Client: Nelson Mandela Bay Municipality, Kelvin Jones Wastewater Treatment Works
Industry: Sewage Wastewater
Region: Eastern Cape, South Africa
Product: VA4, 125m³/h, 250µm
Installation Date: 2021

Challenge

• At Kelvin Jones Wastewater Treatment Works in Uitenhage, final treated effluent (clarifier overflow) is re-used.
• Applications include spray water, irrigation water for agriculture and recreational facilities and process water for industrial clients
• The clarifier overflow contains suspended solids that can block downstream spray nozzles or that are in excess of industrial/agricultural client acceptance standards
• A travelling bridge sand filter provided tertiary filtration
• The sand filter fell into early disuse and was bypassed permanently
• The result was tertiary effluent that did not comply with client acceptance standards leading to a loss in revenue
• Nelson Mandela Bay Municipality required efficient filtration that would deliver compliant, uninterrupted water supply to their customers
• Maintenance and downtime needed to be at a minimum

Application

•  Final Filtration / Spray nozzle protection
• Final Filtration / Industrial re-use

Solution

• Perform on-site diagnostics to determine the needs at the plant
• Provide a solution that is fit for purpose
• Move from filtering “as fine as possible” to filtering “at the appropriate level”
• Provide filtration that is suited to the removal of soft, organic and fibrous solids from process streams
• The gentle, unforced filtration action of the GraviFilter is ideally suited to this application, preventing the break up of flocculated particles and organic matter
• Water gravitates through the screen, avoiding the vulnerability of permanent blockage or damage to the screen.
• Stapling of fibrous suspended solids is greatly reduced
• The integral, continuous self-cleaning mechanism of the GraviFilter ensures uninterrupted filtration for extended periods of time
• The client installed a GraviFilter model VA4 with integral, self-cleaning mechanism. 125m³/h. 250µm screens.

Results

• Travelling bridge sand filter permanently eliminated
• Tertiary effluent that complies with client acceptance standards
• Minimal maintenance
• Downtime approximating zero
• Regeneration of the revenue stream