Benzene-contaminated groundwater remediation using calcium peroxide nanoparticles: synthesis and process optimization

Abstract

Nano-size calcium peroxide (nCaO) is an appropriate oxygen source which can meet the needs of in situ chemical oxidation (ISCO) for contaminant remediation from groundwater. In the present study, an easy to handle procedure for synthesis of CaO nanoparticles has been investigated. Modeling and optimization of synthesis process was performed by application of response surface methodology (RSM) and central composite rotatable design (CCRD) method. Synthesized nanoparticles were characterized by XRD and FESEM techniques. The optimal synthesis conditions were found to be 5:1, 570 rpm and 10 °C for HO:CaSO ratio, mixing rate and reaction temperature, respectively. Predicted values showed to be in good agreement with experimental results (R values were 0.915 and 0.965 for CaO weight and nanoparticle size, respectively). To study the efficiency of synthesized nanoparticles for benzene removal from groundwater, batch experiments were applied in biotic and abiotic (chemical removal) conditions by 100, 200, 400, and 800 mg/L of nanoparticles within 70 days. Results indicated that application of 400 mg/L of CaO in biotic condition was able to remediate benzene completely from groundwater after 60 days. Furthermore, comparison of biotic and abiotic experiments showed a great potential of microbial stimulation using CaO nanoparticles in benzene remediation from groundwater.

Synthesis of CaO2 Nanocrystals and Their Spherical Aggregates with Uniform Sizes for Use as a Biodegradable Bacteriostatic Agent

“…By reacting Ca(OH) 2 with H 2 O 2 in an aqueous solution, CaO 2 microparticles of 0.2 µm in diameter were obtained . Nanoparticles with diameters in the range of 11–62 nm were prepared when CaSO 4 was reacted with H 2 O 2 in aqueous KOH . However, the CaO 2 nanoparticles prepared in aqueous solutions tended to aggregate to give poorly controlled size and morphology due to the hydrolysis of CaO 2 in water.…”

Facile Fabrication of Oxygen-Releasing Tannylated Calcium Peroxide Nanoparticles

“…Several methods have been reported for the preparation of CaO 2 particles by reacting Ca(OH) 2 with H 2 O 2 in an aqueous solution [ 8 ] or reacting CaSO 4 with H 2 O 2 in aqueous KOH [ 9 ]. However, the CaO 2 particles formed in aqueous solutions tend to aggregate because of hydrolysis.…”

An analytical survey on the role of nanotechnology in groundwater remediation

“…Scientific work around the world shows that nanotechnology is one of the significant groundwater remediation techniques (Liang et al 1996;Savage & Diallo 2005;Otto et al 2008;Theron et al 2008;Agarwal & Joshi 2010;Rajan 2011;Li et al 2014;Thomé et al 2015;Mosmeri et al 2017;Corsi et al 2018;Hu & Xia 2018;Jia et al 2019;Newsome et al 2019;Jiang et al 2020;Qian et al 2020). Thomé et al (2015) and Agarwal & Joshi (2010), in particular, offered scientific evidence of effective Nanotechnology for Groundwater Remediation in the US, Europe, and in India, respectively.…”