Distribution and availability of trace elements in municipal solid waste composts

Trace element contamination is one of the main problems linked to the quality of compost, especially when it is produced from urban wastes, which can lead to high levels of some potentially toxic elements such as Cu, Pb or Zn. In this work, the distribution and bioavailability of five elements (Cu, Zn, Pb, Cr and Ni) were studied in five Spanish composts obtained from different feedstocks (municipal solid waste, garden trimmings, sewage sludge and mixed manure). The five composts showed high total concentrations of these elements, which in some cases limited their commercialization due to legal imperatives. First, a physical fractionation of the composts was performed, and the five elements were determined in each size fraction. Their availability was assessed by several methods of extraction (water, CaCl(2)-DTPA, the PBET extract, the TCLP extract, and sodium pyrophosphate), and their chemical distribution was assessed using the BCR sequential extraction procedure. The results showed that the finer fractions were enriched with the elements studied, and that Cu, Pb and Zn were the most potentially problematic ones, due to both their high total concentrations and availability. The partition into the BCR fractions was different for each element, but the differences between composts were scarce. Pb was evenly distributed among the four fractions defined in the BCR (soluble, oxidizable, reducible and residual); Cu was mainly found in the oxidizable fraction, linked to organic matter, and Zn was mainly associated to the reducible fraction (iron oxides), while Ni and Cr were mainly present almost exclusively in the residual fraction. It was not possible to establish a univocal relation between trace elements availability and their BCR fractionation. Given the differences existing for the availability and distribution of these elements, which not always were related to their total concentrations, we think that legal limits should consider availability, in order to achieve a more realistic assessment of the risks linked to compost use.     

Optimisation of a PMAxx™-RT-qPCR Assay and the Preceding Extraction Method to Selectively Detect Infectious Murine Norovirus Particles in Mussels

Human noroviruses are a major cause for gastroenteritis outbreaks. Filter-feeding bivalve molluscs, which accumulate noroviruses in their digestive tissues, are a typical vector for human infection. RT-qPCR, the established method for human norovirus detection in food, does not allow discrimination between infectious and non-infectious viruses and can overestimate potentially infectious viral loads. To develop a more accurate method of infectious norovirus load estimation, we combined intercalating agent propidium monoazide (PMAxx™)-pre-treatment with RT-qPCR assay using in vitro-cultivable murine norovirus. Three primer sets targeting different genome regions and diverse amplicon sizes were used to compare one-step amplification of a short genome fragment to three two-step long-range RT-qPCRs (7 kbp, 3.6 kbp and 2.3 kbp amplicons). Following initial assays performed on untreated infectious, heat-, or ultraviolet-inactivated murine noroviruses in PBS suspension, PMAxx™ RT-qPCRs were implemented to detect murine noroviruses subsequent to their extraction from mussel digestive tissues; virus extraction via anionic polymer-coated magnetic beads was compared with the proteinase K-dependent ISO norm. The long-range RT-qPCR process detecting fragments of more than 2.3 kbp allowed accurate estimation of the infectivity of UV-damaged murine noroviruses. While proteinase K extraction limited later estimation of PMAxx™ pre-treatment effects and was found to be unsuited to the assay, magnetic bead-captured murine noroviruses retained their infectivity. Genome copies of heat-inactivated murine noroviruses differed by 2.3 log₁₀ between RT-qPCR and PMAxx™-RT-qPCR analysis in bivalve molluscs, the PMAxx™ pre-treatment allowing a closer approximation of infectious titres. The combination of bead-based virus extraction and PMAxx™ RT-qPCR thus provides a more accurate model for the estimation of noroviral bivalve mollusc contamination than the conjunction of proteinase K extraction and RT-qPCR and has the potential (once validated utilising infectious human norovirus) to provide an added measure of security to food safety authorities in the hazard assessment of potential bivalve mollusc contamination.

     

Norovirus Foodborne Outbreak Associated With the Consumption of Ice Pop,Southern Brazil, 2020

Food and Environmental Virology - Norovirus is a major cause of foodborne-associated acute gastroenteritis (AGE) outbreaks worldwide. Usually, food products are contaminated either during...     

Assessment of Viral Contamination of Five Brazilian Artisanal Cheese Produced from Raw Milk: a Randomized Survey

Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a...     

Methodological approach towards the definition of new storage conditions for inert wastes

In 1997, the French Ministry of Environment launched studies aiming to define a specific regulation concerning inert waste disposal in order to limit potential impact of such facilities on the environment by fixing minimum requirements. A model (chemical model/hydrodynamic model) was developed to determine dumping conditions. This model was then applied on two defined scenarios (landfill surface, effective rainfalls...) in order to study the sulphate concentrations in aquifer system immediately downstream from the storage facility. Results allow us to determine in which conditions the sulphates concentrations are compatibles with the potentially drinkable character of the groundwater. They more specifically concern the nature of the waste disposed of, the efficient rainfalls and the landfill area.     

Drivers and barriers to a circular economy adoption: a sector perspective on rare earth magnets

Journal of Material Cycles and Waste Management - The transition from the current linear to a circular economy (CE) is a great challenge, especially in industries where the theme was barely...     

Biofiltration of fugitive methane emissions from landfills using scum from municipal wastewater treatment plants as alternative substrate

Journal of Material Cycles and Waste Management - Biofilters have been recognized as a key technology in the mitigation of greenhouse gases (GHG) emitted by landfills. This study aimed to evaluate...     

Drivers and barriers to successful solid waste management: assessing through an aggregated indicator

Journal of Material Cycles and Waste Management - Solid waste management is the main topic of the circular economy and remains a challenge for public management, because despite the recent economic...     

Blending Linz–Donawitz and Blast Furnace slags with the Kambara reactor byproduct to improve their reuse in roadworks

Journal of Material Cycles and Waste Management - The use of industrial byproducts as replacement of natural aggregates has been extensively investigated to design eco-friendly roads. One of the...     

Active Biodegradable Film Based on Chitosan and Cenostigma Nordestinum' Extracts for Use in the Food Industry

Journal of Polymers and the Environment - Bioactive biodegradable films are emerging biomaterials in the food packaging field. This study aims to investigate the effect of different Cenostigma...