Chemical Oxygen Demand ( B.o )

This experiment was centered on metabolic and biochemical testing procedures. The rationale of performing these tests was to distinguish six different microbes from one another and to compare how their metabolic and biochemical processes differ from species to species to determine the unknown sample.

When the dissolved oxygen level drops below 2.0 the trout seem to lose all their coloring. Once they lose their coloring they do not get it back.

The CTDEP collected bottom- dwelling fish and invertebrates and compared the quantity of organisms and number of species with the levels of oxygen in the water. Both of these studies confirmed that severe effects occurred whenever levels of oxygen fell below 2.0 mg/l. Large reductions in the numbers and types of aquatic life present were noted. The lab experiments recorded reductions in both growth and increase in death.

Aquatic environments require different methods for adaptation. The pressure in water increases as depth increases and aquatic organisms have to deal with it. Mobility of small animals versus larger ones help the ones with greater SA:V flow or be moved by currents, which is a disadvantage for bigger animals that have to constantly move. Light limitations also affect living things in water, mostly plants because they have to photosynthesize to grow, and the attenuation of light increases in depth, they have to take advantage of other resources to get the light they need and the nutrients to survive. Salt tolerance is vital; the process of osmosis moves water from high concentration of solutes to low concentration of solutes, if an organism doesn’t have enough salt contents starts losing water and dehydrates

- Having more dissolved oxygen increases the number of fish observed in the body of water.

The increase of oxygen does not necessarily mean the fish will keep up with it. Too much oxygen can be harmful to the fish so you would need a certain amount per area of fish. A constant flow of oxygen going throughout the water habitat.

2. If the ppm of dissolved oxygen is increased in water then there will be more fish observed.

Overall, the more macroinvertebrates in the water, the healthier the stream. pH is a measure of how acidic or basic water is. It is measured on a scale from 0-14. 0 is the most acidic, 14 is the most basic, and 7 is neutral. It is the measure of the relative amount of free hydrogen and hydroxide ions in the water. Acidic water has more hydrogen ions, and basic water has more hydroxide ions. When water’s pH is around neutral (7), that is a suitable and healthy living environment for fish, and indicates a healthy stream. If the water is too acidic or too basic, it can be harmful to the aquatic life. Dissolved oxygen is a measure of how much oxygen is dissolved in the water. As the amount of dissolved oxygen drops below normal levels in water bodies, the water quality is harmed and creatures begin to die off as a result of eutrophication. The higher the level of dissolved oxygen, the healthier the stream. When there is a lot of dissolved oxygen present it makes for a safe environment for fish to live and reproduce. Having all this healthy fish can provide us with food, so overall the more dissolved oxygen, the better. Nitrates are a compound found in fertilizers that is used to help plants grow. It is what is given off as a result of the use of nitrogen in water. The organisms in the soil eat the nitrates and it helps the metabolism and the health of organisms. Plants, such as Algae use nitrates as a source

One example is aquatic life. Animals use up dissolved oxygen to carry out respiration for cellular processes and bacteria use up oxygen to decompose and break down organic wastes removing oxygen from the water to breathe. Therefore dissolved oxygen levels are lower when a body of water contains a lot of decomposing material. Plants also affect dissolved oxygen content as they release oxygen as a bi product of photosynthesis.

The oxidation fermentation test was used to differentiate if the organism utilizes lactose, mannitol, glucose and citrate aerobically (oxidation) or anaerobically (fermentation). A methyl red test was performed to determine if the organism carried out mixed-acid fermentation when supplied glucose. A Voges-Proskauer test was performed to evaluate if the unknown was able to ferment glucose into butanediol. A citrate test was performed to determine if the unknown organism was able to break down citrate into ammonia. An oxidase test was then performed to determine if the unknown culture was oxidase positive or negate.

Two things I learned was from Turtle pond lab was what B.O.D means for the ponds water quality and how to calculate it. To answer question number two I chose to explain the B.O.D results. I didn´t know much about the Biochemical oxygen demand so, I had to do a little bit of research on it. I find out that a high B.O.D measurement is actually bad because it means that the water is polluted and that B.O.D is used to measure a number of dissolved oxygen that an organism needs to break down organic material in a water sample. During this lab, I also learned how to measure BOD. When we were at the pond my job was to take a sample of the water in a black bottle and then 5 days later we would measure the dissolved oxygen in the sample. To find the

Sediments are the main source of water pollution, contributing to turbidity issues as well as irregular or harmful nitrite/nitrate, phosphorus, and pH levels. This contributes to the death of marine organisms and can also change which organisms can survive in the body of water as its conditions change due to runoff. Anthropogenic runoff is also a contributor of adverse water effects, such as cultural eutrophication from fertilizer runoff, and also results in the death of aquatic animals and shifts in which organisms are more prominent in the ecosystem. This lab will address the effects soil will have on variables concerning water quality. There is also the option of including fish and/or aquatic plants in the water column, which are independent variables as well as the soil. The pH, ammonia levels, nitrite levels, temperature, D.O., and physical attributes are the dependent variables that will be measured during the lab. The qualitative physical tests (turbidity and odor) will portray the physical state and cleanliness of the water, as well as the level of runoff from the soil.

Determine the dissolved oxygen for each bottle after 1 day by using CHEMets kits. Snap the tip of the CHEMet ampoule in the water, then remove and mix the ampoule. Wait 2 minute to develop then find which color standard best matched the sample. Then calculate the net and gross productivity and record on data table.

This report provides analysis and evaluation of a newly designed wastewater treatment facility for Sand Valley, Nevada. Analysis will include Biological Oxygen Demand (BOD) along with total, volatile, and fixed suspended solids. Methods for analysis will include the Winkler Test for BOD and a Hatch test for the suspend solids.

A fresh pipette was used to transfer 0.5ml of broth culture of E. coli, to be inoculated, into a tube of molten agar previously boiled to drive off oxygen. The tube was then rolled to distribute the bacteria and allowed time for the agar to harden. The tube was incubated at 37oC for 48 hours. The procedure was repeated for broth cultures of the bacterium Clostridium sporogenes and B. Subtilis.