A pilot study of three-stage biological–chemical treatment of landfill leachate applying continuous ferric sludge reuse in Fenton-like process
| Autor: | Taavo Tenno, Arthur Kivi, Niina Dulova, Ivar Zekker, Marina Trapido, Kati Klein, Toomas Tenno, Erik Mölder |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
Economics and Econometrics Environmental Engineering Waste management Chemistry 0208 environmental biotechnology 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law Reuse 01 natural sciences General Business Management and Accounting 020801 environmental engineering Ferrous Catalysis Activated sludge Reagent medicine Environmental Chemistry Ferric Leachate Industrial and production engineering 0105 earth and related environmental sciences medicine.drug |
| Zdroj: | Clean Technologies and Environmental Policy. 19:541-551 |
| ISSN: | 1618-9558 1618-954X |
| DOI: | 10.1007/s10098-016-1245-5 |
| Popis: | This pilot study describes a three-stage continuous process for treating landfill leachate containing significant concentrations of recalcitrant organic substances. The proposed technological scheme consisted of an activated sludge pre-treatment combined with a Fenton-like process enhanced by continuous sludge reuse and followed by an activated sludge post-oxidation. Biological pre-treatment removed >99, 86, >99, 83 and 86 % of BOD7, COD, NH4 +–N, phenols and the sum of lignin and tannins, respectively. Operational conditions in the ferric sludge-catalysed Fenton-like process stage were carefully adjusted in order to maintain the efficacy and practicability of combined treatment scheme. Although the application of ferric sludge as a catalyst in the Fenton-like oxidation reduced COD removal efficiency by 32 % as compared to the conventional Fenton process, lower process efficiency was compensated by reducing the water exchange ratio to 50 % without increasing the consumption of reagents. Moreover, an intermittent addition (added to every second treatment cycle) of fresh ferrous iron catalyst at a H2O2/Fe2+ w/w ratio of 20/1 increased the BOD7/COD ratio from 0.04 to 0.32 and resulted in 60 % COD removal. A cyclic addition (added to every treatment cycle) of the same amount of catalyst increased the BOD7/COD ratio from 0.09 to 0.32, and a 10 % higher COD removal efficiency as compared to intermittent catalyst addition was achieved. Finally, biological post-treatment of the leachate resulted in more than 95 % removal of each measured parameter. Overall, the combined technological scheme with continuous ferric sludge reuse in the Fenton-like stage proved promising alternative for landfill leachate treatment. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink