Engineering Economics. Ultraviolet vs. Chlorine Disinfection

Introduction

Domestic water should be free of harmful microorganisms to prevent the outbreak of waterborne diseases (Bulfin 1). A number of ways to sanitize water exists. Chlorine is the most popular sanitizers utilized in the treatment of water. There have been concerns that the chemical has a negative effect on the consumers, water treatment operators, and the environment. In this regard, other water treatments have been preferred over chlorine. Another most preferred water treatment method is ultraviolet disinfection. The treatment utilizes the UV light to kill the microorganisms in the water (Darby 1). Disinfection of water using the UV is remarkably effective and ecologically safe compared to the use of chlorine and hypochlorite in small-scale water treatment. In large-scale, chlorine treatment is economical compared with UV treatment. The paper below illustrate that chlorine treatment is more affordable than UV treatment with respect to their operation and maintenance costs.

Chlorine disinfection

Chlorine has been utilized as water disinfectants for decades. Chlorine kills illness-causing microorganisms in the water. Currently, the use of chlorine in water purification has resulted in heated debates (Krakauer 1). Chlorine kills disease-causing organisms in the water. For the reason that chlorine is a poisonous gas, there is a risk linked with its use. For instance, chlorine compounds mixes with carbon-based compounds in water to form potentially dangerous organic by products (Kline 1). The development of the above by-products may be reduced by elimination of carbon-based products in water before being treated with chlorine. Even though chlorine treatment is very efficient in the elimination of microorganisms, it should be noted that it has limited effectiveness with respect to cost.

Ultraviolet

Compared with chlorine treatment, the treatment is very efficient at disarming microorganism in water with less turbidity. UV’s decontamination efficiency declines as turbidity rises (Morgan 1). The reduction in efficiency is linked to an increase in absorption, dusting, and tailing resulting from the particles present in water. A major drawback associated with the use of UV light is that it leaves no enduring decontaminator in the water. In this respect, it is necessary to supplement the treatment with a lasting decontaminator after the UV disinfection process is undertaken.

Analysis

Research indicates that the cost of using chlorine in water treatment is more economical as the capacity of water increases (Leinberger 3). The product prices are $0.0.02 per cubic meter for a 5mg per liter dose for a water treatment plant with capacity to treat 6813 cubic meters of water daily (Achari 5). For smaller water treatment plants, chlorine treatment is more costly. As such, it would cost $0.75 per cubic meter for a water treatment plant with a capacity to treat 90 cubic meters of water daily.

Due to additional application of supplementary decontaminators, the use of ultraviolet treatment is not economical at large scales (U.S. Environmental Protection Agency 2). The product prices are $0.0.03 per cubic meter for a 5mg per liter dose for a water treatment plant with capacity to treat 6813 cubic meters of water daily. For smaller water treatment plants, UV treatment is cheaper. For instance, it would cost $0.07 per cubic meter for a water treatment plant with a capacity to treat 90 cubic meters of water daily. The above figures are captured in the figures below:

Based on the above analysis, it is apparent that it is more economical to treat water using chlorine at large scale compared to the use of UV light. The cost of using UV light increases as the capacity of water increases. On the other hand, the cost of chlorine treatment decreases as the capacity of water increases. In this respect, large water treatment plants should opt for UV treatment. On the other hand, UV treatment should be adopted in domestic water treatment.

An extra cost will be incurred in UV treatment because technical skills will be required to operate the plant. Water treatment plants utilizing UV treatment are more complex than water treatment plants utilizing chlorine. Technicians are required to install and carry out regular maintenance on UV light systems. Owing to this, the cost of UV treatment is expected to increase.

Equally, water treatment plants utilizing chlorine are very economical because they are simple and easy to monitor. When the exchange tanks are gauged in accordance with the flow rate, a simple free-chlorine gauge with low-cost test equipment can point out if the water is disinfected. Therefore, chlorine treatment plants can be automated with ease unlike UV treatment plants saving on the cost of operation.

Recommendations

Regardless of the method of treatment chosen, the home water should be free of disease-causing organisms. Equally, the water should be affordable. In the future, water sources are expected to be more contaminated with toxic substances as the number of industries and population increases (Wegenet 3). Therefore, in the future efficient and economical methods of treatment should be developed (Wegenet 3). Because both chlorine treatment and UV treatment have their pros and cons, they should be evaluated further to determine the most appropriate process with respect to the subject treatment plant.

Similarly, researches should be conducted on how to improve the two water treatment methods. Through the researches, means of minimizing environmental harms resulting from the use of chlorine treatment may be identified. The research may also come up with a means of ensuring chlorine kills all the disease-causing organisms in the water. Researches on UV light will come up with ways of increasing the treatment’s efficiency (Wegenet 3). More studies should be done on how to eliminate to absorption and scattering challenges resulting from the suspended particles present in the water.

Correspondingly, alternative methods of water treatment should be evaluated to determine their cost and effectiveness. Usually, more than two methods of water treatments are combined in water treatment plants to ensure that the domestic water is fit for human consumption. For instance, a number of water treatment plants combine the use of ozone and UV treatment methods in their facilities. In this respect, more researches should be undertaken to identify other treatment methods that should be combined with UV treatment to make it economical (Bulfin 1). In addition, the water treatment plants should automate their operations to reduce on labor cost. By doing so, the plants will be able to minimize on the cost of operation ensuring that the consumer gets affordable water.

Conclusions

In conclusion, it should be noted that chlorine treatment is more affordable than UV treatment with respect to their operation and maintenance costs. Chlorine kills illness-causing microorganisms in the water. During the water treatment process, chlorine is applied either in gaseous form. Chlorine kills disease-causing organisms in the water. Another water treatment method utilized other than chlorine treatment ultraviolet disinfection. The ultraviolet treatment utilizes the UV light to kill the microorganisms in the water. Disinfection of water using the UV is remarkably effective and ecologically safe compared to the use of chlorine and hypochlorite when treating water in small scale. Compared with chlorine treatment, UV treatment is very efficient at disarming microorganism in low turbidity water. UV’s decontamination efficiency declines as turbidity rises.

It is more economical to treat water using chlorine at large scale compared to the use of UV light. The cost of using UV light increases as the capacity of water increases. On the other hand, the cost of chlorine treatment decreases as the capacity of water increases. In this respect, large water treatment plants should opt for chlorine treatment. Contrastingly, UV treatment should be adopted in domestic water treatment (Greenemeier 1). Through this, water treatment will minimize on operation costs.

Works Cited

Achari Gopal 2012. Costs and The Choice Of Drinking Water Treatment. Web.

Bulfin, Gerry 2014. Chlorine vs. UV Light. Web.

Darby, Julian 2014. UV Disinfection. Web.

Greenemeier, Larry 2014. Want Clean Water? Turn on the Lights. Web.

Kline, Gerald 2015. Drinking Water Disinfection Systems: Chlorine & UV Systems. Web.

Krakauer, Peter 2013. Chlorine as Disinfectant for Water. Web.

Leinberger, Jackie 2013. Disinfection of Drinking Water with Ultraviolet Light. Web.

Morgan, James 2011. Ultraviolet (UV) Disinfection in Drinking Water Treatment. Web.

U.S. Environmental Protection Agency 2013. Ultraviolet Disinfection. Web.

Wegenet, Linda 2004. Ultraviolet Radiation for Disinfecting Household Drinking Water. Web.