In:
Water Environment Research, Wiley, Vol. 76, No. 4 ( 2004-07), p. 334-343
Abstract:
This work evaluated the performance of a full‐scale system with wetlands for slaughterhouse (abattoir) effluent treatment in the State of Hidalgo, México. The treatment system consisted of a primary sedimentation tank, an anaerobic lagoon, and a constructed subsurface‐flow wetland, in series. The wetland accounted for almost 30% of the removal of organic matter. In general, the treatment system achieved satisfactory pollutant removals, but the final effluent could not meet the Mexican environmental regulations for fecal coliform counts, five‐day biochemical oxygen demand (BOD 5 ), and total suspended solids (TSS). Overall, removal levels were 91%, 89%, and 85% for BOD 5 , chemical oxygen demand, and TSS, respectively. However, BOD 5 in the final effluent (137 mg/L) was higher than the maximum level of 30 mg/L allowed by the regulatory agency. Although organic nitrogen removal levels were approximately 80%, the nitrogen persisted in oxidation state – 3 as ammonia–nitrogen, the removal of which was only 9% in the wetland stage. On average, phosphorus removal was null, and, on occasion, the phosphorus concentration in the treated effluent was higher than that of the influent. Coliform reductions in the overall system were high (on the order of 5 logs on average), whereas the coliform removal in the wetland was between 2 to 3.5 logs. The treatment system was also effective at removing pathogens ( Vibrio cholerae, Salmonella , and Shigella ). Further laboratory tests with the wetland effluent suggest that post treatment in a sand filter stage followed by disinfection with sodium hypochlorite (NaOCl) could help meet the Mexican discharge regulations, particularly the criteria for coliforms and total BOD 5 .
Type of Medium:
Online Resource
ISSN:
1061-4303
,
1554-7531
DOI:
10.2175/106143004X141924
Language:
English
Publisher:
Wiley
Publication Date:
2004
detail.hit.zdb_id:
1098976-6
detail.hit.zdb_id:
2051010-X
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