## 6 Conclusion and Recommendations  
Red meat processing results in the production of a range of solid organic waste, including FOGs, manure, paunch and sludge. The industry also generates large quantities of wastewater which requires varying levels of treatment prior to disposal to land or waterways. Sources of wastewater include stockyards, slaughter areas, offal processing areas and rendering processes. Depending on plant configuration, these sources can result in varying amounts of blood, fat, manure, meat, paunch and detergents entering the wastewater treatment system if not captured at the source and diverted into the solid waste treatment system. Red meat processing wastewater can generate methane which is a valuable energy source and a greenhouse gas. The primary option available to the processing sector in reducing greenhouse gas emissions is generating energy on site through methane capture and use. This paper reviews a compilation of investigations into improving anaerobic digestion performance of high-strength wastewater. A number of recommendations can be drawn from this series of investigations:  
* Effective primary treatment of the wastewater is essential to break down FOG into a dispersed and useable form or to ensure removal of excess FOG and solids. Primary treatment includes the use of: (i)
* Screens (include static, vibrating, rotary and screw presses) as the first stage of primary pre-treatment to remove solid material including fat particles, paunch and manure from the wastewater; (ii)
* Well-designed save-alls which remove fat effectively; (iii)
* Adequately operated dissolved air flotation (DAF) systems. * Biogas plants should be designed to minimise the effect of shock loading and maximise consistency in feedstock composition. Redundancy should be built in to allow for maintenance. * A degree of mixing may be beneficial to prevent crust accumulation in anaerobic lagoons, though design should be careful as to avoid short-circuiting and washout. * Covered anaerobic lagoons typically operate at ambient temperatures and should be optimised for mesophilic conditions. The integration of heat exchangers into the treatment system could be a simple option to provide constant mesophilic temperature and to improve the anaerobic process of biogas production. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & \multicolumn{2}{c}{**RMP Wastewater**} & \multicolumn{2}{c}{**Optimal Concentration**} \\  & **mg\(\cdot\)kg\({}_{1}^{-1}\)\(\pm\) Std. Dev. (\(n=3\))** & **mg\(\cdot\)kg\({}_{1}^{-1}\)** \\ \hline Iron & \(1458\pm 140\) & 750–5000 \\ Nickel & \(2.40\pm 0.33\) & 4–30 \\ Cobalt & \(0.61\pm 0.14\) & 0.4–10 \\ Manganese & \(90.91\pm 2.44\) & 100–1500 \\ Molybdenum & \(1.49\pm 0.20\) & 0.05–16 \\ Zinc & \(159.44\pm 17.6\) & 30–400 \\ Tungsten & \(<\)detection limit of 0.001 mg\(\cdot\)L\({}^{-1}\) & 0.1–30 \\ Selenium & \(<\)detection limit of 0.01 mg\(\cdot\)L\({}^{-1}\) & 0.05–4 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Trace element concentrations in red meat processing (RMP) wastewater and recommended optimal ranges [28]. * High-rate digesters such as anaerobic membrane reactors and anaerobic filter reactors present opportunities to manage FOG-rich waste streams with high hydraulic loading. * RMP facilities could expand to digest organic waste from co-located, on-farm industries in order to boost energy production, offset energy demand and improve digester performance and longevity. Conceptualization, P.W.H. 50% and B.K.M. 50%. ; writing--original draft preparation, P.W.H. 100%; writing--review and editing, B.K.M. 80%, P.W.H. 20%. ; supervision, B.K.M. 100%. All authors have read and agreed to the published version of the manuscript. The research pertaining to temperature, mixing and TE addition was fully funded by the Queensland Government's Advance Queensland Research Fellowship program. The research pertaining to crust management was fully supported by the Australian Meat Processor Corporation (AMPC) and Meat and Livestock Australia (MLA).