20.500.12556/RUL-144176 Removal of toxic metals from sewage sludge by acid hydrolysis coupled with EDTA washing in a closed-loop process Contamination with toxic metals prevents the use of sewage sludge (SS) as a soil fertilizer. Hydrodynamic cavitation, thermal microwaving, microwave-assisted alkaline, and acid hydrolysis coupled with ethylenediaminetetraacetate (EDTA) washing were tested as a method to remove toxic metals from SS. Acid hydrolysis coupled with EDTA washing was most effective and was used in a closed-loop process based on ReSoil technology. EDTA and process solutions were recycled at a pH gradient of 12.5–2, which was imposed by the addition of quicklime (CaO) and H2SO4. An average of 78%-Pb, 76%-Zn, 1%-Cu, and 17%-Cr were removed from SS in five consecutive batches. No wastewater was generated, only solid waste (40%). The EDTA lost in the process (42%) was resupplied in each batch. In a series of batches, the process solutions retained metal removal efficiency and quality. The treatment removed 70% and 23% of P and N, respectively, from SS and increased the leachability of Zn, Cu, Mn, and Fe in the washed SS by 11.7, 6.8, 1.4, and 5.2 times, respectively. Acid hydrolysis coupled with EDTA washing proved to be a technically feasible, closed-loop process but needs further development to reduce reagent, material, and nutrient loss and to reduce toxic emissions from the washed sludge. sewage sludge toxic metals EDTA hydrolysis microwaves cavitation phosphorus blato iz čistilnih naprav strupene kovine EDTA čiščenje mikrovalovna pečica kavitacija fosfor true false true Angleški jezik Slovenski jezik Članek v reviji 2023-02-02 13:44:33 2023-02-02 13:44:38 2023-02-04 03:19:41 0000-00-00 00:00:00 2023 0 0 13 str. iss. 3, art. 2544 Vol. 20 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 502.1 1660-4601 10.3390/ijerph20032544 140480003 ijerph-20-02544.pdf ijerph-20-02544.pdf 1 BBEBE7F1D75567E6AFA3E7DA7A364F16 6edef2979cc5846abdba6459b308c028a12da12584a75f479c42339f9ff54449 6abaf3c3-a2f7-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=166362 https://www.mdpi.com/1660-4601/20/3/2544 1 111207fc-a2f7-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=166361 Biotehniška fakulteta 0 0 0