The work investigated why anaerobic digesters treating food waste and operating at high ammonia concentrations suffer from propionic acid accumulation which may result in process failure. The results showed deficiency of selenium, essential for both propionate oxidation and syntrophic hydrogenotrophic methanogenesis, leads to this while supplementation allows operation at substantially higher o...

The effect of different organic loading rate (OLR) to an anaerobic reactor performance and sulphate reduction was investigated. Sulphate concentration in the feed varied from 100 to 3000 mg.L and up to 97% removal efficiency was observed at OLR 0.43 1.23 kg COD.m.d. However, the removal efficiency showed some decline (to 53 – 67% removal) at OLR 1.53 – 3.73 kg COD.m.d, probably due to high sulp...

Water scarcity, inappropriate sanitation and wastewater pollution are critically important global issues. Greywater is a sustainable water source for recycling, so this thesis examined simple, robust, low-cost alternatives for on-site treatment of greywater to irrigation water quality. Laboratory-scale pine bark, activated charcoal and sand filters were evaluated as regards their pollutant remo...

The anaerobic digestion of filter cake and its co-digestion with bagasse, and the effect of gradual increase of the organic loading rate (OLR) from start-up to overload were investigated. Understanding the influence of environmental and technical parameters on the development of particular methanogenic pathway in the biogas process was an important aim for the prediction and prevention of proce...

Anaerobic continuous stirring tank reactor (CSTR) was employed for biohydrogen production by anaerobic co-digestion from the mixture of herbal wastewater (HW) and monosodium glutamate (MGW). A series blend volumetric proportions (MGW/HW), organic loading rates (OLR) were used as control strategy evaluated optimal production. The highest 7260±7.7 mL L -1 d attained at proportion 15%, OLR 41 g CO...

Propionate is the most delicate intermediate during anaerobic digestion as its degradation is thermodynamically unfavorable. To determine its maximum possible degradation rates during anaerobic digestion, a reactor was fed Monday to Friday with an organic loading rate (OLR) of 12/14 kg CODbiowaste·m-3·d-1 plus propionate up to a final OLR of 18 kg COD·m-3·d-1. No feed was supplied on weekends a...

Fruit and vegetable wastes are produced in large quantities in Iran, and constitute a source of nuisance in municipal landfills. The objective of this study was to optimize the applications of anaerobic digestion for the treatment of municipal organic wastes. We studied the effect of organic loading rates on anaerobic digestion of vegetable wastes. The complete-mix, pilot-scale digester with wo...

Macroalgae biomass has been considered as a promising feedstock for biogas production. In order to improve the efficiency of anaerobic digestion (AD) of macroalgae, semi-continuous fermentation was conducted to examine the effects of organic loading rate (OLR) on biogas production from Macrocystis pyrifer. Results showed that, under OLRs of 1.37, 2.74, 4.12 and 6.85kgVSsubstrate/(m3·d), the ave...