Toxic metals Some metals are essential for the normal development and well-being of humans and other creatures They include Na, K, ca, Mg, cu, Cr, and Zn Other metals are toxic even when present in an organism at very low concentrations Examples: Antimony, Arsenic, Barium

General types of water pollutants Disease-causing agents(Pathogens) Oxygen-consuming agents Plant nutrients Toxic substances Heavy metals Pesticides Dissolved solids o acids

Objectives of Water Treatment The objectives for water treatment derive from two concerns Human health and welfare The health of aquatic ecosystems

pH of a buffer and buffer capacity Example: For a buffer solution consisting of 0. 1 M acetic acid and o1M sodium acetate the ph of the solution is 4.75 HAc= i If an amount of hydrochloric acid equivalent to 10% of the acetate present, is added to the buffer, what is the new pH of the solution?

What is the pH of natural rain water? pH of natural rain water is determined by acidic and basic species that are

Water content of selected organism and foods of mass of mass Marine 97 Broccoli invertebrates

Ozone in the atmosphere STRATOSPHERE TROPOSPHERE In this region, ozone protects In this region, ozone can us from the sun's harmful damage lung tissue and uitraviolet radiation

The discovery of the ozone hole The British Antarctic Survey has been monitoring for many years, the total column ozone levels at its base at Halley bay in the antarctica Monitoring data indicate that column ozone levels have been decreasing since 1977. This observation was later confirmed by satellite

Whether and climate Weather is the condition of the atmosphere in terms of temperature, humidity, winds and precipitation Climate is defined as the average weather over various time periods ranging from a few weeks to decades to geological timescales Whether and climate are ultimately determined by location, topography, and the exchange of radiant energy between the Sun, Earth, and space

Greenhouse Glass the material lass transmits Glass absorbs and redirects the longer wavelengths of·nerg Remined longer-wavelength infrard ndation that greenhouse is a made of, 1)transmit \ greenhouse affect short-wavelength visible light, 2)