Water Contaminants PDF

Water Contaminants Learning Objectives Identify the different types of water contaminants. Describe the impact of water contaminants on the environment and human health. Natural Contaminants Biological Contaminants Chemical Contaminants...

Water Contaminants Learning Objectives Identify the different types of water contaminants. Describe the impact of water contaminants on the environment and human health. Natural Contaminants Biological Contaminants Chemical Contaminants 3  Rainwater – picks up dust particles and dissolves some O2, N2 and CO2 as it falls through the atmosphere CO2 makes natural water acidic, forming carbonic acid (H2CO3) CO2(g) + H2O(l) → H2CO3(aq) Lightning causes nitrogen, oxygen and water vapor to form nitric acid (HNO3), which is also dissolved in rainwater 3NO2(g) + H2O(g) → 2HNO3(aq) + NO(g) 4  Groundwater contains the naturally occurring gas radon (Rn), which is a product of the decay of radioactive uranium and thorium Radon is only slightly soluble in water, so the water used for showering, washing and cooking contributes only a small proportion (~1-2%) of total Rn exposure indoors 5  As water moves along or beneath the earth’s surface, it dissolves minerals from rocks and soil  Rainwater dissolves matter from decaying plants and animals However, organic matter in the form of traces of lubricants, fuels, some fertilizers and pesticides can also contaminate water 7  Microorganisms – waterborne microorganisms may or may not be pathogenic (disease-causing) Cholera, typhoid fever and dysentery are common water- borne diseases, especially in developing countries Waterborne Diseases Disease and Microbial Sources of Agent General Transmission Agent in Water Supply Symptoms Amoebiasis Protozoan Sewage, non- Abdominal (hand-to-mouth) (Entamoeba treated drinking discomfort, fatigue, histolytica, water, flies in weight loss, cyst-like water supply diarrhea, bloating, appearance) fever 9 Waterborne Diseases Disease and Microbial Sources of Agent in General Transmission Agent Water Supply Symptoms Cryptosporidio Protozoan Collects on water Flu-like symptoms, sis (oral) (Cryptosporid filters and watery diarrhea, loss ium parvum) membranes that of appetite, cannot be substantial weight disinfected, animal loss, bloating, manure, seasonal increased gas, nausea runoff of water 10 Waterborne Diseases Disease and Microbial Sources of Agent in General Transmission Agent Water Supply Symptoms Microsporidiosis Protozoan The species Diarrhea and phylum Encephalitozoa wasting in (Microsporidia), intestinalis has been immunocompromise but closely detected in d individuals related to fungi groundwater, the origin of drinking water 11 Waterborne Diseases Disease and Microbial Sources of Agent in General Transmission Agent Water Supply Symptoms Taeniasis Tapeworms Drinking water Intestinal of the genus contaminated with disturbances, Taenia eggs neurologic manifestations, weight loss, cysticercosis 12  Waterborne Diseases Disease and Microbial Sources of Agent in Water General Transmission Agent Supply Symptoms Cholera Spread by the Drinking water In severe forms it is known to bacterium Vibrio contaminated with the be one of the most rapidly cholerae cholera bacterium fatal illnesses known. Symptoms include very watery diarrhea, nausea, cramps, nosebleed, rapid pulse, vomiting and hypovolemic shock (in severe cases), at which point death can occur in 12-18 hours 13 ACID RAIN Acids formed from sulfur oxides (SOx) and nitrogen oxides (NOx) come down from the sky in the form of acid rain, fog and snow Acid rain corrodes metals, dissolves limestone and marble, and may ruin the finishes on automobiles Acids also from into streams from abandoned mines Acidic water is detrimental to life in lakes and streams, and is linked to declining crop & forest yields 14 Acid Rain Acids are no threat to lakes and streams where limestone (calcium carbonate) is plentiful, since CaCO3 can neutralize excess acid CaCO3(s) + 2H+(aq) → Ca2+(aq) + CO2(g) + H2O limestone acid Where rock is mainly granite, however, no such neutralization occurs 15 Heavy Metals Can be released from numerous sources, including municipal wastewater treatment plants, manufacturing industries, mining, rural agricultural cultivation and fertilization Are transported as either a dissolved compound in water or as a part of suspended sediments May be volatilized to the atmosphere or stored in sediments Toxic heavy metals may be absorbed by a variety of organisms 16 Heavy Metals Tungsten Lead Arsenic Barium Nickel Tin Beryllium Copper Antimony Uranium Platinum Thorium Cadmium Mercury Cesium Thallium Aluminum 17  Heavy Metals http://experttoxicologist.com/toxicology-toxic-substances-heavy-metals.aspx 18 Dying Lakes Due to dumping of human sewage into waterways → breakdown of organic matter by bacteria decreases the dissolved oxygen (DO) in the water and increases the plant nutrients Due to fertilizer runoff from farms, golf courses, lawns and seepage from feedlots → add inorganic nutrients to waterways; may result in an algal bloom 19  Refers to enrichment of water by nutrient salts (mainly N & P) that causes structural changes to the ecosystem such as: ▪ Increased production of algae and aquatic plants ▪ Depletion of fish species ▪ General deterioration of water quality ▪ Other effects that reduce and preclude use *All water bodies are subject to a natural and slow eutrophication process, which in recent decades has undergone a rapid progression due to anthropogenic (human) activities 20 Structural change in water is due to: Use of fertilizers Discharge of runoff into bodies of water Reduction of self-purification capacity Accumulation of sediments which start to fill the lake basin and increases interactions between the water and sediment 21 https://byjus.com/chemistry/eutrophication/ 22 Lake Pollution - Eutrophication oligotrophic lake – low in eutrophic lake – well- nutrients and its water is clear fed, high nutrient levels