![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
Meat plant wastewater quality depends on water usage, the type of animal slaughtered, and the amount of rendering or processing that is done on site. In Ontario and Quebec, abattoir wastewater total chemical oxygen demand (TCOD) ranged from 2333 to 8627 mg/L, and suspended solids (SS) from 736 to 2099 mg/L, volatile suspended solids (VSS) represented 80% of SS, and protein content varied from 444 to 2775 mg/L. Nitrogen (N) and potassium (P) averaged 6.0 and 2.3 g/100 g of TCOD, respectively. Ammonia and sulfide levels were well below the 3000 and 100 mg/L toxicity level, respectively. The chemical oxygen demand (COD) of fresh blood is high at 375,000 mg/L compared to the COD of liquid manure at 15,000–30,000 mg/L. The concentration of the wastewater can be greatly affected by the efficiency of blood recovery in the blood pit. Abattoir wastewater contains several million colony forming units (cfu) /100 mL of total coliform, fecal coliform, and Streptococcus groups of bacteria. The presence of these nonpathogenic microbes indicates the possible presence of pathogens of enteric origin such as Salmonella ssp. and Campylobacter jejuni and of gastrointestinal parasites such as Ascaris sp., Giardia lamblia, Cryptosporidium parvum, and enteric viruses. Giardia lamblia and Cryptosporidium parvum are not a concern in poultry wastewater. Pathogens might threaten public health by migrating into groundwater or through traveling off-site by surface water, wind, or vectors (i.e., animals, birds) etc. Once the treated abattoir wastewater is applied to land, the potential for spread of any pathogens that might remain in the water or sludge varies with the type of crop and soil to which it is applied.