Bio-Filtration System

Bio-filtration is a technique that uses natural systems containing living material to capture and biologically degrade pollutants. Most bio-filtration systems use plants and organic material to achieve this. Plants have large surface areas and exchange gases and water with their surroundings. Air from outside is generally filtered using the bio-filtration systems and then circulated indoors. These systems can also be used indoors to capture pollutants in the air, degrade them and then recirculate the purified air. Typical uses include processing wastewater, capturing harmful chemicals or silt from surface runoff, and microbiotic oxidation of contaminants in the air. They have numerous other benefits including

1. Reduce Exterior Background Noise

2. Reducing Demand on the Water Supply

3. Cooling

4. Reducing Levels of Certain Pollutants

5. Reducing Carbon Dioxide Levels

6. Increasing Humidity

7. Reducing Airborne Dust Levels

8. Controlling Air Temperatures

Plants are used more frequently indoors in educational facilities, healthcare institutions, workplaces, and residences to improve both mental and physical health. It is claimed that indoor plants can de-stress and are natural pain relievers. In a recent study, relations between indoor plants in classrooms and the comfort and performance of students were studied. Dutch children with plants in the classrooms had improved health of 7%. Apart from better health, they were also more creative and had 20% higher test scores. The e[m]ergy diagram, Figure 2, describes the bio-filtration system interlaced with HVAC and occupant control. The indoor air consists of heat from equipment, people, and lights. The equipment that produces heat gains can be divided into devices that use natural gas or electricity generated from renewable or non-renewable resources. Both of which have very high-energy intensities. By combining the e[m]ergy intensities of the heat sources as well as those previously accounted by the envelope and air conditioning systems, we get a full spectrum of energy quantities that account for the internal heat gains. A persistent challenge, however, is to achieve the minimum thermodynamic levels without a significant increase in energy costs while delivering the services of the building typology.

From the e[m]ergy diagram, figure 2, it can be inferred that air that is filtered by the bio-filtration systems is only as good if it can exhaust or recycle the air with the plants and the exterior ecosystem. This is to ensure that the contaminants of the atmosphere are processed, and the waste is expelled. As well as to maintain a healthy balance of a mix of gases. The main benefit of using bio-filtration systems in a dense, urban environment is the removal of pollutants. For a highly e[m]ergy intensive building in an urban environment that relies on mechanical ventilation, the air that is circulated indoors is the air that is rich with contaminants from the exhaust, off-gassing, and pollution from the outside. These pollutants are a considerable strain on the local ecosystem as they are cleaned by natural organisms as fast as it is being generated. Thus, even with the assistance of filters, mechanical systems will circulate stale air indoors. By incorporating natural organisms into HVAC systems, the air can be replenished in a way that cannot be achieved through purely mechanical ventilation systems and a rate that cannot be matched by just natural or passive ventilation systems.