Effects of Bacterial Culture and Calcium Source Addition on Lead and Copper Remediation Using Bioinspired Calcium Carbonate Precipitation

Abstract

Lead and copper ions from wastewater induced by metallurgical processes are accumulated in soils, threatening plant and human health. The bioinspired calcium carbonate precipitation is proven effective in improving the cementation between soil particles. However, studies on capsulizing heavy metal ions using the bioinspired calcium carbonate precipitation are remarkably limited. The present study conducted a series of test tube experiments to investigate the effects of bacterial culture and calcium source addition on the remediation efficiency against lead and copper ions. The calcium carbonate precipitation was reproduced using the Visual MINTEQ software package to reveal the mechanism affecting the remediation efficiency. The degradation in the remediation efficiency against lead ions relies mainly upon the degree of urea hydrolysis. However, higher degrees of urea hydrolysis cause remediation efficiency against copper ions to reduce to zero. Such high degree of urea hydrolysis turns pH surrounding conditions into highly alkaline environments. Therefore, pursuing higher degrees of urea hydrolysis might not be the most crucial factor while remedying copper ions. The findings shed light on the importance of modifying pH surrounding conditions in capsulizing copper ions using the bioinspired calcium carbonate precipitation.

Effect of seepage conditions on the microstructural evolution of loess across north-west China

“…Loess soils are widely distributed in semi-arid and arid regions and are considered susceptible to a sudden decrease in volume when subjected to wetting, referred to also as “collapse” ( Wang, 2003 ; Xue et al, 2021 ). Microstructural deterioration, induced by chemicals, can cause a degradation of the macro mechanical properties ( Hu et al., 2022 ; Wang et al., 2022b ; Xue et al, 2022 ; Bai et al, 2019 , Bai et al, 2021 , Bai et al, 2021 , Bai et al, 2021 , Bai et al, 2022 ). Permeability evolution starts drawing attention in recent years as it is deemed crucial in shale gas exploration and exploitation ( He et al., 2019 ; Nygård et al., 2006 ; Boulin et al., 2013 ; Rezaeyan et al., 2015 ; Wu et al., 2020 ; Bai et al, 2021 ).…”

Reinforcement of reclaimed sand by stimulating native microorganisms for biomineralization

“…In recent years, microbially induced carbonate precipitation (MICP) technology has been extensively studied in the field of geotechnical engineering ( Cheng et al, 2013 ; Liu et al, 2020a ; Liu et al, 2020b ; Cheng et al, 2021 ; Kim et al, 2021 ; Xue et al, 2022 ; Yu et al, 2022 ; Yu and Rong, 2022 ). MICP is controllable, green, and non-toxic ( Deng et al, 2020 ).…”