Enhancing Sludge Dewatering Process by Using Green and Environmental Wastes

Abstract

Sludge dewatering is challenging due to sludge's highly compressible nature and the presence of colloidal particles. The capital, operating, and transportation expenses of wastewater management can be decreased by decreasing the amount of water content in the sludge. In the present study, the sludge samples were taken from municipal WWTP, with a moisture content of 98% and specific resistance to filtration (SRF) 1.2265E+16 m/kg. The samples were chemically conditioned with moringa Olivera at different dosages and physically conditioned with (rice husk and wheat straw) to improve sludge dewatering. The experimental work included evaluating the treated sludge's dewatering ability SRF. The results showed that the chemical coagulation affected the SRF of the sludge; the lowest values were 3.43296E+15 m/kg and time to filtrate (TTF) was 326.6 sec. However, when the rice husk and wheat straw were combined with chemical conditioning, noticeable improvements were noted in the sludge dewatering ability compared to the coagulation conditioning alone. The physical conditioners acted as skeleton builders during this pressure dewatering. The lowest SRF. were 1.62497E+15m/kg and 1.58377E+15m/kg for wheat straw and rice husk, respectively. Hence, the study recommends using rice husk or wheat straw for conditioning.

Could Plant-Based Flocculants Substitute the Conventional Synthetic Chemicals in the Sludge Dewatering Process?

“…To gain more insight into Moringa's capacity to aid sludge dewatering, see Table 3, which compiles the previous research works that have assessed the variations in dewatering properties (such as the SRF and the CST) that occur when using Moringa as a flocculant. In fact, Rabea et al [62] found that the powder of MO seeds decreased the SRF by up to 70%. This result denotes that filterability becomes greater via powder supplementation, hence promoting sludge water removal.…”