Abstract: Fluid purification systems employing a monolithic composite photocatalyst to remove volatile organic compounds (VOCs) and/or pathogenic organisms are disclosed. Pairing of systems tuned to abate each of these materials are discussed in different configurations such as series and parallel, as well as combining systems to target both materials simultaneously. System configurations that allow a portion of the fluid stream to be purified are also disclosed as are configurations that allow regeneration of the photocatalyst. These features may be augmented by sensors that allow closed loop control of bypass and regeneration cycles in the systems.

Abstract: A method of and substances for reducing pitch in pulping and papermaking operations, particularly in furnishes made by mechanical pulping processes containing wood pulp in amounts greater than about 10% by weight, are disclosed. The method comprises adding to a pitch-containing furnish a stable, water dispersible particulate composite substance prepared by irreversibly adsorbing a water soluble cationic polymer, e.g., a poly(diallyldimethylammonium chloride), onto an essentially water insoluble particulate substrate, e.g., kaolin, thereby rendering the cationic polymer insoluble and immobile, the cationic polymer being sufficiently electropositive so that the particulate composite pitch control substance exhibits a zeta potential of at least about +30 mV, and preferably from about +60 mV to about +80 mV, the amount of the composite substance added to the furnish being effective to finely disperse pitch for removal as finely-dispersed pitch-containing aggregates in a paper sheet produced from said furnish.