Process performance assessment of advanced anaerobic digestion of sewage sludge including sequential ultrasound–thermal (55 °C) pre-treatment

2018 ◽  
Vol 262 ◽  
pp. 42-51 ◽  
Author(s):  
Patricio Neumann ◽  
Felipe Barriga ◽  
Claudia Álvarez ◽  
Zenón González ◽  
Gladys Vidal
2012 ◽  
Vol 531 ◽  
pp. 528-531 ◽  
Author(s):  
Na Wei

Anaerobic digestion is an economic and environmentally friendly technology for treating the biomass material-sewage sludge, but has some limitations, such as the low efficient biogass production. In this paper ultrasound was proposed as pre-treatment for effective sludge anaerobic digestion. Sludge anaerobic digestion experiments with ultrasonic pretreatment was investigated. It can be seen that this treatment effectively leaded to the increase of soluble chemical oxygen demand(SCOD) and volatile fatty acids(VFA)concentration. High concentration of VFA leaded to a increase in biogas production. Besides, the SV of sludge was reduced and the settling characteristics of sludge was improved after ultrasonic pretreatment. It can be concluded that sludge anaerobic digestion with ultrasonic pretreatment is an effective method for biomass material transformation.


2014 ◽  
Vol 35 (21) ◽  
pp. 2652-2659 ◽  
Author(s):  
Xiaocong Liao ◽  
Huan Li ◽  
Yingchao Cheng ◽  
Nan Chen ◽  
Chenchen Li ◽  
...  

2019 ◽  
Vol 9 (18) ◽  
pp. 3853 ◽  
Author(s):  
Banafsha Ahmed ◽  
Kaoutar Aboudi ◽  
Vinay Kumar Tyagi ◽  
Carlos José Álvarez-Gallego ◽  
Luis Alberto Fernández-Güelfo ◽  
...  

Lignocellulosic biomass, comprising of cellulose, hemicellulose, and lignin, is a difficult-to-degrade substrate when subjected to anaerobic digestion. Hydrothermal pretreatment of lignocellulosic biomass could enhance the process performance by increasing the generation of methane, hydrogen, and bioethanol. The recalcitrants (furfurals, and 5-HMF) could be formed at high temperatures during hydrothermal pretreatment of lignocellulosic biomass, which may hinder the process performance. However, the detoxification process involving the use of genetically engineered microbes may be a promising option to reduce the toxic effects of inhibitors. The key challenge lies in the scaleup of the hydrothermal process, mainly due to necessity of upholding high temperature in sizeable reactors, which may demand high capital and operational costs. Thus, more efforts should be towards the techno-economic feasibility of hydrothermal pre-treatment at full scale.


2016 ◽  
Vol 177 ◽  
pp. 231-239 ◽  
Author(s):  
A. Serrano ◽  
J.A. Siles ◽  
M.A. Martín ◽  
A.F. Chica ◽  
F.S. Estévez-Pastor ◽  
...  

2006 ◽  
Vol 53 (8) ◽  
pp. 109-117 ◽  
Author(s):  
M. Carballa ◽  
F. Omil ◽  
A.C. Alder ◽  
J.M. Lema

Many novel treatment technologies, usually representing a pre-treatment prior to the biological degradation process, have been developed in order to improve the recycling and reuse of sewage sludge. Among all the methods available, a chemical (alkaline) and a thermal treatment have been considered in this study. The behaviour of 13 substances belonging to different therapeutic classes (musks, tranquillisers, antiepileptic, anti-inflammatories, antibiotics, X-ray contrast media and estrogens) has been studied during the anaerobic digestion of sewage sludge combined with these pre-treatments (advanced operation) in comparison with the conventional process. Two parameters have been analysed: the temperature (mesophilic and thermophilic conditions) and the sludge retention time. While organic matter solubilization was higher with the alkaline process (55–80%), no difference between both pre-treatments was observed concerning volatile solids solubilization (up to 20%). The removal efficiencies of solids and organic matter during anaerobic digestion ranged from 40–70% and 45–75%, respectively. The higher removal efficiencies of pharmaceuticals and personal care products were achieved for the antibiotics, Naproxen and the natural estrogens (>80%). For the other compounds, the values were in the range 20–70%, except for Carbamazepine, which was not removed at any condition tested.


2004 ◽  
Vol 49 (10) ◽  
pp. 105-113 ◽  
Author(s):  
R. Goel ◽  
K. Komatsu ◽  
H. Yasui ◽  
H. Harada

A new process configuration combining anaerobic digestion with ozonation, and operated at long SRT, was studied with the objective of on-site reduction in sludge quantity and improving biogas recovery. The process performance with respect to solid reduction efficiency and other important process parameters like accumulation of inorganic solids, changes in sludge viscosity and dewatering characteristics were evaluated from the data of long term pilot scale continuous experiments conducted using a mixture of primary and secondary municipal sewage sludge. Due to sludge ozonation and long SRT, high VSS degradation efficiency of approximately 80% was achieved at a reactor solid concentration of 6.5%. A high fraction of inorganic solid (>50%) consisting mainly of acid insoluble and iron compounds was found to accumulate in the reactor. The high inorganic content accumulated in the digested sludge did not, however, contribute to the observed increase in sludge viscosity at high solid concentration. The sludge viscosity was largely found to depend on the organic solid concentration rather than the total solid content. Moreover, higher inorganic content in the digested sludge resulted in better sludge dewaterability. For a quick assessment of the economic feasibility of the new process, an economic index based on the unit cost of digested sludge disposal to unit electric cost is proposed.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0237283
Author(s):  
Sky Redhead ◽  
Jeroen Nieuwland ◽  
Sandra Esteves ◽  
Do-Hoon Lee ◽  
Dae-Wi Kim ◽  
...  

Antibiotic resistant bacteria (ARB) and their genes (ARGs) have become recognised as significant emerging environmental pollutants. ARB and ARGs in sewage sludge can be transmitted back to humans via the food chain when sludge is recycled to agricultural land, making sludge treatment key to control the release of ARB and ARGs to the environment. This study investigated the fate of antibiotic resistant Escherichia coli and a large set of antibiotic resistance genes (ARGs) during full scale anaerobic digestion (AD) of sewage sludge at two U.K. wastewater treatment plants and evaluated the impact of thermal hydrolysis (TH) pre-treatment on their abundance and diversity. Absolute abundance of 13 ARGs and the Class I integron gene intI1 was calculated using single gene quantitative (q) PCR. High through-put qPCR analysis was also used to determine the relative abundance of 370 ARGs and mobile genetic elements (MGEs). Results revealed that TH reduced the absolute abundance of all ARGs tested and intI1 by 10–12,000 fold. After subsequent AD, a rebound effect was seen in many ARGs. The fate of ARGs during AD without pre-treatment was variable. Relative abundance of most ARGs and MGEs decreased or fluctuated, with the exception of macrolide resistance genes, which were enriched at both plants, and tetracyline and glycopeptide resistance genes which were enriched in the plant employing TH. Diversity of ARGs and MGEs decreased in both plants during sludge treatment. Principal coordinates analysis revealed that ARGs are clearly distinguished according to treatment step, whereas MGEs in digested sludge cluster according to site. This study provides a comprehensive within-digestor analysis of the fate of ARGs, MGEs and antibiotic resistant E. coli and highlights the effectiveness of AD, particularly when TH is used as a pre-treatment, at reducing the abundance of most ARGs and MGEs in sludgeand preventing their release into the environment.


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