The Coronavirus pandemic and the way forward for the water industry

The Coronavirus outbreak was identified in December 2019 and rapidly spread globally, gaining a pandemic status in March 2020. The effects of this outbreak will be seen in every field, changing life the way we have known it. It will also change the way we do business, affecting Industry in more ways than one.
The water industry too will see several short term and long term effects. In the short term, we are still in the course of medical treatment and action to contain the virus from becoming more challenging, but it has raised alarms in our system and raised questions regarding the ability to handle this situation. In the long term, society at large, the government system and private sector will have to devise and adapt comprehensive control measures so that we are at a lower level of exposure to this loss, than we are at today.
Water needs cannot be curbed. The overall demand for pure and clean water will increase, not only for domestic sanitation but also for mass scale public place disinfection. In addition, there could be a spur in Industrial needs where a large number of people are expected to work together. This will put an increased pressure on water distribution, and treatment needs to be handled by the system.
The primary concern will be in two areas – drinking water safety and the appropriate handling and disposal of sewage waste water. Micro-organisms in untreated or contaminated water will transmit viral pathogens and will cause rapid spread of diseases.
Over one hundred pathogen species that can lead to diseases affecting human beings have been reported. Diseases like hepatitis, gastroenteritis, meningitis, fever, rash and conjunctivitis can all be spread through contaminated water. With advanced detection and characterization methods, many more such virus strains are being discovered in water. although only some of these viruses are human pathogens.
As per the WHO guidelines, the Covid-19 virus has not been detected in drinking-water supplies and, based on current evidence, the risk to water supplies is low. But as per laboratory studies
Corona virus instances that took place in well-controlled environments indicated that the virus could remain infectious in water contaminated with faeces for days, and sometimes even weeks. A number of measures can be taken to improve water safety, starting with protecting the source water itself from trespasses, treating water at the point of distribution, collection, or consumption; and ensuring that treated water is safely stored in regularly cleaned and covered containers.
Although there is no current evidence of the spread of Covid-19 through drinking water, the need of the hour is that conventional, centralized water treatment methods that use filtration and disinfection should be equipped to inactivate this virus. There should be a residual concentration of free chlorine of ≥0.5 mg/L maintained for at least 30-60 minutes of contact time at pH level of 8.0 pH. A chlorine residual should be maintained throughout the distribution system. A continuous real time measurement for residual chlorine, Turbidity and pH would be minimum techniques to sound an alarm to the managing authority in case of any abnormality in supply or distribution of drinking water.
Also as per WHO guidelines, in places where centralized water treatment and safe piped water supplies are not available, a number of household water treatment technologies are effective in removing or destroying viruses, including boiling or using high-performing ultrafiltration or nano-membrane filters, solar irradiation and, in non-turbid waters, UV irradiation and appropriately dosed free chlorine have to be adopted. This will ensure appropriate disinfection of the virus and make the water safe for human consumption. However, the detailed studies to see the pattern of this virus in fresh water to reach a definite conclusive result have yet to be conducted.
Sewage water on the other hand contains many viruses that are detrimental to human health. Proper sewage water treatment will therefore play an instrumental role in keeping the virus at bay.
As part of an integrated public health policy and the international procedure, as of WHO Interim guidance 19 March 2020 wastewater carried in sewerage systems should be treated in well-designed and well-managed centralized wastewater treatment works. Each stage of treatment results in a further reduction of the potential risk. This will therefore call for appropriate aeration treatment, increased retention time, exposure to UV light, exposure to higher temperature and use of disinfection chemicals prior to discharging the water to natural resources. This should be practiced without exemption.
The most important decision for sewage treatment plants will be regarding tertiary treatment procedures, which will kill any bacteria or viruses present. Currently most plants conduct tertiary treatment and disinfection by chlorine, chlorine dioxide or ozone, but only when the treated wastewater is recycled in the same process, or utilised for other purposes. However, looking at the Covid situation, disinfection should adopted widely prior to discharge of water to natural source.
Chlorination remains the most common form of waste water disinfection due to its low cost and history of effectiveness. One disadvantage is that chlorination of residual organic material can generate chlorinated-organic compounds that may be carcinogenic. Since residual chlorine is harmful for aquatic life, water needs to be de-chlorinated before mixing with natural sources like river, lake.
Ozonation is a safer way of disinfection. Ozone is very unstable and reactive. It oxidizes most organic material it comes in contact with, thereby destroying many pathogenic microorganisms. Ozone is considered to be safer than chlorine because ozonation produces fewer disinfection by-products than chlorination. Ozonation is, however, not as economical as chlorination, and currently difficult to implement on a wide spread basis.
Water is an essential part of everyday life. If not managed and handled carefully in such pandemic situation, it can become the cause for wider spread. In a water treatment plant, personnel are exposed to waste water at different stages of treatment. Appropriate care has to be taken by plant operators and engineers who are exposed to such water vicinity so that they don’t get affected pathogens that may still be active. All in all comprehensive efforts have to be implemented to control the spread of, and eradicate the Covid-19 pandemic. Water treatment and continuous real time monitoring of specific analytical parameters like, residual chlorine, dissolved oxygen, PH, temperature, turbidity, etc., will play a vital role in handling the situation in an effective and efficient way.”

SHANTANU CHOUDHARI
Product Manager, Process Analytics
Forbes Marshall