In recent years, a group of chemicals known as polyfluoroalkyl substances (PFAS) has become a cause of concern for the entire world. These chemicals are used in the manufacturing of many household items and are discharged into the water with industrial effluents. PFAS remain in the environment permanently and cause serious water pollution. In many cases, they have reached the groundwater aquifers and through that, entered the drinking water.
PFAS enter the human body through drinking water. Long-term exposure to PFAS causes liver damage, increases risk of asthma and thyroid diseases, lowers fertility, and in more serious cases, could cause cancer.
PFAS pollution in India
PFAS pollution is a serious issue in India. A 2018 study showed that PFAS had entered many water aquifers which were more than 100 meters deep. The PFOS levels here ranged from <0.1 – 33 ppt, far higher than the permissible limit of 20 ppt which is set in the US. Significant PFAS levels have been found in waters of major Indian rivers such as the Ganga and Yamuna.
A staggering 93 ppt level of PFOA chemicals was sound in the Noyyal river in Tamil Nadu in the Western Ghats. PFOA is Perfluorooctanoic acid, which is a part of the larger group of chemicals that is PFAS.
Studies have also found PFAS pollutants in the breast milk of mothers in Kerala and Bengal. The PFAS in women’s breast milk avered around 46 ppt, which again is almost double the permissible limit of 20 ppt.
Regulations needed
The Stockholm Convention on Persistent Organic Pollutants added PFAS to its list of restricted chemicals in 2006. India became a party to the treaty in 2006, but it still does not have any regulatory mechanism to check PFAS pollution. The first step towards adopting standards to check PFAS pollution was taken in 2020.
The Bureau of Indian Standards has announced that it will adopt key ISO standards to check the PFAS pollution in the country. These include :
- ISO 3696:1987 water for analytical laboratory use – specification and test methods;
- ISO 5667-1 water quality – sampling – part 1: guidance on the design of sampling programmes and sampling techniques; and
- ISO 8466-1:1990 water quality – calibration and evaluation of analytical methods and estimation of performance characteristics – part 1: statistical evaluation of the linear calibration function.
The right technology to filter PFAS
The selection of the technology to filter PFAS is influenced by the following factors
- Water temperature and flow rate
- Length of the chemical chain
- Amount of PFAS concentration in the effluent
- Presence of other contaminants in the water
Treating PFAS is a complex process. Generally, ion exchange, reverse osmosis, and granular activated carbon, are considered for filtration PFAS from water. However, The GAC and IX technologies have certain limitations. Moreover, the IX system can also be attractive within the PFAS compounds. The RO system uses semi-permeable membranes to filter PFAS. Thus, all that remains in the wastewater is dissolved solids.
Reverse Osmosis has displayed around 90% effectiveness in filtering a wide range of PFAS compounds from industrial wastewater.
Inovar has over 5 years of experience and expertise in the design, manufacturing and installation of customized RO systems to tackle all sorts of filtration challenges. Inovar is a technology-focused company that offers end-to-end water treatment solutions for facilities of any size. Our services include feasibility studies, engineering design, manufacturing, and installation.
Inovar RO systems are designed to minimize operating costs while offering totally automated and reliable operations with consistent performance.
As an expert in the design and manufacture of high-performance and cost-effective RO plants, Inovar can become your reliable partner for zero liquid discharge systems.