BACKGROUND Understanding the effects of pretreatment on anaerobic digestion of sludge waste from wastewater treatment plants is becoming increasingly important, as impetus moves towards the utilization of sludge for renewable energy production. Although the field of sludge pretreatment has progressed significantly over the past decade, critical questions concerning the underlying microbial inte...

Sludge production in wastewater treatment plants is increasing worldwide due to the increasing population. This work investigated the effects of ultrasonic (ULS), ultrasonic-ozone (ULS-Ozone) and ultrasonic + alkaline (ULS+ALK) post-treatments on the anaerobic digestion of sewage sludge in semi-continuous anaerobic reactors. Three conditions were tested with different hydraulic retention times ...

Knowledge of the net energy production of anaerobic fermenters is important for reliable modelling of the efficiency of anaerobic digestion processes. By using the Anaerobic Digestion Model No. 1 (ADM1) the simulation of biogas production and composition is possible. This paper shows the application and modification of ADM1 to simulate energy production of the digestion of cattle manure and ren...

Background: Wheat straw is one of the most abundant crop residues produced in the world, making it highly interesting as a substrate for biogas production. However, due to the complex structure, its degradability and gas yield are low. The degradability can be improved by pre-treatment, making the material more accessible to microbial degradation. Methods: To investigate the microbial response ...

In order to obtain basic design criteria for anaerobic digestion of a mixture of poultry manure and wheat straw, the effects of different temperatures and organic loading rates on the biogas yield and methane contents were evaluated. Since poultry manure is a poor substrate, in term of the availability of the nutrients, external supplementation of carbon has to be regularly performed, in order ...

BACKGROUND Environmental issues, such as the fossil energy crisis, have resulted in increased public attention to use bioethanol as an alternative renewable energy. For ethanol production, water and nutrient consumption has become increasingly important factors being considered by the bioethanol industry as reducing the consumption of these resources would decrease the overall cost of ethanol p...

This report is based on several years of co-operation of our research groups with Danish biogas plants. Throughout the years, there has been a fruitful exchange of know-how and experiences in lab-scale on the one hand and large-scale on the other, leading to a better understanding of the principles of the anaerobic digestion process and to an optimization of its large-scale implementation. In o...

The problem of slaughterhouse waste water can be resolved by mixing it with serum from lacteal industry to produce a biogas. The effect of serum addition on the anaerobic co-digestion of solid and liquid slaughterhouse waste has been studied. The experimental device consisted of a continuous digester by recirculation of biogas produced in the anaerobic digestion. The input effluent was a mixtur...

In order to obtain basic design criteria for anaerobic digesters of swine manure, the effects of different digesting temperatures, temperature shocks and feed loads, on the biogas yields and methane content were evaluated. The digester temperatures were set at 25, 30 and 35 degrees C, with four feed loads of 5%, 10%, 20% and 40% (feed volume/digester volume). At a temperature of 30 degrees C, t...