Orthogonal experimental study on hydrothermal treatment of municipal sewage sludge for mechanical dewatering followed by thermal drying

2019 ◽  
Vol 209 ◽  
pp. 236-249 ◽  
Author(s):  
Wenyi Deng ◽  
Jinchen Ma ◽  
Jiamin Xiao ◽  
Lei Wang ◽  
Yaxin Su
2013 ◽  
Vol 448-453 ◽  
pp. 693-698 ◽  
Author(s):  
Li Li Qian ◽  
Shu Zhong Wang ◽  
Xing Ying Tang

Wastewater treatment plants produced large amounts of municipal dewatered sewage sludge with about 80wt% moisture content. High moisture content is the bottleneck of sludge treatment and disposal. Hydrothermal treatment could economically disrupt sludge cells, release bound water and finally improve sludge dewaterability instead of thermal drying technology with high energy consumption. In this paper, hydrothermal treatment experiments were carried out and the combustion performance of the original sewage sludge and the hydrothermal treatment sewage sludge was analyzed to verify the possibility of burning after sludge hydrothermal treatment. The results show that the optimal reaction temperature, initial moisture content, pressure and time are 170°C, 87wt%, 0.9MPa and 40min, respectively, obtaining a final moisture content lower than 50wt% by centrifugation. Total Organic Carbon (TOC) results show that higher temperature and pressure, as well as longer reaction time are of benefit to the hydrothermal treatment of the municipal sewage sludge. Furthermore, Thermal Gravimetric Analysis (TGA) of the original sewage sludge and the hydrothermal treatment sewage sludge shows that a hydrothermal treatment can improve the combustion performance of the sludge, which is beneficial to the subsequent incineration process.


2014 ◽  
Vol 908 ◽  
pp. 457-460 ◽  
Author(s):  
Li Li Qian ◽  
Shu Zhong Wang ◽  
Xing Ying Tang

In China, over 28 million tons of dewatered sewage sludge, with 80 wt% moisture content, was generated from wastewater treatment plants in 2011. High moisture content is the bottleneck of sludge treatment and disposal. Thermal drying technology can significantly reduce the moisture content of sludge but its cost is too high. Hydrothermal treatment technology based on cell-break principle can efficiently and economically reduce the moisture content of sludge. This paper will introduce the specific process, features, treatment effect of this technology and propose an economic evaluation. The results show that hydrothermal treatment technology is a reasonable and economical method for treating sewage sludge in cities.


Agronomie ◽  
2001 ◽  
Vol 21 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Giovanni Gigliotti ◽  
Pier Lodovico Giusquiani ◽  
Daniela Businelli

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.


2014 ◽  
Vol 665 ◽  
pp. 404-407 ◽  
Author(s):  
Wan Yu ◽  
Pei Sheng Li

Moisture distribution in sewage sludge was considered as the essential of thermal drying. Some methods were given in literatures to test the moisture distribution, but there was no standard method to determine the critical water content between different kinds of water. The municipal sewage sludge was dried by hot air in this work. Based on the drying curve, the derivative of drying rate with respect to dry basis moisture content was brought out to analyze the moisture distribution in sewage sludge. Results show that this method can easily determine the free water, interstitial water, surface water and bound water with a high accuracy. The present work can provide new insight to determine the moisture distribution in sewage sludge, which was still lacking in the literatures.


2011 ◽  
Vol 383-390 ◽  
pp. 3799-3804
Author(s):  
Xiao Xu Fan ◽  
Lei Zhe Chu ◽  
Li Guo Yang

The fuel characteristics of municipal sewage sludge are suitable for dual fluidized bed(DFB) gasification, which can get middle calorific value gas through volatile pyrolysis, and reduce volume through char combustion. The hot test results of municipal sewage sludge on DFB rig were showen that the temperature distribution along combustor heigh is uniform, and the carbon content of fly ash is about 2~3%. In the experiment, with the increase of gasifier temperatrue, the more volatile of the sewage sludge was pyrolyzed. When the temperature of the gasifier reached 800°C, the calorific value of gas was 6.9MJ/Nm3; the emissions of SO2, NOx and HCl were appropriate to the standard. The leaching toxicity of heavy metal of the fly ash was lower than the discharge standard.


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