Distribution of Cr and Pb in artificial sea water and their sorption in marine sediments: an example from experimental mesocosms

Abstract

The uptake of two heavy metals (chromium and lead) in sediments in experimental mesocosms under exposure to different metal concentrations was evaluated by monitoring their concentrations over time both in seawater and in sediment. Two separate experiments under laboratory-controlled conditions were carried out for the two metals. Sediments were collected from a protected natural area characterized by low anthropic influence and were placed in mesocosms that were housed in aquaria each with seawater at a different metal concentration. At pre-established time intervals, seawater and sediment samples were collected from each mesocosm for chemical analyses. Quantification of chromium and lead concentration in seawater and sediment samples was carried out by atomic absorption spectrometer with graphite furnace. Low doses of chromium and lead (<1 mg L) do not entail an uptake in sediments and waters. At doses ≥1 mg L, evolution of concentrations over time shows significant differences between these two metals: (i) chromium absorption from seawater is twice faster than lead; (ii) lead accumulates in considerable amount in sediments. The different behaviour of the two investigated heavy metals could be ascribed to different interactions existing between metal ions and different components of sediment.

The response of cultured meiofaunal and benthic foraminiferal communities to lead exposure: Results from mesocosm experiments

“…Following the available data and interpretation of Maccotta et al (), a clear temporal evolution of Pb release in seawater and absorption in sediment was observed (Figure ). Concentrations <1 ppm in seawater did not lead to any appreciable increase in sediments: these concentrations were comparably lower by 1 order of magnitude than the initial Pb levels naturally present in the sediments.…”

“…The methods used for analysis, including quality assurance/ control and Pb concentration results in water and sediment, have been reported in Maccotta et al (2016). In short, sediment was dried in an oven at 40 8C for 48 h, powdered, and digested (HNO 3 -H 2 O 2 -HF).…”

“…The concentration and time considered for meiofaunal and benthic foraminiferal communities are in bold. Modified fromMaccotta et al (2016).…”

Cytogenetic Effect of Heavy Metal Exposure in Alzheimer’s Disease Rat Model

“…As depicted from figure (2), AD control group resulted in significant increase in AChE gene expression by 5.8 folds when compared to normal group. The effect of PDC injection to AD-rats was much harmful, reaching 7.6 folds when compared with normal rats and 1.3 folds of the AD control.…”

“…Chromium (Cr) is a heavy metal found naturally and represents the seventh most available element on earth. There are two oxidation conditions that chromium occurs in the natural environment, Cr 3+ [Cr(III)] and Cr 6+ [Cr(VI)] 2 . Out of the two chromium forms, Cr 6+ is the most labile, mobile and toxic form.…”