Work

Oxidative treatment of waste activated sludge by different activated persulfate systems for enhancing sludge dewaterability

Year: 2016

Type: article

Abstract: The enhancement in dewaterability of waste activated sludge (WAS) by oxidative treatment using thermally- and alkali-activated persulfates (i.e., peroxymonosulfate (PMS) and peroxydisulfate (PDS)) was studied with two indices representing dewaterability change, i.e., centrifuged weight reduction (CWR) and standardized-capillary suction time (SCST). The tested conditions include 50 °C/PMS, 50 °C/PDS, 80 °C/PMS, and 80 °C/PDS as thermally-activated persulfate systems and NaOH/PMS, NaOH/PDS, KOH/PMS, and KOH/PDS as alkali-activated persulfate systems. The oxidation by activated persulfates caused the disintegration of bacterial cells and extracelluar polymeric substance (EPS) of WAS, affecting the sludge dewaterability. The highest dewaterability was found at the KOH/PDS treatment in CWR and at the 80 °C/PDS treatment in SCST. The EPSs were stratified as soluble, loosely-bound (LB) and tightly-bound (TB) fractions, and contents of protein and polysaccharide in each fraction were measured to characterize the EPS matrix before and after treatments. The statistical analysis of the relationship between EPS character and dewaterability indicated that the protein content in LB-EPS was the dominant negative factor for the dewaterability represented by SCST, whereas the polysaccharide content in soluble-EPS was identified as the dominant positive factor for the dewaterability by CWR.

Source: Sustainable Environment Research

DOI: 10.1016/j.serj.2015.10.005

Authors: Ki-Myeong Lee, Min Sik Kim, Changha Lee

Institution: Ulsan National Institute of Science and Technology

Language: English

Topic: Coagulation and Flocculation Studies

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $1,990