MATERIALS AND PROCESSING SCIENCE

[Audio] MATERIALS AND PROCESSING SCIENCE Water quality.

[Audio] Topics To Be Covered: What are the effects of alkalinity and acidity in drinking water? Discuss the process of groundwater contamination occur. How do filtration membranes in water purification work? Describe the source of storm water ..

[Audio] What are the effects of alkalinity and acidity in drinking water?.

[Audio] What is pH? pH is a measurement of electrically charged particles in a substance. It indicates how acidic or alkaline that substance is. The pH scale ranges from 0 to 14. Acidic water has a pH lower than 7. Strongly acidic substances can have a pH of 0. Alkaline water has a pH of 8 or above. Pure water has a pH of 7 and is considered "neutral" because it is neither acidic or basic. World Health Organisation( WHO), recommends that municipal drinking water suppliers keep their water at pH 6.5 to 8.5..

[Audio] Effects of Acid in drinking water on: humans: Due to potential heavy metal contamination, it's not recommended to drink acidic water, as it can lead to heavy metal poisoning or toxicity. Additionally, the acidity of the water can erode tooth enamel. 2. Plants: Acid rain leaches aluminium from the soil. That aluminium maybe harmful to plants as well as animals. Acid rain removes minerals from the soil that trees need to grow. 3. Animals: At lower pH levels, some adult fish die. Some acidic lakes have no fish. Even if a species of fish or animal can tolerate moderately acidic water, the animals or plants it eats might not. For example, frogs have a critical pH around 4, but the mayflies they eat are more sensitive and may not survive pH below 5.5..

[Audio] Effects of Alkaline drinking water on: Humans: Lowers the natural stomach acidity, which helps kill bacteria and expel other undesirable pathogens from entering your bloodstream. Additionally, an overall excess of alkalinity in the body may cause gastrointestinal issues and skin irritations. Too much alkalinity may also agitate the body's normal pH leading to metabolic alkalosis. 2. Plants: If water is too alkaline, calcium builds up, effectively cutting off the flow of nutrients to plants roots. 3. Animals: When the pH of freshwater becomes highly alkaline ( i.e., 9.6), the effects on fish may include: death, damage to outer surfaces like gills, eyes, and skin and an inability to dispose of metabolic wastes. High pH may also increase the toxicity of other substances..

[Audio] Discuss the process of groundwater contamination occur..

[Audio] Process of groundwater contamination. Groundwater is the water that exists in saturated zones beneath the land surface. Although groundwater is located underground, it can be contaminated through the following sources: Chemicals: Chemicals used on lawns and farm fields to kill weeds and insects and to fertilise plants, and other products used in homes and businesses. When it rains, these chemicals can seep into the ground and eventually into the groundwater. 2. Road Salts: Road salts are used in the wintertime to put melt-ice on roads to keep cars from sliding around. When the ice melts, the salts gets washed off the roads and eventually ends up in the water. Landfills: Landfills are places that our garbage is taken to be buried. Landfills should have a protective layer to prevent contaminants from getting into water. If there is no layer or it has cracked, contaminants from the landfill( car battery acid, paint, household, cleaners, etc.) can make their way down into the groundwater..

[Audio] How do filtration membranes in water purification work?.

[Audio] How do filtration membranes in water purification work? Filtration membrane is defined as essential microporous barriers of polymetric, ceramic or metallic which are used to separate dissolved materials( solutes), colloids, or fine particulate from solution. There are four basic pressure-driven membrane filtration processes separations. Namely: Microfiltration Ultrafiltration Nanofiltration Reverse Osmosis These processes differ based on the size of particles that can be separated and the type of substances that can be passed through the membrane..

[Audio] Microfiltration Microfiltration is the direct removal of suspended particles using a membrane, which separates according to particle size. It rejects only suspended solids, while allowing even proteins to pass the membrane freely. The membrane can be symmetrical or asymmetrical and has a thin film of 10- 150micrometer. The size of the surface pores of the membrane is between 4– 0.02 micrometer..

[Audio] microfiltration process Microfiltration is achieved by using crossflow isolation which includes introducing the feed stream under pressure into the membrane and passing it through a membrane surface in a regulated flow path, the small part of the feed stream that goes through the membrane is called permeate. soluble particles that were rejected by the membrane are washed away and are called concentrate or feed. The crossflow membrane filtration makes use of a high crossflow rate to promote passage and reduce blockage..

[Audio] 2. ULTRAFILTRATION Ultrafiltration is a technique that separates components in water `according to molecular size. This technique forces water through a semi-permeable membrane, where suspended particles and dissolved substances with high molecular weight stay behind on the retentate side of the membrane. The membrane is symmetrical and has a thin film of 1µICROMETER. The size of the surface pores of the membrane is between 0.2 – 0.02 µICROmETER. Ultrafiltration extracts many organic compounds, viruses, salts, and inorganic acids. This method generates uniform water quality regardless of the source of water being treated, it also eliminates 90- 100% of pathogens and does not use chemicals unless membranes are being cleaned. Ultrafiltration is used mostly in water and wastewater treatments..

[Audio] 3. NANOFILTRATION Nanofiltration is a method of filtration that makes wastewater to be recycled by providing a greater reflux rate while using less energy. Nanofiltration uses membranes extremely small holes down to 600 Dalton's. It allows only tiny and single charged ions to flow through at high pressures like 50 bar while bigger ions with more than one negative charge, such as sulphate or phosphate and all organic materials are rejected by the membrane. The rejection of sodium chloride in nanofiltration varies from 0-50 percent depending on the feed concentration. The membrane is symmetrical and has a thin film of 1µicrometer. The size of the surface pores of the membrane is less than 0.002µicrometer. Nanofiltration is used to concentrate and demineralize substances such as whey and ultrafiltration permeate..

[Audio] 4. REVERSE OSMOSIS Reverse osmosis is the tightest possible membrane process in separation, that only allows water to pass through. Suspended and dissolve material are not allowed to pass through. The membrane is symmetrical and has a thin film of 1µICROmETER. The size of the surface pores of the membrane is less than 0.002 µICROMETER..

[Audio] REVERSE OSMOSIS PROCESS Reverse osmosis uses pre-filters to extract residues and chlorine from the water, before forcing it through a semi-permeable membrane to remove total dissolved solids. After filtration by reverse osmosis, the water is channelled through post-filters to increase the taste and appearance of the water. RO is used in desalination of drinking water and the production of deionized water.

[Audio] Describe the source of storm water .. Describe the source of storm water ..

[Audio] Sources of storm water What is stormwater? Stormwater is water that arises from precipitation which includes heavy rain and or melt water from heavy rain and snow..

[Audio] Slot drains They are great for outdoor areas that don't require excessive drainages. they tend to flood easily when exposed to heavy rainfall..

[Audio] Open Storm Drain Open storm drains are drains that usually run parallel to a nearby road or parallel to the edge of a property. They feature long, uncovered channels to carry free-flowing stormwater. These channels often direct water into a local sewer system where it can be treated and managed.

[Audio] Closed Storm Drain Most of the stormwater management systems you see now are stormwater grates that lead to a local, underground sewer system. Closed storm drain grates can be found in the low areas of parking lots, the trenches near sidewalks, and other areas where water intentionally or unintentionally tends to collect..

[Audio] THE END. GROUP MEMBERS. Miss KC Cosa Mr M Funyufunyu Miss MN Makhubele Miss CK MashimbyE Miss TK MochekgechekgE MISS H NKADIMENG Mr K Mokonyane Mr XI Sibiya.

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