7 ) Sludge treatment works. Sludge conditioning :• Sludge conditioning is the process of water from sludge.• Conditioning is the process of separation of flocwater entrapped in sludge.i. Physical conditioning: (wash water ).ii. Chemical conditioning: (Ferric chloride, Copperas (Ferrous sulphate), Alum and Lime are used for conditioning of sludge. Vacuum filtration : Sludge is conveyed in a trapezoidal bowl. A rotating drum fitted with cloth shall be rotating in it so that its bottom 1/4th or 1/5th of its diameter is submerged in sludge. Incineration : When the sludge is dense and contains more than 30% solids of which more than half (50%) are of volatile nature then the sludge can be incinerated. Sludge disposal : Treated sludge can be dried or dumped into huge water bodies of good velocity and currents of flow. De-watering : It is the process of separation of water from sludge by force. The water is squeezed out while sludge solids almost devoid of water emerge out. Filter pressing : It is compressing the sludge between the two horizontal plates of filter press and applying a pressure of 700 kPa Centrifuging : It is injecting the sludge into a tapering rotating bowl fixed with blades causing the segregation of liquids and solids. Air drying : Sludge is applied over this bed in 200 to 300 mm thick layers and allowed to dry for one week to many weeks depending on the solar insolation. Dumping into sea : Wet digested sludge may be dumped into huge water bodies with powerful currents as perennial rivers and oceans to cause high dilution and effective homogeneous dispersion
đang được dịch, vui lòng đợi..
