Using of the Ornamental Fish in Wastewater Biological Treatment

• Published in: Clean : soil, air, water Vol. 40; no. 5; pp. 499 - 505
• Main Authors: Saidi, Nourhène, Jabeur, Chedia, Bakhrouf, Amina
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.05.2012; WILEY‐VCH Verlag; Wiley-VCH; Wiley Subscription Services, Inc
• Subjects: Aeromonas hydrophila; Aquaculture; BOD; Clarias batrachus; COD; Earth sciences; Earth, ocean, space; Escherichia coli; Exact sciences and technology; Fish growth; Freshwater; Gambusia affinis; Health risk; Hydrology; Hydrology. Hydrogeology; Poeciliidae; Purification; growth rates; Chordata; bacteria; Tertiary; effluents; Fish growth; chemical analysis; Health risk; Vertebrata; prokaryotes; water treatment; solution; Pisces; purification; BOD; fish; COD; growth; Cenozoic; Phanerozoic; reduction; Aquaculture
• ISSN: 1863-0650; 1863-0669
• DOI: 10.1002/clen.201000258

Breeding ornamental fish in wastewater was a successful solution not only to decrease sanitary risks but also to encourage fish growth. In fact, the secondary treated effluent was used to grow a walking catfish (Clarias batrachus), a western mosquitofish (Gambusia affinis; Poeciliidae), and a leopard pleco (Glyptoperichthys gibbiceps). The growth rate of fish reared in final treated wastewater was significantly higher than of treated effluent (25 and 50%) and the relative growth rate during 2 months reached 2, 4, and 2.5, respectively. Bacterial loads were important in the gills compared to other fish organs (intestine, skin, and edible muscles). However, the total aerobic germs ranged between 2 × 103 and 3.4 × 103 cfu/g in the edible fish species cultured in secondary treated effluent. The pathogenic bacteria Aeromonas hydrophila was absent in all examined fish muscles. However, the presence of tested fishes did not prevent the reduction of the treatment biological parameter (BOD and COD) at half, in the three treated wastewater proportions (25, 50, and 100%) and thereafter, they clearly participated to the tertiary biological treatment of used water. Further bacteriological and physico‐chemical analyses indicated that the use of treated wastewater in aquaculture is safe and risks to human health are reduced. The diminution of total coliforms, fecal coliforms, and total germs number in breeding water proved the important intervention of fish to eliminate a great number of wastewater microorganisms. The bacteriological examination of primary, final treated effluent, and fish organs confirmed the presence of Escherichia coli and Aeromonas hydrophila in low number or absence in fish muscles.