First approaches to valorizate fat, oil and grease (FOG) as anaerobic co-substrate with slaughterhouse wastewater: Biomethane potential, settling capacity and microbial dynamics

Identification of some microbial flora contained in slaughterhouse effluent and likely to be effective in its treatment by biological process

The specific contributions of the different bacterial flora during the biological treatment of slaughterhouse effluents remain unclear. The objective of this study is to identify the different microbial flora which mainly contribute to the efficiency of the biodegradation of the organic, nitrogenous and phosphate loads contained in the slaughterhouse effluent during its biological treatment. To achieve this, the effluent to be treated was sampled from three slaughterhouses in the city of Ngaoundéré (Cameroon). The various effluents underwent a physicochemical and microbiological characterization. The effluent was subjected to biological treatment. The biodegradation process (biological treatment) took place in two reactors, each operating in batch. One of the two reactors was supplied with oxygen (aeration). The effluent being treated underwent a physicochemical and microbiological characterization for 30 days. The results obtained show organic matter and ammonium contents >1,000 mgO2/L in each of the three effluents. Bacillus cereus (69 × 108 CFU/mL), Pseudomonas aeruginosa (201 × 107 colony forming unit (CFU)/mL) and Yeasts (101 × 106 CFU/mL) globally constitute the majority of microbial groups among the seven microorganisms identified in the effluents of the three slaughterhouses. There is no real oxygenation effect of the medium on the growth of the three microbial flora during the treatment.

Microbial Behavior and Influencing Factors in the Anaerobic Digestion of Distiller: A Comprehensive Review

Anaerobic digestion technology is regarded as the most ideal technology for the treatment of a distiller in terms of environmental protection, resource utilization, and cost. However, there are some limitations to this process, the most prominent of which is microbial activity. The purpose of this paper is to provide a critical review of the microorganisms involved in the anaerobic digestion process of a distiller, with emphasis on the archaea community. The effects of operating parameters on microbial activity and process, such as pH, temperature, TAN, etc., are discussed. By understanding the activity of microorganisms, the anaerobic treatment technology of a distiller can be more mature. Aiming at the problem that anaerobic treatment of a distiller alone is not effective, the synergistic effect of different substrates is briefly discussed. In addition, the recent literature on the use of microorganisms to purify a distiller was collected in order to better purify the distiller and reduce harm. In the future, more studies are needed to elucidate the interactions between microorganisms and establish the mechanisms of microbial interactions in different environments.

Characterization of Slaughterhouse Wastewater and Development of Treatment Techniques: A Review

Commercialization in the meat-processing industry has emerged as one of the major agrobusiness challenges due to the large volume of wastewater produced during slaughtering and cleaning of slaughtering facilities. Slaughterhouse wastewater (SWW) contains proteins, fats, high organic contents, microbes, and other emerging pollutants (pharmaceutical and veterinary residues). It is important to first characterize the wastewater so that adequate treatment techniques can be employed so that discharge of this wastewater does not negatively impact the environment. Conventional characterization bulk parameters of slaughterhouse wastewater include pH, color, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and coliform counts. Characterization studies conducted have revealed the effects of the pollutants on microbial activity of SWW through identification of toxicity of antibiotic-resistant strains of bacteria. Due to the high-strength characteristics and complex recalcitrant pollutants, treatment techniques through combined processes such as anaerobic digestion coupled with advanced oxidation process were found to be more effective than stand-alone methods. Hence, there is need to explore and evaluate innovative treatments and techniques to provide a comprehensive summary of processes that can reduce the toxicity of slaughterhouse wastewater to the environment. This work presents a review of recent studies on the characterization of SWW, innovative treatments and technologies, and critical assessment for future research.