Wastewater Treatment Surface Chemistry Aspects

One of the biggest challenges mankind faces today is the availability of clean drinking water. Waste-water contains different kinds of pollutants (dissolved substances, suspended particles, and colloids). Wastewater is treated in suitable plants before the processed water is released into the surroundings. The substances that are found in wastewater (solutes) are in either molecular (such as benzene, coloring substances, etc.) or ionic form (such as Na+, CL, Mg +, K+, Fe +, etc.) (Birdi, 2010a Cheremisinoff, 2002). 

The concentrations of pollutants are generally given in various units  

Weight/w (mg/kg parts per million [ppm] parts per billion [ppb]) Molarity (mmol/L) 

Methods needed to treat these pollution systems also depend on the quantitative amounts of substances present. The specific unit used depends on the amounts present. The unit used for trace amounts, such as benzene, is given in ppm or ppb. The hardness of drinking water (mostly Na, Ca, Mg) concentration is given as mg/L. The typical values as found are in the range of less than 10 mg/L (soft water) or hard water (over 20 mg/L). 

Commercially available electrophoresis instruments are used whae the quartz cells designed for any specific system are available. The magnitude of zeta potential, is obtained from the following relation  

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