Rainwater Harvesting and Treatment: State of the Art and Perspectives

Abstract

Rainwater harvesting is an ancient practice currently used for flood and drought risk mitigation. It is a well-known solution with different levels of advanced technology associated with it. This study is aimed at reviewing the state of the art with regards to rainwater harvesting, treatment, and management. It focuses on the environmental and social benefits of rainwater harvesting and links them to the Sustainable Development Goals. The review identifies characteristics of laws and regulations that encourage this practice and their current limitations. It presents methodologies to design a rainwater harvesting system, describes the influence of design variables, and the impact of temporal and spatial scales on the system’s performance. The manuscript also analyzes the most advanced technologies for rainwater treatment, providing insights into various processes by discussing diverse physiochemical and biological technology options that are in the early stages of development. Finally, it introduces trends and perspectives which serve to increase rainwater harvesting, water reuse, and effective management.

Pollutant Removal Efficiency in a Rainwater Treatment System in Roztocze National Park (Poland)

“…It first passes through filter 1 with a 20 μm pore-size polypropylene cartridge (3), then through filter 2 with a 5 μm pore-size polypropylene cartridge (4) and finally through filter 3 with an activated carbon cartridge (5). Microbial contaminants, especially coliform bacteria originating from avian faecal droppings accumulated on the roofs, are removed with a UV disinfection lamp (Eko Technika (Gliwice, Poland) TMA D6, 2.3 m 3 /h) (6). Because the effectiveness of the lamp is strongly contingent on water clarity, it is located at the end of the treatment train, downstream of the three filters.…”

“…Recently, more and more research indicates that the harvesting and utilisation of rainwater can help to surmount the problems connected with water deficits caused by climate change in various regions of the world [4,5]. Raimondi et al [6] have reported that the number of publications recorded yearly in the Scopus database containing the keyword "rainwater harvesting" increased from zero in 1985 to over 400 in 2021. According to the UN, climate change is the greatest threat to social and economic development.…”

“…Kim et al [20] have reported that rainwater is used as the main source of water supply for millions of people in developing countries. In recent years, however, climate change, droughts, and the rising costs of water have also forced highly developed countries to invest in waterharvesting and utilisation technologies [6,21]. The potential of using rainwater on an urban scale for the example of Turin in Italy was presented by Carollo et al [22], while the potential of rainwater harvesting in the retail sector in Portugal was presented by Ferreira et al [23].…”

“…The advantages of rainwater collection systems have been discussed in detail by Morey et al [24], Yawalkar et al [25], and Ertop et al [26]. Those authors have noted that rainwater can be utilised (1) as an additional source of water where demand is high but water from other sources is scarce, (2) to protect water resources, (3) to reduce the consumption of surface and groundwater resources, (4) to produce safe drinking water in the process of purification, (5) for watering plants and landscaping, and (6) to reduce unproductive outflow of water through rivers into the seas and oceans; at the same time, rainwater utilisation systems are (6) simple, easy to maintain, and cheap to operate, (8) can be used anywhere, regardless of the terrain, geology, or land development pattern, (9) can be used on-site in households or public utility facilities, (10) can improve the water management system, and (11) can protect urban areas from flooding and reduce the severity of floods during heavy rainfall. It has also been demonstrated that excess rainwater can be diverted and captured for groundwater recharge.…”

Integrated Design and Control of a Sustainable Stormwater Treatment System

“…Rainwater harvesting is an ancient practice that was used to combat the risk of floods and droughts; it is currently more important because it helps supply water needs in areas where there is a water shortage [1].…”