A new integrated treatment for the reduction of organic and nitrogen loads in methanogenic landfill leachates

Because of their high organic and nitrogen loads and the presence of toxic and phytotoxic compounds, methanogeniclandfill leachates are not easily biodegradable; therefore, direct biological treatment of these wastewaters in conventionaltreatment plants is not recommended.In the present paper, we report the results of an experimental investigation conducted with the aim of defining aninnovative integrated process that is low in cost and easily manageable and that is able to substantially improve thecharacteristics of methanogenic leachates.Thus, an initial oxidation process was developed using hydrogen peroxide without a catalyst, which, operatingunder ambient conditions, reduces the phytotoxic compound content to 10% of the initial level, reduces the COD(chemical oxygen demand) content by 50% and increases the rapidly biodegradable substrate content by 50%. Next,nitrogen removal is accomplished by means of struvite precipitation using seawater bittern and bone meal as sourcesof magnesium and phosphorus, respectively, with this process, abatements were reached of approximately 90% ofthe ammonia nitrogen, which was recovered as struvite powder.