Tank bottoms, treatment

Maxhib AC-5080 demulsifier, syndet bars Antaro F-88 FLK Poloxamor 238 demulsifier, tank bottom treatment... 

Self-cleaning clarifiers, in which the solids are discharged at intervals while the centrifuge is operating at full-speed (Fig. 20.12). They are available for both wort and beer clarification with throughputs of up to 600 hl/hr (370 brl/hr). The same machines used for beer recovery from fermenters and tank bottoms operate at up to 40 hl/hr (25 brl/hr). Many of these machines used for beer treatment are hermetically sealed so that neither carbon dioxide is lost nor oxygen taken up. 

In heavily contaminated systems, biocide treatment alone may not be sufficient to address the problem. Melton et al. (1988) found that a combination of mechanical centrifugation/filtration of distillate fuel followed by biocide treatment provided the best results for long-term fuel storage protection from microbial contamination. It may be possible to remove particulate matter, including microbial contamination, by recirculating the fuel through 0.5 micron filters (Chesneau, 1991). The contaminated fuel system should be kept static for an appropriate period of time (approximately a week) to allow the contaminants to settle out in the tank bottom before filtration and separation is initiated (Rogers and Kaplan, 1968). 

Uses Emulsion breaker and demulsifier in the reduction of sludge, the elimination of viscous oil/water interfaces, and the wafer-wetting of entrained solids in the treatment of tank bottoms, waste oils, low gravity crudes and high solids emulsions... 

Pulsed beds of ac tivated carbon are used in water and wastewater treatment systems. The adsorber tank is usually a vertical cylindrical pressure vessel, with fluid distributors at top and bottom, similar to the arrangement of an ion exchanger. The column is filled with granular carbon. Fluid flow is upward, and carbon is intermittently dis-... 

The Asahi process (Fig. 16-63) is used principally for high-volume water treatment. The hquid to be treated is passed upward through a resin bed in the adsorption tank. The upward flow at 30-40 m/h [12-16 gal/(min ft")] keeps the bed packed against the top. After a preset time, 10 to 60 min, the flow is interrupted for about 30 s, allowing the entire bed to drop. A small portion (10 percent or less) of the ion-exchange resin is removed from the bottom of the adsorption tank and transferred hydraulically to the hopper feeding the regeneration tank. 

Septic Tank Untreated liquid household wastes (sewage) will quickly clog your absorption field if not properly treated. The septic tank is a holding tank in which this treatment can take place. When sewage enters the septic tank, the heavy solids settle to the bottom of the tank the lighter solids, fats and greases partially decompose and rise to the surface and form a layer of scum. The solids that have settled to the bottom are attacked by bacteria and form sludge. 

Trickling filter An attached culture,wastewater treatment system. A large tank generally filled with rock or rings (see Bio-Tower). Wastewater is sprayed over the top of the media, providing the opportunity for the formation of slimes or biomass to remove wastes from the wastewater, through revolving arms which have spray nozzles. Water is pumped from the bottom of a trickle filter to a secondary clarifier. 

Materials and Techniques. The tanks and chambers for treatments 1, 3 and 4 were constructed of 3/16-inch-thick OP-4 Plexiglas those for treatment 2 were constructed of iM-inch-thick OP-2 Plexiglas. Mylar D (thickness 4 mils) was placed over the top of treatment tank 3 to reduce levels of ambient UV-B. Transmission spectra of these materials are shown in Fig. 3. Enhancement of UV-A and UV-B was achieved by placing four FS-20 Westinghouse fluorescent sunlamps underneath treatment tank 4. In order to exclude most of the radiation less than 290 nm wavelength emitted by the lamps, a sheet of 4 mils thick Kodacel (TA 401), which had been preconditioned by exposure to a sunlamp for approximately 100 hours, was placed between the sunlamps and the bottom of the enhanced UV tank. 

This system consists of an in situ polyethylene tank, an application system, and a bottom water recovery system.65 An underlying, permeable, water-bearing zone facilitates the creation of ingradient water flow conditions. The tank defines the treatment area, minimizes the potential for release of bacterial cultures to the aquifer, and maintains contaminant concentration levels that facilitate treatment. The ingradient conditions facilitate reverse leaching or soil washing and minimize the potential for outmigration of contaminants. 

The bottom water recovery system uses existing wells or new wells to create the water recovery system for removal of the water used to wash the contaminated soil. Reverse leaching or soil washing can be conducted by controlling the water levels within the tank. This design minimizes the volume of clean ex situ water entering the system for treatment. Extremely dense clays may be difficult to treat with this technology. 

The pumping unit consisted of a submersible pump installed in a 10,000-gal reservoir tank, which also served as a holding tank (Figure 12.16). Fluids pumped from the wells were all returned to the tank for separation. All the oil and some water produced overflowed from the tank into another oil-water separator and then into the slop oil treatment system of the refinery. Clarified water from the bottom of the tank was recycled by the submersible pump through the eductor units to continue operations. 

In some Norwegian sewage sludge and wastewater treatment plants iron oxide filters have been installed with success. The filter consists of mixed wood chips and iron oxide, and the odorous compounds are oxidized in the filter. The total odour strength was measured in such a filter where the air from sludge tanks providing an offensive odour was finely dispersed at the 3m2 bottom of the filter box (total filter volume 3m3, containing 300 kg iron oxide). 

The first field test was successful. Both dimethoate and malathion declined exponentially (Figure 9) and exhibited efficiency factors comparable to the efficiency factors found in the pilot tests. An efficiency factor could be calculated for baygon, but not for diazinon. Some sediment was present into the bottom of the holding tank which could have been slowly releasing baygon and diazinon in the bulk liquid. Nevertheless, after 24 hours of treatment, all pesticides were below the limit of detection. 

The slow increase in (in the W/0 tanks) with time may represent release of polar metabolites from the bottom sediment. Total in water on day 57 represented 1 and 3% of the total C added to each tank at the start, for the W and W/0 sediment treatments, respectively. In addition, C recovered from the 100 ml water samples decreased from 88% of the total (1 ml samples) on day 3 to 51% on day 57. These results indicate that polar metabolites increased with time since they are not recovered by Sep Paks. Only small amounts of DDE and DDD (7 and 13% of total by day 8 and 15, respectively) were detected in water. 

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