In the last 30 years, there have been significant advances in waste and landfill management practices in response to European Union (EU) directives. These have led to changes in leachate composition, in the volumes of leachate produced and in its treatability. Furthermore, increasingly stringent wastewater discharge requirements mean that the co-treatment of leachate in municipal wastewater treatment plants (WWTPs) with other forms of wastewater can now be a challenge for some WWTPs. Key challenges faced by WWTP operators treating landfill leachate include high ammonium-nitrogen (NH4-N) concentrations in leachate and the increased cost of treating wastewater to increasingly stringent standards. It is anticipated that the requirement to meet these standards will drive WWTP operators to consider their incoming load profile.
The aims of this project were to:
● characterise the volumes and composition of leachate from landfills in Ireland;
● survey WWTP and landfill operators and conduct a technical review of how leachate is handled by WWTPs;
● examine the co-treatment of leachate with other forms of wastewater in WWTPs, specifically the impact of leachate-loading regime or rate of leachate addition on WWTP performance, and quantify the hydraulic and mass (expressed as mass nitrogen) loading of landfill leachate (as a percentage of the total in uent loading rate) above which the performance of a WWTP may be inhibited; and
● analyse the costs of on-site (at land ll) and off-site treatment of landfill leachate.