Review on Current Research Status on Bottom Ash: An Indian Prospective

Abstract

India focuses on attention towards ''greener and cleaner'' environment surrounding us. For that, the engineers and scientists have joined hands together to accept the challenges for recycling wastes from industries. The generation of Bottom Ash (BA) from thermal power plants which are being increased day by day and facing disposal and environmental problems. In spite of that, it is being used as landfills which has no commercial value, but now needs to think on its utilization as useable supplementary materials. But from the literature survey, it was found that a little amount of research have been carried out on BA in the area based on its adsorption capability of dyes; pelletization efficiency of cold bonded aggregate; compressive strength, durability, water absorption characteristics and density variation in concrete and mortar; in order to ensure its usage as adsorption as well as construction material. The present paper deals with a critical review on BA as an adsorbent, light weight aggregate as well as partial replacement of fine aggregate in concrete. In addition, physical and chemical properties, transportation and disposal mechanism and environmental effects are also discussed.

Application of Bottom Ash as Filter Media for Construction Site Runoff Control

“…The chemical analysis based on SEM-EDS results indicates that the main chemical compounds including silicates (SiO 2 ), aluminates (Al 2 O 3 ), and iron oxide (Fe 2 O 3 ) with other compounds in trace amounts. This result is consistent with the previous studies [21] reporting that silicates (SiO 2 ) was found the most abundant, aluminates (Al 2 O 3 ) was found the second most abundant constituent, followed by iron oxide (Fe 2 O 3 ).…”

“…As is evident by SEM images and energy-dispersive X-ray spectroscopy (EDS) displayed in Figure 2, BA used in this study consisted of mesoporous and spherical particles. This observation is mainly due to both melting and expelling of ash from BA particles through high temperature and pressure processes of pulverized coal-fired combustion [21]. In a pulverized coal-fired combustion, the furnace operating temperatures are typically over 1400 • C, where most mineral matters within the coal could be oxidized, decomposed, fused, disintegrated, or agglomerated [22].…”

Synthesis and Characterization of Amorphous Iron Oxide Nanoparticles by the Sonochemical Method and Their Application for the Remediation of Heavy Metals from Wastewater

“…In a thermal power plant, there are two types of ashes; bottom ash and fly ash [71]. Bottom ash is generally larger in size and hence there is possibility of lesser concentrations of heavy metals on their surface [72] while the fly ash is finer in size, so comparatively there will be higher concentrations of heavy metals on their surface [72]. The composition of heavy metals along with other elements present in fly ash aqueous solution is given below in Table 1.…”

Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction

“…The increased demand for energy requirement of the industry results in increased production of CCR during the coal combustion process such as pulverized coal combustion (PCC) and fluidized bed combustion (FBC). By the year 2020, it is being expected that about 190 million tons of CCR will be generated in India per annum (CEA, 2011; Mandal and Sinha, 2014).…”

“…The physicochemical characteristics of coal combustion residues are controlled by the use of types of coal, boiler and its operating temperatures. Due to the high temperature of the PCC boiler, melting of ash occurred, resulting in the formation of bulk agglomerated gas entrapped bottom ash (Kim, 2002; Kutchko and Kim, 2006; Senior et al, 2000); whereas, bottom ash produced in the FBC boiler consists of free non-agglomerated particles due to lower temperature generation (<1000°C) (Mandal and Sinha, 2014, 2017a, 2017b, 2017c). The bottom ash produced during the FBC process is attracting more attention due to the novelty of coal combustion technology.…”