Speciation of Zn, Cu, and Pb in the soil depending on soil texture and fertilization with sewage sludge compost

Abstract

Background, aim, and scope Heavy metal (HM) mobility in soil depends on the HM species in it. Therefore, knowledge of the HM speciation in soil allows the prediction of HM impact on the environment. HM speciation in soil depends on the metal chemical origin, soil texture, and other factors such as the origin and level of soil contamination. Recently, the problem of organic waste utilization is of great importance as the amount of this recyclable material is continually increasing. One of the possible ways of recycling is the use of processed organic wastes for agricultural needs. In this research, aerobically composted sewage sludge was used, the utilization of which is of essential importance. But one of the most serious restrictions is HM transfer from such material to the soil. Therefore, a prediction of HM mobility in soil and its migration in the environment is an important issue when using sewage sludge compost (SSC) in agriculture. Zn, Cu, and Pb speciation was performed according to the modified methodology of Tessier et al. (Anal Chem 51:844-851, 1979) in two different (sandy and clay) soils with background HM amounts and in soil samples amended with aerobically digested SSC to find out the predominant species of the investigated HM and to predict their potential availability. Materials and methods The modified method of sequential extraction initially proposed by Tessier et al. (Anal Chem 51:844-851, 1979) is designed for HM speciation into five species where HM mobility decreases in the order: F1-exchangeable HM (extracted with 1 M MgCl 2 at an initial pH of 7 and room temperature), F2-carbonate-bound HM (extracted with 1 M CH 3 COONa buffered to pH 5 at room temperature), F3-Fe/Mn oxide-bound HM (extracted with 0.04 M NH 2 OH·HCl at an initial pH of 2 at 96°C), F4-organic matter-complexed or sulfide-bound HM (extracted with 0.02 M HNO 3 and 30% (v/v) H 2 O 2 at a ratio of 1:1 and an initial pH of 2 at 85°C), and F5-the residual HM (digested with HNO 3 , HF, and HCl mixture). After digestion, HM amounts in solution were determined by atomic absorption spectrometry (AAS 'Hitachi'). Mixtures of uncontaminated soils of different textures (clay and sandy) with SSC in ratios 20:1, 10:1, and 5:1 were used to simulate the land application with SSC. During a period of 7 weeks, changes in Zn, Cu, and Pb content within species were investigated and compared weekly in soil-SSC mixtures with their speciation in pure soil and in the SSC. Results Results in the SSC showed that more HM were found as mobile species compared to the soils, and in sandy soil, more were found in the mobile species than in clay soil. But the HM speciation strongly depended on the metal chemical origin. According to the potential availability, HM ranked in the following order: Zn>Pb>Cu. Zinc generally occurred in the mobile species (F1 and F3), especially in sandy soils amended with SSC, and changes of the Zn speciation were insignificant at the end of the experiment. Pb transfer to insoluble compounds (F5) was evident in the SSC-soil m...

Achilles heel of environmental risk from recycling of sludge to soil as amendment: A summary in recent ten years (2007–2016)

“…For instance, relatively high sludge amendment rates on sandy soils may pose risks to water quality because the amounts of Cd, Ni, Pb and Zn leached from the soil to the groundwater may increase. Significant negative effects on the mobilities and potential availabilities of heavy metals have been found only for sandy soils and high sludge amendment rates (Brazauskiene et al, 2008). Jalali and Arfania (2011) thought that amendment of sludge to sandy soil may pose little risk of groundwater becoming contaminated with Cd, Ni and Pb.…”

“…In addition, some soil properties, such as high cation exchange capacity (CEC) also had a relatively sufficient retention capacity to heavy metals (Antoniadis et al, 2010). The uptaken amount of heavy metals in soil and edible plant tissue exhibited higher level in sandy loam soil than clayey loam soil, implying that soil type plays important role in mobility, potential availability even uptaken ability to heavy metal by plant grown in amended soil (Bai et al, 2010;Brazauskiene et al, 2008;Singh and Agrawal, 2007). Results obtained by Li et al (2012) showed that level in the grain were found to be in the order of Zn > Cu > Cd, but for the straw the order was Cd > Cu > Zn, indicating different organs or tissues exhibited difference in bioconcentration factor for heavy metal.…”

Relationship between organic matter humification and bioavailability of sludge-borne copper and cadmium during long-term sludge amendment to soil

“…From 2007 to 2014, many studies have reported the heavy metals risk associated with the amendment of sludge to soil (Alcantara et al, 2009;Antoniadis et al, 2007;Brazauskiene et al, 2008;Carbonell et al, 2009;Lag-Brotons et al, 2014;Oladeji et al, 2012;Yeganeh et al, 2010). However, there is certain boundedness on the conclusions obtained by these researchers mentioned above.…”

Metal bioavailability and uptake by Potato plants (Solanum Tuberosum L.) grown in soils amended with MSW Compost

“…Soil pH has a direct impact on the mobility of metals as it affects their solubility and their capacity to form chelates in soil [14]. It has been reported that more than 50 % of the Pb fraction was residual fraction by the MSWC amendments, but the amount of exchangeable Pb increased over the course of the experiment [15]. Present study showed that the bioavailability of metals in MSWC treatments increased over the incubation.…”