Preliminary And Primary Treatment Process In Wastewater
Preliminary And Primary Treatment Process In Wastewater
Wastewater Treatment Processes
Approximately 93% of Jamaica’s municipal wastewater is handled by the NWC
Municipal Wastewater consists of: Black water Grey water Storm water Infiltration
There are approximately 68 NWC Wastewater Treatment Plants with varying methods and equipment
Treated Effluent The discharge from Wastewater Treatment Plants must meet the
standards for treated effluent as set out by NEPA
Preliminary and Primary Treatment
Both have to do with the physical aspect of the treatment processPreliminary consists of removal of large particles
Primary removes the smaller particles by settling and skimming of the top of the wastewater
Preliminary Treatment
Screening
Bar Rack Bar Screen
ComminutorGrit Chamber Comminutor
Flow Equalization
Is used for storage
To prevent short circuit
Control the waste water
Primary Treatment
Circular Clarifier
Rectangular Clarifier
Effective Primary Treatment
Primary Treatment removes:50-70% of suspended solids25-50% of organic content25-30% of BOD565% of oil and grease10% insoluble phosphorousSome organic nitrogen, phosphates, heavy
metals
Primary Effluent
Primary effluent still contains:Colloidal and dissolved solidsHigh levels of organic material NutrientsPathogens
Primary effluent is disinfected with chlorine to reduce pathogen load
References
Baker, S. (2015). Wastewater Management Systems. Lecture, University of Technology, JamaicaMinistry of Health - Environmental Health Unit. (2007). Minimum
requirements for wastewater treatment systems and excreta
management in Jamaica. Kingston: Ministry of Health.Office of Utilities Regulation. (2011). water and sewerage sector report.
Kingston: Office of Utilities Regulation.Wastewater treatment. (2015, August 18). Retrieved from National Water Commission: http://www.nwcjamaica.com/WASTE_WATER.asp