Introduction
Forward osmosis and vacuum membrane distillation are common tailing water treatment methods. In forward osmosis, the solvent is passed through a tube of varying concentrations. During the process, solutes move from a region of low concentration to high concentrations. In thermal membrane distillation, a combination of membrane technology and phase change is used. As a result, volatile organic compounds are separated from the aqueous region. The solid organic compounds are redirected to the tailing ponds. Vacuum membrane distillation is applied in water tailing and purification processes (Howe & Hand, 2012).
Despite the benefits of the two water tailing treatment technologies, a number of challenges limit their application. The two techniques are affected by technical, safety, and environmental concerns. These challenges remain the major setbacks to the adoption of the two technologies in water tailing treatment. This report will discuss the technical, environmental, economic, and safety concerns facing water tailing technologies (Xie & Nghiem, 2013).
Environmental challenges
There are many environmental impacts and challenges associated with the treatment of tailings water. For example, the need for a tailings pond affects the environment. Existing tailing ponds cover a large surface area. This is a major environmental hazard to the people living near the treatment plants. Other environmental challenges also arise during the operation of the tailings pond. For example, the bottom that consists of clay and water takes longer to settle.
The prolonged solidification process affects the growth of planktons on the water surface. The extraction stage also contaminates the remaining water portion with oil and natural chemicals. This affects the survival of aquatic organisms, such as fish in the tailing pond. Oil masks the upper surface of the pond and reduces air circulation in the water. Some extraction chemicals are poisonous to fish and the aquatic planktons (Howe & Hand, 2012).
Tailing water increases the contamination of other potable water surfaces around the pond. At the beginning of the process, water is channeled to the tailings pond. Improper construction of the ponds allows deep seepage of the water to other ponds around the area. The natural chemicals in the tailings water contaminate the potable water within the ecosystem. As a result, the potable water becomes unfit for both human and animal consumption. Such water must first be treated and decontaminated before human consumption (Howe & Hand, 2012).
Tailings water from the ponds contains 70% contaminants such as oil, heavy metals, and hydrocarbons. In most facilities, the wastes are released to nearby water bodies. This presents a major environmental challenge to the local inhabitants and the government. With forward osmosis and vacuum distillation, the tailing water must be treated before being released to the environment. Most agencies involved in water tailing have faced environmental sanctions due to a lack of proper treatment of tailing discharge. The environmental concerns have affected the adoption of forwarding osmosis and vacuum distillation in tailing water treatment (Fane & Matsuura, 2011).
The adoptions of the two technologies have also faced resistance to environmental lobby groups. Despite the measures adopted to improve the efficiency of the approaches, lobby groups have openly expressed their opposition. This has affected the successful implementation of the two technologies in the treatment of tailing water. Forward osmosis and vacuum distillation are not sustainable to the environment. The energy consumption of forwarding osmosis and vacuum distillation is unsustainable. With focus shifting to green and renewable energy, operating machines with high energy consumption is uneconomical (Howe & Hand, 2012).
Technical challenges
Tailing water treatment using forward osmosis and vacuum distillation has a number of technical challenges. First, the available designs of the two approaches do not allow the level of water to be increased. As a result, waste materials float on top of the ponds and cannot be removed to maintain the safety of the water. To solve this challenge, the size of the plant must be increased. This allows for the accommodation of a large volume of water and the elimination of challenges associated with waste removal (Xie & Nghiem, 2013).
Manufacturing designs for tailing water treatment equipment have similar sizes. An increase in water volume and overflow is not factored during manufacturing. This affects the economic viability and adoption of devices by different companies. Storage facilities during tailing water treatment are not designed to accommodate the volume for most companies. The design of the treatment equipment for the two methods does not consider the impact of the exhaust. Lack of proper exhaust consideration has caused leakages of the tailing water. This presents a technical and environmental challenge to the use of the two methods (Fane & Matsuura, 2011).
Safety concerns
The design of industrial equipment must consider the safety of the operators and other employees within the facility. The environmental concerns raised affect the operators of the equipment before filtering to the environment. Chemicals released during the treatment of tailing water have carcinogenic properties. Though studies have not been conducted to determine the epidemiology of tumor conditions, there is evidence that the chemical components of the wastes are toxic (Howe & Hand, 2012).
Improper treatment of the waste by the two methods presents significant health challenges to the public. Such toxic chemicals affect fetal development due to their teratogenicity. Exhaust wastes released into the air must be properly cleaned to safeguard the health of the locals. Though treated tailing water has been used for domestic purposes, their safety cannot be ascertained. Adequate measures must be put in place to ensure that tailing water treated through forwarding osmosis and vacuum distillation are examined. Chlorination and sieving can be used to purify the water and kill pathogenic microorganisms (Fane & Matsuura, 2011).
Economic challenges
Despite being efficient, hybrid forward osmosis is costly to acquire and install. Companies that intend to install the hybrid forward osmosis and vacuum distillation incur extra cost as compared to traditional technologies. Product manufacturers have argued that returns on investment using the two technologies is short. However, the cost of installation and operation affects their use in different organizations (Howe & Hand, 2012).
The dykes are also affected by constant blockages and breakdown. This arises from the high suspension nature of the water treated. Constant repair, maintenance and employment of qualified engineers must be done to enhance performance. As a result, the maintenance costs of the treatment plants are very high. Cost is also incurred due to the need to clean the membranes and pipes or channels. This is done to ensure that clean water is channeled to the reservoir (Howe & Hand, 2012).
These two technologies also require highly skilled professionals to operate. This increases the wage gap of organizations that adopt them in the treatment of tailing water. The process is also very expensive to monitor because it requires constant evaluation and monitoring to ensure efficiency. Exhaust wastes released into the air must be properly cleaned to safeguard the health of the locals. Though treated tailing water has been used for domestic purposes, their safety cannot be ascertained (Xie & Nghiem, 2013).
Environmental liabilities also increase the cost of operating the two technologies. For example, the construction of the tailing pond demands for compensation of the displaced. Environmental agencies must also be involved in ensuring that the process meets the set standards. For companies who have limited land, the adoption of forward osmosis and vacuum distillation for tailing water treatment increase the cost of acquiring more capital (Fane & Matsuura, 2011).
The emerging environmental regulations make the two techniques uneconomical. Organizations that increase carbon emission are denied carbon credit and forced to pay for the greenhouse effect caused. This increases the operational cost of such companies. The cost of health hazards and complications arising from the installation of tailing water treatment equipment is high. The introduction of the two technologies must, therefore, be based on the financial strength of the organization and availability of funds (Xie & Nghiem, 2013).
Conclusion
Tailing water treatment has a number of applications in the manufacturing sector. The introduction of forward osmosis and vacuum distillation is believed to have enhanced the process. However, a number of challenges have negatively affected their adoption in different sectors of the economy. This paper has highlighted the economic, technical, and environmental and safety challenges of tailing water treatment using forward osmosis and vacuum distillation methods.
References
Fane, G., & Matsuura, T. (2011). Advanced membrane technology and applications. New York: John Wiley & Sons.
Howe, J., & Hand, W. (2012). Principles of water treatment. New York: John Wiley & Sons.
Xie, M., & Nghiem, D. (2013). A Forward Osmosis-Membrane Distillation Hybrid Process for Direct Sewer Mining: System Performance and Limitations. Environmental Science & Technology, 47(23), 13486-13493. Web.