Editorial: Plastics in the Environment: Understanding Impacts and Identifying Solutions

Plastics are one of the most widely used materials in the world which society will always be dependent on. This dependency has been clearly highlighted by the requirements for hygiene and protection during the recent global COVID pandemic (Adyel, 2020; Prata et al., 2020). Plastics are broadly integrated into today’s lifestyle and are present in almost all consumer and industrial sectors and their production continues to increase (Geyer et al., 2017). Unfortunately, one of the characteristics of plastics that make them so useful—their durability—also ensures that they persist in the environment for very long periods of time. Additionally, and because of their low cost, many plastic objects have long been perceived as disposable. The consequence of this, coupled with the difficulty in developing effective waste management strategies, has been the ubiquitous contamination of the entire planet by plastic debris. Even if proposed global actions to recycle more plastic or prevent the export of plastic waste to countries with poorly developed waste infrastructure through the Basel Convention are implemented, plastic emissions are expected to increase for the foreseeable future unless significant breakthroughs in plastic design or waste management are realized (Lau et al., 2020). Increasing emissions also imply that exposure to plastic pollution and its degradation products, like microplastics, nanoplastics, plastic additives, and other chemical leachates, will continue to increase. Such an accumulating plastic cocktail can result in complex and unpredictable impacts, including those on ecological processes (Rillig et al., 2021) or the global carbon cycle (Zhu, 2021)

Advances in research on the use of biochar in soil for remediation: a review

Purpose: Soil contamination mainly from human activities remains a major environmental problem in the contemporary world. Significant work has been undertaken to position biochar as a readily-available material useful for the management of contaminants in various environmental media notably soil. Here, we review the increasing research on the use of biochar in soil for the remediation of some organic and inorganic contaminants.  Materials and methods: Bibliometric analysis was carried out within the past 10 years to determine the increasing trend in research related to biochar in soil for contaminant remediation. Five exemplar contaminants were reviewed in both laboratory and field-based studies. These included two inorganic (i.e., As and Pb) and three organic classes (i.e., sulfamethoxazole, atrazine, and PAHs). The contaminants were selected based on bibliometric data and as representatives of their various contaminant classes. For example, As and Pb are potentially toxic elements (anionic and cationic, respectively), while sulfamethoxazole, atrazine, and PAHs represent antibiotics, herbicides, and hydrocarbons, respectively.  Results and discussion: The interaction between biochar and contaminants in soil is largely driven by biochar precursor material and pyrolysis temperature as well as some characteristics of the contaminants such as octanol-water partition coefficient (KOW) and polarity. The structural and chemical characteristics of biochar in turn determine the major sorption mechanisms and define biochar’s suitability for contaminant sorption. Based on the reviewed literature, a soil treatment plan is suggested to guide the application of biochar in various soil types (paddy soils, brownfield, and mine soils) at different pH levels (4–5.5) and contaminant concentrations ( 50 mg kg−1).  Conclusions: Research on biochar has grown over the years with significant focus on its properties, and how these affect biochar’s ability to immobilize organic and inorganic contaminants in soil. Few of these studies have been field-based. More studies with greater focus on field-based soil remediation are therefore required to fully understand the behavior of biochar under natural circumstances. Other recommendations are made aimed at stimulating future research in areas where significant knowledge gaps exist

Influence of pyrolysis temperature and production unit on formation of selected PAHs, oxy-PAHs, N-PACs, PCDDs, and PCDFs in biochar - A screening study

The influence of reactor type and operating conditions of the pyrolysis unit on the final concentration of toxic contaminants in biochar remains unclear. Therefore, we determined the concentrations of polycyclic aromatic hydrocarbons (PAHs), oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs), nitrogen-containing polycyclic aromatic compounds (N-PACs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) in biochars produced from three different feedstocks (softwood, wheat straw, and anaerobic digestate). Different scaled pyrolysis units (one batch and two continuous units) at two different temperatures (550 and 700 degrees C) were considered. The results revealed that the type of biomass had a significant influence on the PAH, oxy-PAH, and N-PAC content of the biochars. The configuration and type of the pyrolysis unit influenced only the wheat straw pyrolyzed at 550 degrees C. PCDDs and PCDFs occurred at very low levels in the biochars. In terms of PAH, PCDD, and PCDF content, the biochars assessed in this study represent a low risk to the environment, regardless of the temperature and type and size of the pyrolysis unit.Correction: Weidemann, E., Buss, W., Edo, M. et al. Environ Sci Pollut Res (2018) 25: 3941. https://doi.org/10.1007/s11356-017-0804-6Bio4Energ