Review of Method and a New Tool for Decline and Inactive SARS-CoV-2 in Wastewater Treatment

Mega-scale desalination efficacy (Reverse Osmosis, Electrodialysis, Membrane Distillation, MED, MSF) during COVID-19: Evidence from salinity, pretreatment methods, temperature of operation

The unprecedented situation of the COVID-19 pandemic heavily polluted water bodies whereas the presence of SARS-CoV-2, even in treated wastewater in every corner of the world is reported. The main aim of the present study is to show the effectiveness and feasibility of some well-known desalination technologies which are reverse osmosis (RO), Electrodialysis (ED), Membrane Distillation (MD), multi effect distillation (MED), and multi stage flashing (MSF) during the COVID-19 pandemic. Systems' effectiveness against the novel coronavirus based on three parameters of nasopharynx/nasal saline-irrigation, temperature of operation and pretreatment methods are evaluated. First, based on previous clinical studies, it showed that using saline solution (hypertonic saline >0.9% concentration) for gargling/irrigating of nasal/nasopharynx/throat results in reducing and replication of the viral in patients, subsequently the feed water of desalination plants which has concentration higher than 3.5% (35000ppm) is preventive against the SARS-CoV-2 virus. Second, the temperature operation of thermally-driven desalination; MSF and MED (70-120°C) and MD (55-85°C) is high enough to inhibit the contamination of plant structure and viral survival in feed water. The third factor is utilizing various pretreatment process such as chlorination, filtration, thermal/precipitation softening, ultrafiltration (mostly for RO, but also for MD, MED and MSF), which are powerful treatment methods against biologically-contaminated feed water particularly the SARS-CoV-2. Eventually, it can be concluded that large-scale desalination plants during COVID-19 and similar situation are completely reliable for providing safe drinking water.

Various advanced wastewater treatment methods to remove microplastics and prevent transmission of SARS-CoV-2 to airborne microplastics

Microplastics (MPs) and SARS-CoV-2 interact due to their widespread presence in our environment and affect the virus' behaviour indoors and outdoors. Therefore, it is necessary to study the interaction between MPs and SARS-CoV-2. The environmental damage caused by MPs is increasing globally. Emerging pollutants may adversely affect organisms, especially sewage, posing a threat to human health, animal health, and the ecological system. A significant concern with MPs in the air is that they are a vital component of MPs in the other environmental compartments, such as water and soil, which may affect human health through ingesting or inhaling. This work introduces the fundamental knowledge of various methods in advanced water treatment, including membrane bioreactors, advanced oxidation processes, adsorption, etc., are highly effective in removing MPs; they can still serve as an entrance route due to their constantly being discharged into aquatic environments. Following that, an analysis of each process for MPs' removal and mitigation or prevention of SARS-CoV-2 contamination is discussed. Next, an airborne microplastic has been reported in urban areas, raising health concerns since aerosols are considered a possible route of SARS-CoV-2 disease transmission and bind to airborne MP surfaces. The MPs can be removed from wastewater through conventional treatment processes with physical processes such as screening, grit chambers, and pre-sedimentation.

A comprehensive review of various approaches for treatment of tertiary wastewater with emerging contaminants: what do we know?

In the last few decades, environmental contaminants (ECs) have been introduced into the environment at an alarming rate. There is a risk to human health and aquatic ecosystems from trace levels of emerging contaminants, including hospital wastewater (HPWW), cosmetics, personal care products, endocrine system disruptors, and their transformation products. Despite the fact that these pollutants have been introduced or detected relatively recently, information about their characteristics, actions, and impacts is limited, as are the technologies to eliminate them efficiently. A wastewater recycling system is capable of providing irrigation water for crops and municipal sewage treatment, so removing ECs before wastewater reuse is essential. Water treatment processes containing advanced ions of biotic origin and ECs of biotic origin are highly recommended for contaminants. This study introduces the fundamentals of the treatment of tertiary wastewater, including membranes, filtration, UV (ultraviolet) irradiation, ozonation, chlorination, advanced oxidation processes, activated carbon (AC), and algae. Next, a detailed description of recent developments and innovations in each component of the emerging contaminant removal process is provided.

Critical role of Hyssop plant in the possible transmission of SARS-CoV-2 in contaminated human Feces and its implications for the prevention of the virus spread in sewage

The significant issue affecting wastewater treatment is human faeces containing SARS-CoV-2. SARS-CoV-2, as a novel coronavirus, has expanded globally. While the current focus on the COVID-19 epidemic is rightly on preventing direct transmission, the risk of secondary transmission via wastewater should not be overlooked. Many researchers have demonstrated various methods and tools for preventing and declining this virus in wastewater treatment, especially for SARS-CoV-2 in human faeces. This research reports two people tested for 30 d, with written consent, at Mosa-Ebne-Jafar Hospital of Quchan, Iran, from September 1st to October 9th, 2021. The two people's conditions are the same. The Hyssop plant was used, which boosts the immune system's effectiveness and limonene, rosemary, caffeic acids and flavonoids, all biologically active compounds in this plant, cause improved breathing problems, colds, and especially for SARS-CoV-2. As a result, utilising the Hyssop plant can help in reducing SARS-CoV-2 in faeces. This plant's antioxidant properties effectively reduce SARS-CoV-2 in faeces by 30%; nevertheless, depending on the patient's condition. This plant is also beneficial for respiratory and digestive health.