The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include: (a) a phosphonium compound; and (b) a compound having formula:
M(XO.sub.2).sub.n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.

The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include: (a) a phosphonium compound; and (b) a compound having formula:
M(XO.sub.2).sub.n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.

Embodiments of the present subject matter provide a biocidal composition comprising an aqueous mixture of (a) a phosphonium compound and (b) a polymeric ammonium compound, wherein the weight ratio of compound (a) to compound (b) is from 0.2:1 to 20:1, and wherein the phosphonium compound (a) has formula:

##STR00001## wherein each R is independently a C.sub.1-C.sub.6 alkyl group which is unsubstituted or substituted by a cyano, hydroxyl, esterified hydroxyl or aryl group; R.sup.1 represents a C.sub.8-C.sub.18 alkyl group which is substituted or unsubstituted; and X represents either chlorine or bromine; and wherein the polymeric ammonium compound (b) comprises the repeat unit:

##STR00002## wherein each R.sup.2 is independently a C.sub.1-C.sub.2 alkyl group which is substituted or unsubstituted; R.sup.3 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted; and R.sup.4 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted, a diethyl ether group, an isopropanol group, a N,N-dipropylurea group, or a 2-butene group.

In some embodiments, the biocidal composition has a synergy index (SI) of less than 1 in relation to the effect of the composition on the inhibition of growth of biological organisms.

Embodiments of the present subject matter provide a biocidal composition comprising an aqueous mixture of (a) a phosphonium compound and (b) a polymeric ammonium compound, wherein the weight ratio of compound (a) to compound (b) is from 0.2:1 to 20:1, and wherein the phosphonium compound (a) has formula:

##STR00001## wherein each R is independently a C.sub.1-C.sub.6 alkyl group which is unsubstituted or substituted by a cyano, hydroxyl, esterified hydroxyl or aryl group; R.sup.1 represents a C.sub.8-C.sub.18 alkyl group which is substituted or unsubstituted; and X represents either chlorine or bromine; and wherein the polymeric ammonium compound (b) comprises the repeat unit:

##STR00002## wherein each R.sup.2 is independently a C.sub.1-C.sub.2 alkyl group which is substituted or unsubstituted; R.sup.3 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted; and R.sup.4 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted, a diethyl ether group, an isopropanol group, a N,N-dipropylurea group, or a 2-butene group.

In some embodiments, the biocidal composition has a synergy index (SI) of less than 1 in relation to the effect of the composition on the inhibition of growth of biological organisms.

Embodiments of the present subject matter provide a biocidal composition comprising an aqueous mixture of (a) a phosphonium compound and (b) a polymeric ammonium compound, wherein the weight ratio of compound (a) to compound (b) is from 0.2:1 to 20:1, and wherein the phosphonium compound (a) has formula:

##STR00001## wherein each R is independently a C.sub.1-C.sub.6 alkyl group which is unsubstituted or substituted by a cyano, hydroxyl, esterified hydroxyl or aryl group; R.sup.1 represents a C.sub.8-C.sub.18 alkyl group which is substituted or unsubstituted; and X represents either chlorine or bromine; and wherein the polymeric ammonium compound (b) comprises the repeat unit:

##STR00002## wherein each R.sup.2 is independently a C.sub.1-C.sub.2 alkyl group which is substituted or unsubstituted; R.sup.3 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted; and R.sup.4 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted, a diethyl ether group, an isopropanol group, a N,N-dipropylurea group, or a 2-butene group.

In some embodiments, the biocidal composition has a synergy index (SI) of less than 1 in relation to the effect of the composition on the inhibition of growth of biological organisms.

The present invention relates to water treatment. In one embodiment there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method comprises adding treatment agents to said aqueous system and wherein said treatment agents comprise: (a) a phosphonium compound; and (b) a halogen oxide compound.

The present invention relates to water treatment. In one embodiment there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method comprises adding treatment agents to said aqueous system and wherein said treatment agents comprise: (a) a phosphonium compound; and (b) a halogen oxide compound.

The present invention relates to water treatment. In one embodiment there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method comprises adding treatment agents to said aqueous system and wherein said treatment agents comprise: (a) a phosphonium compound; and (b) a halogen oxide compound.

Methods and compositions for biofilm removal in industrial applications and systems with prevalent biofilm and/or slime are disclosed. Various industrial processing, such as food and beverage processing, mining pipelines, cooling towers, and energy services applications benefit from the biofilm removal disclosed herein. In particular, the methods and compositions employ alumina nanoparticles alone or in combination with conventional biocides to remove biofilm and/or slime.

Methods and compositions for biofilm removal in industrial applications and systems with prevalent biofilm and/or slime are disclosed. Various industrial processing, such as food and beverage processing, mining pipelines, cooling towers, and energy services applications benefit from the biofilm removal disclosed herein. In particular, the methods and compositions employ alumina nanoparticles alone or in combination with conventional biocides to remove biofilm and/or slime.