Wastewater Pollution: Comparing Three Treatment Methods - Research Proposal Example

?Wastewater Pollution: Comparing Three Treatment Methods Wastewater comes as a result of an industrial process that has added chemicals and biosolids that are harmful to human health and to the environment. Whole ecosystems have been destroyed because of the mishandling of wastewater in the past. Three methods of treating wastewater which can be tested against one another for effectiveness and costs are the activated sludge method, the reed bed method, and a new method that has just been discovered in Australia which consists of adding hydrotalcites to wastewater or encouraging hydrotalcites that already exist in the water to form. The three methods can be compared in order to establish their effectiveness and costs as they relate to the removal of contaminants. In addition, the water that has been treated can be compared for quality and value once the contaminants have been removed through these methods. The following research study proposal discusses the use of these three methods as a means for treating wastewater. Through a comparison of their effectiveness, the value of the methods can be discussed after examining the results of using these methods. In addition, comparing the costs monetarily, to the environment from the use of energy and resources, and to the companies who use these methods can be evaluated. Hypotheses and Specific Aims The activated sludge method uses bacteria to treat wastewater before reintroducing it into the environment. The reed bed method is a natural method of removing biosolids from wastewater, creating a method of extraction. Wang writes that “biosolids from wastewater treatment plants are applied to an actively growing stand of a common reed under controlled conditions. The growing reeds derive moisture and nutrients from the biosolids, and with time the rooted plants and the accompanying root ecosystem alter the characteristics of the biosolids” (138). The result of this process is that the condition and the biosolids have improved characteristics. The use of hydrotalcites is a new method created this year in order to assist mining operations in removing contaminants in wastewater. These three methods all provide for cleaning wastewater so that it can be reintroduced back into the environment. While all three methods of approaching the pollutants in wastewater are effective, a comparison of the three processes will lead to further understanding of how safe wastewater is when it goes back into the environment. This is essential in order to produce the safest possible agricultural results so that pollutants do not contaminate the food supply. While modern life includes the results of air, water, and ground soil pollution as a persistent problem, it is clear that there is a high level of concern with decontaminating from previous damage to the soil and water, as well as preventing further damage. Using experimentation under controlled conditions provides invaluable information towards protecting the environment from the effects of contaminated wastewater when it can be treated and reintroduced under safe conditions. Aims: The specific aim of this project will be to compare the results of the activated sludge method, the reed bed method, and the use of hydrotalcites as a method of removing contaminants from wastewater. In addition to measuring the methods for removing contaminants, the condition of the water after the use of these three methods will be measured. The condition of these three methods of wastewater treatment will be examined for the costs to the environment in terms of energy used to provide the treatment, waste that must be disposed of after the treatment and any other impact that might affect environmental balance. Recommendations for using the methods will be made in relationship to effectiveness and costs. Hypotheses: Hypothesis 1: The reed based method proves to be the most effective in terms of environmental costs and overall effectiveness. Alternative Hypothesis 1: The reed based method does not prove to be the most effective in terms of environmental costs and overall effectiveness. Hypothesis 2: The activated sludge method is the most costly both in monetary and environmental costs. Alternative Hypothesis 2: The activated sludge method is not the most costly in either monetary or environmental costs. Hypothesis 3: The hydrotalcites method is the most time effective method for removing contaminants from wastewater. Alternative Hypothesis 3: The hydrotalcites method is not the most time effective method for removing contaminants from wastewater. Background and Significance Wastewaters that come from a variety of resources contaminate the water system and the soil, creating problems in agriculture where the food that is then grown embodies the pollutants from the resources in which it has been grown. A large percentage of wastewater is never fully cleaned, its chemical pollutants remaining in the water and being spread throughout the ecosystem. The other problem that can occur is that the chemicals used to clean the waters that come from various sources can be also polluting and ruinous to the environment. There are a number of different methods for treating wastewater. Much of it is treated in wastewater treatment plants that use a great deal of energy in their processing, further damaging the environment.1 Surfactants become a part of the environment when they are discharged into the soil and bodies of water through treated wastewater. In order to understand the effect of the surfactants on the ecosystem, it is necessary to understand their behaviors. Sorption of a surfactant is dependent on a variety of factors, including the physiochemical properties, parameters within the environment, and the nature of the sediment and soil. Surfactants undergo sorption in soil, sludge, and sediment in a specific order: “cationic>non-ionic>anionic”.2 Without effective treatment, the soil and water that is used in agriculture can become contaminated with chemicals that are yet to be understood for how they can have an effect the body. Further exploration of the treatments that are being used for treating wastewater is essential in order to learn how to clean water so that it is at its optimum level of clarity. Agricultural practices are often the cause of contamination of waters, creating wastewaters in natural environments. Terrado, Barcelo and Tauler found that the Ebro River was contaminated through local agricultural practices, creating problems within the ecosystem. The contamination pattern was shown to include high levels of polycyclic aromatic hydrocarbons with a pyrolitic origin. In addition to this problem, past industrial activities that had created a large amount of untreated wastewater has contaminated the river on a long term level.3 This example shows that untreated wastewater and poor agricultural practices can create problems in large bodies of water that will affect the regions that exist all along its path. This is why it is crucial for experimental study to be continual in order to improve processes. One of the most significant water treatment processes for wastewater is the activated sludge process. The activated sludge process is based on using microbiological means in which to treat wastewater so that the pollutants are neutralized (Rosenberg 27). Wastewater treatment through this method includes monitoring bacteria that is use to degrade nitrogenous wastes, which are considered nitrifying bacteria. It also includes bacteria that are used to degrade carbonaceous waste which means the removal of cBOD. Monitoring these bacteria is essential in order to make sure that changes in operations do not create changes in the bacteria that will affect is efficiency or worse, further the contamination.4 One of the most common forms of an organic nitrogen compounds is urea, which is expressed as NH2CONH2. This is common urine. In fresh water urine will degrade quickly through the process of nitrification which means that oxygen infiltrates the ammonium ion, splitting them from carbon dioxide (CO2).5 Activated sludge methods were used by Li and Zhang in order to remove antibiotics from freshwater systems where contamination was found. Targeting eleven different antibiotics, the activated sludge method was used through a biodegradation system for both fresh water and saline sewage water. Erythromycin-H20 could not be removed through the activated sludge system, leaving the water contaminated. Li and Zhang write that “Divalent cations (Ca2+ and Mg2+) in saline sewage significantly decreased the adsorption of the three fluoroquinolones onto activated sludge. These three fluoroquinolones also exhibited certain biodegradability in the saline activated sludge reactor”.6 Reed beds are constructed to emulate nature. The process was first created in the 1960s and 1970s at the Max-Planck Institute of West Germany. The original system was intended for dewater wastewater from biosolids, but in 1980 it began to be used to dewater biosolids as well. The following is a breakdown of how reed beds are constructed in order to be used for the process: Bed construction is similar to that of sand drying beds. Often retro-fitted sand drying beds are used. Excavated trenches are lined with an impermeable material and filled with two sizes of gravel and a top layer of filter sand Reed root stock or small plants are planted in the sand layer, and the trenches are flooded to promote reed growth A 1-m freeboard above the sand layer is provided to allow for long-term biosolids storage. After plants are well established, stabilized, thickened biosolids (3% to 4% solids) are applied to the bed in 10cm (4in) intervals Annual harvesting of reeds and their disposal by landfilling, burning or composting is required. Biosolids are not removed regularly. Biosolids removal cycle time is 6-10 years.7 Another process that has been recently discovered in Australia is a method of adding hydrotalcites, which are layered minerals that have aluminium and magnesium. The discovery that Dr. Grant Douglas found was that if you encourage growth of hydrotalcites in wastewater it will remove a wide variety of contaminants as it solidifies. This creates a one step process which traps the contaminants which can then be very easily removed. Dr. Douglas states that “Mining wastewater often contains substantial magnesium and aluminium concentrations. This means that we can create hydrotalcites utilising common contaminants that are already present in the wastewater, by simply adjusting their concentrations and adding alkaline compounds to rapidly increase the pH level.”.8 The process has successfully removed contaminants that include rare earth elements, uranium, transition metals, anions, and metalloids. Centrifugation has been used in order to remove the hydrotalcites, which leaves less sludge which is far cleaner than other methods such as adding lime which is a common method for mining operations to clean their wastewater. The initial tests have shown that around 80 to 90 percent less sludge than comes from using lime treatments which lessons the amount of handling and disposal in the end. Dr. Douglas went on to suggest that “Around the world the minerals industry is keen to find more efficient ways to treat their wastewaters and reduce their environmental footprint. With the inherent technical advantages and added benefits of using hydrotalcites, there’s a high likelihood of the mining industry adopting this technology globally”.9 Disposing of wastewater is a difficult problem with a variety of costs which include monetary cost and environmental costs. While most industries that create wastewater are regulated, with requirements for onsite facilities to treat wastewater, the compliance level and the effect of treatment is subjective as to whether or not they truly protect the health and well-being of people who live near those plants. In addition the effect on ecosystems must be continually monitored to protect and maintain systems that are likely interrelated to systems that connect to agriculture. Research Design and Methods The research design will include methods of testing the effectiveness of each of the three methods that are being examined. An experiment will be conducted to create primary data on the use of the three methods and their effectiveness on wastewater treatment. In addition, primary data will come from a survey done of industries on the costs that are associated with their methods of wastewater treatment. Finally, secondary research will give depth and meaning to the raw data that is collected in relationship to the aims of the study. In discovering both the effectiveness and the costs of the treatment systems, it will be necessary to place that information in to context. A recent article from the University of Gothenberg suggests that the activated sludge process can benefit from introducing alternating high and low nutrient levels to the bacteria that is being used. A dissertation on this method was successfully defended by Robert Almstrand.10 Secondary Research Secondary research will be used in order to both enhance the experimental section of the research and to examine the costs associated with the three methods of wastewater treatment that are being examined. Van, Meyer, and Sebranek discuss the purpose of secondary research which is to become symbiotic to the primary research. Van Meyer and Sebranek write that “understanding the symbiotic relationship between primary and secondary resources is just as important as understanding the two source types themselves”.11 Primary research is intended to create raw data from which to support hypotheses, while secondary research is used to give depth and meaning to the raw data. In this research study secondary research will be compiled and examined in order to understand the costs associated with each of the methods of wastewater treatment. Survey Instrument In addition to secondary research, primary research will be used to determine costs to specific industries. This research will conducted through a survey instrument constructed for the purpose of this study and first tested through a brief pilot study. The instrument will be used as a tool to examine the costs that are experienced by different industries as they treat wastewater. The instrument will be given through an interview process, but the answers will be numerically defined so that they can be examined through SPSS software to search for frequencies and means. Experiment The experiment that will be used for this study will require an identified contaminant be introduced into water, and then three methods used in order to clean the contaminant from the water. This will require setting up a station that for each of the three methods of wastewater treatment, including the growth of a small reed bed. The first station will provide a place in which to use bacteria to clean the contaminant from the water. The second will be a reed bed that has been constructed, with the third being a place where hydrotalcites can be encouraged to form. The typical layout of the activated sludge process is shown in Figure 1. Additional layouts are shown in Figure 2.12 Figure 1: Typical Activated Sludge Layout 13 The first step in the experiment process will be to establish the three stations, which will mean creating a small reed bed and allowing it tine to grow. Once the three stations are prepared, the experiment can begin. The first station consists of the activated sludge method which will then be examined though mathematical modeling as described by Reiger in relationship to the costs that are involved and are the result of this experiment along with the survey results and the secondary research results (11). This examination will provide context for the effectiveness of the method in comparison to the costs that are associated with using this method. Oxidation in order to nitrate the nitrifying bacteria will be done on a rotating cycle of high levels to low levels before examining the biosolids that are left behind.14 Ammonia will be the contaminant and the bacteria will be found at a fish supply outlet. The following is the Activated Sludge process and information on the equation: Sludge Age Many consider sludge age to be the key activated sludge operating parameter. Sludge age is the average solids retention time in the biological treatment process. The solids retention time is equal to the mass of solids in the aeration tank divided by the mass of solids leaving the system (waste activated sludge solids) each day. The sludge age is calculated as shown in Equation 1.15 Equation 1: Sludge Age Formula Where, Rs = sludge age, days V = aeration tank volume, million gallons X = mixed liquor suspended solids concentration, mg/L Qw = sludge wasting rate, million gallons per day Xu = solids concentration of the waste sludge, mg/L16 The second station is the reed bed through which the wastewater will be filtered in order to seek the biosolids that will consist of the filtered contaminants. The third station was prepared with Mg–Al -based hydrotalcite with a Mg2+/Al3+ molar ratio equal to 2.17 The method used by Alves, Stefani, Parizotto and Souza Filho was to stir for 2 hours after which the solid matter was centrifuged out of the water.18 The water will be tested for contaminants before and after the experiment in order to define whether or not any progress has been made through the use of the various methods. Whether or not ammonia is removed will be tested through water testing kits that are readily available on the internet. One of the potentials is that the hydrotalcite method will not remove the ammonia. If this is the case, then secondary research on the effectiveness of this method will be used to supplement the experiment. The aim of the research is to determine the effectiveness of these methods, but the hydrotalcite method is still relatively new and will require some leeway in its effectiveness for this contaminant. Works Cited Activated Sludge Process. 2013. Web. 25 June 2013. AJM. “CSIRO Develops New Wastewater Treatment”. Australian Journal on Mining, 13 June 2013. Web. 22 June 2013. Alves, O. L., D. Stefani, N. V. Parizotto and A. G Souza Filho. “Hydrotalcites: a Highly Efficient Ecomaterial for Effluent Treatment Originated from Carbon Nanotubes Chemical Processing. Journal of Physics. 304 (2011): 1-8. Gerardi, Michael H. Nitrification and Denitrification in the Activated Sludge Process. Hoboken, NJ: John Wiley & Sons, 2001. Print. Li, Bing, and Tong Zhang. "Biodegradation and adsorption of antibiotics in the activated sludge process." Environmental science & technology 44.9 (2010): 3468-3473. Lichtfouse, Eric. Organic Farming, Pest Control and Remediation of Soil Pollutants. Dordrecht: Springer, 2009. Print. “New Methods for Purification of Wastewater”. Phys.org. 5 March 2012. Web. 19 June 2013. Orhan, D. & Arten, N. (2013). Modeling of activated sludge systems. London: Routledge. Rieger, Leiv. Guidelines for Using Activated Sludge Models. London: IWA publishing, 2013. Print. Robinson, Kevin G. Use of Novel Techniques to Quantify Phenotypes in Biological Treatment Processes. Alexandria, VA: Water Environment Research Foundation, 2004. Print. Rosenberg, Eugene. Microorganisms to Combat Pollution. Dordrecht: Kluwer Academic. Publ, 2012. Print. Terrado, Marta, Damia Barcelo, and Roma Tauler. "Multivariate curve resolution of organic pollution patterns in the Ebro River surface water–groundwater–sediment–soil system." Analytica Chimica Acta 657.1 (2010): 19-27. Van, Rys J, Verne Meyer, and Patrick Sebranek. The Research Writer: Curiosity, Discovery, Dialogue. Boston, MA: Wadsworth, 2012. Print. Wang, Zhao-Wen. Molecular Mechanisms of Neurotransmitter Release. Totowa, N.J.?: Humana Press, 2008. Print Read More