Estimation of Sludge Production in Water Treatment Plants (WTPs)

This calculation uses parameters such as the flow rate of the WTP, the average turbidity of raw water, and the average dosage of aluminum sulfate. It estimates:

• The daily solid mass produced.
• The daily sludge volume discharged from flocculators and settling tanks.
• The daily volume of washwater produced by filters.

These results assist in the design and operation of Sludge Treatment Plants (STP).

Observations

• Assumed percent removal of solids in flocculators and settling tanks: 90%.
• Assumed percent removal of solids in filters: 10%.
• Solids concentration in the bottom discharge:
  • Settling tanks with daily bottom discharge: 1%.
  • Settling tanks with monthly bottom discharge: 10%.
• Solids concentration in filter washwater:
  • Single-layer sand filters: 0.01%.
  • Double-layer sand and anthracite filters: 0.02%.

Note: This calculation provides estimated values (first approximation) based on average values obtained in practice. These estimates should be validated through specific studies tailored to practical applications.

Input Data

Parameter	Standard units	Description
Water treatment plant flow rate	$L/s$	Flow rate of water treated at the WTP.
Average dosage of aluminum sulfate	$mg/L$	Average concentration of aluminum sulfate dosed.
Average turbidity of raw water	uT	Indicator of impurities in raw water.
Percentage removal of solids permitted in flocculators and settling tanks	%	Percentage of solids removed during decantation.
Percentage removal of solids allowed in filters	%	Percentage of solids removed in filters.
Solids concentration allowed in the bottom discharge	%	Solids in the discharged sludge.
Solids concentration allowed in filter washwater	%	Solids in the filter washwater.

Output Data

Parameter	Standard units	Description
Daily mass of solids produced	$kg/d$	Amount of solids produced daily.
Daily volume of sludge produced by settling tanks	$m^3$	Daily volume of sludge generated by settling tanks.
Daily volume of washwater produced by filters	$m^3$	Daily volume of water used for filter washing.