Microbial Desalination

Today, desalination is a common process that's used in seaside cities and towns worldwide. There are more than 15,000 desalination plants around the world providing freshwater from salt and brackish water alike (Planet Green 2011). This number continues to grow as researchers work to improve the process, both in terms of cost effectiveness and energy efficiency (DSE 2011). But countries such as Australia, Israel and even the United States are continually adding desalination plants of various sorts into their water-management portfolios. The facilities are common in North Africa and the Mideast, where freshwater is scarce (Chandler 2008).

The microbial fuel cell (MFC) is an upsurging technology in the field of bio-energy generation along with wastewater treatment. The microbial fuel cell generates energy with the help of microbes that makes it green future source of energy. In MFC, anaerobic microbes degrade organic matter and produce hydrogen ions (H+) and electrons (e-) at the anode. H+ ion diffuses through the proton exchange membrane (PEM); and e- are transported through an electrode via an external circuit to the cathode. At a cathode, e- and H+ ions combine with oxygen to form water (H2O), this results in power generation [1]. MFC has limited open circuit voltage (OCV) of 1.14 V because of the standard redox potential of NADH/ NAD+ and O2/H2O of -0.32 V and +0.82 V

Since proton takes part in the oxidation of MTX, the pH value of solution will greatly influence the Ipa [45]. The effects of stripping pH value of the PBS buffer solution on the electrochemical performance of MTX were also tested with the pH varying from 3.0 to 9.0 using 0.05 M PBS buffer and theresults were depicted in Fig. 9.The results showed a maximum of Ipa when the buffer solution pH was 4.0 (Fig. 9). Therefore, in subsequent experiments, the stripping was carried out in 0.05 mol L-1 phosphate buffer with pH

The earth seems is drying up in certain areas of the world at the moment. We have already seen some of the hottest summers on record in the last decade. Summer 2016 was the hottest summer on record since the records were started back in 1880 (Doyle, 2016). The effects of this heat have manifested themselves as drought in areas of the western United States. One of those areas happens to be our home of Southern California. Water resources have slowly declined and conservation has been the key tool to battle the decline. In an effort to find new ways of conserving or creating fresh water supplies, technology has been called upon. The need for technology that can help us meet our fresh water demands becomes more important every day. One of the technologies that has gotten a lot of attention recently is desalination. In fact a large scale desalination plant was just opened in Carlsbad, Ca. The facility is capable of delivering 50 million gallons per day (MGD) (Bienkowski, 2015). Despite this impressive achievement the plant still only accounts for 8% of the total water demand in San Diego County (CDP, 2016). In this paper I will explain the process of desalination, identify a promising new technology, and provide a comparison of technologies.

Freshwater is the most essential renewable resource for life, food production and industrial development. It is expected in the future soon the clean water resources will be deducted by one-third. The difficulty to purify water and the high cost to transport aggravates the problem of water deficits. Therefore, the exploitation of seawater and brackish-water desalination has drawn unprecedented attention. Desalination is a possibility choice to produce drinking water from Saline water, although most desalination processes are energy-consuming and expensive. The main desalination technologies currently used are reverse osmosis, electrodialysis, and distillation. A drawback of the conventional desalination technologies is the intensive consumption of energy. Whereas, energy consumption has increased with an enormous trend In the last decades. Fossil fuels are a common type of non-renewable which include a huge portion of energy consumption. Despite of being nonrenewable, fossil fuels also negatively affect the human life by the emission of carbon dioxide. This limitation turn energy crisis eyes into renewable energy sources such as solar energy or energy produced from wind and water. As a result, one of the lately suggested alternative energy sources is fuel cell (FC). FC has several advantages over other types of energy generators such as zero pollution and higher efficiency.

Desalination and water reuse possess their own process and require different level of energy and material. According to Côté et al.

The process of desalination can be described as any process that removes salts and other mineral particles present in a salt water environment from water. Desalination processes can help variety of industries as well as human consumption. In the very beginning desalination processes were associated with much higher costs but since the massive researched and improvements in the technology started happening, desalination processes started competing with less expensive methods for cleanliness of water (Krishna, 1). Two distinct techniques for water treatment processes use either electrical-driven or pressure-driven technologies. For the purpose of this technical report the main focus will revolve around pressure-driven membrane operation which will encompass four overlapping membrane types. These categories compiled of Reverse Osmosis, Nanofiltration, Ultrafiltration and Microfiltration (Pangarkar, Sane, Guddad, 2011).

Desalination is the removal of salt from seawater to provide freshwater especially in developing countries. Currently, MFCs (Microbial Fuel Cells) have generated electricity from biomass using bacteria. These microbes cause an electric current where electrons flow from the anode to the cathode where the reduction of oxygen occurs. A revolutionary new method called MDCs (Microbial Desalination Cells) could potentially desalinate water and produce energy depending on the design or set up of the cell. This process is similar to water electrodialysis but uses bacteria as the source of energy rather than an external source.

Distillation is a process which is used to obtain fresh water from salty, brackish or contaminated water. Without fresh water human life is not possible even industries and agriculture also need fresh water. Earlier fresh water is easily available from rivers, lakes and ponds in plenty. Now it’s becoming scarce because of industrialization. Growing population leads to assumption that by the year 2025 two thirds of the population will lack sufficient fresh water. The areas with the water shortages are the warm, arid countries in the northern Africa and southern Asia within the latitudes 15-35ºN. Sunlight is one of several forms of heat energy that can be used to power the process of water purification. It is difficult to use solar thermal energy in large scale plants because of low thermal efficiency and considerable land area

The availability and patterns of nutrient uptake in biofilms differs from that of planktonic cells. The bacterial cells in biofilms exchange nutrients and metabolites by means of water channels between the micro-colonies (Kokare et al., 2009). The microbes living deep within natural biofilms may often receive low nutrition due to restricted rates of diffusion of nutrients through the biofilm (Petroff et al., 2011). Biofilms are also known to provide a suitable environment for syntrophic relationships between the two metabolically distinct bacteria for the exchange of substrates/nutrients (Kokare et al., 2009).

In view that future application would most likely be based on the use of multiple modules connected together instead of one large reactor, the MDC module in this study was made up of 30 individual tubular MDCs. Each MDC consists of one anion exchange membrane (AEM) tube inside the cation exchange membrane (CEM) tube. Two ways of parallel connections of the MDC were investigated. One way was via combined connection whereby all the anodes or cathodes are connected to form one anode or cathode (total 1

Nowadays, the most common commercially FO membrane has been the asymmetric CTA membrane. In spite of the CTA membranes have proper characteristics that including high chlorine resistant and high hydrophobicity, they possess some drawbacks that hinder the future development. The CTA membranes have limited stability to pH, temperature and microorganisms. Accordingly, the feed and draw solutions must be maintain at pH between 4 and 6 and temperature below

Wastewater treatment is an energy intensive process, consuming about 1,900 kJ/m3 of treated wastewater [22]. Wastewater contains almost 9 times more energy than the energy used to treat an equivalent volume, thus creating the need to harness this energy through the use of a Microbial Fuel Cell (MFC) [22]. Microbial Fuel cell (MFC) is a device designed for electricity generation in the process of wastewater treatment [23]. Microbial fuel cell is a new form of renewable energy, which uses bacteria in wastewater to convert organic matter into electricity, while simultaneously treating the wastewater. MFCs can provide an answer to several of the problems which traditional wastewater treatment faces. They enable the recovery of energy out of the wastewater, while limiting both the energy input and the excess sludge production [24].

The present has brought many benefits like new technologies. But along with benefits, the present also brought consequences. One consequence would be the pollution in the atmosphere and environment. Scientists have come up with many alternative energy methods like wind power, solar power, and tidal power. Along with those sources of energy comes a form of energy not yet implemented into the system.High energy requirement of conventional sewage treatment systems are demanding for the alternative treatment technology, which will be cost effective and require less energy for its efficient operation. In addition, due to global environmental concerns and energy insecurity, there is emergent interest to find out sustainable and clean energy source.[3] One such method is This method uses microbial fuel cells (MFCs). A microbial fuel cell (MFC) is a bioreactor that converts chemical energy in the chemical bonds in organic compounds to electrical energy through catalytic reactions of microorganisms under anaerobic conditions, [6]meaning Microbial Fuel Cells function by the reduction of oxygen or nitrates. This process can only generate electrical energy if it is performed under anaerobic conditions. While creating energy, this process can also simultaneously treat wastewater. Since this process is able to both treat water, supply

Water is the world’s most natural resource and without it there would be no life on earth. Nature limits our available supply of water. Virtually all of human uses require fresh water. 97% of the Earth’s water is salt water and only 2.5% is fresh water of which over two thirds is frozen in glaciers and polar ice caps. The unfrozen freshwater is mainly ground water with only a fraction on the surface. Fresh water is a renewable resource but the world usage of clean water is resulting in a steadily decreasing supply. There is a process know as Desalination which is an artificial process by which saline water (sea water) is converted into fresh water. This process is known as reverse osmosis.