Anaerobic continued filter

This process, according to the manufacturer,54 has been developed in such a way that space requirements are kept to a minimum. A BIOPAQ IC reactor is used as the initial step in the treatment process. The name of this anaerobic reactor is derived from the gas-lift driven internal circulation that is generated within a tall, cylindrical vessel. These reactors have been operational in the paper industry since 1996. The second step in the purification process is a mechanically mixed and aerated tank. The aerating injectors can be cleaned in a simple way without the need to empty the aeration tank. Potential scaling materials are combined into removable fine particles. At the same time, the materials that may cause an odor nuisance are oxidized into odorless components. The process can be completed by a third and a fourth step. The third step focuses on suspended solids recovery and removal. The fourth step is an additional water-softening step with lamella separation and continuous sand filters in order to produce fresh water substitute. The benefits claimed by the manufacturer are as follows54 ... 

Using standard anaerobic techniques, a 100-mL Schlenk flask equipped with a stir bar is charged with 50 mL dry benzene and 2 mL (1.96 g, 0.0172 mol) distilled free amine. If crude daco is used, the product will be less pure and of lower yields. The mixture is warmed to 50-60°C under N2. Three 1-mL (0.05 mol) portions of ethylene sulfide are added, allowing 20 min reaction time between additions. The mixture is then heated under N2 for 1 h. Complete reaction is indicated by the formation of a finely divided white precipitate after the final addition. The reaction mixture is filtered anaerobically through a bed of celite in a glass-fritted funnel. Solvent is removed under vacuum while continuing to heat at 50-60°C. The H2-bme-daco is obtained as a colorless to pale yellow oil. Irrespective of color, this material is of suitable quality to be converted to the nickel complex. If distilled daco is used, the product is quite pure. Attempts at vacuum distillation (bpo.immHg = 135°C) resulted in partial decomposition. Yield 3.21 g (80%). 

A third type of reactor system is the upflow anaerobic sludge blanket (UASB) reactor system. The UASB is a continuous-flow system that maintains a dense flocculated biomass that is granular. The waste-water passes through this dense sludge blanket to achieve desired treatment efficiency. The UASB, anaerobic filter, and fluidized-bed systems have all been applied successfully to treat a variety of industrial waste streams. Table 22-44 summarizes some of the applications of these treatment technologies. 

A special type of membrane bioreactor is called a porous pot reactor (PER) [19,37,90,91]. A 0.48-cm-thick filter grade porous polyethylene membrane is used in all applications to separate biomass from effluent. The same format is used to enrich bacterial cultures in continuous suspension systems, both under aerobic and anaerobic conditions [43,54]. 

The packed-bed anaerobic filter had a gross volume of 18.5/ and a void ratio of 0.63. Filter effluent was recirculated continuously to the inlet end at a recirculation ratio of 5.1 (defined as the ratio fo the recycle flow rate to the daily feed flow rate) to dilute the incoming feed and accelerate the transport of digestion products out of the culture. The filter had a hydraulic detention time of about 2.33. days (defined as the gross volume divided by the daily feed flow rates). 

FIGURE 1. Continuous bimodal lifetime distribution function (fractional contribution to the total intensity versus lifetime) for open (left) and closed (ri t) reaction center of Photosystem II at 4 C under anaerobic conditions. Inserts ow the respective phase (a) and modulation (X) data as a function of frequency (MHz) with the best bimodal distribution fit (-). Sanples were excited at 580 nm with a collimated 1 mW laser beam. Emission was observed through a monochromator at 680 nm (FWHM bandpass 16 nm) and a Hoya R-64 cut-off filter to eliminate scattered excitation light. 

From the beginning of the project, the average injection rate of polymer solution was kept dose to 420 m3/day. The cumulative volume of solution injected has been nearly equal to the cumulative volume of oil and water produced from wells located in the enhanced oil recovery zone (fig. 4 and 5). The polymer was diluted in treated field water. Produced formation water was separated from the oil and the sediments (shale particles) under anaerobic conditions and formaldehyde was added at an active concentration of 300 ppm to kill the bacteria. The water was then distributed to the polymer-mixing stations (fig. 6). The polymer was supplied in a water-oil emulsion form containing 30% active polymer dissolved in water. Because the continuous phase is oil, an inverter was added to the water before mixing. The polymer solution was then filtered through 10 micron screens before reinjection into the formation. 

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