water contamination.pptx which discuss water

ppt

1. Water contamination

2. MEMBRANE TECHNOLOG Y FOR WATER TREATMENT

3. Membrane technology is considered to be the most promising development in water treatment, as it could provide a permeate quality far beyond the current regulatory requirements for drinking water. I I. Introduction

4. Drinking water treatment Waste-water treatment Clarification of fruit juice Ultrapure water in the semiconductor industry Metal recovery as colloidal oxides or hydroxides Pharmaceuticals Medical applications: transfusion filter set Purification of condensed water at nuclear plants Separation of oil-water emulsions Some Industrial Applications

5. Semipermeable barrier that separates solutes and solvents What is a membrane?

6. 0.0001 0.001 0.01 0.1 1 10 100 m m hair Crypto- sporidium smallest micro-organism polio virus Suspended solids Parasites Bacteria Org. macro. molecules Viruses Colloids Dissolved salts Sand filtration Microfiltration Ultrafiltration Nanofiltration Reverse Osmosis Membranes for Water Treatment

7. Membrane processes (MF and UF) that remove pathogens without relying on chemical disinfection, or that reduce the precursors of dissolved contents directly (NF) have received more attention from the drinking water industry. Application of membranes to water treatment is relatively recent.

8. Critical thinking Japan releases nuclear wastewater into the Pacific. How worried should we be? The plan to gradually discharge more than a million tons of treated water from the crippled Fukushima nuclear plant has deeply divided nations and scientists. Read here: Japan releases Fukushima water into the Pacific—is it dangerous? (nationalgeographic.com)

9. Case study: Cleveland’s Cuyahoga River fire Citizens opened their copies of Time Magazine to see a story on the Cuyahoga fire, along with a photo of the 1952 fire. The conditions it described, which included a river that “oozes rather than flows,” caught readers’ attention. Soon, cries for regulation of water pollution became a roar. A grand jury investigation of the causes of the fire followed. In early 1970, President Richard Nixon called for sweeping environmental reform. He created a council on environmental reform which, shortly afterward, was consolidated into the Environmental Protection Agency. Though the Cuyahoga River fire did not directly lead to the formation of the EPA, it was an important landmark for a burgeoning environmental movement. Today, the river is no longer stagnant or filthy. Public and private efforts have diverted sewage and cleaned up its banks. According to the National Parks Service, the river still has unhealthy amounts of sewage in some areas. But in March 2019, the Ohio EPA announced that its fish are now safe to eat.

10. From big pieces of garbage to invisible chemicals, a wide range of pollutants ends up in our planet's lakes, rivers, streams, groundwater, and eventually the oceans. Water pollution—along with drought, inefficiency, and an exploding population—has contributed to a  freshwater crisis , threatening the sources we rely on for drinking water and other critical needs. Research has revealed that  one pollutant in particular  is more common in our tap water than anyone had previously thought: pfas , short for poly and perfluoroalkyl substances. PFAS is used to make everyday items resistant to moisture, heat, and stains; some of these chemicals have such long half-lives that they are known as "the forever chemicals." CASE STUDY: THE FOREVER CHEMICALS