Advances in sewage sludge application and treatment: Process integration of plasma pyrolysis and anaerobic digestion with the resource recovery

Sustainable Treatment of Spent Photovoltaic Solar Panels Using Plasma Pyrolysis Technology and Its Economic Significance

“…Near the end of the 20th century, plasma pyrolysis appeared as a sustainable technology, which provides a suitable solution to destroy some hazardous waste, including medical waste, plastics, sewage sludge, biomass, and industrial waste, in both an environmental and economic manner. The versatile and intense heat generated by plasma torches allows the treatment of different types of waste materials, such as municipal solid waste [65], medical waste [66], polymer waste [67], sewage sludge [68], and other hazardous waste materials in a reliable and safe manner. This treatment process has a constant temperature supply because of the plasma equilibrium within temperature ranges around 10 6 to 10 8 K. The strong energy supplied to the plasma carrier gas (including nitrogen, hydrogen, or argon), facilitates the production of electrons and ions.…”

“…Comparing plasma pyrolysis with other types of pyrolysis methods has been widely presented and discussed [70]. Plasma pyrolysis offers several advantages, including high efficiency for HM removal, negligible emission of toxic gases, thermal stability, resource recovery, short reaction time, and a significant decrease in the volume of waste [68]. The past and recent studies on the valorization of wastes under the plasma pyrolysis process are shown in Table 2.…”

“…The AD process is well-known to treat organic waste materials; therefore, the direct feed of EoL PV modules is not optional, owing to the fact that DPS is considered electronic waste products. The HMs can be recovered through the plasma pyrolysis process [68]; therefore, DSP should first be treated with plasma pyrolysis for syngas production and to recover valuable materials, such as HMs and other chemical agents, and for slag generation, which will further be used in the AD process for full resource utilization. By-products from both processes can be cleaned and advanced to produce H 2 and methane, which are great sources of energy, while slag will enhance the overall performance of the AD process and improve the digestates' properties, which will be applied as soil amendment.…”

Effectiveness of Torrefaction By-Products as Additive in Vacuum Blackwater under Anaerobic Digestion and Economic Significance

“…The associated merits, challenges, and recommendations are briefly highlighted in Table 5. The energy produced from the by-products of these processes can be utilized to operate the treatment facility or be sold to the power grid, thus generating extra income [107] Processes Torrefied biomass has a higher calorific value, making it a strong feedstock as biofuel [112], and its high energy density can significantly decrease transport costs [113]. However, there are challenges associated with the use of torrefied biomass.…”

“…Nevertheless, the high quality of the energy by-products generated during operations can offset the cost. The energy produced from these processes can be utilized to operate the treatment facility or be sold to the power grid, thus generating extra income [107]. Furthermore, the by-products of torrefaction, both in solid and liquid form, can undergo additional treatment to yield high-value products such as biochar.…”