Wastewater sludge conditioning with flocculant-NaCl-straw to improve sludge dewaterability

Abstract

One of the major improvement points in wastewater treatment processes is sludge treatment. The effectiveness of existing sludge treatment processes is highly limited due to poor dewaterability and compressibility of sludge. In this paper, a new sludge conditioning method was studied. The results show that combining NaCl and straw powder with commercial flocculant significantly improves sludge dewaterability and reduces moisture content, while increasing heat value. Adding NaCl in 0.25M dosage and 50% straw powder (dried and sieved to 0.125 – 0.063 µm) resulted in significant reduction of specific resistance to filtration and sludge moisture content. The results also suggest that it would be possible to partially substitute the flocculant with less expensive conditioners, which could potentially reduce the cost of sludge dewatering.