One cubic foot of water weighs 62.4 pounds and contains 7.48 gallons. A column of water 2.31 feet high will exert 1.0 psi Example To produce a pressure of 40 psi requires a water column of: 40 psi X 2.31 ft/psi = 92.4 ft

1 m3 = 1000 kg approx

coagulation reactions are rapid , detention period for flash mixers is between 60 seconds to 90 seconds, the detention time for flocculation basins is between 5 to 30 minutes. ,

The equation to calculate detention time is : Detention time = Volume of tank / flow rate

Coagulation in water and waste water treatment is series of chemical and mechanical operations by which coagulants are applied . These operations comprise of two phases: (1) rapid mixing to disperse coagulant chemicals by violent agitation into the water being treated, and (2) flocculation to agglomerate small particles into well-defined floc by gentle agitation for a much longer time

Coagulation results from adding salts of iron or aluminum to the water and is a reaction between one of the following (coagulants) salts and water: Alum — aluminum sulfate , Sodium aluminate , Ferric sulfate , Ferrous sulfate , Ferric chloride , Polymers

Flocculation follows coagulation in conventional water treatment process. Flocculation is physical process of slowly mixing the coagulated water to increase the probability of particle collision. Through experience, we see that effective mixing reduces the required amount of chemicals and improves the sedimentation process, which results in longer filter runs and higher quality finished water. The goal of flocculation is to form a uniform , floc that entraps the fine, suspended, and colloidal particles and carries them down rapidly in settling basin. To increase the speed of floc formation and the strength and weight of the floc, polymers are added

To enable the source to operate at a predetermined rate.

MBBR stands for Moving Bed Bioreactor

1.Turbidity

2. Color

3. Odour

4. Temperature

1. Total solids , suspended solids , settleable solids

2. pH value

3. chloride content

4. nitrogen

5. presence of fats , greases and oils

6. sulphides , sulphates and H2S gas

7. dissolved oxygen

8. Chemical Oxygen Demand (COD)

9. Bio Chemical Oxygen Demand (BOD)

Nitrogen Content : The presence of nitrogen in sewage indicates the presence of organic matter , and may occur in one or more of the following forms

1. Free ammonia , called ammonia nitrogen

2. Albuminoid nitrogen called as organic nitrogen

3. Nitrites and

4. Nitrates

The Biological Sludge which does not settle well and compacts poorly in the secondary settling tank , leaving a small amount of clear supernatant at the top is Bulking Sludge. Bulking occur due to the presence of toxic substances , insufficient aeration , frequent shock loadings and excessive rate of supply of substrate. Bulking of Sludge is controlled by a mixture of copper sulphate and lime in 1:1 ratio by weight

Sugar industry is considered to be the most pollution ( water and wastewater ) emitting industry. the major pollution characteristics of sugar industry comprises of 1. High BOD 2. High Volatile solids 3. Low pH . The suggested treatment method for sugar industry is Biological treatment with Ultra filtration or Nano filtration for reusing the recycled water in the process.

Diary industry is among major waste water producer industries and produce effluent which contain 1. High Dissolved Solids 2. High Suspended Solids 3. High BOD 4. Presence of Oil and Grease , Suggested treatment method for dairy industry is biological treatment with DAF ( Dissolved air flotation )

The problem with oil refinery is with free and emulsified oil , the suggested treat for oil and refinery industry is Oil separation Chemical treatment biological treatment

Pollution Characteristics of this industry mainly consists of High ammonia content high phenol content high BOD low suspended solids high cyanide , suggested treatment method is Chemical treatment Biological Treatment

Pharmaceutical industry require high level of treatment for their effluent as the effluent mainly consists High total solids High COD High COD/BOD ratio either acidic or alkaline , suggested treatment is Chemical treatment Biological Treatment with lamella clarifier or DAF

Alkaline chlorination process is used for oxidation of cyanides to carbon dioxide and nitrogen, Treatment for cyanides is carried out prior to the heavy metals removal , cyanide treatment process is carried out in two reactors , In first Tank / reactor at pH range between 9.5 to 10 cyanide oxidize to cyanate by the mixing of chlorine ( sodium hypochlorite ) , In second Reaction Tank at pH 8 cyanate oxidize to carbon dioxide and nitrogen through the addition of chlorine.

Strong color high BOD High COD/BOD ratio Highly alkaline high sodium content are the main issues with paper and pulp industry suggested treatment for effluent is Chemicals recovery lime treatment for color Biological Treatment