Original scientific paper

Pig slurry hygienization with hydrogen peroxide - silvercomplex, an environmentally acceptable disinfectant.

Alenka Tofant ; Department of Animal Hygiene, Environment and Ethology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Željko Pavičić ; Department of Animal Hygiene, Environment and Ethology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Kristina Matković ; Department of Animal Hygiene, Environment and Ethology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Suzana Hađina ; Department of Animal Hygiene, Environment and Ethology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Josip Križanić ; Varaždin Veterinary Station, Croatia

Abstract

Liquid fraction of pig slurry sampled at the site of drainage into an aerobic lagoon was treated with a hydrogen peroxide-based disinfectant with silver ions for catalytic action in order to define a hygienically acceptable substrate according to its organoleptic, physicochemical and especially microbiologic properties, intended for environmental disposal. In the in vitro experiment using substrate mixture with the disinfectant at a final concentration of 2%, time of action of 1 hour, and efficacy control at 24 hours, the following results were observed: the dark, turbid, green-brown, malodorous slurry samples turned light and the intensity of malodour declined substantially. The concentration of ammonium ions and nitrite decreased significantly (P<0.01 and P<0.05, respectively), whereas the nitrate concentration increase (P<0.05) was presumably due to oxidation. Oxidizing processes led to a significant reduction (P<0.01) in the biochemical oxygen demand (BOD5). However, its value of 1992.50 ± 244.59 mgO2/L was still ecologically unacceptable to be drained into waters. The percentage of dry matter and sedimentation decreased, (P<0.05), pH showed a slight increase, whereas the proportion of organic matter and electric conductivity remained unchanged. The number of mesophilic and total coliform bacteria decreased significantly (P<0.01). The efficacy of disinfection expressed as log10 reduction factor (RF) was 3.23 for mesophilic bacteria and 3.12 for total coliform bacteria, showing a >99% reduction in their number. The results obtained in the study pointed to efficient hygienization with hydrogen peroxide and silver ions, rendering pig slurry a more acceptable substrate to be disposed of into the environment.

Keywords

hygienization; pig slurry; disinfectant; hydrogen peroxide - silver complex

Hrčak ID:

76748

URI

https://hrcak.srce.hr/76748

Publication date:

21.12.2003.

Article data in other languages: croatian

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