Alkali‐activated composites of calcium carbide and black rice husk ash for immobilizing electroplating sludge

Abstract

This study investigated the use of two waste products, black rice husk ash (BHA) from biomass power plants and calcium carbide residue (CCR) from acetylene gas production as an alkali‐activated binder to solidify and stabilize the heavy metal plating sludge (PS) from electroplating plants. Optimum strength of the alkali‐activated product was obtained using a weight percentage ratio of CCR to BHA of 60:40. CCR‐BHA compacts containing 50 wt % PS developed strength after 3 days, but the addition of 2 wt % Na2SiO3 or 4 wt % Na2CO3 developed strength in all the samples after 1 day. The CCR‐BHA paste containing 50 wt % PS developed a 7‐day strength >0.35 MPa in the sample containing 4 wt % Na2SiO3 and the same strength was developed after 3 days in the sample containing 4 wt % Na2CO3. The Cr concentration of leachate from all the samples was greater than the regulatory limit except for the CCR‐BHA paste containing 50 wt % PS and 4 wt % Na2CO3. After contacted all samples with synthetic acid rain, less corroded surface was observed from sample containing Na2SiO3 and Na2CO3. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018

Reuse of calcium carbide and water treatment residues in the bottom clay liner of a municipal solid waste landfill

“…After curing for 14 days, the development of the UCS was observed only from the compacted clay containing CCR. The results showed that at 28 and 56 days of curing, compacted clay containing all levels of CCR from 10 to 30 wt% gave a greater UCS than that of the control sample (no CCR) 15,16 . The UCS gain was caused by the pozzolanic reaction between the clay and CCR.…”

“…The presence of OH − ions causes a highly alkali environment for clay, and thus, SiO 2 and Al 2 O 3 present in clay dissolve and react with Ca 2+ ions from the CCR. As a consequence, calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH) are formed and contribute to the UCS of compacted clay 15‐17 …”

“…The coefficient of permeability of compacted clay containing various amounts of WTR and cured for 56 days is shown in Table 3 [15][16][17] The rate of the UCS development of the compacted clay increased with increasing CCR content except at 56 days of curing (Figure 4). The highest UCS gain was 3.18 MPa, which was obtained from compacted clay with 20 wt% CCR after curing for 56 days.…”

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

“…Rice husk ash contains SiO 2 ,w hich makes this husk ap ozzolanic materialf or producing compressed blocks of earth. [176] The strength of a mortarp repared from 50:50 (w/w) CCR and rice husk ash increases from 15.6 MPa at 28 days to 19.1 MPa at 180 days. [152] CCR solutionsh ave high pH values and can be used to increase the pH of soils or water tanks.…”

Workability and environmental evaluation of using sunflower stalk ash (SSA) as an alkali activator with blast furnace slag (BFS) and black rice hull ash (BRHA) to prepare geopolymer grouts

“…S1. BA is also used as a raw material in the preparation of cementitious materials owing to its chemical composition [22][23][24]. Carrillo-Beltran et al [25] studied the feasibility of a fully prepared geopolymer using chamotte, ceramic industry residue, y ash from olive biomass, and residue from the olive oil industry.…”