Upgradation of sludge deep dewatering conditioners through persulfate activated by ferrous: Compatibility with sludge incineration, dewatering mechanism, ecological risks elimination and carbon emission performance

Aimin Li; Chou Huang; Xuan Feng; Yuzhi Li; Hanwen Yang; Shuo Wang; Ji Li

doi:10.1016/j.envres.2022.113024

Upgradation of sludge deep dewatering conditioners through persulfate activated by ferrous: Compatibility with sludge incineration, dewatering mechanism, ecological risks elimination and carbon emission performance

Environ Res. 2022 Aug:211:113024. doi: 10.1016/j.envres.2022.113024. Epub 2022 Mar 4.

Authors

Aimin Li¹, Chou Huang¹, Xuan Feng¹, Yuzhi Li¹, Hanwen Yang², Shuo Wang³, Ji Li⁴

Affiliations

¹ Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China.
² Wuxi Guolian Environmental Science and Technology Co.Ltd., Wuxi, 214000, China.
³ Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Wuxi, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China. Electronic address: shuowang@jiangnan.edu.cn.
⁴ Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Wuxi, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China.

PMID: 35248567
DOI: 10.1016/j.envres.2022.113024

Abstract

Serious loss of organic substances and notable release of refractory intracellular organics and cell-free antibiotic resistance genes (ARGs) caused by cell lysis are found when quick lime, FeCl₃, and cationic polyacrylamide (CPAM) were used as sludge conditioners, which is not feasible to sludge separate incineration and increases ecological risks. Therefore, persulfate oxidation through ferrous (Fe²⁺-Na₂S₂O₈) activation was applied for the upgradation of sludge conditioner in China, the specific resistance to filtration (SRF) and capillary suction time (CST) significantly decreased and the removed water increased from 40% to 54%, implying that the persulfate activated by ferrous (PAF) conditioner presents good performance in sludge dewatering. Organic matter content and heating value of sludge merely decreased, and Cl^- content in sludge simultaneously decreased with the use of the PAF conditioner, thereby effectively reducing the corrosion risk to the incinerator and showing good compatibility with sludge separate incineration. In accordance with ferrous activation, sulfate radical plays an important role in sludge dewatering process because remarkable decrease in polysaccharides and protein contents from tightly bound extracellular polymeric substances (TB-EPS) was discovered. Based on flow cytometry analysis, slight cell lysis presented better filtrate quality by the use of PAF conditioner, 49.3% of refractory intracellular organics was removed and the respective ermB, tetW and blaTEM decreased by factors of 37.3%, 54.5% and 63.6% due to the strong oxidizing property of sulfate radical. The intensive decrease in refractory intracellular organics and cell-free ARGs will reduce the ecological risks. The total carbon emission significantly decreases to 1771.1 kgCO₂/tDS when PAF conditioner was employed, which is beneficial to the upgradation of sludge deep dewatering conditioners.

Keywords: Carbon emission; Cell-free ARGs; Flow cytometry; Refractory intracellular organics; Sludge separate incineration; Sulfate radical (SO− 4·); Tightly bound extracellular polymeric substance (TB-EPS).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carbon
Extracellular Polymeric Substance Matrix
Incineration
Sewage*
Waste Disposal, Fluid*
Water

Substances

Sewage
Water
Carbon