Effects of substrate types on the transformation of heavy metal speciation and bioavailability in an anaerobic digestion system

Fe2(SO4)3-assisted anaerobic digestion of pig manure: the performance of biogas yield and heavy metal passivation

“…Moreover, AD effectively passivated Cu, Zn, and As, and the addition of Fe 2 (SO 4 ) 3 made this passivation effect more pronounced. However, Table 4 Economic benefits analysis of Fe 2 (SO 4 ) 3 affected AD of PM (1) The cost of Fe 2 (SO 4 ) 3 was 1023.01 $/t; (2) Bc is the energy content of the biogas that was generated by PM; (3) Eg is the energy produced from the biogas that was generated from 1 g of VS of PM; (4) Energy produced was estimated from 1 kWh is equivalent to 0.23 USD [24]; (5) The price of solid digestate was 37.96 $/t [48]; (6) the passivated Cd performance during this process can be negligible. Furthermore, the addition of Fe 2 (SO 4 ) 3 can reduce the toxicity of the end products of AD to plants.…”

“…Anaerobic digestion (AD) is an effective and low-cost technique for decomposing organic matter through microbial metabolism under anaerobic conditions with the generation of biogas and biomass fertilizer [6], and such technology has been widely used to treat livestock manure. At present, pig manure (PM) is one of the major livestock manures, and its amount was reached 411 million tons per year in China [7].…”

Cleaner technologies to combat heavy metal toxicity

“…Nanoparticles in some cases are found to increase the heavy metal absorption in plants that had previously identified as prospective candidates for heavy metal remediation (Zand et al, 2020). In addition to various methods, it can be noted that anaerobic digestion using different organic substrates such as plant-based rice straw displayed more heavy metal retention ability in contrast to animal-based manure, thereby pointing out the role of plant derivatives in heavy metal remediation (Zheng et al, 2021).…”