AWWA WQTC50433

Recycling treatment plant waste streams has become an important issue and the EPA is currently developing a rule to control and potentially limit these streams. The impact to the overall treatment process and the relative risk of various recycle streams can be evaluated with a materials balance model of a treatment plant. A steady-state materials balance model was developed and applied to the recycle of backwash waste water, clarifier sludge supernatant, and sludge dewatering supernatant. Recycling backwash water reduced the plant treatment effectiveness from 3.0 log to 2.95 log removal when the recycle stream was treated (0.5 log removal) and 2.84 log removal when not treated. Recycling clarifier sludge supernatant resulted in a reduction of performance from 3.0 log to 2.78 log removal with adequate treatment (0.5 log removal) and 1.95 log removal with inadequate treatment (10% removal). Pilot scale testing has been conducted to test the underlying assumptions of the mass balance model. Includes 4 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/1999

File Size:

1 file , 1.7 MB