Reviews in Environmental Science and Bio/Technology

, 10:215

Application of physico-chemical pretreatment methods to enhance the sludge disintegration and subsequent anaerobic digestion: an up to date review

Reviews

DOI: 10.1007/s11157-011-9244-9

Cite this article as:
Tyagi, V.K. & Lo, SL. Rev Environ Sci Biotechnol (2011) 10: 215. doi:10.1007/s11157-011-9244-9

Abstract

Anaerobic digestion of waste activated sludge (WAS) is most commonly used at wastewater treatment facilities to stabilize the sludge. However, poor biodegradation efficiency of sludge and longer retention times (20–30 days) are the major limitations of anaerobic digestion method, which can be overcome by disintegrate the sludge and make intracellular material readily available to anaerobic biodegradation. Several sludge disintegration techniques (Thermal, chemical and mechanical) and their combinations were studied previously in order to improve the anaerobic digestibility of sludge, reduce the sludge retention time and enhance the production of biogas. However, none of the pretreatment technique shows a real breakthrough in enhancement of anaerobic digestibility of WAS due to associated drawbacks, such as high operational and capital cost, poor sanitization and energy intensive. On the other hand, hybrid pretreatment techniques endow with promising outcomes through neutralizing the associated drawbacks with individual pretreatment techniques. Nevertheless, the research on the application of hybrid pretreatment techniques is in its infant stage, presently. Therefore, the satisfactory research in this direction can lead to policy maker and environmental protection agency to select more robust and sustainable solution for sludge treatment. This review encompasses the up-to-date information about the thermal, chemical and mechanical sludge disintegration techniques (principle, performance at lab, pilot and full scale, advantages and disadvantages). A comparative evaluation of these techniques are also presented in terms of COD solubilization, dewaterability, pathogens removal, lab/pilot/full scale application, capital and, operation and maintenance cost involved and energy requirement.

Keywords

Anaerobic digestionPhysico-chemical pretreatmentSludge disintegration

Abbreviations

COD

Chemical oxygen demand

CST

Capillary suction time

DOC

Dissolved organic carbon

DS

Dry solids

EPS

Extracellular polymeric substances

HPH

High pressure homogenizer

HRT

Hydraulic retention time

MW

Microwave

PAH

Polycyclic aromatic hydrocarbons

PCB

Polychlorinated biphenyl

RPM

Rotations per minute

SRF

Specific resistance to filtration

SRT

Sludge retention time

SVI

Sludge volume index

TOC

Total organic carbon

TS

Total solids

TSS

Total suspended solids

VS

Volatile solids

VSS

Volatile suspended solids

WAS

Waste activated sludge

WWTP

Wastewater treatment plants

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Graduate Institute of Environmental EngineeringNational Taiwan UniversityTaipei 106Taiwan, Republic of China