Figure 11.14 illustrates the flow diagram of a conventional water treatment plant in which (a) the..

Figure 11.14 illustrates the flow diagram of a conventional
water treatment plant in which (a) the spent filter backwash wastewater is
discharged to a holding tank for sludge settling and supernatant recycling and
(b) the settled waste sludge is thickened in a gravity thickener. The
thickener’s supernatant is also recycled to the head of the water treatment
plant, and the thickener’s settled sludge is hauled away for disposal. If the
volume of the thickener’s settled sludge is too high to be handled and disposed
of economically, further sludge dewatering may become necessary. Propose a flow

Figure 11.14 illustrates the flow diagram of a conventional
water treatment plant in which (a) the spent filter backwash wastewater is
discharged to a holding tank for sludge settling and supernatant recycling and
(b) the settled waste sludge is thickened in a gravity thickener. The
thickener’s supernatant is also recycled to the head of the water treatment
plant, and the thickener’s settled sludge is hauled away for disposal. If the
volume of the thickener’s settled sludge is too high to be handled and disposed
of economically, further sludge dewatering may become necessary. Propose a flow
diagram of a conventional water treatment plant which is similar to Fig. 11.14,
except that the thickened sludge is further dewatered by a filter press or
centrifuge.

Figure 11.14