7 Log Virus Removal in a Simple Functionalized Sand Filter

Viruses in Wastewater-A Concern for Public Health and the Environment

Wastewater monitoring provides essential information about water quality and the degree of contamination. Monitoring these waters helps identify and manage risks to public health, prevent the spread of disease, and protect the environment. Standardizing the appropriate and most accurate methods for the isolation and identification of viruses in wastewater is necessary. This review aims to present the major classes of viruses in wastewater, as well as the methods of concentration, isolation, and identification of viruses in wastewater to assess public health risks and implement corrective measures to prevent and control viral infections. Last but not least, we propose to evaluate the current strategies in wastewater treatment as well as new alternative methods of water disinfection.

Development of a simple and low-cost method using Moringa seeds for efficient virus concentration in wastewater

Effective virus concentration methods are essential for detecting pathogenic viruses in environmental waters and play a crucial role in wastewater-based epidemiology. However, the current methods are often expensive, complicated, and time-consuming, which limits their practical application. In this study, a simple and low-cost method was developed using the extract of Moringa oleifera (MO) seeds (MO method) to recover both enveloped and non-enveloped viruses, including pepper mild mottle virus (PMMoV), murine norovirus (MNV), Aichivirus (AiV), murine hepatitis virus (MHV), and influenza A virus subtype H1N1[H1N1] in wastewater. The optimal conditions for the MO method were determined to be a concentration of MO extract at the UV280 value of 0.308 cm-1 and an elution buffer (0.05 M KH2PO4, 1 M NaCl, 0.1 % Tween80 [v/v]) for recovering the tested viruses in wastewater. Compared to other commonly used virus concentration methods such as InnovaPrep, HA, PEG, and Centricon, the MO method was found to be more efficient and cost-effective in recovering the tested viruses. Moreover, the MO method was successfully applied to detect various types of viruses (PMMoV, AiV, norovirus of genotype II [NoV II], enterovirus [EV], influenza A virus [matrix gene] [IAV], and SARS-CoV-2) in raw wastewater. Thus, the developed MO method could offer a simple, low-cost, and efficient tool to concentrate viruses in wastewater.

SARS-CoV-2 detection and inactivation in water and wastewater: Review on analytical methods, limitations and future research recommendations

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in wastewater. Wastewater-based epidemiology (WBE) is a practical and cost-effective tool for the assessment and controlling of pandemics and probably for examining SARS-CoV-2 presence. Implementation of WBE during the outbreaks is not without limitations. Temperature, suspended solids, pH, and disinfectants affect the stability of viruses in wastewater. Due to these limitations, instruments and techniques have been utilized to detect SARS-CoV-2. SARS-CoV-2 has been detected in sewage using various concentration methods and computer-aided analyzes. RT-qPCR, ddRT-PCR, multiplex PCR, RT-LAMP, and electrochemical immunosensors have been employed to detect low levels of viral contamination. Inactivation of SARS-CoV-2 is a crucial preventive measure against coronavirus disease 2019 (COVID-19). To better assess the role of wastewater as a transmission route, detection, and quantification methods need to be refined. In this paper, the latest improvements in quantification, detection, and inactivation of SARS-CoV-2 in wastewater are explained. Finally, limitations and future research recommendations are thoroughly described.

Moringa oleifera-derived coagulants for water treatment: Floc structure, residual organics, and performance trade-offs

The study explored the suitability of unfractionated extracts from the seeds of the Moringa oleifera tree as a coagulant for water treatment. The coagulant was obtained by soaking crushed and sieved seeds in a low salinity aqueous solution: a simple and inexpensive alternative to conventional coagulants in settings where specialized expertise and equipment are lacking. The performance of M. oleifera-derived coagulants was quantified in terms of turbidity removal, bacteriophage clearance, concentration of residual organics, as well as meta-parameters such as floc size and fractal dimension. Treating high turbidity clay suspensions at the optimal coagulant dosage (14.7 mg(DOC)/L) and flocculation mixing conditions ([Formula: see text]= 22.4 s^-1) removed > 94% of turbidity, similar to that recorded in reference tests with alum. Floc size distribution shifted to larger sizes during the first 10 min of flocculation with no change afterwards, while the floc fractal dimension, [Formula: see text], continued to increase, pointing to the gradual formation of denser ([Formula: see text]= 2.1 to 2.2), more settleable flocs. Preliminary tests with MS2 bacteriophage showed that coagulation with M. oleifera decreased the viable MS2 titre by ~ 1.3 log, which was significantly above the turbidity removal (~ 1 log). The extraction process, however, allowed a large amount of residual organics (> 78% of extracted DOC) into the treated water. Combining the coagulants with downstream filtration and adsorption, employing UV or solar disinfection, or limiting applications to non-potable reuse is suggested for mitigating the concerns related to residual DOC.

The novel SARS-CoV-2 pandemic: Possible environmental transmission, detection, persistence and fate during wastewater and water treatment

The contagious SARS-CoV-2 virus, responsible for COVID-19 disease, has infected over 27 million people across the globe within a few months. While literature on SARS-CoV-2 indicates that its transmission may occur predominantly via aerosolization of virus-laden droplets, the possibility of alternate routes of transmission and/or reinfection via the environment requires considerable scientific attention. This review aims to collate information on possible transmission routes of this virus, to ascertain its fate in the environment. Concomitant with the presence of SARS-CoV-2 viral RNA in faeces and saliva of infected patients, studies also indicated its occurrence in raw wastewater, primary sludge and river water. Therefore sewerage system could be a possible route of virus outbreak, a possible tool to assess viral community spread and future surveillance technique. Hence, this review looked into detection, occurrence and fate of SARS-CoV-2 during primary, secondary, and tertiary wastewater and water treatment processes based on published literature on SARS-CoV and other enveloped viruses. The review also highlights the need for focused research on occurrence and fate of SARS-CoV-2 in various environmental matrices. Utilization of this information in environmental transmission models developed for other enveloped and enteric viruses can facilitate risk assessment studies. Preliminary research efforts with SARS-CoV-2 and established scientific reports on other coronaviruses indicate that the threat of virus transmission from the aquatic environment may be currently non-existent. However, the presence of viral RNA in wastewater provides an early warning that highlights the need for effective sewage treatment to prevent a future outbreak of SARS-CoV-2.

Coronavirus 2 (SARS-CoV-2) in water environments: Current status, challenges and research opportunities

The outbreak of COVID-19 has posed enormous health, social, environmental and economic challenges to the entire human population. Nevertheless, it provides an opportunity for extensive research in various fields to evaluate the fate of the crisis and combat it. The apparent need for imperative research in the biological and medical field is the focus of researchers and scientists worldwide. However, there are some new challenges and research opportunities in the field of water and wastewater treatment concerning the novel coronavirus 2 (SARS-CoV-2). This article briefly summarizes the latest literature reporting the presence of SARS-CoV-2 in water and wastewater/sewage. Furthermore, it highlights the challenges, potential opportunities and research directions in the water and wastewater treatment field. Some of the significant challenges and research opportunities are the development of standard techniques for the detection and quantification of SARS-CoV-2 in the water phase, assessment of favorable environments for its survival and decay in water; and development of effective strategies for elimination of the novel virus from water. Advancement in research in this domain will help to protect the environment, human health, and managing this type of pandemic in the future.

The role of wastewater treatment plants as tools for SARS-CoV-2 early detection and removal

The world is facing the third coronavirus caused pandemic in less than twenty years. The SARS-CoV-2 virus not only affects the human respiratory system, but also the gastrointestinal tract. The virus has been found in human feces, in sewage and in wastewater treatment plants. It has the potential to become a panzootic disease, as it is now proven that several mammalian species become infected. Since it has been shown that the virus can be detected in sewage even before the onset of symptoms in the local population, Wastewater Based Epidemiology should be developed not only to localize infection clusters of the primary wave but also to detect a potential second, or subsequent, wave. To prevent a panzootic, virus removal techniques from wastewater need to be implemented to prevent the virus dissemination into the environment. In that context, this review presents recent improvements in all the fields of wastewater treatment from treatment ponds to the use of algae or nanomaterials with a particular emphasis on membrane-based techniques.