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Mature landfill leachate treatment by denitrification and ozonation

The removal of nitrate from a mature landfill leachate with high nitrate load in a lab-scale anoxic rotating biological contactor (RBC) was studied. Under a phosphorus-phosphate concentration of 10mg P-PO4 3− L−1 and nitrogen-nitrate concentrations above 530mgN-NO3 − L−1 the reactor achieved nitrogennitrate removal efficiencies close to 100%, without nitrite or nitrous oxide accumulation. Although the reactor p...

Denitrification of a landfill leachate with high nitrate concentration in an an...

The denitrification performance of a lab-scale anoxic rotating biological contactor (RBC) using landfill leachate with high nitrate concentration was evaluated. Under a carbon to nitrogen ratio (C/N) of 2, the reactor achieved N-NO3 − removal efficiencies above 95% for concentrations up to 100 mg N-NO3 − l−1. The highest observed denitrification rate was 55 mg N-NO3 − l−1 h−1 (15 g N-NO3 − m−2 d−1) at a nitrate...

Evaluation of fenton and ozone-based advanced oxidation processes as mature lan...

Fenton treatment (Fe2+/H2O2) and different ozone-based Advanced Oxidation Processes (AOPs) (O3, O3/OH− and O3/H2O2) were evaluated as pre-treatment of a mature landfill leachate, in order to improve the biodegradability of its recalcitrant organic matter for subsequent biological treatment. With a two-fold diluted leachate, at optimised experimental conditions (initial pH 3, H2O2 to Fe2+ molar ratio of 3, Fe2+ ...

Landfill leachate treatment - where lies the solution

As society and technology has developed, an increasing amount of municipal solid waste (MSW) along with industrial and agricultural waste has been generated and the management of waste became a very organized, specialized and complex activity. The huge amounts of waste produced every day have several detrimental impacts of great concern, where the depletion of natural resources is one of the most important. Alt...

Landfill leachate treatment in rotating biological contactors

Tese de doutoramento em Engenharia Química e Biológica ; Sanitary landfilling is the most used and accepted method to eliminate municipal solid waste worldwide due to its economic advantages. The generation of leachate is an inevitable consequence of this practice. Landfill leachate is a high-strength wastewater with great chemical complexity and diversity. In order to avoid discharges to the environment causi...

Ozonation as polishing treatment of mature landfill leachate

Mature landfill leachate is typically resistant to biological processes. In order to enhance the biodegradability of a pre-treated mature landfill leachate, ozonation treatments in a lab-scale column were assayed under different ozone concentrations, contact time, initial pH, and hydrogen peroxide concentrations. Degradation of the landfill leachate by ozone was favoured at higher pH values and with the additio...

Denitrification and ozonation processes for mature landfill leachate treatment

Denitrifying activity of activated sludge in suspension and in biofilm

A method based on measuring substrate depletion rate was developed to evaluate the denitrifying activity of activated sludge in suspension and in biofilm form in anoxic serum flasks. The adapted activated sludge inoculum was grown as biofilm in an anoxic rotating biological contactor (RBC). Acetate was used as external carbon source to obtain a carbon to nitrogen ratio (C/N) of 2. The results showed that the sp...

Fenton’s oxidation as post-treatment of a mature municipal landfill leachate

Mature landfill leachates contain some macromolecular organic substances that are resistant to biological degradation. Recently, Fenton’s oxidation has been investigated for chemical treatment or pre-treatment of mature landfill leachates. The aim of this study was to reduce the recalcitrant organic load still remaining after the complete treatment of a mature landfill leachate by Fenton’s oxidation post-treatm...

Effect of operating parameters on denitrification in an anoxic rotating biologi...

The presence of nitrate in water and wastewater is a serious environmental problem. Anoxic rotating biological contactors (RBC) are a promising novel technology for nitrate removal. In this study the effect of two carbon/nitrogen (C/N) molar ratios (1.5 and 3.0) on denitrification, using acetate as a carbon source, were investigated in an anoxic bench-scale RBC, treating synthetic wastewater. The effect of diff...