Effluent Recycling Pump

FIG. 7.35.9 Schematic diagram of two fluidized-bed reactors in series for biological wastewater treatment. (Reprinted, with permission, from E.T. Oppelt and J.M. Smith, 1981, U.S. Environmental Protection Agency research and current thinking on fluidised-bed biological treatment, in Biological fluidised bed treatment of water and waste water, edited by P.F. Cooper and B. Atkinson, Chichester Ellis Horwood Ltd., Publishers.) to 4.8 kg m3 day for a standard oxygen-activated sludge process. The...

Table 7551 Design Considerations For Aerobic Sludge Composting Processes

Both untreated and digested sludge can be composted successfully. Untreated sludge has a greater potential for odors, particularly for windrow systems. Untreated sludge has more energy available, degrades more readily, and has a higher oxygen demand. Amendment and bulking agent characteristics, such as moisture content, particle size, and available carbon, affect the process and quality of the product. Bulking agents should be readily available. Wood chips, sawdust, recycled compost, and straw...

Table 333 Operationsbased Pollution Prevention Strategies

Implement a computerized raw material inventory tracking system. Maintain product inventory to minimize changeovers for batch operations. Purchase raw materials in totes and other reusable containers. Purchase raw materials with lower impurity levels. Practice first-in first-out inventory control. Housekeeping Practices Recycle and reuse wooden pallets used to store drums. Implement procedures to segregate solid waste from aqueous discharges. Implement procedures to segregate hazardous waste...

Recycling Waste Streams Directly

If waste streams can be recycled directly, this way is clearly the simplest to reduce waste and should be considered first. Most often, the waste streams that can be recycled directly are aqueous streams which, although contaminated, can be substituted for part of the freshwater feed to the process. Figure 3.8.2 is a flowsheet for the production of iso-propyl alcohol by the direct hydration of propylene. Propylene containing propane as an impurity is reacted with water to give a mixture which...