Biological Biofilm Processes

Introduction: Activated carbon filtration (AC) is effective in reducing certain organic chemicals and chlorine in water. It can also reduce the quantity of lead in water although most lead-reducing systems use another filter medium in addition to carbon. Water is passed through granular or block carbon material to reduce toxic compounds as well as harmless taste- and odor-producing chemicals. This fact sheet discusses the principles and processes of typical activated carbon filtration systems.

This is an introduction to water treatment systems and technology. It is not a design manual or an exhaustive treatise. It is intended for engineers who are not regularly involved in water treatment projects, but who are interested in learning some of the basics involved. Criteria to be followed in determining the necessity for and the extent of treatment are discussed here, as are procedures applicable to the planning of water treatment projects.

All over the world the presence of arsenic in water sources for human consumption has been raising great concern in terms of public health since many epidemiologic studies confirm the potential carcinogenic effect of arsenic. Because arsenic removal is the most frequent option for safe drinking water, the development of more efficient and sustainable technologies is extremely important. Membrane separation processes are suitable for water treatment because they can provide an absolute barrier for bacteria and viruses, besides removing turbidity and colour. Their application is a promising technology in arsenic removal since it does not require the addition of chemical reagents nor the preliminary oxidation of arsenite required in conventional treatment options. However, since membrane technologies such as reverse osmosis can be a very expensive and unsustainable treatment option for small water supply systems, it becomes crucial that alternative methods are developed. This work presents a few conclusions based on a laboratorial study performed to evaluate the efficiency of arsenic removal using ultrafiltration, microfiltration and solar oxidation processes under different experimental conditions for relevant parameters. The results showed removal efficiencies higher than 90%. Key-words: safe drinking water, arsenic removal, membranes, public health.

• Describe how water treatment plants comply with their minimum federal and state monitoring requirements. • List the three ways in which management ensures that the staff complies with monitoring requirements. • Discuss reporting requirements when complying with federal and state regulations.