Leaching characteristics and curing mechanism of magnesium phosphate cement solidified zinc-contaminated soil in an acid rain environment

Abstract

A semi-dynamic leaching test was used to simulate the erosion effect of acid rain on magnesium phosphate cement (MPC)-stabilized/solidified zinc-contaminated soil. The leaching characteristics and curing mechanism were studied with a combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Influences of the initial pH value of the simulated acid rain, the ratio of the curing agent (MgO/KH2PO4, abbreviated M/P), and the mass of water glass on the leaching characteristics of Zn<sup>2+</sup> and conductivity in the leachate of the sample were studied. It is shown that the curing effect of the cement component on Zn<sup>2+</sup> is better for M/P = 6 when compared to M/P = 4 in a strong acid environment. While in a weak acid environment, it is observed that the curing effect is superior when M/P = 4. Also it is observed that 4% water glass content can effectively improve the cement curing effect of heavy metal Zn in an acid rain environment. These results indicate that water glass can be effectively applied to MPC solidified heavy metal Zn.

Enhancing the removal efficiency of methylene blue in water by fly ash via a modified adsorbent with alkaline thermal hydrolysis treatment

“…1 Moreover, the unsanitary landll can change the soil salinity, contaminate groundwater, and release toxic compounds into the soil. 3,11,12 Researchers have been focusing on developing new techniques for recycling coal FA waste to use in production and life toward sustainable development goals. One of them is coal FA that has been used to produce zeolite and geopolymers, further applied in environmental remediation such as wastewater treatment and air pollution treatment.…”