Ultrasound, thermal and alkali treatments affect extracellular polymeric substances (EPSs) and improve waste activated sludge dewatering

2015 ◽  
Vol 50 (3) ◽  
pp. 438-446 ◽  
Author(s):  
Maria Ruiz-Hernando ◽  
Esther Cabanillas ◽  
Jordi Labanda ◽  
Joan Llorens
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Waste Activated Sludge ◽  
Sludge Dewatering

Extracellular polymeric substances and dewaterability of waste activated sludge during anaerobic digestion

2014 ◽  
Vol 70 (9) ◽  
pp. 1555-1560 ◽  
Author(s):  
Fenxia Ye ◽  
Xinwen Liu ◽  
Ying Li
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Extracellular Polymeric Substance ◽  
Extracellular Polymeric Substances ◽  
Waste Activated Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Relationship Analysis ◽  
The Relationship ◽  
Insight Into

Anaerobic digestion of waste activated sludge was conducted to gain insight into the mechanisms underlying change in sludge dewaterability during its anaerobic digestion. Unexpectedly, the results indicated that sludge dewatering properties measured by capillary suction time only deteriorated after 10 days of anaerobic digestion, after which dewaterability recovered and remained stable. The loosely bound extracellular polymeric substance (LB-EPS) content increased three-fold after 20 days of anaerobic digestion, and did not change significantly during the remaining 30 days. The tightly bound EPS (TB-EPS) content reduced slightly after 20 days of anaerobic digestion, and stabilized during the last 30 days. Polysaccharides (PS) and proteins (PN) content in LB-EPS increased after 10 days of anaerobic digestion. However, PS and PN contents in TB-EPS decreased slightly. The relationship analysis showed that only LB-EPS correlated with dewaterability of the sludge during anaerobic digestion.

scholarly journals Enhancing Phosphorus Recovery and Dewaterability of Waste Activated Sludge for Combined Effect of Thermally Activated Peroxydisulfate and Struvite Precipitation

2021 ◽  
Vol 13 (17) ◽  
pp. 9700
Author(s):  
Zicong Liao ◽  
Yongyou Hu ◽  
Yuancai Chen ◽  
Jianhua Cheng
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Phosphorus Recovery ◽  
Waste Activated Sludge ◽  
Optimal Conditions ◽  
Capillary Suction ◽  
Radical Oxidation ◽  
Thermally Activated ◽  
Struvite Precipitation ◽  
The Cost

Phosphorus is a nonrenewable and irreplaceable limited resource, and over 90% of phosphorus in influenttransfers into sludge in wastewater treatment plants. In this study, thermally activated peroxydisulfate (TAP) treatment was combined with struvite precipitation to enhance waste activated sludge (WAS) dewaterability and phosphorus recovery. TAP simultaneously enhanced dewaterability and solubilization of WAS. The optimal conditions of TAP treatment were PDS dosage 2.0 mmol/g TSS, 80 °C, pH 4.0~7.0 and 40 min, which enhanced dewaterability (capillary suction time (CST) from 94.2 s to 28.5 s) and solubilization (PO43−-P 177.71 mg/L, NH4+-N 287.22 mg/L and SCOD 10754 mg/L). Radical oxidation disintegrated tightly bound extracellular polymeric substances (TB-EPS) and further released bound water. The acidification effect neutralized the negative surface charge of colloid particles. Compared with thermal hydrolysis, TAP effectively promoted the release of PO43−, NH4+ and SCOD. Cation exchange removed most Ca and Al of the TAP treated supernatant. The optimal conditions of struvite precipitation were Mg/P 1.4 and pH 10.0, which achieved phosphorus recovery of 95.06% and struvite purity of 94.94%. The income obtained by struvite adequately covers the cost of struvite precipitation and the cost of WAS treatment is acceptable.

scholarly journals Nitrogen aeration alters the spatial distribution and metal adsorption of extracellular polymeric substances in waste-activated sludge

RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33981-33989
Author(s):  
Ying Liu ◽  
Wenzhou Lv ◽  
Siqing Xia ◽  
Zhiqiang Zhang
Keyword(s):  
Spatial Distribution ◽  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Metal Adsorption ◽  
Waste Activated Sludge

Nitrogen aeration was superior to air aeration because of the higher EPS production and Pb2+ adsorption in the utilization of WAS.

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