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From 2012.igem.org

Project Overview

Background

The waste water treatment is an essential process. It is especially important for industries for waste discharge and water reuses and also important for muncipals. While there are different processes which are used for waste water treatment, two major processes are the conventional process and the membrane bioreactor process (MBR). The conventional process uses action of microorganisms to breakdown chemical components of effluent system. But the MBR need to be used due to growing populations. Membrane Bioreactors Process :- The MBR was developed 40 years ago and have been used commercially for almost 30 years in Japan. Apart for muncipal and industrial purposes, the MBR is also for (1)Filtration (2) Ultrafiltration (3) Microfiltration (4) Removal of salts (5) Reverse Osmosis (6) Nanofiltration (7) Irrigation. This is process uses membrane coupled aerobic bioreactors with the activated sludged system with an integrated membrane, eliminating the need for a final clarifier. There is also something known as membrane fouling which in other words is the membrane performance. This performance is dependent on the effluent quality of the biofilm reactor and it varies with the hydraulic retention time (it's the time the wastewater takes to pass through the system). Due to the increase in population, MBR must be used. Apart from this there are several other advantages MBR has over the conventional process. Some advantages of MBR are : (1) Reduction of importance of biomass sedimentation, thus allowing a significantly smaller tank compared to conventional process. (2) The biosolids which are to be treated are low dense solids, theirs rate of settlement would be slow. Thus a larger tank (more space) js required in the conventional process. (3) Consistently high effluent quality, and operational separation of solids retention time( it is the average time for the activated sludge solids to be in the system. This is usually expressed in days) and hydraulic retention time. While there are advantages too, there are disadvantages as well. (1) The membrane fouling uses aeration since fouling is best achieved by large bubbles. Thus it uses a lot of energy for aeration and compared to conventional treatment. Technical Project

Biofilms are adherent aggregates of microorganisms that develop on surfaces. They can be found in a multitude of natural circumstances (for example, the bottom of streams, inside of plants, and on teeth) and can be utilized for tasks such as water treatment. In water treatment, water is run over the biofilm, and microorganisms absorb and digest undesirable compounds. The force of the water can cause part of the biofilm to break off and become a sludge that must later be removed.

A silica barrier on the exterior of the biofilm would help to prevent sludge while still allowing the biofilm to function. Furthermore, a silica coat would act as a mechanical filter to remove any large particles from the water. In order for this silica coat to form, silica binding protein (SBP) needs to be expressed on the surface of the microorganisms. Our objective is to develop a device in Escherichia coli that will induce the expression of adhesion proteins to facilitate biofilm formation and will induce the production of SBP after a biofilm has formed.

Human Practices

In addition to the technical component of the project, an iGEM project entails a element promoting public awareness and education of synthetic biology and genetic engineering, designated "Human Practices". We are proud to represent this element of our project with our flagship effort - the foundation of the Biomaker Bench , a community biotech laboratory in Noblesville, IN. In addition, the team has been commissioned by the Central Indiana Regional Office of Girl Scouts of America to develop a curriculum for a badge in biotechnology. For more information on these projects and to view other efforts in community involvement and public awareness, visit the page Human Practices .

Collaboration

If you would like to collaborate with Purdue, please send an email to purdue.igem@gmail.com