Abstract: The invention is a method to inhibit the growth of at least one microorganism in an aqueous system capable of supporting such growth. This includes controlling, and preferably preventing, slime formation in the aqueous system. The method mixes a persulfate salt, a bromide salt, and water under conditions sufficient to form an active bromine-containing, [Br+], solution and then adds an effective amount of the active bromine-containing solution to an aqueous system to inhibit the growth of at least one microorganism in the aqueous system. Also, the invention is a method to inhibit the growth of at least one microorganism on a substrate capable of supporting such growth. The method contacts the substrate with an effective amount of active bromine-containing solution to inhibit the growth of at least one microorganism on the substrate. Combining an amine source with the persulfate salt and bromide salts generates an active bromine-containing solution which also contains bromamines.

Abstract: The invention relates to a method to inhibit bacteria from adhering to a submergible surface. The method contacts the submergible surface with an effective amount of at least one sulfamic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling biofouling of an aqueous system. This method adds an effective amount of at least one sulfamic acid or salt thereof to inhibit bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the fouling organisms. The sulfamic acid used in the method of the invention has the formula R1R2NS(O)2(OH). In this formula, R1 and R2 are independently a hydrogen, a C4-C20 alkyl group or a cyclohexyl group. However, R1 and R 2 are not both hydrogen.

Abstract: A biofouling monitor is described which has a column having an inlet and an outlet; a microorganism nutrient feed line located upstream of the inlet; and a first pressure sensor located upstream of the inlet for measuring flow pressure and a second pressure system located downstream of the outlet for measuring flow pressure. Also described is a biofouling monitor which further has a recirculation system and optionally inert packing material located in the column. A method to monitor or detect biofouling ahead of time in an aqueous system is further described.

Abstract: 5′-substituted, 4′,5′-dihydropsoralen compounds (5) bearing tertiary amines (and salts thereof), quaternary ammonium moieties or organomercurial moieties are described. Also described are 2-substituted mercurimethyl-2-3-dihydro-benzofurans of forumla (7): Also reported are versatile direct syntheses through a hitherto unknown compounds such as 3-R-4,8-dimethyl-4′,5′-dihydro-5′-bromomethylpsoralen or a 3-R-4,8-dimethyl-4′, 5′-dihydro-5′-iodomethylpsoralen to prepare a structurally diverse array of partially reduced psoralens and benzofurans. The presence of a permanent ammonium charge in these psoralens precludes membrane passage and the mono-unsaturation precludes the cross-linking of nuclear DNA, thereby minimizing the mutagenic/carcinogenic side effects long associated with psoralen-derived therapies.

Abstract: A composition for minimizing biological and/or colloidal fouling is described, which includes an anionic antiscalant and a cationically charged biocide. Further, a method of controlling fouling is described and achieved by introducing a formulation of the present invention into an aqueous system which uses a separation membrane. The compositions used in the present invention are compatible with such separation systems and preferably prevent membrane fouling.

Abstract: The invention relates to 4′-substituted-4′,5′-dihydropsoralen compounds of formula(V): In the formula R is hydrogen, a halogen, CN or an acyl group; T is a halogen, CN, a carboalkoxy group NR1R2, or (N+R1R2R3)X−, R1 and R2 are independently a C1-C6 alkyl, or R1 and R2 together with the nitrogen form a 5-8 member heterocyclic ring, or when T is (N+R1R2R3)X−, R1 and R2 together with the nitrogen form a 5-8 member heterocyclic ring or heterocyclic aromatic ring; R3 is hydrogen, a C1-C12 alkyl, or, when R1 and R2 together with the nitrogen form a heterocyclic aromatic ring, R3 is a double bond within the heterocyclic aromatic ring; X− is a halide. In another embodiment, the invention relates to processes for preparing 4′-substituted-4′,5′-dihydropsoralen compounds described above.

Abstract: The invention relates to a method to inhibit bacteria from adhering to a submergible surface. The method contacts the submergible surface with an effective amount of at least one sulfamic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling biofouling of an aqueous system. This method adds an effective amount of at least one sulfamic acid or salt thereof to inhibit bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the fouling organisms. The sulfamic acid used in the method of the invention has the formula R.sup.1 R.sup.2 NS(O).sub.2 (OH). In this formula, R.sup.1 and R.sup.2 are independently a hydrogen, a C.sub.4 -C.sub.20 alkyl group or a cyclohexyl group. However, R.sup.1 and R.sup.2 are not both hydrogen. Alternatively, R.sup.1 and R.sup.

Abstract: The invention relates to a method to inhibit bacteria from adhering to a submergible surface. The method contacts the submergible surface with an effective amount of at least one amino methyl phosphonic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling biofouling of an aqueous system. This method adds an effective amount of at least one amino methyl phosphonic acid or salt thereof to inhibit bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the fouling organisms. The amino methyl phosphonic acid used in the methods of the invention has the formula R.sup.1 R.sup.2 NCH.sub.2 P(O)(OH).sub.2. In this formula, R.sup.1 and R.sup.2 are independently a C.sub.6 -C.sub.20 alkyl group or a CH.sub.2 P(O)(OH).sub.2 group. However, R.sup.1 and R.sup.2 are not both a CH.sub.2 P(O)(OH).sub.2 group. Alternatively, R.sup.1 and R.sup.

Abstract: Metals contained in various wastewaters are selectively recovered as metal precipitates and/or as spinel ferrite and water suitable for discharge into the environment is obtained. High grade magnetic spinel ferrite is recovered from wastewaters having aluminum and arsenic if present in the wastewater, removed from the wastewater. There are three process stages for the treatment of wastewater. In the first process stage which is optional, at least a portion of at least one non-ferrous or non-ferric metal is precipitated from the wastewater by subjecting the wastewater to an oxidizing agent to increase the oxidation-reduction potential of the water, by adjusting the pH of the wastewater to a pH at which the metal precipitates from the water and by adding an organic or inorganic sulfur compound, capable of causing the metal to form a precipitate, to the water in a quantity sufficient to precipitate the metal.

Abstract: A method for controlling the chemical treatment of a solution comprises the steps of feeding a treatment chemical into the solution, applying an external voltage across a reference electrode and a working electrode of a voltammetric sensor while the electrodes are immersed in the solution, measuring a current that flows through the working electrode, converting the measured current into a feedback signal indicative of the concentration of treatment chemical in the solution, and using the feedback signal to control the rate of feeding the treatment chemical.

Abstract: Halogenated 4'-methoxyacetophenones of formula I: ##STR1## wherein X is a halogen; Y is a halogen; and n is 1 or 2 as microbicides for inhibiting the growth of microorganisms in aqueous systems and on surfaces, as well as for inhibiting slime formation in aqueous systems and biocidal compositions containing effective amounts of the halogenated 4'-methoxyacetophenones.

Abstract: Discoloration of surfaces, such as painted or treated wood surfaces, by tannin-staining caused by the complexing of certain transition metal ions with tannate ions (the process is often referred to in the art as "tannin-stain bleed") is reduced or prevented by contacting a transition metal ion on a painted surface or surface to be painted with a complexing agent for the transition metal ion, such as by the addition of the complexing agent for the transition-metal ion to paint formulations or by pretreatment of the wood surface with the complexing agent before painting. It is believed that the complexing agents form coordination complexes with transition-metal ions on the surface of and within the paint film, thus preventing the formation of highly-colored complexes of the transition metal ions with the tannate ions derived from the tannins in the wood.