## 1 Introduction
Finally, the applications of the low-cost, sustainable bioremediation processes are not disregarded, since, in this critical environmental and economic circumstance, the biological techniques are the need of the hour for wastewater treatment and reuse, in spite of their known drawbacks in time and land requirements [38; 39; 40]. Design and performance of pilot- and large-scale constructed wetlands (CWs) have been recently reviewed by [PERSON] et al., offering a deep investigation by statistical tools of the factors influencing CW effectiveness [41]. Unfortunately, a great disproportion exists between the great number of innovative proposals coming from the scientific community and the procedures actually applied at wastewater treatment plants (WWTPs) and sites. Several research projects are still at the bench level, since the effectiveness of the removal process is just one of the factors to match together to design a real remediation-reuse process. Research performed at the pilot scale or directly at the full-scale level represents the necessary step forward to demonstrate the feasibility of new bench technologies for real application, providing both knowledge and experience in the transition of these systems to large-scale application. However, few reviews are focused just on these experimental setups that are most interesting to readerssearching for ready-to-use technologies suitable to solve their WW management and water supply problems or for an unexpected inspiration to boost their research. In this review, only the most recent (years 2020-2024) pilot- and full-scale investigations are collected in order to highlight the positive outcomes as well as the hindrances encountered in applying bench-level methodologies to a larger experimental dimension. Our aim was to propose an overview of the recent attempts to treat polluted water of different origins, obtaining water remediation and reuse with completely different points of departure and final targets. This review paper aims to provide useful, up-to-date information to all operators working in this field, independently from the geographical area, specific needs, technological solutions and income at their disposal, shedding light on potential further advancements. Literature review methodology. This literature review was conducted using the Web of Science Core Collection and the Scopus databases. Searches used combinations of relevant keywords: wastewater, remediation, bioremediation, water pollution, pilot plant, full-scale, industry, water reuse, advanced oxidation processes, groundwater, water recovery, water supply and combinations. Inclusion criteria, such as language and type of publication, field of study and year of publication, were used. The focus was on publications from the last five years reporting the experience obtained by traditional or emerging water treatment technology applications, at the pilot- or full-scale level, to remediate real wastewater or polluted water. In the case of wastewater treatment, preference was given to papers approaching the contamination as a whole, i.e., not focused on the removal of a single compound and/or suggesting possible remediated water reuse. Over 900 articles, research papers and review papers were examined. After a title and abstract screening, a full-text screening was performed aimed to exclude articles in which experimental design was not implemented, at least to a certain extent, at pilot-scale conditions. In total, 163 articles were shortlisted for writing this review, and the papers were gathered together according to the central or decentralized treatment site the works are dealing with. The urban wastewater treatment plants (UWWTPs) and the TPs at the industrial production site were considered as centralized sites, while the decentralized treatment section includes all methodologies developed to reclaim domestic, agricultural and industrial wastewater in rural or isolated locations and to improve the quality of conventional (surface and groundwater) and not conventional water sources.