Calculations
Recommendations
Sludge removal device for settling tank (BIOWASSERTRACK®)Ferric chlorideLiquid aluminium sulfateSettling tank for percolator biologic filterEstimation of sludge production in water treatment plantsTrenches of residencial septic tankSanitary wastewater sludge drying beds
Input data
Sludge daily production
Sludge concentration
Sludge height to apply in each bed - see note 2
Output data
Sludge produced each 28 days
Area needed for operating drying beds
Sugested number for drying beds(half in operation; half resting or being cleaned)
Suggested width for each bed
Suggested lenght for each bed
Total area for all operating beds
Sludge volume applied in each bed
Sludge volume applied in all operatingn beds
Total solids suspention load, in kg SS / m² - see Note
Description
Given the daily sludge production, its concentration and the sludge height to be applied in each bed, calculates, among others, the produced sludge volume, the needed area for the beds, the suggested number of beds and its dimentions.
Drying bed
Notes
- It is assumed that the sludge will be applied in a drying bed during 28 days, removed after 21 resting days and that the bed will be cleaned whitin 7 days. According to Brazilian Standard ABNT NBR 12209:2011:
- Sludge height over the draining bed shall not exceed 0,35 m.
- Drying bed shall be used only for stabilizad sludge.
- The total area of the drying bed must be divided in at least 2 chambers. Maximum distance for manual transport of the dried sludge in the interior of the drying bed can not be greater than 10 m.
- The sludge discharge into the drying bed can not exceed 15 kg SS/m² (total suspended solids / draining area) in each operating cycle, except in justified cases.
- The use of syntetic geotextile fabrics in addition or substitution of sand must be justified.
- Drying beds can be covered with good tranparency material.