TY - JOUR
T1 - A one-step acidification strategy for sewage sludge dewatering with oxalic acid
AU - Chen, Na
AU - Tao, Shuangyi
AU - Xiao, Keke
AU - Liang, Sha
AU - Yang, Jiakuan
AU - Zhang, Lizhi
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2020/1
Y1 - 2020/1
N2 - Sewage sludge dewatering is an efficient approach to reduce the volume of sludge for the subsequent disposal. In this study, a novel one-step acidification sludge dewatering method was developed with using oxalic acid as a conditioner. In laboratory-scale experiments with the dosage of 200 mg/g dry solid (DS), the normalized capillary suction time and the specific resistance to filtration were respectively decreased by 78.7% and 60.0% after 30 min of oxalic acid conditioning, much more efficient than those conditioned with sulfuric acid and hydrochloric acid at the same pH value. This superior dewatering performance was attributed to two factors. One was that oxalic acid could more efficiently promote the hydrolysis of polysaccharide, especially pectins, to release bound water. The other was that OA could dissolve more Fe3+ and Al3+, as well as form precipitate with Ca2+ in sludge, which may act as flocculants or co-precipitator for the subsequent sludge particles coagulation. In pilot-scale experiments, the water content of oxalic acid conditioned sludge cake was reduced to 60% under the optimum conditions, while the reagent cost was as low as 110.0 USD/t DS. This work provides a cost-effective and easy-operated sewage sludge disposal technique, and also sheds light on the potential of oxalic acid in environmental waste treatment.
AB - Sewage sludge dewatering is an efficient approach to reduce the volume of sludge for the subsequent disposal. In this study, a novel one-step acidification sludge dewatering method was developed with using oxalic acid as a conditioner. In laboratory-scale experiments with the dosage of 200 mg/g dry solid (DS), the normalized capillary suction time and the specific resistance to filtration were respectively decreased by 78.7% and 60.0% after 30 min of oxalic acid conditioning, much more efficient than those conditioned with sulfuric acid and hydrochloric acid at the same pH value. This superior dewatering performance was attributed to two factors. One was that oxalic acid could more efficiently promote the hydrolysis of polysaccharide, especially pectins, to release bound water. The other was that OA could dissolve more Fe3+ and Al3+, as well as form precipitate with Ca2+ in sludge, which may act as flocculants or co-precipitator for the subsequent sludge particles coagulation. In pilot-scale experiments, the water content of oxalic acid conditioned sludge cake was reduced to 60% under the optimum conditions, while the reagent cost was as low as 110.0 USD/t DS. This work provides a cost-effective and easy-operated sewage sludge disposal technique, and also sheds light on the potential of oxalic acid in environmental waste treatment.
KW - Extracellular polymeric substances
KW - Hydrolysis
KW - Oxalic acid
KW - Pectins
KW - Sewage sludge dewatering
UR - http://www.scopus.com/inward/record.url?scp=85070925280&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2019.124598
DO - 10.1016/j.chemosphere.2019.124598
M3 - 文章
C2 - 31446276
AN - SCOPUS:85070925280
SN - 0045-6535
VL - 238
JO - Chemosphere
JF - Chemosphere
M1 - 124598
ER -