Abstract: A solid-state fluorometry instrument is provided. The instrument is based on either diode laser or light-emitting diode (LED) excitation sources that are capable of being used in a wide range of applications. The solid-state diode laser based fluorometer instrument monitors fluorescent tracers, particularly suitable for industrial water sample stream applications. Using the instrument, a solid-state diode laser or light-emitting diode (LED) is used as an excitation source to excite fluorescent tracer molecules. The fluorescence resulting from the diode laser excitation is imaged with a lens onto a silicon photodiode detector. An optical filter is placed between the sample cell and the photodiode detector to reject scattered laser light. The output from the photodiode is amplified to produce an output voltage proportional to the quantity of fluorescence striking the photodiode detector.

Abstract: The invention comprises a method for clarifying ink-laden water obtained from the recycling of paper stocks by treating said water with a hydrophilic dispersion polymer. The hydrophilic dispersion polymer of the invention is a copolymer of a diallyl N,N-disubstituted ammonium halide cationic monomer and (meth)acrylamide (AcAm). Following dosing with the polymer, a floc is formed. The floc contains ink and impurities which are removed from the water process stream by means of solid liquid separation; the solid liquid separation comprising a dissolved air flotation method. A preferred copolymer is formed from DADMAC and AcAm.

Abstract: The present invention provides a method of monitoring a papermaking system and unit operations contained therein to optimize the overall papermaking process. The method comprises employing a fluorescent tracer that is selectively carried through the entire papermaking system or in a specific unit operation and is sufficiently inert and sufficiently stable under the environmental and chemical conditions of the system from its addition point to the sampling point. A sample is withdrawn from the papermaking environment (either via `grab` or on-line side stream sampling) and the withdrawn sample subjected to analysis. The analysis comprises comparing the tracer concentration to a standard to determine the concentration of tracer in the sample and/or determining the time of first appearance of said tracer from addition point to the sampling point and/or subsequent decay of said tracer concentration at the sampling point.

Abstract: The invention comprises a method for clarifying ink-laden water obtained from the recycling of paper stocks by treating said water with a conventional coagulant followed by treatment with a hydrophilic dispersion polymer. The hydrophilic dispersion flocculant of the invention is a copolymer of dimethylaminoethyl (meth)acrylate methyl chloride quat (DMAEA.multidot.MCQ) cationic monomer and (meth)acrylamide (AcAm). Following dosing with the flocculant, a floc is formed. The floc contains ink and impurities which are removed from the water process stream by means of solid liquid separation; the solid liquid separation comprising a dissolved air flotation method.

Abstract: The invention is a method for clarifying ink-containing effluent water from recycled paper production which comprises the step of adding a water-soluble, surface active, silicon-containing polyelectrolyte polymer coagulant to the ink-containing effluent water from recycled paper production, wherein the polymer has from 0.01 to 10 mole percent of a vinyl alkoxysilane monomer. A preferred silicon-containing polyelectrolyte polymer is the product of a free radical synthesis from vinyltrimethoxysilane and diallyldimethylammoniumchloride monomers.

Abstract: The invention relates to the clarification of deinking process waters which result from the recycling of paper. More specifically, the present invention relates to the use of containing vinylamine as water clarifying agents in said processes.

Abstract: A method for deinking of repulped xerographic paper comprising adding an organic polymeric particulate and a substantially water insoluble organic ester to a repulped aqueous slurry containing xerographic toner particles in an amount sufficient to at least partially agglomerate the xerographic toner particles within the slurry to larger particle sizes; and removing the xerographic toner particles from the slurry by one or more liquid/solid separation techniques.

Abstract: A chemically modified electrode is provided for selectively and sensitively detecting the presence of precipitant within wastewater. A system and a method, utilizing the chemically modified electrode, are provided to monitor and control feed of a precipitant to a reservoir containing a fluid, such as wastewater, with metals therein. The chemically modified electrode in conjunction with a reference electrode are provided in the reservoir for measuring current flowing therebetween. In response, the feed of the precipitant may be controlled to maintain the current within a predetermined range.

Abstract: A method for deinking of repulped xerographic paper comprising adding an organic polymeric particulate and a substantially water insoluble organic ester to a repulped aqueous slurry containing xerographic toner particles in an amount sufficient to at least partially agglomerate the xerographic toner particles within the slurry to larger particle sizes; and removing the xerographic toner particles from the slurry by one or more liquid/solid separation techniques.

Abstract: Novel copolymers of polydiallyl dimethyl ammonium chloride and 3-acrylamido-3-methylbutanoic acid are useful in the clarification of deinking paper mill waste water resulting from the processing of recycled paper stock.