摘要：Landfill leachate possesses high concentrations of ammonia, micropollutants, and heavy metals, and
are characterised for low biodegradability. For this reason, conventional treatment technologies may result
ineffective for complete pollutant removal. Electrochemical oxidation allows most of the of recalcitrant
pollutants to be oxidised effectively within an easy operational and acceptable retention time, without the need
to provide additional chemicals, and without producing waste materials. The mineralisation efficiency and
electrode durability depend on the nature of the electrode material. The conventionally adopted anodes can
contain critical raw materials (CRMs), and are subject to extreme corrosion conditions. CRM-free electrodes,
such as carbon and graphite-based, exhibit a lower efficiency, and are subject to faster deactivation, or, as for
lead-dioxide-based electrodes, can constitute a hazard due to the release into the effluent of the coating corrosion
products. In this study, the relationship between electrode type, CRM content, and the removal efficiencies of
organic compounds and ammonium-nitrogen (N-NH4) was investigated. Material criticality was estimated by
the supply risk with economic importance indexes reported in the 2017 EU CRM List. The COD and N-NH4
removal efficiencies were obtained from a literature analysis of 25 publications. The results show that, while
single and multi-oxide-coated electrodes may contain low amounts of CRM, but with limited efficiency, borondoped
diamonds (BDD) may constitute the best compromise in terms of a reduced content of CRM and a high
mineralisation efficiency.
其他摘要：Landfill leachate possesses high concentrations of ammonia, micropollutants, and heavy metals, and are characterised for low biodegradability. For this reason, conventional treatment technologies may result ineffective for complete pollutant removal. Electrochemical oxidation allows most of the of recalcitrant pollutants to be oxidised effectively within an easy operational and acceptable retention time, without the need to provide additional chemicals, and without producing waste materials. The mineralisation efficiency and electrode durability depend on the nature of the electrode material. The conventionally adopted anodes can contain critical raw materials (CRMs), and are subject to extreme corrosion conditions. CRM-free electrodes, such as carbon and graphite-based, exhibit a lower efficiency, and are subject to faster deactivation, or, as for lead-dioxide-based electrodes, can constitute a hazard due to the release into the effluent of the coating corrosion products. In this study, the relationship between electrode type, CRM content, and the removal efficiencies of organic compounds and ammonium-nitrogen (N-NH4) was investigated. Material criticality was estimated by the supply risk with economic importance indexes reported in the 2017 EU CRM List. The COD and N-NH4 removal efficiencies were obtained from a literature analysis of 25 publications. The results show that, while single and multi-oxide-coated electrodes may contain low amounts of CRM, but with limited efficiency, boron-doped diamonds (BDD) may constitute the best compromise in terms of a reduced content of CRM and a high mineralisation efficiency.
关键词：Recalcitrant pollutants ; anodic oxidation ; mineralisation efficiency ; critical raw materials ;
boron;doped diamonds ; advanced oxidation process
其他关键词：Recalcitrant pollutants ; anodic oxidation ; mineralisation efficiency ; critical raw materials ; boron-doped diamonds ; advanced oxidation process
