Abstract: A process for separating ash particles from an aqueous slurry containing a mixture of regenerated adsorbent (e.g., carbon) and ash particles includes the steps of settling the slurry to produce a solid phase including the mixture of adsorbent and ash particles and a supernatant or a clarified aqueous phase. After separation of the aqueous phase, a slurry of the solid phase is diluted with water and a dispersing agent for promoting suspension of the ash particles and an anionic polymer for promoting settling of the adsorbent particles are added. The thus-treated, dilute slurry is settled to produce an aqueous phase containing primarily suspended ash particles and a solid phase including carbon particles. After separation, the solid phase can be returned to a wastewater treatment system.

Abstract: Suspended ash in wastewater is efficiently concentrated and removed by mixing the ash suspension with thermally conditioned sludge. The solids in the resulting ash/sludge mixture are easily settled and dewatered by conventional means.

Abstract: A method for accelerating the startup of biological nitrification systems for wastewater treatment and preventing or reducing the effects of toxic or inhibitory materials or excursions of pH, temperature or dissolved oxygen upon nitrifying organisms. A rapidly metabolized soluble or miscible organic material containing little or no nitrogen is added to the carbon-consuming step of the process. Heterotrophic organisms consume the added material together with soluble ammonia to generate additional organisms. The soluble ammonia concentration in the wastewater is reduced to a non-toxic, less toxic, or less inhibitory level.

Abstract: A method for controlling the pulsing of a granular medium filter, based on determination of the rise rate of liquid level above the filtration medium. A pulse system is activated whereby sub-fluidizing pulses of a fluid are directed upwardly through the filter medium from an array of orifices, and each pulse is initiated whenever the determined rise rate attains a predetermined value. The pulses dislodge solids from the upper surface of the bed and store a portion of the solids within the bed itself at particular loci, for decreasing the resistance of the bed and reducing the rise rate. The frequency of backwash is optimized over a wider range of solids load, liquid load and other factors affecting the filtration.

Abstract: A process for treating high strength BOD containing liquors includes the step of mildly mixing and contacting the liquors with anaerobic bacteria and a powdered adsorbent support medium to remove a substantial portion of the organic matter and generate a methane fuel gas. Use of the powdered support medium at 0.1-20 g/l enables high removal of BOD in short treatment times, rapid clarification of treated liquors, and increased adsorbability of liquor color.In a subsequent decolorizing embodiment, digested and clarified liquors are contacted with reduced concentrations of powdered color adsorbent to produce a treated liquor low in dissolved organic matter and color.The spent streams of powdered adsorbent support medium-biomass and/or powdered color adsorbent are preferably regenerated and reused.

Abstract: A blowdown pot is provided with an inlet pressure control valve through which the pot receives unwanted residue e.g., ash from a high pressure chemical reactor, and this reactor residue can thereby be continuously or semi-continuously blown out from the high pressure, high temperature chemical reactor into the relatively low pressure blowdown pot which includes means maintaining a liquid level therein minimizing steam flashing and vessel wear. At the same time the reactor residue is removed from the pot with a liquid overflow.

Abstract: Vanadium and nickel are recovered from fluid coke or fly ash concurrently with cogeneration of steam by a wet oxidation process at 500.degree.-650.degree. F. and elevated pressure, with a leaching pH of approximately 0.3 maintained by generation of sulfuric acid in situ. Vanadium products are precipitated by oxidation with for example sodium perchlorate with concurrent or subsequent pH adjustment to about pH 2. Following separation of the vanadium pentoxide, nickel powder is preferentially recovered by reduction with hydrogen and ammonia. Steam is generated by recovery of the thermal energy present in the offgases.

Abstract: A two-stage starved air furnace system is controlled to simultaneously achieve desired temperatures and percent stoichiometric air operation in the primary stage by modulating transformation relay functions acting upon measured temperature deviations to change both primary combustion air and primary auxiliary burner operation. At the set-point value of percent stoichiometric air, the relay functions are modulated in reverse direction to satisfy changing heat demands.

Abstract: A multiple hearth furnace chamber where each arched or conical hearth is independently supported by the outer metal shell. An expansion joint below each hearth allows for vertical movement of the interior refractory wall panels without significant vertical movement of the hearths. The expansion joint comprises an insulating refractory material which absorbs the expansion of the inner refractory (firebrick) wall panels without significant permanent deformation.