CL420: Water Engineering 2 CL978: Water and Wastewater Treatment Design Project Design, part 2 Case Solution

Biochemical operation has three basic types; the first one contributes to the elimination of organic resins which are composed from detergent and body wastes.The second type contributes to insoluble matter for stabilization and digestion and the wastage is produced by food particles or body waste.Moreover,the third type is nitrogen and phosphorus transformation, which comprises of soluble in organics matters.

The environmentsof the biochemical operation are anaerobic and aerobic.

Aerobic:The environment of aerobic in waste water treatment system has sufficient amount of dissolved oxygen, which assures thatif thereis any lack of oxygen for the growth of microorganisms. The main advantage of the aerobic environment is that it completely dissolvesthe sewage and reduces the BOD to a low level.

Anaerobic: The environment of anaerobic in waste water treatment system does not dissolve oxygen or has very low concentration of dissolved oxygen. The working principle of the anaerobic is that the insoluble organic matter should be converted as soon as possible to the end products such as gases and liquids.

Nitrogen Elimination:

Waste water contains nitrogen in different forms. Through the micro-organism process, organic nitrogen is converted into ammonia by being broken down rapidly and it is in the basic form in septic tank. Nitrate forms by bacteria, which breaks the ammonia down in the presence of oxygen to form nitrate.

Nitrogen has a serious harmful affect to healthas it enters the body through different ways and then the nitrogen is converted to ammonia and as a result, it forms into nitrate.However, some technologies have been designed to convert nitrogen bacteria to ammonia, nitrate and gaseous nitrogen and this gaseous nitrogen is released in air.

The process of ammonia to gaseous nitrogen is based on two main steps; firstly the ammonia is oxidized to nitrate and after that the nitrate is converted into nitrogen gas and this process is usually carried out in waste water treatment system.

This process is called nitrification process in which we convert the nitrogen to nitrate and this requires oxygen and it contributesto the biochemical oxygen demand (BOD) of the sewage. This process of nitrification is processed under the conditions of aerobic.

The second step in the elimination of nitrogen is de-nitrification in which we convert the nitrate to nitrogen gas. This process also requires aerobic conditions in order to dissolve oxygen level near to zero or zero. In order toconvert nitrogen from nitrate bacteria it requiresfood source for energy and BOD provides this source of food for bacteria’s growth.

There are two main conditions aerobic and anaerobic under which both process can be placed successfully.

 Phosphorus Elimination:

Phosphorus comes in waste water from the body waste.There are different forms of phosphorus, such as ortho phosphate and poly phosphate. The organically bound phosphorus is generated from body or waste water and then it is changed from  phosphorus to orthophosphates through biological decomposition.Most of the phosphate in waste water is poly phosphate, which comes from the detergents and contributes almost half of the phosphates and poly phosphates after being converted to orthophosphate by being hydrolyzed. This form of orthophosphates contains PO43-, HPO42- and H2 PO4;these ions can make their combination with cations.

Phosphorus reduces in conventional septic system however,the amount is unknown. Through the chemical precipitation, the phosphorus is removedin septic system under the leaching facility and to convert the phosphorus to biomass some of phosphorus is utilizedby bio-organism.

The process of elimination of phosphorus in the form of precipitation is insoluble precipitation.

rse osmosis, Aeration, chemical feeding and sludge handling. and cleaning water h, climate, watershed and degree of impoundment

One of the best methods to increase the elimination of phosphors from the waste water is that the area under the leaching should be located above the ground water at least more than 5 feet vertically……….


The primary purpose of water treatment plant is to remove the pollutants that can harm the aquatic environment if it discharges into the lake, stream and ocean. Over here we focus on the given BOD5 and TSS condition that we have provided for this project. We design our water treatment plant according to BOD and TSS condition. The primary process for water treatment plant are:

  • Preliminary Treatment
    Grit Removal
    Storm overflow
  • Mixing and Flocculation
  • Primary Treatments
    Gravitational settling of particles
    Primary sedimentation……………..

This is just a sample partial work. Please place the order on the website to get your own originally done case solution

Share This