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This study verifies and validates the superiority of sulfur concrete (SC) over the ordinary Portland cement concrete (PCC) and sulfate-resistant concrete (SRC) in sewer harsh environments. A field study was performed in an actual sewage environment, specifically at the sewer’s gas and sludge environments. Performance of the PCC, SRC and two types of SC was assessed after 3, 6, 10, 18 and 24 months of exposure. Specimen’s durability was evaluated through physical appearance, change in weight and mechanical and hydraulic properties. The microstructure and the composition of the specimens were studied by means of scanning electron microscopy and X-ray diffraction. Attempts have been made to explain the mechanism of deterioration, the basic chemical interactions involved in the deterioration processes and the effect of such interactions on the concrete and reinforcing steel. It was found that SC is highly resistant to sewer environment compared to PCC and SRC, and that there was a significant weight loss of 8·0% and 13·6% in PCC and SRC, respectively, whereas a smaller weight loss of 2·2% was noticed in SC. This is consistent with the observed reduction in strength, increase in permeability and noticeable steel bar corrosion for the PCC and SRC relative to the SC.

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Plastics have become an essential commodity due to their superior engineering properties, durability and low cost to be used by a wide range of commercial products. However, the degradation of plastics due to mechanical, chemical, biological, and photolytic stresses has led to the formation of microplastics (MPs). MPs have risen to the top of environmental concerns due to their affinity to pollute the environment, and to pass to the food chain, threatening human health. In this context, attempts have been made to extract and characterize MPs from aqueous and solid matrices. A problem that not only hampers research but also regulatory decisions is the variety of methods used for the extraction and characterization of MPs, especially in organic solid matrices (OSMs) with organic (OM) > 5%, making the comparison of results difficult. This paper aims to address this need, by critically assessing the methodologies and protocols used for extraction of MPs from OSMs, which includes sample collection, dispersion, OM removal, and separation, as well as the qualitative and quantitative characterization of MPs. Further, current impediments in the accurate characterization of MPs are identified along with recommendations for future developments. Finally, recent efforts by various countries to legislate against certain sources of MPs, as well as issues and novel techniques to remediate MPs from the soil, and wastewater have been highlighted.