Abstract: An apparatus for filtering solid particulates from fluid flows having a honeycomb filter body formed by a matrix of thin, interconnected porous walls which define inlet and outlet faces of the body and a plurality of hollow inlet and outlet cells each extending through the body from at least one of the inlet or outlet faces, the thin walls having internal interconnected open porosity sufficient to allow the fluid to travel completely across the thin walls in their narrower dimension and through the thin walls in their longer dimensions between the inlet and outlet cells and to prevent at least a significant portion of the solid particulate material carried by the fluid from passing either completely across or through the walls. Solid particulate filtering occurs on all thin wall surfaces of the inlet cells regardless of whether those thin walls are shared with adjoining inlet or outlet cells.

Abstract: The filter of honeycomb construction has a matrix of thin, interconnected walls which define a multiplicity of cells and which have interconnected open porosity of a volume and size sufficient to enable the fluid to flow completely across the thin walls in their narrow dimensions between adjoining cells and through the thin walls in their longer dimensions between adjoining or neighboring cells and to restrict the particulates in the fluid from flowing either completely across or through any of the thin walls, and has the cells divided into an inlet group and an outlet group and providing the inlet group of cells with substantially greater desirably about 25% or more greater, collective thin wall surface area than is provided to the outlet group of cells. Portions of the inlet group cells adjoin one another and share in common the same thin wall.

Abstract: Apparatus for filtering solid particulates from suspension in fluid streams (especially carbon particulates from exhaust gas of diesel engines) comprising a honeycomb filter with thin porous walls defining cells extending therethrough, with the transverse cross-sectional shapes of the cells forming a repeating pattern of geometric shapes without interior corner angles of less than 30.degree. and with alternate cells forming an inlet group and an outlet group. The inlet group is open at the inlet face and closed adjacent the outlet face. The outlet group is closed adjacent the inlet face and open at the outlet face. Each cell of each group shares cell walls only with cells of the other group. The walls have a volume of substantially uniform interconnected open porosity and a mean pore diameter of the pores forming the open porosity lying within the area defined by the boundary lines connecting points 1-2-3-4 in FIG. 4.

Abstract: Immobilized enzyme composites comprising enzymes bonded to porous, high surface area support materials can be economically prepared by contacting "spent" composites with a solution of NaOCl to remove substantially all contaminants resulting from previous use of the composites and then reacting the cleaned support materials with a solution of active enzymes under conditions sufficient to permit the bonding of enzymes to the surfaces of the support materials.

Abstract: Highly porous MgO-Al.sub.2 O.sub.3 particulate support materials useful for the immobilization of glucose isomerase can be regenerated for reuse by circulating a sodium hypochlorite solution through the particles thereby permitting in situ enzyme carrier regeneration.

Abstract: Highly porous MgO-Al.sub.2 O.sub.3 support materials useful for the immobilization of glucose isomerase can be regenerated for reuse by pyrolysis under conditions sufficient to remove substantially all carbonaceous matter, followed by treatment with a neutralized citrate solution.