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Douglas Merrill,Brown and Caldwell ► process engineer, conducts the flocculat- ed suspended solids test. j liquor has not had enough time to floc- r \r culate after leaving the turbulence of the ; aeration basin or that some conveyance mode (i.e.,a channel,free fall,or piping network) has caused significant floc a a- breakup before the mixed liquor entered i the clarifier.Further testing can isolate the location of floc breakup. If nothing Flocculation: ` A process in water and wastewater treat- ment that causes fine particles to clump together,forming larger masses of solids. ------ - - - - – - - - Usually achieved by mechanical or hydimdic stirring. Because this sampler can ,. ., to „ and settle a mixed liquor sample for adispersed suspended Dispersed Suspended Solids(DSS): solids test,the megnty of the solids is preserved. Solids remaining in the supernatant after 30 minutes of settling without additional flocculation. Flocculated Suspended Solids(FSS): SCHEMATIC OF Solids remaining in the supernatant after 30 minutes of settling with additional SAMPLER flocculation. KEMMERER can be done to remove the breakup problem or if the problem is one of inadequate flocculation time,then a flocculation step should be added prior to secondary clarification.In some cases, Upper Closure you may need to build a flocculation Drawn zone in the clarifier to alleviate the Messen•_rInsertion of Siphon ' problem. If there are low concentrations of Upper Siphon both DSS and FSS,then the incoming Internal I ■ '� mixed liquor is well flocculated,and Support hydraulic short-circuiting in the clarifier is most certainly the problem. Often, short-circuiting can be alleviated with Rope Support appropriate baffling or improved sludge Clear Supernatant blanket management. If there are high concentrations of both DSS and FSS,then inadequate floc- Ring Stand culation is the problem.However,this Support problem cannot he solved with the addi- tion of a flocculation step. the high FSS Settled Sludge concentration points to a biological prob- lem in the aeration basin or the existence of something in the plant influent that is acting as a dispersant or toxicant. Lower Internal Brown and Caldwell has used the Suppor® DSS and FSS tests to successfully diag- • _ r Closure nose secondary clarifier problems both at Sealed plants with activated sludge and trickling filter/solids contact processes.■ ��,�1��%%%% Bottom Drain —Eric Wahlberg and Denny Parker BROWN AND CALDWELL OUARTERLY