present invention provides a process of oxygenated feed-water treatment of boilers in power station, carried out under an OT treatment process, suitable for both the monotube type boiler and the drum type boiler, and comprising an oxygenation stage comprising: a normal oxygenation converting stage and a decreased oxygenation film-supplementing stage; the normal oxygenation converting stage is a stage in which the feed water system is oxygenated both at the outlet of a condensate polishing system and at the inlet of a feed water pump of a high pressure feed water system, and the concentration of dissolved oxygen in the main steam is controlled to be 5 g/L; the decreased oxygenation film-supplementing stage is a stage in which, after an oxide film is formed in the feed water system, the amount of oxygenation at the high pressure feed water system is decreased so that the amount of the oxygen added is only for supplementing and maintaining the oxide film, while the concentration of dissolved oxygen in the main steam is controlled to be 5 g/L. It can ensure that a dense protection film can be formed and maintained on the metal surface of the pipes in a feed water system, thereby reducing the iron content in the feed water; excessive oxygen is prevented from entering the high temperature heating surface and causing the peeling off of the oxide skin; and the amount of oxygen consumed is significantly reduced, thereby decreasing the amount of maintenance.

The present invention provides a process of oxygenated feed-water treatment of boilers in power station, carried out under an OT treatment process, suitable for both the monotube type boiler and the drum type boiler, and comprising an oxygenation stage comprising: a normal oxygenation converting stage and a decreased oxygenation film-supplementing stage; the normal oxygenation converting stage is a stage in which the feed water system is oxygenated both at the outlet of a condensate polishing system and at the inlet of a feed water pump of a high pressure feed water system, and the concentration of dissolved oxygen in the main steam is controlled to be 5 g/L; the decreased oxygenation film-supplementing stage is a stage in which, after an oxide film is formed in the feed water system, the amount of oxygenation at the high pressure feed water system is decreased so that the amount of the oxygen added is only for supplementing and maintaining the oxide film, while the concentration of dissolved oxygen in the main steam is controlled to be 5 g/L. It can ensure that a dense protection film can be formed and maintained on the metal surface of the pipes in a feed water system, thereby reducing the iron content in the feed water; excessive oxygen is prevented from entering the high temperature heating surface and causing the peeling off of the oxide skin; and the amount of oxygen consumed is significantly reduced, thereby decreasing the amount of maintenance.