Sustainable sludge treatment strategies vital

25th April 2014

  

Font size: - +

More municipalities are looking to enhance the energy potential of their sewage plants to ensure economically and ecologically sustainable plant solutions, says biogas manufacturer Weltec Biopower sales manager Hajo Schierhold.

“Sustainable anaerobic fer- mentation and sludge treatment strategies are vital, as many countries plan to discontinue the use of sludge as fertiliser,” he says, adding that these framework conditions and rising energy prices amp- lify the need for municipalities to act.

Therefore, Germany-based bio-gas manufacturer Weltec Biopower has developed an enhanced anaerobic sludge treatment approach and a retro- fit package for anaerobic sludge treatment, he notes.

Anaerobic sludge fermentation – during which the sewage gas develops – is the process step that offers the sewage plant a particularly high energy use and saving potential, Schierhold points out.

“With this possibility to generate power for their own consumption, sewage plants can cut their energy costs by up to 25%,” he stresses.

Additionally, the heat produced by the cogeneration unit can be used directly and inexpensively to heat buildings’ digesters or bio- reactors to accelerate the entire fermentation process, he points out.

Further, Schierhold notes that fermentation also reduces the amount of sludge, ultimately resulting in lower sludge disposal costs, further reducing sewage plant operating costs.

Meanwhile, the reduction helps companies avoid harmful greenhouse-gas emissions that diffuse into the atmosphere during aerobic sludge stabilisation.

However, to benefit from these advantages, Schierhold explains that appropriate plant techno- logy must be implemented, such as a suitable anaerobic unit for sludge stabilisation, adding that this unit must be equipped with a special roof for intermediate storage of the fermentation gas as an energy source for the energy cogeneration (CHP) supply, which involves the generation of energy from different processes.

He asserts that Weltec Bio-power’s modular digesters are particularly suited for this purpose. “In these mature stainless-steelbioreactors, harmful carbon compounds are efficiently converted into methane by means of micro- biological decomposition pro- cesses in the absence of air,” he says.

“In view of mounting energy prices, the advantages of a reduced sludge volume and the upgrade of sewage plants to use fermentation gas for energy purposes are particularly attractive for the range of 10 000 to 30 000 population equivalent municipalities.”

He concludes that operators in European countries have invested in the Weltec package comprising the specially designed fermenters, high-quality components and enhanced energy extraction processes, with investors appearing impressed by the extensive biogas technology expertise, from the ground slab to digester technology to CHP systems.

Edited by Megan van Wyngaardt
Creamer Media Contributing Editor Online

Comments

The content you are trying to access is only available to subscribers.

If you are already a subscriber, you can Login Here.

If you are not a subscriber, you can subscribe now, by selecting one of the below options.

For more information or assistance, please contact us at subscriptions@creamermedia.co.za.

Option 1 (equivalent of R125 a month):

Receive a weekly copy of Creamer Media's Engineering News & Mining Weekly magazine
(print copy for those in South Africa and e-magazine for those outside of South Africa)
Receive daily email newsletters
Access to full search results
Access archive of magazine back copies
Access to Projects in Progress
Access to ONE Research Report of your choice in PDF format

Option 2 (equivalent of R375 a month):

All benefits from Option 1
PLUS
Access to Creamer Media's Research Channel Africa for ALL Research Reports, in PDF format, on various industrial and mining sectors including Electricity; Water; Energy Transition; Hydrogen; Roads, Rail and Ports; Coal; Gold; Platinum; Battery Metals; etc.

Already a subscriber?

Forgotten your password?

MAGAZINE & ONLINE

SUBSCRIBE

RESEARCH CHANNEL AFRICA

SUBSCRIBE

CORPORATE PACKAGES

CLICK FOR A QUOTATION