Lec. 2 & 3: Environment and Pollution PDF

Lec. 2: Environment and Pollution 1- Natural environment: In the natural environment, the pollutants come from earth events like storms, earthquakes, volcanoes, floating, wastes of domestic. The subsequent of these events results in outbreaking the diseases, economic damaging and so. 2- Artificial...

Lec. 2: Environment and Pollution 1- Natural environment: In the natural environment, the pollutants come from earth events like storms, earthquakes, volcanoes, floating, wastes of domestic. The subsequent of these events results in outbreaking the diseases, economic damaging and so. 2- Artificial environment: It is an constructed environment made by human and defined as a synthetic environment. The towns and factories are examples of this type of environment. The pollutants discarded by these environment are termed as anthropogenic pollutants because they produced by human activities. Conventional wastes are consisting of 1- Solid wastes 2- Liquid wastes: Disposed from houses to the derange and composed of COD, BOD, Oil and Greases, pH and detergent. This pollutants represent the conventional pollutants or domestic sewage or municipal wastewaters. The anther type of wastewater is the rainfall and washing water of streets. All these types of wastewater reach the stations of conventional wastewaters treatment through the net of pipelines. This type of conventional wastewaters treatment is known as activated sludge treatment or biological treatment because the biological activities responsible for treating and removing these pollutants. Industrial wastes: They are including wastewaters, solids wastes and gaseous wastes. They are recognized pollutants according to the type of industry. Each type of these wastes is needed to the specific treatment because of their high risks on the living beings. They include the heavy metals (HM), Hydrocarbons (HC), Organic and inorganic compounds. Table -1, shows some industries and their pollutants discharging. Table -1 : The pollutants disposed from industries o. Industry Pollutants 1 Food Technology Colures, BOD,SS 2 Petrochemical , Petroleum HM, Phenols, CN, Oil and Greases, S=, Solvents, COD, BOD. 3 Metallurgical industries Zn, Fe, Cd, Cu, HM. 4 Electroplating HM, (Cr+6 , Cd, Cu, Ni, CN, NH3, Fe, Pb), 1  S=,Oil. 5 Synthetic wool Acrylonitrile, Acetonitrile, HCN, Hg, 6 Fertilizers NH3, SS, NO3, HM (V, As). 7 Sugar, Dairy products, SS, BOD. Effect of Pollutants on Human Health (US-EPA 2010) EPA( Environmental Protection Agency) : It is a US federal agency that deals with the environment, pollution and environmental legislations and issues environmental specifications for all types of pollutants. The agency announced the impact of pollutants on human health after long studies and experiments. The table below shows the effect of these pollutants, according to their classification, on human health. Table -2: Effect of pollutants on human health according to the list published by Environmental Protection Agency (EPA) Pollutant Effect (Above standard limitations) Turbidity Microbial contamination, Diseases. Br- Induced cancer ClO- Anemia in infants and children, harmed to the nerves (Hypochlorous ) Chloramines Eyes and nose irritants, Stomach disturbed, anemia ClO2 Anemia, Nerves INORGANICS Antimony (Sb) Cholesterol increasing in blood, reduced glucose in blood As Arsenic (As) Edema, circulation problems, tumor induced Asbestos(>10 Tumor in intestinal mucous tissues micron) Ba Hypertension Beryllium (Be ) Intestinal Cancer, Kidney failure (Damage), Toxic. Cd Toxic , Skin inflammatory. Nerves damage , Thyroid gland disturbed. 2 Cr -6 Brain Damage, Slow brain developing in children CN Kidney failure, toxic, reproduction problems Bone disease , bone color in infants Pb Nail loss, Hair falling Hg F ORGANICS 2,4D Adrenalin failure, Kidney troubles, liver Chlordane Cancer, Kidney, liver. Dioxin ( synthetic Reproduction problems, Cancer waste burning ) Vinyl Chloride Cancer Di – phthalate Reproduction problems , Cancer , Liver diseases Q: Which is more dangerous, Cr +3 or Cr +6? **Chemical and other contaminants Contaminants may include organic and inorganic substances. 1- Organic pollutants include: 1- Detergents 2- Disinfection by-products found in chemically disinfected drinking water, such as chloroform. 3- Food processing waste, which can include oxygen-demanding substances, fats and grease. 4- Insecticides and herbicides, a huge range of organohalides and other chemical compounds. 5- Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil) and lubricants (motor oil), and fuel combustion byproducts, from stormwater runoff. 3  6- Tree and bush debris from logging operations. 7- Volatile organic compounds (VOCs), such as industrial solvents, from improper storage. 8 - Chlorinated solvents, which are dense non-aqueous phase liquids (DNAPLs), may fall to the bottom of reservoirs, since they don't mix well with water and are denser. 9- Polychlorinated biphenyl (PCBs): Trichloroethylene. 10 - Perchlorate (ClO-4) 11- Various chemical compounds found in personal hygiene and cosmetic products. 2- Inorganic pollutants include: 1- Acidity caused by industrial discharges (especially sulfur dioxide from power plants).(SO2----- H2SO4 in water) 2- Ammonia from food processing waste. (---- NH2(OH)3 Hydroxylamine , carcinogenic ) 3- Chemical waste as industrial by-products. 4- Fertilizers containing nutrients--nitrates and phosphates--which are found in stormwater runoff from agriculture, as well as commercial and residential use. 5- Heavy metals from motor vehicles (via urban stormwater runoff) and acid mine drainage. 6- Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land clearing sites. 7 - Macroscopic pollution—large visible items polluting the water—may be termed "floatables" in an urban stormwater context, or marine debris when found on the open seas. 3- Thermal pollution 4 Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Elevated water temperatures decreases oxygen levels (which can kill fish) and affects ecosystem composition. Thermal pollution can also be caused by the release of very cold water from the base of reservoirs into warmer rivers. Lec. 3 : Measurement Water pollution may be analyzed through several broad categories of methods: physical, chemical and biological. Most involve collection of samples, followed by specialized analytical tests. Some methods may be conducted in situ, without sampling, such as temperature, DO. Government agencies and research organizations have published standardized, validated analytical test methods to facilitate the comparability of results from disparate testing events. 1- Sampling a- Sampling of water for physical or chemical testing can be done by several methods, depending on the accuracy needed and the characteristics of the contaminant. Many contamination events are sharply restricted in time, most commonly in association with rain events. For this reason "grab" samples are often inadequate for fully quantifying contaminant levels. Scientists gathering this type of data often employ auto- sampler devices that pump increments of water at either time or discharge intervals. b- Sampling for biological testing involves collection of plants and/or animals from the surface water body. Depending on the type of assessment, -the organisms may be identified for biosurveys (population counts) and returned to the water body, (like fishes),or 5 - they may be dissected for bioassays to determine toxicity. A- Physical testing Common physical tests of water include temperature, solids concentrations (e.g., total suspended solids (TSS) and turbidity. B- Chemical testing Water samples may be examined using the principles of analytical chemistry. Many published test methods are available for both organic and inorganic compounds. Frequently used methods include pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), nutrients (nitrate and phosphorus compounds), metals (including copper, zinc, cadmium, lead and mercury), oil and grease, total petroleum hydrocarbons (TPH), and pesticides. 3- Biological examination Biological testing involves the use of plant, animal, and/or microbial indicators to monitor the health of an aquatic ecosystem. Control 1 –Domestic sewage Domestic sewage is 99.9 percent pure water, while the other 0.1 percent are pollutants. Although found in low concentrations, these pollutants pose risk on a large scale. Municipal treatment plants are designed to control conventional pollutants: BOD and suspended solids. Well-designed and operated systems can remove 90 percent or more of these pollutants. Some plants have additional sub-systems to treat nutrients and pathogens. Most municipal plants are not designed to treat toxic pollutants found in industrial wastewater. 2- Industrial wastewater Some industrial facilities generate ordinary domestic sewage that can be treated by municipal facilities. Industries that generate wastewater with high concentrations of conventional pollutants (e.g. oil and grease), toxic pollutants 6 (e.g. heavy metals, volatile organic compounds) or other nonconventional pollutants such as ammonia, need specialized treatment systems. Methods of industrial wastewater treatment : 1- Some of these facilities can install a pre-treatment system to remove the toxic components, and then send the partially-treated wastewater to the municipal system. 2- Some industries have been successful at redesigning their manufacturing processes to reduce or eliminate pollutants, through a process called pollution prevention. e.g. , Heated water generated by power plants or manufacturing plants removed by using specific treatments. 7