Biogas production by anaerobic digestion of fruit and vegetable waste. A preliminary study

✍ Scribed by Wieger Knol; Michael M. Van Der Most; Jacobus De Waart

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 561 KB
• Volume: 29
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740290913

✦ Synopsis

Abstract

Waste of apples, asparagus, carrots, green peas, French beans, spinach and strawberries from a canning factory have been screened on mesophilic anaerobic digestion in 90‐day experiments at loading rates varying between 0.80 and 1.60 kg volatile solids (VS) m^−3^ day^−1^ at a retention time of 32 days. Average biogas yields varied from 0.30 to 0.58 m^3^ kg‐^1^ VS day^−1^. High percentages of reduction in VS, carbohydrate and crude fibre were obtained in most experiments. Some waste materials showed unbalanced digestion, as might be expected from carbohydrate‐rich substrates. In those cases alkali addition, feed interruption and mixing with a nitrogen‐rich substrate were used to overcome unbalanced digestion. Residual solids in the digested sludges were removed by flocculation with a polyelectrolyte and centrifugation; liquids with lower CODs remained after flocculation.