Parameters of Industrial Wastewater Treatment

In industrial wastewater treatment known three main parameters: (1) Dissolved oxygen (OT) or Dissolved Oxygen (DO), (2) Biological Oxygen Demand (KOB) or Biologycal Oxygen Demand (BOD) and (3) Chemical Oxygen Demand ( KOK) or Chemical Oxygen Demand (COD).Dissolved oxygen (OT) or Dissolved Oxygen (DO)
Oxygen is a very important parameter in water. Most of the creatures living in water need oxygen to sustain life, both plant and animal water, depending on the dissolved oxygen. Fish is an aquatic creature with the highest oxygen demand, and invertebrates, and the smallest are the bacteria needs oxygen.
The balance of dissolved oxygen (OT) in water are naturally occurring sustainably. Mikoorganisme as the smallest creatures in the water, for its growth requires an energy source that is the element carbon (C) which can be obtained from the organic material originating from plants, algae die, as well as oxygen from the air.
Organic material by microorganisms will duraikan menadi carbon dioxide (CO2) and water (H2O). CO2 subsequently utilized by plants for photosynthesis in water to form oxygen, and so on.
Oxygen is utilized for the decomposition of organic material will be replaced by the incoming oxygen from the air and from other sources as quickly as exhaustion of dissolved oxygen used by bacteria or in other words oxygen is taken up by biota, water is always equilibrium with the incoming oxygen from the air or from the photosynthesis of aquatic plants.
If at any time of organic matter in water is exceeded as a result of the entry of waste of human activity (such as organic wastes from industry), which means the supply of carbon (C) abundant, causing microorganism growth rate will double, which means also increased oxygen demand, while supply fixed amount of oxygen from the air. In these conditions, the equilibrium between the oxygen that goes into the water with that utilized by the biota, water is not in balance, resulting in a deficit of oxygen dissolved in water. If the decrease in dissolved oxygen continues until it reaches zero, the water biota that require oxygen (aerobic) will die and be replaced by the growth of microbes that do not require oxygen or microbial anerobik. Similarly, the microbial aerobic, anaerobic microbes will also take advantage of carbon from organic material. This form of anaerobic respiration of methane (CH4) as well as acid gases formed sulfide (H2S) which smells foul.The entry of other solutes in the water disrupt the solubility of oxygen in water
The entry of other solutes in the water disrupt the solubility of oxygen in waterBOD and COD
To determine the rate of decline in water quality can be seen from the decrease in oxygen levels terlatut (OT) as a result of the inclusion of organic material from the outside, commonly used test and BOD or COD.
Biological Oxygen Demand (BOD) or biological oxygen demand (KOB) shows the amount of dissolved oxygen required by living microorganisms to break down or oxidize organic matter in water.
Therefore, the value of BOD is not a value that shows the amount or levels of organic matter in water, but a relative measure the amount of oxygen required by microorganisms to oxidize or describe these organic materials. High BOD indicates that the amount of oxygen required by microorganisms to oxidize the organic material in water is high, it means the water is oxygen deficit. The number of microorganisms that grow in water due to the quantity of food available (organic material), thus indirectly BOD is always associated with higher levels of organic matter in water.
BOD5 is the determination of BOD raw measure of the amount of oxygen that is spent within five days by microorganisms in aerobic decomposers in a volume of water at a temperature of 20 degrees Celsius.
500mg/liter BOD5 (or ppm) oxygen mgram means 500 will be spent by the microorganisms in a liter of sample water for five days at a temperature of 20 degrees Celsius.
Some basic often used to determine water quality seen in the levels of BOD are:
BOD is closely related to COD. In the waste material, not all organic chemicals can be decomposed by microorganisms quickly.
Organic material in water is:

    * Can be broken down by bacteria (biodegradation) within five days
    * Organic materials that are not decomposed by bacteria within five days
    * Materials are not biodegradable organic
COD test includes all the organic material on top, both of which can be decomposed by microorganisms and which can not be described. Therefore, COD test results will be higher than the BOD test.