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Abstract:
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As textile manufacturing production has increased and chemical usage has changed
over the years, some of the same textile waste treatment plants built 20 to 30 years ago
are still being used today. If the operation of the plant with respect to design
parameters has not changed accordingly, efficiency losses may be extensive. This
forces volume requirements up and plants are faced with construction of additional
capacity. However, if the design parameters were re-evaluated, the system volume
requirements could possibly be reduced simply by manipulating other design
parameters (e.g., HRT, biomass concentration).
Previous research suggests that aerobic activated sludge treatment systems with
retention times less than 24 hours are capable of reducing the chemical oxygen
demanding substances, also referred to as the COD, present in textile wastes to a
satisfactory level. Since the plant treatment systems are operated on a continuous basis,
the majority of the research has been conducted on a continuous basis. The sludge age
does not vary significantly in the steady state operation of the continuous flow systems.
As the sludge age varies, so do the COD removal and retention time required. In this
study, sludge age and retention time were varied to determine their effect on COD
removal for a batch reaction system. Findings indicated that hydraulic retention times
of less than 48 hours may be feasible, if toxicity is not an issue in the plant.
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