Fundamental processes and implications during in situ aeration of old landfills

Monitoring transitory profiles of leachate humic substances in landfill aeration reactors in mesophilic and thermophilic conditions

“…Increased organic loads in the leachate have been observed by the current study and Oncu et al [17]. COD decrease after aeration was reported by Ritzkowski et al [5], Prantl et al [14] and Raga and Cossu [20]. Many factors including waste age, waste types as well as aeration procedures, might play different roles in these studies leading to different results.…”

“…Unlike those passive measures, in situ aeration targets to reduce the pollution potential of the waste materials before contamination occurs [4]. By supplying a controlled amount of air to landfills, in situ aeration promotes aerobic biodegradation via interruption of existent anaerobic process [5]. In contrast to the slow rate presented by anaerobic pathway, in an aerobic environment biodegradable organic matter together with those semi-degradable and hardly degradable organics such as cellulose and lignin could be oxidized into carbon dioxide in a significantly shorter timeframe [4].…”

“…E.g. temperature above 40 °C may inhibit nitrification [5]. In landfill bioreactor at 45 °C, a delay of biodegradation process was observed, when operation condition was changed from anaerobic to aerobic at start-up phase [20].…”

Kinetic approach and balancing of aerobic stabilization of solid wastes in lysimeters

“…After separation of variables and integration in the range from t = 0 and S = S o to t = t and S = S, we have: (8) where: S o -initial concentration of VFA, k -rate constant selected so as to obtain the best fitting of the model to experimental data (constant k was calculated using the OriginPro7 program). The yield of carbon dioxide production from volatile fatty acids is:…”

Landfill In-Situ Aeration Process and Technology

“…By means of in situ aeration, the conditions in the landfill can be converted from anaerobic into aerobic with the subsequent acceleration of stabilization processes of the biodegradable fraction, with the aim of a faster reduction of the residual potential emissions and of the related environmental impact (Cossu et al, 2007, Ritzkowski et al, 2006. Leachate extraction carried out from the aeration wells enable faster biological stabilization of waste due to the enhancement of air diffusion in the landfill body and provides enhanced mechanical properties of the landfill at the same time.…”