Heavy Metal in Your Water?

Wastewater is polluted with organic pollutants and heavy metals that is being discharged into a wide range of environments, leading to an accumulation of non-biodegradable toxic buildup. To combat this problem, efforts are being made to create a method of combining the use of light as a catalyst and using electrical currents to reduce the dissolved metal cations that for in the polluted water. Using sunlight as a catalyst is also explored in this newly emerging study that could one day be used together to simultaneously remove heavy metals and organic pollutants from wastewater so that it may be recycled and reused. 

 Source: http://thewatchers.adorraeli.com/2011/08/19/heavy-metal-in-and-around-the-lakes/

References

Kim, G., Igunnu, E. T., & Chen, G. Z. (2014). A Sunlight Assisted Dual Purpose Photoelectrochemical Cell for Low Voltage Removal of Heavy Metals and Organic Pollutants in Wastewater. Chemical Engineering Journal, 244, 411-421. doi:10.1016/j.cej.2014.01.090

Rocks Giving Energy? What?

 

Solar energy can increase a country’s energy security through reliance on an indigenous, inexhaustible resource, enhance sustainability, reduce pollution, lower the costs of mitigating global warming, and keep fossil fuel prices lower.  Traditionally, the energy is stored in tanks with beds of packed rock but rock expands and contracts with changes in temperature.  The movement of rock, called “thermal ratcheting”, stresses the walls of the storage tank and can cause it to break.  A new method to store the energy consists of a quartzite-rock bed that is charged with hot air flow and discharged by cold air counter-flow, essentially turning the storage into a generator.  This storage method (essentially returning the energy the grid) benefits the solar industry through significantly reduced energy storage costs which in turn benefits the country and its people.

References:

Mertens, N., Alobaid, F., Frigge, L., Epple, B.  Dynamic simulation of integrated rock-bed thermocline storage for concentrated solar power.  110 (2014) 830-842.  doi:10.1016/j.solener.2014.10.021

December 5, 2014

Waste Treatment should be a Smart Treatment

                                                     Figure 1. Toy Story 3 Incinerator  

Source: http://54disneyreviews.wordpress.com/page/8/

           Biological waste treatment is utilized as a management system that is made to decrease the environmental impact and use of resources. These management system’s purpose is to omit waste in the most efficient and economic way. Three different conditions were designed to treat solid waste with conventional sewage treatment: incineration with heat recovery, composting, and anaerobic digestion. Anaerobic digestion was found to have the lowest environmental impact of all three solid waste management systems, yet it was expensive. The cheapest way to treat solid waste is with incineration with heat recovery. On the other hand, composting has environmental advantages compared to the incineration and has no significant increase costs. Therefore, composting is more sustainable to the environment and economically favorable. 

Article used:
Sonesson, U., Bjorklund, A., Carlsoon, M., etc. Environmental and economic analysis of management systems for biodegradable waste. ScienceDirect, January 2000. Web. 29 Nov. 2014. http://www.sciencedirect.com/science/article/pii/S0921344999000294

Natural farming

The degradation of grasslands via overgrazing negatively affects the environmental and animal husbandry. China has decided to assess the issue by restoring degraded grasslands. Unfortunately, china’s efforts were economically unfavorable. The experiment conducted involved the utilization of natural grasslands to both house and feed chickens to replace the traditional husbandry system. It was determined that the new approach improved surface soil water content and the above plant biomass was not decreased (Liu et al, 2013).This approach increases environmental sustainability by decreasing degradation of grasslands. It is also more economically favorable approach. Furthermore, it has given degraded grasslands the opportunity   to regenerate, and has resulted in the farming of organic poultry.  

Source: 

http://www.realgreenlawns.com/austin_tx_texas/yellowing_st_augustine_grass.htm

Citation:

Liu, M., Wang, B., Osborne, C. P., & Jiang, G. (January 01, 2013). Chicken farming in grassland increases environmental sustainability and economic efficiency. Plos One, 8,1.)

Plants Can Clean?

 

Phytoremediation is the use of plants to treat environmental problems, such as contaminated soils, without excavating the contaminant material and disposing of it elsewhere.  The plants able to accomplish this mitigate the concentrations of the pollutant is contaminated soils, water, or air contain, degrade, or even eliminate the contaminants from the media.  The contaminants that can be mitigated in this fashion include metals, pesticides, solvents, explosives, crude oil and its derivatives.  Phytoextraction is a sub-process of phytoremediation.  This sup-process uses trace element-accumulating plants to concentrate the contaminant in the plant’s tissues.  The contaminants are then removed from the medium by harvesting the plant.

References:

Sessitsch, A.; Kuffner, M.; Kidd, P., Vangronsveld, J., Wenzel, W.W., Fallmann, K., Puschenreiter, M.  The role of plant-associated bacteria in the mobilization and phytoextraction of trace elements in contaminated soils.  60 (2013) 182-194.  doi:10.1016/j.soilbio.2013.01.012

December 5, 2014

Lindane will no longer linger

Lindane is a chemical that was often used by farmers as a pesticide and insecticide. Lindane has been banned because it is considered toxic and can negatively affect organisms. Unfortunately, Lindane has low solubility and high persistence which is seen as environmentally unfavorable. A scientific study conducted determined that Iron nano particles have the capability to degrade Lindane. Furthermore, the iron particles were able to transform the Lindane into less harmful substances. This advances environmental sustainability because the iron nano particles are able to safely remove an environmentally unfavorable chemical from the environment. The accumulation of the iron nano particles does not occur because they increase the degradation of the Lindane (2014).

Source: 

http://www.theresiliencyinstitute.net/wp-content/uploads/2013/05/Hands-holding-soil.jpg

Citation

Iron nanoparticles degrade lindane to clear up environmental pollution. (January 01, 2014). Trends in Analytical Chemistry, 53

Don't Just Wear Your Silver, Drink It.

Silver “nanopatches” are made into a ceramic porous media to help disinfect water. Two types of clays were used: 1) Redart’s clay composed of minerals illite and kaolinite 2) South Africa clay: composed of smectite minerals. Figure 2A demonstrates the reduction of E. Coli for both types of clay and Figure 2B demonstrates the low levels of Ag EPA approved (<0.1 mg/L). Also, these nanopatches were used for 154 days showing no change in Ag release (Figure 5).

Figure 2A demonstrates the correlation of the E. Coli Reduction as time progressed using both the South African and Redart's nanopatches.

Figure 2B demonstrates the total number of Silver released, not changing much as time passed for both the South African and Redart's nano patches. 

Figure 5 demonstrates a linear linear line of the amount of silver being released over a period of 154 days. This indicated the reusability of these nanopatches for a minimum of 154 days.

The benefits of this study were the reusability of these nanopatches, the fact that Ag levels disinfect better than chlorine, and it is cheap to produce ($2 U.S.D). The costs of this renovations is that it is dependent on the user and needs to be studied in vivo.  However, this study is important because it can be taken to countries where water is not highly sanitized, being inexpensive and reusable.

References: 

Ehdaie, B., Krause, C., & Smith, J. A. 2014. Porous Ceramic Tablet Embedded with Silver Nanopatches for Low- Cost Point-of-Use Water Purification. Environ. Sci. Technol. 48: 13901−13908.