Solubility analysis and disposal options of combustion residues from plants grown on contaminated mining area

Abstract

Biomass, as a renewable energy source, is an excellent alternative for the partial replacement of fossil fuels in thermal and electric energy production. A new fuel type as biomass for energy utilisation includes ligneous plants with considerable heavy metal content. The combustion process must be controlled during the firing of significant quantities of contaminated biomass grown on brownfield lands. By implementing these measures, air pollution and further soil contamination caused by the disposal of the solid burning residue, the ash, can be prevented. For the test samples from ligneous plants grown on heavy metal-contaminated fields, an ore mine (already closed for 25 years) was chosen. With our focus on the determination of the heavy metal content, we have examined the composition of the soil, the biomass and the combustion by-products (ash, fly ash). Our results confirm that ash resulting from the combustion must be treated as toxic waste and its deposition must take place on hazardous waste disposal sites. Biomass of these characteristics can be burnt in special combustion facility that was equipped with means for the disposal of solid burning residues as well as air pollutants.

Influence of Biomass Incineration Temperature on the Content of Selected Heavy Metals in the Ash Used for Fertilizing Purposes

“…In the case of biomass grown on contaminated sites, the content of various heavy metal elements in ash may be very high. According to Kovacs et al [14], ash from plants cultivated in contaminated mining areas should be treated as toxic waste. In addition, biomass usually exhibits higher chlorine concentrations, which, according to the thermodynamic equilibrium calculations, are believed to particularly improve the mobilization of a number of metals from fuel particles, particularly under reducing conditions.…”

Mineralogy, chemical composition and leachability of ash from biomass combustion and biomass–coal co-combustion

“…Zn above 1 wt%, Pb up to 2800 ppm (Michalik et al 2013). According to Kovacs et al (2013), ash from plants grown on contaminated mining areas must be treated as toxic waste.…”

Effective Pretreatment of Heavy Metal-Contaminated Biomass Using a Low-Cost Ionic Liquid (Triethylammonium Hydrogen Sulfate): Optimization by Response Surface Methodology–Box Behnken Design

“…Lignocellulosic biomasses have been known as the most abundant and beneficial source of biomass for biofuel production (globally ∼200 Gt year –1 ) − and chemical precursor and resource recovery, without competition with food sources and holding higher biofuel yields, compared to first-generation biomass. , However, plants and vegetation can be contaminated on account of the uptake of heavy metals (HMs) during natural processes and/or engineered phytoremediation of highly polluted soils (so-called brownfields) and waste­(water) bodies caused from various anthropogenic activities. , As has been elucidated in Supporting Information Figure S1, various pathways, such as direct disposal, pretreatment, and reuse (bioenergy, resource and metals recovery), have been explored to deal with such a considerable amount of heavy metal-contaminated biomasses (HMCBs). − Among them, the direct landfilling and composting of HMCBs have not been recommended due to some limitation and inherent disadvantages, such as the risk of transfer and/or leaching of HMs into soil and water. , On the other hand, some other researchers have comprehensively reviewed the importance, advantages, and obstacles for linking phytoextraction and HMCBs valorization with emphasis on the fate of HMs and their transfer into product(s) and the necessity of effective HMCBs pretreatment prior to thermochemical and biological valorization pathways. ,, …”

“…9−13 Among them, the direct landfilling and composting of HMCBs have not been recommended due to some limitation and inherent disadvantages, such as the risk of transfer and/or leaching of HMs into soil and water. 14,15 On the other hand, some other researchers have comprehensively reviewed the importance, advantages, and obstacles for linking phytoextraction and HMCBs valorization with emphasis on the fate of HMs and their transfer into product(s) and the necessity of effective HMCBs pretreatment prior to thermochemical and biological valorization pathways. 10,13,16 Generally, lignocellulosic biomasses possess a sophisticated structure consisting of 30%−50% cellulose, 20%−40% hemicellulose, and 25%−35% lignin (dry weight (dry wt)).…”