The objective of this study was to build and develop anaerobic biodigesters for optimization of biogas production using food waste (FW) and sewage (S) co-digestion from a wastewater treatment plant (WWTP). The biodigesters operated with different mixtures and in mesophilic phase (37 °C). During the 60 days of experiments, all control and monitoring parameters of the biodigesters necessary for biogas production were tested and evaluated. The biodigester containing FW, S and anaerobic sludge presented the biggest reduction of organic matter, expressed with removal of 88.3% TVS (total volatile solid) and 84.7% COD (chemical oxygen demand) the biggest biogas production (63 L) and the highest methane percentage (95%). Specific methane production was 0.299 LCH₄/gVS and removed. The use of biodigesters to produce biogas through anaerobic digestion may play an important role in local economies due to the opportunity to produce a renewable fuel from organic waste and also as an alternative to waste treatment. Finally, the embedded control and automation system was simple, effective, and robust, and the supervisory software was efficient in all aspects defined at its conception.

Dye-containing effluent generated in textile industries is polluting and complex wastewater. It should be managed adequately before its final destination. The up-flow anaerobic blanket (UASB) reactor application is an ecofriendly and cost-competitive treatment. The present study briefly reviews the UASB application for dye-containing wastewater valorization. Bioenergy and clean-water production potential during dye-containing wastewater treatment are emphasized to promote resource recovery in textile industries. Hydraulic retention time (HRT), organic loading rate (OLR), pH, temperature, and hydraulic mixing influence sludge granulation, microbial activity, and dye removal. HRT and OLR ranges of 6–24 h and 1–12 kg m⁻³ d⁻¹ of chemical oxygen demand (COD) at a mesophilic temperature (30–40 °C) are recommended for efficient treatment. In these conditions, efficiencies of color and COD of 50–97% and 60–90% are reported in bench-scale UASB studies. Complex dye structures can hinder biomineralization. Pretreatment may be necessary to reduce dye concentration. Carbon-source and redox mediators are added to the UASB reactor to expedite kinetic reactions. A biogas yield of 1.48–2.70 L d⁻¹ in UASB, which treats dye-containing effluents, is documented. Cotreatment of dye wastewater and locally available substrate could increase biogas productivity in UASB reactors. Organic waste generated in the textile industry, such as dye sludge, cotton, and starch, is recommended to make cotreatment cost competitive. Bioenergy production and water reuse allow environmental and economic benefits. Studies on combined systems integrating UASB and membrane processes, such as ultrafiltration and nanofiltration, for the production of reusable water and pretreatment of wastewater and sludge for improvements in biogas production might realize the complete potential for resource recovery of UASB technology. UASB bioenergy usage for integrated treatment trains can reduce operating costs and assist process sustainability in the textile industry.

The objective of this work was to develop an automated anaerobic biodigester capable of operating in a semi-continuous or batch system for biogas production. Low biodegradability biomass has little efficiency in the production of biogas by anaerobic digestion processes and an efficient alternative is the use of bioprocesses in semi-continuous system. Two experiments were carried out in the same proportions but in different processes, and all control and automation parameters were tested and evaluated. For testing, mixtures of organic waste, anaerobic sludge (inoculum) and raw sewage without any treatment from the sewage treatment plant, in mesophilic phase (37 °C), were used during the 60 days of experiment. The semi-continuous system showed the greatest reduction in organic matter, expressed by the removal of 80.7% Total Solids Volatile (TVS) and the greatest volume (68.5 L) and methane percentage (78.5%). Finally, with these and other results found, it is possible to conclude that the biodigester developed for semi-continuous system, with the automation and control system, was satisfactory for the reduction in organic matter and biogas production. In addition, all operating system worked properly and with the use of current, low-cost technologies, the application and development on a larger scale becomes viable in the future.

Additive manufacturing (AM) is an Industry 4.0 technology that assists or replaces the conventional manufacturing (CM) of complex geometries in various sectors, including transport, steel, aerospace, military, and architecture. The aim is to improve processes, reduce energy consumption, atmospheric emissions, and solid waste, and streamline stages while complying with the new environmental regulations. The main objective of this work was to carry out a cradle-to-gate Life Cycle Assessment (LCA), considering the raw material extraction, pre-processing, manufacturing, and post-processing stages, comparing two manufacturing methods for the same ER-90 metal flange part, conventional forging and wire and arc additive manufacturing (WAAM), all following the requirements and operations proposed by the ISO 14040/44 standard. WAAM is a Directed Energy Deposition (DED) technology that uses welding techniques to produce 3D objects with more complex geometries. Compared to the forging industry, which requires a lot of heat and kinetic energy in its metal part production stages, WAAM is a more sustainable and modern alternative because it does not require high temperatures and energy to produce the same parts. The environmental indicators compared in the process stages were energy consumption, greenhouse gas (GHG) emissions, and solid waste. The total energy consumption in AM was 18,846.61 MJ, the GHG emissions were 864.49 kgCO₂-eq, and the solid waste generated was 142.34 kg, which were 63.8 %, 90.5%, and 31.6% lower than the environmental indicators calculated for CM, respectively.

Additive Manufacturing (AM) has been proving suitable to support or even replace traditional manufacturing in several industries, offering many advantages such as delivery time and reduction in terms of material waste, energy consumption and greenhouse gas (GHG) emissions. This study aimed to carry out a comparative assessment of the life cycle, from gate to gate, in the production of a low alloy carbon steel flange part using ER-90 wire. The methods utilized were Wire and Arc Additive Manufacturing (WAAM) and conventional manufacturing (CM) by forging, and comparative factors were energy demands, GHG emissions and generated solid waste. The total energy consumption in WAAM was 10,239.40 MJ, total carbon footprint in CO2 equivalent (CO2e) was 714.1 kgCO2e kg-1, and generated solid waste was 68.6 kg, respectively, 90%, 95% and 76% lower than consumption calculated in conventional manufacturing.