Sustainable management of municipal and industrial solid waste constitutes a core pillar in transitioning toward a circular economy and achieving environmental energy security. Thermal and biological treatment technologies offer integrated engineering pathways that transform the environmental hazards of waste accumulation, soil contamination, and water pollution into valuable opportunities for material recovery and clean electricity generation, significantly shrinking landfill footprints and mitigating greenhouse gas emissions.The primary technical and engineering challenges stem from the high heterogeneity, elevated moisture content, and variable fraction of organic matter in solid waste streams, which depress the calorific value of derived fuels and lower the overall efficiency of power generation plants. In thermochemical processing (such as incineration, gasification, and pyrolysis), contaminants induce toxic flue gas emissions, boiler tube corrosion, and reactor fouling caused by heavy tars and carbon deposits. In biological processing (such as anaerobic digestion and fermentation), main bottlenecks include slow microbial reaction kinetics, bacterial sensitivity to pH and temperature fluctuations, and the presence of corrosive trace compounds like hydrogen sulfide ($H_2S$) in raw biogas, which severely degrades internal combustion engines and power generators.To resolve these technical hurdles, researchers and engineers have developed a suite of advanced technological solutions. Foremost among these is the deployment of Mechanical Biological Treatment (MBT) facilities to sort, homogenize, and pre-dry solid waste into high-quality Refuse-Derived Fuel (RDF) with stable thermal properties. Additionally, high-temperature Plasma Gasification technology converts hazardous and mixed waste into ultra-pure synthesis gas (Syngas) optimized for high-efficiency gas turbine power cycles. On the biological front, implementing multi-stage anaerobic digesters equipped with real-time process telemetry, alongside advanced Biogas Upgrading and gas-scrubbing systems to strip $H_2S$ and moisture, yields high-purity biomethane suitable for direct integration into synchronous generation sets and smart power grids. Al-Mustaqbal University – The First Private University in Iraq