EPS solubilization and waste activated sludge acidification enhanced by alkaline-assisted bi-frequency ultrasonic pretreatment revealed by 3D-EEM fluorescence

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 80493-80500 ◽  
Author(s):  
Jing Peng ◽  
Kaili Wen ◽  
Wenzong Liu ◽  
Xiuping Yue ◽  
Aijie Wang ◽  
...  

The effect of alkaline-assisted bi-frequency (28 + 40 kHz) ultrasonic pretreatment on extracellular polymeric substances (EPS) solubilization and waste activated sludge (WAS) acidification was investigated.

2014 ◽  
Vol 70 (9) ◽  
pp. 1555-1560 ◽  
Author(s):  
Fenxia Ye ◽  
Xinwen Liu ◽  
Ying Li

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.


2021 ◽  
Vol 13 (17) ◽  
pp. 9700
Author(s):  
Zicong Liao ◽  
Yongyou Hu ◽  
Yuancai Chen ◽  
Jianhua Cheng

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.


RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33981-33989
Author(s):  
Ying Liu ◽  
Wenzhou Lv ◽  
Siqing Xia ◽  
Zhiqiang Zhang

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


RSC Advances ◽  
2018 ◽  
Vol 8 (56) ◽  
pp. 32172-32177 ◽  
Author(s):  
Ying Liu ◽  
Wenzhou Lv ◽  
Zhiqiang Zhang ◽  
Siqing Xia

The spatial distribution and adsorption capacity of extracellular polymeric substances (EPS) were systematically investigated for waste activated sludge (WAS) treated by a short-time aerobic digestion (STAD) process.


Sign in / Sign up

Export Citation Format

Share Document