8th <scp>European</scp> Bioremediation Conference (<scp>EBC</scp>‐<scp>VIII</scp>)

The tradition of the successful European bioremediation conferences continues and after 21 years of the first one, the 8th European Bioremediation Conference (EBC-VIII) took place in Chania, Crete on 12–17 June 2022. This series of conferences started in 2001, organized by the Technical University of Crete (TUC) with financial support by EU's Marie Curie High Level Conferences for the first two events (2001 and 2003). Since EBC-IV, this event has been co-organized by TUC and the University of Bologna under the auspices of the Environmental Biotechnology section of the European Federation of Biotechnology. EBCs bring together scientists and engineers to discuss and highlight innovative and key-point research on advances in environmental remediation technologies. The topics of EBC-VIII were expanded to include new challenges, future trends, directions and most recent technological innovations for management and restoration of a wide range of contaminated sites and marine environments as well as for resource preservation through recycling and biobased reclamation, towards a circular economy model implementation. This Special Issue of the Journal of Chemical Technology and Biotechnology (JCTB) includes 11 selected peer-reviewed research papers, originally presented at EBC-VIII as oral or poster communications, from the various thematic areas covered in the conference. In total, 198 papers were submitted from 29 countries, joining in a face-to-face conference after the COVID period. The relationship with JCTB is well established, as this is the sixth special issue associated with the EBCs. Moreover, the journal, through our publishers Wiley & Sons, regularly sponsors prizes for exceptional platform and poster presentations, as a support to students and young scientists. The collection of papers in this issue focuses on the most recent advances, in terms of environmental applications and restoration/bioremediation practices. In particular, the topics addressed are (a) innovative approaches for water and wastewater treatment, (b) the biodegradation of various pollutants and environmental bioremediation and (c) the circular economy and the valorization of waste products. Challenges in water/wastewater technologies are presented and discussed in four studies. Kaliakatsos et al. investigated the special characteristics of real hospital wastewater (HWW) and the potential of photocatalysis application in order to reduce HWW's ecotoxicity and to remove chemical pollutants, antibiotic-resistant bacteria and antibiotic-resistance genes.1 Furthermore, the mini-review by Kokkinos et al. highlights the environmental risks raised by wastewater treatment during the COVID-19 pandemic.2 The authors underline the importance of the development of cost-effective decentralized water and wastewater treatment facilities for low- and middle-income countries for the abatement of coronaviruses. Two other studies deal with water and ballast water purification. Kyriazi et al. express a scholarly opinion on newly developed water disinfection techniques and the major effect of ‘water matrix’ on their performance.3 Seridou et al. go one step further, as they investigate the special treatment of ballast water upon application of ozone nanobubbles (OzNBs).4 The main objective of this research was to evaluate whether the use of OzNBs has any significant impact on microorganism inactivation and residual activity of ozone during treatment. Bioremediation and biodegradation applications are discussed in three studies. Belenioti et al. report the ability of Chlamydomonas reinhardtii to biodegrade phenolic compounds from grape pomace via aerobic processes.5 C. reinhardtii biodegrades a sufficient number of polyphenols in grape pomace with a high rate, while the product contains high concentrations of minerals and low levels of polyphenols. Kannan and Sivaperumal worked with marine archaea with a view to bioremediate the environment polluted by caesium (Cs+).6 That study concluded that Halococcus sp. ENMS8 can immobilize caesium through extracellular polymeric substances in an eco-friendly approach. Finally, Obregon-Maldonado et al. propose a Peruvian strain of Pseudomonas aeruginosa 6K-11 and its rhamnolipid biosurfactant, which can be applied to accelerate oil biodegradation in bioremediation processes.7 The final cluster of papers deals with the circular economy and the valorization of valuable waste products. Alcalde et al. worked with the same bacterial strain as the one previously mention, i.e. P. aeruginosa, as the means of rhamnolipid production.8 Rhamnolipids are biosurfactants that have their main application in bioremediation processes, increasing the biodegradation and detoxification rates from industrial effluents. Other researches aimed at the recovery of metals from acid mine drainage (AMD). Delgado et al. propose the recovery of metals from AMD by a combination of an electromembrane process (electrodialysis) and a subsequent bioelectrochemical operation as a microbial fuel cell and microbial electrolysis cell.9 Another study by Száková et al. presents and clarifies the impact of various factors and their interactions on the variation in the mobile proportions of the individual elements in soil and assesses the importance of changing pH in biochar-treated soils.10 The final subject discussed in this issue refers to a more robust colorimetric method for the evaluation of compost stages that would solve many operational problems. Tsivas et al. investigate the CIELAB colour model and its relationship with composting time and elucidate if colour change can depict the transformation of compost organic composition.11 This would allow for detecting the different stages of a green waste composting process up to the point of maturity. Thanks are due to the Editorial Board of JCTB, and in particular Editor-in-Chief Prof. Dionissios Mantzavinos, who gave us the opportunity to compile this Special Issue. Special thanks are also due to Natalie State (JCTB Editorial Office) for her invaluable assistance in putting everything together. Finally, we are indebted to all the reviewers who helped in making this issue on bioremediation a valuable reference material.