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In Chlef, the management of urban solid bio-waste is limited to "all in controlled landfill or in wild landfill". This bio-waste can be treated by composting-methanization. With this in mind, two temperature regimes were chosen, the mesophilic regime (35°C) and the thermophilic regime (55°C). The choice of a neutral pH is an optimal value indicating the stability and the good progress of the anaerobic digestion. As well as monitoring the parameters of the composting process. The results of the composting process show that the values of temperature (35°C to 62°C), pH (5 to 8), moisture content (60% and 40%) and percentage of organic matter (74% to 41%) indicate that the fermentation process is going well. The composting process enters the cooling phase after 60th day of fermentation. While the results of the methanization show that a substrate with an organic matter content of 73% causes an accumulation of acids in the digester and a stop of the reaction in mesophilic conditions. Therefore, the thermophilic mode is more suitable for the anaerobic degradation of raw bio-waste. The tests were conclusive in obtaining a flammable biogas. The values of the VFA (Volatile Fatty Acid)/ACT (Alkalimetric Title) ratios below 0.1 show the good functioning of the anaerobic digestion. The methanization of two masses of substrate at the beginning and during the cooling phase of composting allows a gain in residence time, thus a lower energy cost. [ABSTRACT FROM AUTHOR]

This experimental study carried out on the scale laboratory and reveals the main results of the anaerobic digestion of the effluents from food industry. In this study, it consists of a mixture of apricot and orange juice. The parameters that affect directly the fermentation process have been monitored, such as: growth, chemical oxygen demand (COD), pH. The cumulative biogas volume found was about 23055NmL, it was reached after 552 h of digestion in acid medium. In such case, the degradation of the organic matter reached about 60%. Furthermore, the methane content was measured using a (GC/MS), it was found to be of the order of 71%. The kinetics of biogas production was modeled with the modified Gompertz model. A good agreement between this model and the experimental data was obtained. [ABSTRACT FROM AUTHOR]