New insights towards disinfecting viruses – short notes

Water treatment specialists need more and more to understand how viruses behave in potable water pipes and wastewater setups. This work discusses the late advances in dealing with viruses present in water treatment processes. Activated carbon adsorption (ACA) remains one of the most efficient and credible physicochemical methods. Nanoparticles have been utilized to turn activated carbon into a more efficient sorbent. Membrane filtration could lead to total elimination of viruses and ensure the safety of drinking water plants. As a feasible utilization for disinfecting potable water, solar disinfection (SODIS) remains a green and cost-efficient technology with its optical and thermal pathways and deserves more interest in its large and industrial implementation. Identically, solar distillation remains a viable solution for disinfecting and treating water. The water treatment techniques that are currently utilized for surface water treatment are appropriate for eliminating viruses like influenza A viruses, as proved by the literature. More strict precautions have to be taken to secure viruses’ total elimination from water and wastewater as for influenza A and H5N1 in terms of advanced oxidation processes, ACA, and membrane processes application. Before reaching surface water, pathogens have to be removed efficiently from hospital and municipal wastewaters.


INTRODUCTION
With diameters from 20 to 300 nm, viruses are a menace to potable water safety (Zhang & Zhang ; Shimabuku et al. ; Ghernaout a). Both underground water and surface water may begin to be polluted with viruses from diverse fecal sources (Gerba ). A massive quantity of resistant bacteria has been found in treated sewage (Huang et al. a, b; Ghernaout & Elboughdiri a). To make matters worse, viruses and bacteriophages are known to remain longer than bacteria following disinfection applications (Allue-Guardia et al. This work discusses removing viruses using nanotechnological processes, drinking water treatment techniques. Further, it presents a simple functionalized sand filter as a promising method. Special attention is accorded to the solar disinfection (SODIS) and electrochemical engineering applied in killing viruses. Merging processes such as coagulation-membrane filtration for ultraviolet (UV) disinfection is also an attractive approach. Finally, dealing with viruses in the water cycle is suggested.

APPLIED TECHNIQUES FOR REMOVING VIRUSES
Removing viruses using nanoparticles' processes This material was used in an easy low-temperature solvothermal-hydrothermal procedure to eliminate human adenovirus type 2 (HAdV-2). The sample of O-g-C 3 N 4 / HTCC-2 with a uniform coverage of HTCC, strong visible light absorption, and a narrow band gap depicted the high virucidal activity versus highly resistant HAdV-2 under visible light irradiation, juxtaposed to HTCC, bulk g-C 3 N 4 , and O-g-C 3 N 4 ( Figure 2). A titer of 10 5 MPN/mL viruses was eliminated during 120 min of photocatalysis, and the viral elimination efficiency was improved with the elevation of water temperature from 4 C to 37 C, the diminution of pH from 8 to 5, salinity (NaCl), and hardness (Ca 2þ ). Moreover, its performance in HAdV-2 elimination in actual potable water and the excellent photocatalyst stability of O-g-C 3 N 4 /HTCC-2 were encouraging results that suggest this material could be used for disinfecting water. The ame-  Their findings revealed an identical behavior for both MS2 and Qβ surrogates; however, the GA surrogate was especially atypical. The infectious character of MS2 and Qβ bacteriophages was mainly eliminated following clarification by sand filtration techniques (more than a 4.8-log reduction). At the same time, genomic copies were reduced more than 4.0-log following the full treatment process. In contrast, the GA bacteriophage was only slightly reduced via clarification pursued by sand filtration, with less than a 1.7-log and 1.2-log removal, respectively. Following attainment of the full treatment process, GA bacteriophage was reduced with less than 2.2-log and 1.6-log reduction, They investigated the molecular pathway of such increased

Thermal elimination
The absorption of sunlight, particularly solar infrared radi-

Electrochemical technology for viruses' removal
Treating water electrochemically remains an encouraging option for small-scale and distant water setups that need working capability or appropriate access to chemicals for classical coagulation and disinfection (Ghernaout b; Ghernaout & Elboughdiri c, d, e, f). Following hydraulic backwash, MS2 rejection was still maintained consistently at 100%.  (Ghernaout & Elboughdiri i, j).

Antiseptics
Wastewater from hospitals must be thoroughly disinfected.
Wastewater treatment plants receiving sewage from hospitals and isolation centers treating virus patientsand urban sewage from zones of known pollutioncould have increased levels of viruses. Highly polluted water from these sources has to be purified through a collection of processes to reduce the infection effects on the adjacent receiving ecosystems (Lénès et al. ).

CONCLUSIONS
Here, we review and discuss recent improvements in applied processes for removing viruses from water. Water treatment specialists need to understand how viruses behave in potable water pipes and wastewater setups.
From this work, the following conclusions can be drawn.