Solar Windows

Solar technology has been used to produce heat and electricity. Solar PV panels are installed on the roof of a building to produce household energy. Solar technology can be applied as a solar window for energy production and conservation. Heat and energy exchange occurs through windows of a house in different ways. Non- solar heat losses and gains in the form of conduction, convection and radiation, solar heat gains in the form of radiation, ventilation and infiltration are possible pathways of energy exchange through windows (US Department of Energy, 2007).

Rate of transfer through the windows is measured as thermal transmittance or U-factor. Low U-factor of a window denotes less heat exchange through the windows which conserves energy allowing consistent and comfortable room temperature (NHPC, n.d.). Solar heat gains through the windows in the form of radiation is measured by Solar heat gain coefficient (SHGC) and lower the value of SHGC, lesser the amount of solar heat transmitted through the window(NHPC, n.d.).

Solar window technologies have been developed to improve the energy efficiency. Building-integrated photovoltaics (BIPV) technology uses a transparent solar panel with standard mono-crystalline PV cells (Martin, 2011). BIPV solar windows have lower U-value and generated energy using PV cells (Martin, 2011). Passive solar design techniques can be applied to new homes to collect and store solar heat passively. Passive solar de-sign includes direct gain or the application of transparent south facing windows to collect heat, indirect gain or the thermal storage of collected heat between the south-facing windows and the living spaces mostly using a Trombe wall and isolated gain or sunspace similar to greenhouse (US Department of Energy, 2001).

References

Martin II, J. (2011) Solar PV Windows: BIPV Technology by Pythagoras Solar [Online] Available at http://www.solarchoice.net.au [Accessed on 23 October 2014].

National Home Performance Council (NHPC) Understanding Energy Efficient Windows [Online] Available at http://www.nhpci.org [Accessed on 23 October 2014].

US Department of Energy (2001) Passive Solar Design for the Home [Online] Available at http://www.nrel.gov [Accessed on 23 October 2014].

US Department of Energy (2007) Selecting Windows for Energy Efficiency [Online] Available at http://www.windows.lbl.gov [Accessed on 23 October 2014].

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Bio-augmentation

Microorganisms can be used to degrade waste pollutants in bio-augmentation process. Bio- augmentation is a sustainable approach to pollutant remediation. Bio-augmentation is a mimic of natural process, it uses less energy, it releases less air pollutant and it helps to destroy the contaminants permanently (Environmental Expert, 2009). Effectiveness and affordability of bio augmentation, a powerful remediation measure, has been proved in the past few decades.

Pre-adapted native microbes or genetically modified microorganisms have been used in bio augmentation for pollution biodegradation (Nasseri et al., 2010).  Bacterial species such as Pseudomonas, Flavobacterium, Sphingobium, Alcaligens, Achromobacter, Rhodococcus, Mycobacterium, Bacillus and Fungal species such as Absidia, Achremonium, Aspergillus, Verticillium, Pencillium and Mucor have been applied to degrade pollutants (Gentry et al., 2004; Mrozik and Piotrowska-Seget, 2009).

Biodegradation of compounds such as nitrophenols, chlorinated solvents, methyl tert-butyl ether, oil, pentachlorophenol, polychlorinated biphenyls, polycyclic aromatic hydrocarbons and pesticides such as atrazine, dicamba and carbofuran has been carried out with microorganisms induced bio-augmentation (Gentry et al., 2004).  Effective bio augmentation technologies include cell culture, activated soil bio-augmentation, gene bio augmentation and phytoremediation (Gentry et al., 2004).

Factors such as contaminant concentrations, site hydro geochemical conditions, and competition with indigenous microorganisms, in situ growth, transport and decay of microbes affect the amount of microorganisms needed for remediation which ultimately affects the cost and performance associated with bio augmentation (Steffan et al., 2010). Temperature, moisture, pH, organic matter, aeration, nutrient content and soil type are determining factors for bio augmentation (Gentry et al., 2004; Mrozik and Piotrowska-Seget, 2009).

References

Cornelius, J. R. and Faigle, J.D. (2008) Bio-augmentation: An Effective Method for Reducing Contaminant Concentrations. [Online] Available at http://www.biovationenv.vom [Accessed on 11 October 2014].

Environmental Expert (2009) Bio-augmentation is a cost effective and sustainable remediation alternative [Online] Available at http://www.environmental-expert.com [Accessed on 23 October 2014].

Gentry, T.J., Rensing, C., Pepper, I.L. (2004) New Approaches for Bio-augmentation as a Remediation technology. Reviews in Environmental Science and Technology, Vol 34, pp. 447-494.

Mrozik, A. and Piotrowska-Seget, Z. (2009) Bio-augmentation as a Strategy for Cleaning up Soils Contaminated with Aromatic Compounds. Microbiological Research, Vol 165(5), pp. 363-375.

Nasseri, S., Kalantary, R.R., Nourieh, N., Naddafi, K., Mahvi, A.H. and Baradaran, N. (2010) Influence of Bio-augmentation in Biodegradation of PAHs-contaminated soil in Bio-Slurry Phase Reactor. Iran Journal of Environmental Health, Science, Engineering, Vol 7(3), p. 199-208.

Steffan, R., Schaefer, C. and Lippincott, D. (2010) Bio-augmentation for Groundwater Remediation [Online] Available at http://www.clu-in.org [Accessed on 12 October 2014].