Wet wastes to bioenergy and biochar: A critical review with future perspectives

Prediction of Soil Heavy Metal Immobilization by Biochar Using Machine Learning

“…Biochar application to contaminated soil is considered a promising method for HM immobilization because biochar can adsorb and immobilize HMs as its surface area (SA), microporosity, surface functional groups, pH, and cation exchange capacity are superior to those of raw feedstock. , A variety of biochars produced from various feedstocks (e.g., sewage sludge, manure, crop residue) under different production conditions (e.g., slow pyrolysis, fast pyrolysis, gasification, and hydrothermal carbonization) have been used to immobilize HMs (and metalloids) such as As, Cd, Cu, Pb, Cr, Ni, Co, and Zn in soils. , The HM immobilization efficiency in biochar-amended soils varies depending on the type of biochar (e.g., production conditions and physicochemical properties), soil properties (e.g., soil pH, organic matter content, and electrical conductivity (EC)), and HM properties (e.g., valency and ionic radius). , Studies have shown that immobilization efficiency is influenced by various adsorption/immobilization mechanisms and factors such as cation exchange, electrostatic interaction, precipitation, and complexation by surface functional groups . However, the optimum conditions for enhanced HM immobilization in soils using biochar vary considerably among studies.…”

Utilization of Sea Sand for Preparation of High-Performance CoAl2O4 Composite Pigments via a Cleaner Mechanochemistry Route

“…Generally, the five vibration modes and corresponding signal locations of CoAl 2 O 4 are A 1g (764 cm −1 ), F 2g (1) (203 cm −1 ), F 2g (2) (511 cm −1 ), F 2g (3) (644 cm −1 ), and E g (413 cm −1 ). 14,41 The four Raman shifts at 198, 405, 508, and 648 cm −1 correspond to the F 2g (1), E g , F 2g (2), and F 2g (3) vibration modes of CoAl 2 O 4 in CP-TTS and CP-ZPS, respectively (Figure 5d). The Raman peak shift of the F 2g (1) mode is closely related to the kinds of divalent metal ions in the tetrahedral sites of the spinel structure.…”

“…14,41 The four Raman shifts at 198, 405, 508, and 648 cm −1 correspond to the F 2g (1), E g , F 2g (2), and F 2g (3) vibration modes of CoAl 2 O 4 in CP-TTS and CP-ZPS, respectively (Figure 5d). The Raman peak shift of the F 2g (1) mode is closely related to the kinds of divalent metal ions in the tetrahedral sites of the spinel structure. 41,42 Interestingly, no shift is observed in CP-ZPS compared with CP-TTS; it can be inferred that the divalent metal ions in TTS do not enter the tetrahedral sites of CoAl 2 O 4 due to the higher purity of ZPS.…”

“…Available land and natural resources on earth are essential for the welfare of human beings. The situation of resource depletion is becoming increasingly severe with the rapid growth of the global population, and feasible strategies for efficient utilization and protection of natural resources must be developed. − However, collecting valuable minerals or useful elements from natural resources often causes serious environmental problems and consumes large amounts of human and financial resources. , With the advancement in science and technology, comprehensive utilization of natural resources in a high-value and green sustainable way is highly desired by many countries, which will contribute to alleviating the current situation of resource depletion and environment pollution.…”

A comprehensive review on sewage sludge as sustainable feedstock for bioenergy production

“…Several researchers looked at the potential for manufacturing high-hydrogen fuel gases using thermochemical processes such as pyrolysis, drying, and gasification of wet sewage sludge. Wet sewage sludge is heated to high temperatures (1000 • C) and high heat rate during pyrolysis to enhance the production of H 2 -rich fuel gas (Li et al, 2022). Furthermore, wet sludge is pyrolyzed rather than dry, producing gaseous products with a much greater hydrogen concentration.…”