Using hybrid packing materials in biofiltration systems takes advantage of both the inorganic and organic properties offered by the medium including structural stability and a source of available nutrients, respectively. In this study, hybrid mixtures of compost with either lava rock or biochar in four different mixture ratios were compared against 100% compost in a methane biofilter with active aeration at two ports along the height of the biofilter. Biochar outperformed lava rock as a packing material by providing the added benefit of participating in sorption reactions with CH4. This study provides evidence that a 7:1 volumetric mixture of biochar and compost can successfully remove up to 877 g CH4/m3·d with empty-bed residence times of 82.8 min. Low-affinity methanotrophs were responsible for the CH4 removal in these systems (KM(app) ranging from 5.7 to 42.7 µM CH4). Sequencing of 16S rRNA gene amplicons indicated that Gammaproteobacteria methanotrophs, especially members of the genus Methylobacter, were responsible for most of the CH4 removal. However, as the compost medium was replaced with more inert medium, there was a decline in CH4 removal efficiency coinciding with an increased dominance of Alphaproteobacteria methanotrophs like Methylocystis and Methylocella. As a biologically-active material, compost served as the sole source of nutrients and inoculum for the biofilters which greatly simplified the operation of the system. Higher elimination capacities may be possible with higher compost content such as a 1:1 ratio of either biochar or lava rock, while maintaining the empty-bed residence time at 82.8 min.

Few studies have focused so far on plastic ingestion by sharks in the Mediterranean Sea. The aim of this paper was to determine, for the first time, the plastic litter ingested by blue sharks (Prionace glauca), categorized as “Critically Endangered” in the Mediterranean Sea by IUCN, caught in the Pelagos Sanctuary SPAMI (North-Western Mediterranean Sea). The analysis of the stomach contents was performed following the MSFD Descriptor 10 standard protocol implemented with FT-IR spectroscopy technique. The results showed that 25.26% of sharks ingested plastic debris of wide scale of sizes from microplastics (<5 mm) to macroplastics (>25 mm). The polyethylene sheetlike user plastics, widely used as packaging material, are the most ingested debris. This research raises a warning alarm on the impact of plastic debris on a threatened species, with a key role in the food web, and adds important information for futures mitigation actions.

In the present study, the recycled post-consumption polyethylene terephthalate (PET) flakes were investigated as possible raw materials for the production of food packaging. After heating at 220 °C for 1 h, a steaming stage was conducted as a control test to assess the quality of the product. Different samples were characterized by ¹H-NMR, FT-IR, DSC/TGA analysis, viscosity index (VI), and trace metals analysis. The results showed that the recycled post-consumed PET flakes’ properties were generally conform to the standard norms of PET except the color of some flakes turned to yellow. Subsequently, a complementary study was undertaken to assess whether the material could be possibly reused for food packaging. For this purpose, rheological, thermal, and mechanical characterizations were performed. The results of the comparative study between the virgin and the recycled PET flakes concluded that the PET recycling affected the rheological properties but did not have any significant effect on their thermal and mechanical characteristics. Hence, it was deduced that the post-consumed PET flakes could be reused as a packaging material except food products.

The goal of this study is to use life cycle assessment (LCA) tool to assess possible environmental impacts of different municipal solid waste management (MSWM) scenarios on various impact categories for the study area Dhanbad City, India. The scenarios included in the present study are collection and transportation (denoted as S1); baseline scenario consisting of recycling, open burning, open dumping, and finally unsanitary landfilling without energy recovery (denoted by S2); composting and landfilling (denoted by S3); and recycling and composting followed by landfilling of inert waste without energy recovery (denoted by S4). One ton of municipal solid waste (MSW) was selected as the functional unit. The primary data were collected through sampling, surveys, and literatures. Background data were obtained from Eco-invent data of SimaPro 8.1 libraries. The scenarios were compared using the CML 2 baseline 2000 method, and the results indicated that the scenario S1 had the highest impact on marine aquatic ecotoxicity (1.86E + 04 kg 1,4-DB eq.) and abiotic depletion (2.09E + 02 kg Sb eq.). S2 had the highest impact on global warming potential (9.42E + 03 kg CO₂ eq.), acidification (1.15E + 01 kg SO₂ eq.), eutrophication (2.63E + 00 kg PO₄³⁻ eq.), photochemical oxidation (2.12E + 00 kg C₂H₄ eq.), and human toxicity (2.25E + 01 kg 1,4-DB eq.). However, S3 had the highest impact on abiotic depletion (fossil fuels) (2.71E + 02 MJ), fresh water aquatic ecotoxicity (6.54E + 00 kg 1,4-DB eq.), terrestrial ecotoxicity (3.36E − 02 kg 1,4-DB eq.), and ozone layer depletion (2.73E − 06 kg CFC-11 eq.). But S4 did not have the highest impact on any of the environmental impact categories due to recycling of packaging waste and landfilling of inert waste. Landfilling without energy recovery of mixed solid waste was found as the worst disposal alternative. The scenario S4 was found as the most environmentally suitable technology for the study area and recommended that S4 should be considered for strategic planning of MSWM for the study area.

Low methane (CH₄) emission reduction efficiency (< 25%) has been prevalent due to inefficient biological exhaust gas treatment facilities in mechanic biological waste treatment plants (MBTs) in Germany. This study aimed to quantify the improved capacity of biofilters composed of a mixture of organic (pine bark) and inorganic (expanded clay) packing materials in reducing CH₄ emissions in both a lab-scale experiment and field-scale implementation. CH₄ removal performance was evaluated using lab-scale biofilter columns under varied inflow CH₄ concentrations (70, 130, and 200 g m⁻³) and corresponding loading rates of 8.2, 4.76, and 3.81 g m⁻³ h⁻¹, respectively. The laboratory CH₄ removal rates (1.2–2.2 g m⁻³ h⁻¹) showed positive correlation with the inflow CH₄ loading rates (4–8.2 g m⁻³ h⁻¹), indicating high potential for field-scale implementation. Three field-scale biofilter systems with the proposed mixture packing materials were constructed in an MBT in Neumünster, northern Germany. A relatively stable CH₄ removal efficiency of 38–50% was observed under varied inflow CH₄ concentrations of 28–39 g m⁻³ (loading rates of 1120–2340 g m⁻³ h⁻¹) over a 24-h period. The CH₄ removal rate was approximately 500–700 g m⁻³ h⁻¹, which was significantly higher than relevant previously reported field-scale biofilter systems (16–50 g m⁻³ h⁻¹). The present study provides a promising configuration of biofilter systems composed of a mixture of organic (pine bark) and inorganic (expanded clay) packing materials to achieve high CH₄ emission reduction. Graphic abstract ᅟ