Biochemical Oxygen Demand (BOD) Analysis in Water Quality Assessment

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THE MINISTRY OF EDUCATION, CULTURE, RESEARCH, AND TECHNOLOGY

FACULTY OF ENGINEERING, UNIVERSITAS ANDALAS DEPARTMENT OF ENVIRONMENTAL ENGINEERING WATER LABORATORY

Limau Manis Unand Campus, Padang 25163

4.1Discussion

4.1.1 Biochemical Oxygen Demand (BOD)

Based on the experimental results, the BOD levels in the water samples are 0.63 mg/L. According to Government Regulation No.

22 of 2021 on the Implementation of Environmental Protection and Management for class II water, which is suitable for

recreation, freshwater fish farming, animal husbandry, crop irrigation, and other similar uses, the acceptable BOD

concentration is 3 mg/L. Therefore, the practicum results indicate that the BOD levels in the samples meet the established quality standards.

High BOD levels in a water body result from the discharge of domestic organic waste. This waste is the primary cause of

decreased dissolved oxygen levels in the water. As aerobic bacteria decompose and degrade the organic matter, the dissolved oxygen levels drop significantly over time, leading to higher BOD levels.

The presence of high Biochemical Oxygen Demand (BOD) content in a water body is a significant indicator of pollution and poses a serious threat to the aquatic ecosystem. BOD measures the

amount of oxygen that microorganisms require to decompose organic matter in the water. When BOD levels are elevated, it indicates a high concentration of biodegradable material, often resulting from industrial discharge, agricultural runoff, or

untreated sewage. This organic matter serves as food for bacteria and other microorganisms, which consume a substantial amount

MUZAKKI GUSRON EFENDI 2210942013

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of dissolved oxygen during the decomposition process.

Consequently, the oxygen levels in the water decrease, creating a hypoxic or anoxic environment that is detrimental to aquatic life.

Biofilm technology is a highly effective method for reducing BOD (Biochemical Oxygen Demand) in wastewater treatment. Biofilms consist of communities of microorganisms that adhere to surfaces within a water treatment system, forming a slimy layer. These microorganisms, including bacteria, fungi, and protozoa,

metabolize organic pollutants present in the wastewater. As the wastewater flows over the biofilm-coated surfaces, the

microorganisms break down the organic matter, thereby reducing BOD levels. The efficiency of biofilm systems lies in their large surface area for microbial attachment and their ability to

maintain high microbial activity. This process not only improves water quality by lowering harmful organic compounds but also enhances the stability and resilience of the treatment system.

Biofilm technology is advantageous due to its relatively low maintenance requirements, high treatment efficiency, and adaptability to various wastewater types, making it a valuable solution for both municipal and industrial wastewater

management.

The Bachelor of Environmental Engineering can utilize his

knowledge to prevent or control a water body. Prevention can be done by processing waste before it is discharged into water bodies.

In addition, every industry that produces waste needs to provide waste treatment facilities as a control measure against pollution of water bodies by the waste produced.

4.3.2 Chemical Oxygen Demand (COD)

Based on the experimental results, the COD level in the water samples is 16 mg/L. According to Government Regulation No. 22 of 2021 on the Implementation of Environmental Protection and Management for class IV water, which is suitable for recreation, freshwater fish farming, animal husbandry, crop irrigation, and other similar uses, the acceptable COD concentration is 80 mg/L.

Therefore, the practicum results indicate that the COD levels in the samples meet the established quality standards.

The presence of COD in the environment is largely determined by organic waste, both from household and industrial waste.

Households and industries are the main sources of organic waste

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and are the main cause of high COD concentrations. Household waste comes from residential housing, hotels, offices and hospitals, while industrial waste comes from the processing and production of organic materials such as the food industry. Other sources that also cause high COD concentrations are livestock waste and fish feed if the water comes from fish ponds.

The presence of COD in the environment is mainly due to organic waste from both household and industrial sources. Households and industries are the primary contributors to high COD levels.

Household waste originates from residential areas,

hotels, offices, and hospitals, while industrial waste is generated from the processing and production of organic materials, such as in the food industry. Additionally, livestock waste and fish feed from fish ponds also contribute to elevated COD concentrations.

Activated sludge is an effective method for processing COD (Chemical Oxygen Demand) in wastewater treatment. This

process involves aerating the wastewater to promote the growth of aerobic microorganisms that form flocs. These microorganisms metabolize organic pollutants, significantly reducing COD levels.

As the wastewater passes through the aeration tank, the activated sludge absorbs and breaks down the organic matter. The treated water is then separated from the sludge, resulting in lower COD concentrations and improved water quality. This method is widely used due to its efficiency and ability to handle various types of wastewater.

The role of Bachelor of Environmental Engineering that can be done is to find solutions to reduce high BOD and COD levels in waters by creating new technologies or updating existing

technologies. It is intended that the technology created or updated can be utilized properly. Therefore, technology must have

advantages over previously existing technology. In addition, Environmental Engineering graduates can conduct research whose results can be informed to the community around waters that have the potential to pollute, so that the community can overcome or can prevent the impact that will occur.

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CHAPTER V CLOSING 5.1Conclusion

The conclusions that can be drawn based on the practicum that has been carried out are:

1. The BOD and COD concentrations obtained after the

practicum were 0.63 mg/L and 16 mg/L, in accordance with Government Regulation No. 22 of 2021 concerning the Implementation of Environmental Protection and

Management class II, stipulating that the levels of BOD and COD that comply with the quality standards are 3 mg/L and 80 mg/L, so that the concentration of BOD and COD in the sample meet the established quality standards.

2. High levels of BOD and COD in water are due to the large amount of organic waste, household waste, and industrial waste discharged into water bodies.

3. The impact of high BOD and COD levels is to damage the water ecosystem so that the life of living things in it is disrupted.

4. The treatment technology to reduce BOD and COD levels is the process of adding biofilm for BOD and activated sludge for COD.

5. The role of prospective Bachelor of Environmental

Engineering is that if the levels of BOD and COD exceed the quality standards, the Bachelor of Environmental

Engineering will use his knowledge to find solutions, create new technologies, and update existing technologies to

overcome BOD and COD problems in waters.

5.2 Suggestion

Suggestions that can be given after doing the practicum are:

1. Practitioners are expected to be more careful and careful when practicing and better understand the experimental procedures of the Oxygen Demand module before carrying out the practicum in order to get accurate results.

2. Society should be able to do good processing of waste generated by households so as not to pollute the environment.

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KEMENTERIAN PENDIDIKAN, KEBUDAYAAN, RISET, DAN TEKNOLOGI

FAKULTAS TEKNIK, UNIVERSITAS ANDALAS DEPARTEMEN TEKNIK LINGKUNGAN LABORATORIUM AIR

Kampus Unand Limau Manis, Padang 25163

3. Government should support community efforts in

maintaining the environmental cleanliness from existing pollutants and contribute to providing a technology to reduce BOD and COD levels in water.

4. Thw Bachelor of Environmental Engineering should begin to provide an approach through efforts and innovations in terms of water treatment in order to reduce the

concentration of BOD and COD in water.

KBI