Speciation Evolutions of Heavy Metals during the Sewage Sludge Incineration in a Laboratory Scale Incinerator

Abstract

With the growing application of sludge incineration, the thermal behavior of heavy metals during this process is increasingly a concern. This work was conducted to determine the speciation evolutions of heavy metals during sewage sludge incineration on a laboratory scale. It was found that the acid-soluble fraction of Zn was more inclined to volatilize. As for Pb and Cr, the volatilization of residual fractions and oxidizable fractions dominated, respectively. For Cu without moisture and Ni, the speciation evolutions were by the way of inner transformation. The speciation redistributions of Zn, Pb, Cr, and Cu (40% and 80% moisture) were mainly controlled by the initial volatilization. The speciation evolutions were controlled by the volatilization tendencies of different fractions and were possibly influenced by the reactions with an ash matrix. In addition, most likely, moisture promoted the formation of the acid-soluble fraction of Cu, and some residual fractions of Zn, Pb, and Cr were from hydrolyzation.

Chemical speciation, mobility and phyto-accessibility of heavy metals in fly ash and slag from combustion of pelletized municipal sewage sludge

“…Heavy metals are still an issue. Some studies have been focused on the speciation of heavy metals in slag from combustion of MSS in laboratory scale experiments (Chen and Yan, 2012;Liu et al, 2010). Yao et al (2010) and Zhao et al (2009) reported the speciation of heavy metals in fly ash and slag during combustion of hospital waste and municipal solid waste ground on field experiments.…”

Porous Ca-based bead sorbents for simultaneous removal of SO2, fine particulate matters, and heavy metals from pilot plant sewage sludge incineration

“…Material dp a (m) a (g/cm 3 measurement was taken, and the specific surface area was assessed from the nitrogen adsorption data according to a partial relative pressure range of 0.05-0.25 using the Brunauer-Emmett-Teller (BET) method [29,30]. The size distribution of the macropores of the samples was determined using digital microscopy equipped with an image analysis system (KH-7700, HIROX) [25,31].…”

“…disposal was banned in 2012 to comply with the 1996 Protocol of the London Convention. Thus, new approaches are now required to treat sewage sludge, and these include recycling, biological treatment, and thermal treatment [1,3,4]. In South Korea, the total amount of sewage sludge produced in 2012 was 3653 million tons, and the incineration rate significantly increased from 16% in 2006 to 25.2% in 2012 [5].…”

“…The Ministry of Environment (MOE) forecasts that 28% of the total sewage sludge produced in 2015 will be incinerated [5], and the thermal process offers many advantages, such as volume reduction, destruction of organic pollutants, and energy recovery. Although incineration has significant potential as a method for treating sewage sludge, it has a drawback in that it also generates air pollutants, such as dioxins, SO 2 , NO x , particulate matter (PM), and heavy metals (including mercury) [3,4,[6][7][8][9].…”

A simple kinetic analysis of syngas during steam hydrogasification of biomass using a novel inverted batch reactor with instant high pressure feeding

“…Many thermochemical methods in practice have been widely studied, such as combustion, pyrolysis, and gasification (Bridgwater, 2003, Chen et al, 2008, Liu et al, 2010and Ruth, 1998. In particular, fungible transportation fuels can be synthesized over commercialized catalysts using synthetic gas (syngas) from various gasification technologies.…”