## 1 Introduction
Most of the population experiencing poverty tend to live in rural areas and depend on agriculture (small-scale farming) for substance and these people can produce the majority of the food in developing countries, yet they are usually the most susceptible and deprived individuals lacking resources, provision, and appropriate technologies to mitigate the environmental impact of their activities [16]. Nevertheless, small-scale farmers might not demonstrate economic flexibility to procure advanced treatment options, including sequencing batch reactors, trickling filters, or engineered wetlands. Therefore, in developing regions, the usual animal manure management practice at small-scale farms is direct land application of manure on fields without treatment or treatment via oxidation lagoons [6]. Apparently, at small farms in developing communities, appropriate technologies for treatment should utilise locally available resources, be economically affordable, and should, in turn, safely provide resources to the farmer [17]. Microbial anaerobic degradation of these wastes taking place within a chamber devoid of oxygen or air (biodigester) is considered a good option to properly manage these wastes because it produces biogas (a renewable energy source) and biofertilizer, as well as causes decontamination of the wastes [18]. Notwithstanding, the generation of biogas or biofertiliser (as resources) does not only diminish the use of fuel and synthetic fertiliser but can likewise ease the adverse environmental influences of GHG emissions and eutrophication potential (caused by microbial and chemical contents of the manure) [19]. The microbial makeup of animal manure varies from one farm to the other, depending on the producing animals (growth stage of the animals), the feeding regime, and the waste management practices [20]. It is also clear that the biodigester type (design) and operational factors (temperature) of the process and manure characteristics affect the overall effectiveness of the anaerobic digestion process. The organic loading rate (OLR) is an important design parameter, which depends on the biodigester design (type) and substrate characteristics, as well as indicates the quantity of the volatile solids (VSs) to be fed per unit volume of the biodgester. The factor is crucial as the overloading of substrates can cause digester failure in little time [21]. The OLR in conjunction with temperature are regarded as key parameters for digestion and their suitable application influences the outcome in relation to energy feasibility [22]. The composition of these pathogens occurring in animal manure is observed as one amongst the major restrictions to the use of raw animal manure for soil fertilization in order to enhance food production in the quest to alleviate hunger and poverty [18]. The inactivation of pathogens (belonging to the bacteria domain) in animal manure serves as a prerequisite if manure is intended for subsequent uses which include recycling, disposal, or land application [6]. The decontamination of the wastes is attributed to several factors, including ammonia, pH, temperature, feedstock characteristics, proteins, volatile fatty acids, and carbohydrates [18]. Nevertheless, temperature is the leading cause of pathogen inactivation, causing prominent decontamination of effluent slurry. Based on temperature, a biodgester can be operated at psychrophilic (15-20 \({}^{\circ}\)C or less than 30 \({}^{\circ}\)C), mesophilic (30-40 \({}^{\circ}\)C), or thermophilic temperatures (50-60 \({}^{\circ}\)C) ranges and inactivation rates occur faster with increasing temperature from the psychrophilic to the thermophilic range [22]. However, the potential of a biodgester to cause pathogen inactivation relies on the digester temperature, the concentration of volatile fatty acids, the retention or treatment time, the type of feedstock, as well as the type of pathogen [18]. According to [PERSON] et al.