AWWA WQTC65696

The sludge burden wastewater from coagulation, flocculation and filter backwashing maycreate large problems for many water suppliers concerning discharge or recyclingpossibilities. The approach taken by the Waterworks Hosterwitz in Dresden, Germany, investigatedvarious options for sludge recycling before selecting biological treatment and subsequent recycling inrecultivation. Further, different treatmenttechnologies have been studied to evaluate the resulting advantages concerning sludgewithdrawal and treatment. Feasible variants of the considered technologies (indirectdischarge, modification and supplementation of the present technology, compactcoagulation, and membrane filtration) have been designed to allow for acomparison of performance, space requirements and resulting capital expenses (CAPEX)and operating expenses (OPEX). Following investigation and economical comparisons,the option of direct sludge withdrawal from coagulation/sedimentation basins by an externalcompany, and construction of a sludge storage volume as basin or tank was selected. Sludge withdrawal from sedimentation basins presented the most economically beneficial solution, but the low costs of this option faces technologicalshortcomings, since water and sludge treatment cannot be completely separated, andtherefore, mutual interactions can not be excluded. Providing additional sludge storagevolume and treatment appears to be technologically more beneficial but is space consuming.Generally, modification and supplementation of the present technologies appeared to beeconomically the best solution. Onsite sludge storage and treatment would be preferable,if the required space is available. If not, compact coagulation and membrane filtrationare the more promising alternatives to reducing sludge production. Includes 5 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

6

File Size:

1 file , 110 KB