(under subclass 601) Process including a step of drying or compression of solids to lower the liquid content.
(1) Note. For placement in this subclass, a treatment by living organism step must be positively recited.
SEE OR SEARCH THIS CLASS, SUBCLASS:
702+, for dewatering of sludge by addition of a precipitant.
767+, for dewatering of sludge, per se, which sludge may have been derived by treatment by living organism.
SEE OR SEARCH CLASS
34, Drying and Gas or Vapor Contact With Solids, appropriate subclasses for processes and apparatus for drying sewage sludge which do not include decomposition of the sewage.
71, Chemistry: Fertilizers, 12+, for processes of making fertilizer from sewage which go beyond mere drying of the sludge.
516, Colloid Systems and Wetting Agents; Subcombinations Thereof; Processes of Making, Stabilizing, Breaking, or Inhibiting,
98+, for colloid systems of continuous or semicontinuous solid phase with discontinuous liquid phase (flocs, coagulates) or agents for such systems or making or stabilizing such systems or agents, subclasses 113+ for compositions for or subcombination compositions for or breaking of or inhibiting of colloid systems (e.g., foam breaking, emulsion breaking, dispersion inhibiting, suspension settling, gel breaking, smoke suppressing, coagulating, flocculating); in each instance, when
generically claimed or when there is no hierarchically superior provision in the USPC for the specifically claimed art. Class 516 is the locus for the breaking of colloid systems generically claimed and provides for (a) the separation or purification of liquids, generally claimed, when performed by a Class 516 process, such as by breaking an emulsion, dispersion, or foam, and for such processes further including ancillary steps, such as, decanting, or passing through a separatory funnel, etc., or (b) processes in which recovery is intended of both water and another product. Class 210 provides for (a) processes which include a step of colloid system resolution of liquids, generally claimed, when combined with a step of separation of a diverse component, unless that step is also a Class 516 step (i.e., multiple Class 516 steps are proper for placement in Class 516), or (b) a step of colloid system breaking, per se, for the purpose of obtaining water, wherein the water may be intended for use or intended to be made suitable for disposal, thus, decontaminating of sewage waste water to be dumped into the ocean using an emulsion breaking step is proper for Class 210.
