PHOSPHORUS REMOVAL OF WATER TREATMENT SUPPLIERS PHILIPPINES

Phosphorus is present in raw wastewater at typical concentrations of 6-12 mg/l. A typical biological treatment unit will remove at least 2 mg/l of phosphorus. To remove additional phosphorus water treatment suppliers Philippines uses biological phosphorus removal that takes a specific design and closer operator control, or chemical addition. The most common form of chemical addition is a Metal Salt Chemical Addition that forms an insoluble precipitate with orthophosphate. Phosphorus removal efficiencies decrease in cold weather due to decreased settleability of chemical flocs. Chemical addition of metal salts can lower pH levels in the effluent to concentrations below permit limits so pH control may be required. Very low concentrations may also require the addition of polymer to aid in chemical floc settling.

CHEMICAL PHOSPHORUS REMOVAL

If phosphorus concentrations less than 1.0 mg/l are required and metal salt chemical addition is proposed, the following included in the design of a water treatment suppliers Philippines.

1. Two-point chemical addition – Metal Salts shall be added prior to the primary pretreatment unit and before the final clarifier. The addition of the chemicals shall be flow paced and the chemical shall have adequate a good turbulent mixing zone of at least 30 seconds travel time with the wastewater so a floc can be formed between the chemical and the wastewater.
2. Polymer Addition – Design for addition of polymer to the wastewater in addition to the metal salt addition to aid in settling of inorganic solids in the clarifiers. Inorganic solids may carry over to the RBC or final sand filter if polymer is not added. water treatment suppliers Philippines understands the facts that inorganic solids going to an RBC will result in a biofilm layer that will interfere with normal treatment.
3. pH control – Metal Salts will drop the pH in the effluent and bring the facility out of compliance with permit limits.
4. Effluent polishing – A filter will be required after flocculation and settling to remove remaining suspended solids.
5. Solids handling – Chemical addition for phosphorus removal can double the amount of sludge handled at the facility. The sludge storage tanks of water treatment suppliers Philippines are sized as large as possible to accommodate the additional sludge. In addition, the clarifiers should have lower loading rates, <600 gpd/sq.ft to aid in the settling of the sludge.
6. The Suspended Solids concentrations must be 15 mg/l or less. The treatment system should be designed for stricter TSS removal.
7. Eye Wash and Emergency showers should be located close by. Hand and face protection will be required when handling.
8. Sludge streams must be treated to prevent removed phosphorus from being released from the sludge. Phosphate release occurs from sludge when there are changes in pH, in the redox condition or in anoxic or anaerobic conditions. Additional storage facilities other than the pretreatment tank will be necessary to prevent phosphorus release.
9. For facilities using ultraviolet (UV) light for disinfection, the use of iron salts is discouraged as they produce fouling of the quartz jackets. This leads to an accumulation of scale over the wetted surface of the quartz jacket and will impede radiation transmission.
10. For facilities using aluminum salts, water treatment suppliers Philippines takes special care to insure that their addition will not lead to a violation of effluent standards for aluminum.