Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

Abstract

Leachates exhibiting an unstable ratio of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of approximately 0.45 are typical of new landfills in the City of Cachoeira Paulista, Brazil. Although the organic matter portion is bio-treatable, the presence of refractory leached organic material requires unconventional effluent-treatment processes. Leachate treatment with ozone oxidation, in the presence of ferric ions, acts as catalyst in the formation of hydroxyl radicals. Ozone was obtained by corona-discharge from high-purity O2 gas. The treatment was performed in natura in a jacketed borosilicate glass reactor containing 900 ml of leachate. The analyzed response variable was expressed as the concentration of dissolved organic carbon (DOC). In order to determine the optimal proportions to produce the greatest degradation rate for organic materials, variations in experimental O2 flow-fed to the generator, the Fe(iii) concentration, and the output of the ozonator were conducted over two experimental runs. Experimental models showed a DOC degradation on the order of 81.25%

Arsenic removal from waste water by ozone oxidation combined with ferric precipitation

“…In their findings, the catalytic ozonation was more efficient than that the ozonation alone by increasing OH· (O 3 < O 3 + Fe(III) < O 3 + Fe(II) < O 3 + Mn(II) < O 3 + Cu(II)). Also, many researchers have been determined that the Fe(III) catalytic ozonation was more effective in degradation of organic and inorganic compounds than the ozone alone, due to the generation of OH· radicals [5,8,12,24,28]. …”

“…A lot of researchers focused on the methods for oxidation of As(III) to As(V) using different oxidants [5][6][7]8]. In several studies, ozone applications have been reported for treatment of wastewater and water, but very few studies are for oxidation of As [6][7][8][9][10]. The most characteristic chemical properties of ozone are its strong oxidizing and high standard redox potential according to the reaction conditions.…”

Característica de alguns frutos das palmeiras nativas da Amazônia Brasileira

“…Souza et al (2013), utilizando o mesmo efluente e processo de tratamento por ozonização (catalisado pelo íon férrico), porém com níveis mais altos para a vazão de oxigênio (2 L h -1 , 4 L h -1 e 6 L h -1 ) e potência do ozonizador (20 W, 40W e 60W), obtiveram uma redução de 71,5% de TOC, 62,24% de COD, 29,2% de BOD 5 e 0,475 para a razão BOD 5 /COD. As características do chorume obtido por este tratamento, também não permitem seu descarte em rios.Tabela 4.…”