Organic and inorganic amendment application on mercury-polluted soils: effects on soil chemical and biochemical properties

Abstract

On the basis of a previous study performed in our laboratory, the use of organic and inorganic amendments can significantly modify the Hg mobility in soil. We have compared the effectiveness of organic and inorganic amendments such as digestate and fly ash, respectively, reducing the Hg mobility in Chernozem and Luvisol soils differing in their physicochemical properties. Hence, the aim of this work was to compare the impact of digestate and fly ash application on the chemical and biochemical parameters in these two mercury-contaminated soils in a model batch experiment. Chernozem and Luvisol soils were artificially contaminated with Hg and then incubated under controlled conditions for 21 days. Digestate and fly ash were applied to both soils in a dose of 10 and 1.5 %, respectively, and soil samples were collected after 1, 7, 14, and 21 days of incubation. The presence of Hg in both soils negatively affected to processes such as nitrification, provoked a decline in the soil microbial biomass C (soil microbial biomass C (MBC)), and the microbial activities (arylsulfatase, and β-glucosaminidase) in both soils. Meanwhile, the digestate addition to Chernozem and Luvisol soils contaminated with Hg improved the soil chemical properties (pH, dissolved organic carbon (DOC), N (Ntot), inorganic-N forms (N-NH4 (+) and N-NO3 (-))), as consequence of high content in C and N contained in digestate. Likewise, the soil MBC and soil microbial activities (dehydrogenase, arylsulfatase, and β-glucosaminidase) were greatly enhanced by the digestate application in both soils. In contrast, fly ash application did not have a remarkable positive effect when compared to digestate in Chernozem and Luvisol soil contaminated with mercury. These results may indicate that the use of organic amendments such as digestate considerably improved the soil health in Chernozem and Luvisol compared with fly ash, alleviating the detrimental impact of Hg. Probably, the chemical properties present in digestate may determine its use as a suitable amendment for the assisted-natural attenuation of mercury-polluted soils.

The Mercury Behavior and Contamination in Soil Profiles in Mun River Basin, Northeast Thailand

“…The pH value in soil can strongly change the mobility of mercury by influencing the different presence forms of mercury. As pH increases in soil, the bioavailability and mobility of mercury decreases [46,47,48], and the content of mercury increases, which is in agreement with our results. In the agricultural land, the occurrence of mercury content decreased in TS1, and the second peak in TS5 (Figure 4) was attributed to the influence of pH value change.…”

Remediation of Lead-contaminated Farmland Soil: Efficacy of Low-cost Natural Amendments in [Im]mobilization of Lead

“…The reduction of Pb levels in soil extracts and test plant seeds is proved by the application of these substance (García-Sánchez, García-Romera, Száková, Kaplan, & Tlustoš, 2015). Bioslurry also reduces the toxicity of Hg on soil microorganisms which is proved by the increase of weight and activity of microorganism biomass in amended soil (García-Sánchez, Klouza, Holečková, Tlustoš, & Száková, 2016). Utilization of natural lime-based materials showed that the addition of 1% eggshell and oyster shell can reduce 26.60% Pb in TCLP leachate (Lim et al, 2013).…”

Multi-Trait Wheat Rhizobacteria from Calcareous Soil with Biocontrol Activity Promote Plant Growth and Mitigate Salinity Stress

“…ARS have been key enzymes in the bacterial cell response against S limitation, and they can potentially hydrolyze sulphate esters from environmental sources or from the reserves of the bacterial cell [ 18 , 19 ]. In agriculture, arylsulfatase is one of the enzyme activities used to evaluate the soil biological diversity in natural or burdened ecosystems due to intensive crop systems, application of pesticides, and overdosed fertilization [ 19 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Increased arylsulfatase activity in soils is an indication of plant cultivation and crop rotations [ 31 , 32 , 33 , 34 ] and vice versa; the decrease of arylsulfatase activity in field soil is an indication of metal and pesticides contaminations [ 33 , 34 , 35 , 36 ].…”

“…In agriculture, arylsulfatase is one of the enzyme activities used to evaluate the soil biological diversity in natural or burdened ecosystems due to intensive crop systems, application of pesticides, and overdosed fertilization [ 19 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Increased arylsulfatase activity in soils is an indication of plant cultivation and crop rotations [ 31 , 32 , 33 , 34 ] and vice versa; the decrease of arylsulfatase activity in field soil is an indication of metal and pesticides contaminations [ 33 , 34 , 35 , 36 ]. A soil with arylsulphatase microbial activity improves or alters its biological composition by affecting its fertility [ 35 , 36 , 37 , 38 ].…”