Use of Flocsure Flocculant in Primary treatment for waste water

Primary treatment for waste water

Broad guideline given here describes briefely the approach for primary treatment of waste water, its advantages and usefulness of flocculants in the same. In the case of many industries the primary treatment for waste water can be of great advantages due to the following reasons;

  1. It is relatively Simple and Quick.
  2. In some cases it can eliminate major portion of pollutants and thus load for further treatment can be reduced. e.g. reduction BOD, COD suspended solids, bacteria, colouring matter, collid particles, etc.
  3. In some cases recovery and re-use of oil, water may be possible.
  4. In some cases effluents which are difficult to treat can be treated by this process e.g. dyes, pigments, textile, pesticide industry effluents.

The primary treatment basically involves one or more of the following steps.

  1. Removal of oil and grease with the help of flocculant addition.
  2. Neutralisation of excess acid or alkali to bring pH value within 6-8.
  3. Addition of small dose of flocculant solution for faster separation of suspended solids from waste water.
  4. In some cases, like waste water from dye, pigment, tanneries, pesticides, paper & pulp, textiles and petrochemical industries, a prior of small quantity of solution of conditioner may be required before addition of flocculant.
  5. pH at the end should be adjusted between 6 - 8 The settling is generally carried out in conical bottom flask.
  6. Excessive CaCO3 contamination of lime used for pH adjustment may cause CO2 liberation causing flocs to float up because of buyoyancy.
  7. The treatment with flocculant results in highly enhanced rate of separation of oil/grease and later on of settling of insoluble suspended matter (Organic or inorganic). The settled sludge can be filtered, centrifuged or sent to drying beds before further disposal as per environment regulations.
  8. Minimum quantity of conditioners should be used as it can give settled sludge which is slow to filter.
  9. If insoluble matter contains organic matter, this process can result in reduction of BOD and COD in addition to reduction of suspended solids in the treated water. Supernatent clear water can be further treated or disposed off or recycled depending upon quality of the same.