In situ soil treatments to reduce the phyto- and bioavailability of lead, zinc, and cadmium

A study was established near a former Zn and Pb smelter to test the ability of soil amendments to reduce the availability of Pb, Zn, and Cd in situ. Soil collected from the field was amended in the lab with P added as 1% P-H3PO4, biosolids compost added at 10% (referred to hereafter as "compost"), and a high-Fe by-product (referred to hereafter as "Fe") + P-triple superphosphate (TSP) (2.5% Fe + 1% P-TSP) and incubated under laboratory conditions at a constant soil pH. Changes in Pb bioavailability were measured with an in vitro test and a feeding study with weanling rats. Field-amended and incubated soils using these plus additional treatments were evaluated using the in vitro extraction and tall fescue (Festuca arundinacea Schreb. cv. Kentucky-31) metal concentration. Reductions were observed across all parameters but were not consistent. In the feeding study, the 1% P-H3PO4 and compost treatments resulted in a decrease of 26% in rat tissue Pb concentration compared with the control soil. The 2.5% Fe + 1% P-TSP showed a 39% decrease. The 1% P-H3PO4 treatment caused the greatest reduction in in vitro extractable Pb from field samples (pH 2.2) with a measured reduction of 66%, while the compost treatment had a 39% reduction and the 2.5% Fe + 1% P-TSP treatment a 50% reduction. The in vitro extraction (pH 1.5) run on field samples showed no reduction in the compost or Fe treatments. The 1% P-H3PO4 treatment was the most effective at reducing plant Pb, Zn, and Cd.     

Chemical Recovery of Useful Chemicals from Polyester (PET) Waste for Resource Conservation: A Survey of State of the Art

In this paper we present the main technologies developed over the last decades on chemical recycle of PET from a practical and economical point of view. We show details of plants used to carry out solvolitic reactions emphasising steps of purification, which are sometimes not considered when discussing chemical, recycle but which, in fact, are the key feasibility factors. The recycling or modification of PET to obtain monomers and other useful chemicals as intermediates and additives is carefully considered.     

Yessotoxin determination in Mytilus galloprovincialis revealed by an in vitro functional assay

Yessotoxins (YTXs) are polycyclic ether compounds produced by phytoplanktonic dinoflagellates and accumulated in filter-feeding shellfish. Mouse bioassay is still the official method to detect these toxins, even if it is lacking of specificity and sensitivity. Moreover, there is growing resistance against the use of animal experiments. Many efforts have been made to determine YTXs with other methods. The detection of YTX using a functional assay allows its quantification with an automated and repetitive technique at concentrations in the range of the 1 mg of YTX equivalent/kg European regulatory limit. In this study, an in vitro functional assay based on YTX treatment of MCF-7 cells and resulting in the accumulation of a 100-kDa fragment of E-cadherin was developed on samples of Mytilus galloprovincialis collected from the Adriatic Sea, Italy, along the coasts of Abruzzo, Molise, and Emilia Romagna regions. The YTX concentrations ranged from 0.2 to 1.8 mg of YTX equivalent/kg. The occurrence of levels exceeding the above mentioned limit was observed only in samples of Emilia Romagna region. This last result could represent a risk for human health, but these shellfish were not intended to consumers, because they belonged to a preventive monitoring program.