Designed to treat the effluent on site to acceptable levels for direct discharge to field soakaway
Gross solids screened out of the effluent
Reduction in COD/BOD of 85% and Suspended solids of 90%
Above-ground installation that reduced civil cost and installation time scale
Low operation and maintenance cost
Project Description
F J Needs Ltd WWTP is a bespoke effluent treatment system and is based on our high-performance modular Eco-SAF biological system comprising of:
Inlet pump chamber
Mechanical brush screen for solids separation
Hydraulic flow control
Up-flow Bioreactor based on Submerged Aerated Filter (SAF) technology
Final clarification in a Lamella Clarifier
Flow
4m3/day
Average COD
5900mg/l
Average BOD
3500mg/l
Average S/S
2500mg/l
Design flow
0.12l/s
The effluent treatment system is to treat the site wastewater to the minimum trade effluent quality as follows:
Parameter
Unit
Discharge standard
COD (settled)
mg/l
< 1000
BOD (5 day settled)
mg/l
< 500
Suspended solids
mg/l
< 120
Preliminary treatment:
Comprising of the following elements
Inlet pump station c/w Duty/Assist set back vortex impellor submersible pumps
Mechanical brush screen
Secondary Treatment:
The Eco-SAF module – the essential biological stage where bacterial microorganisms are cultivated and actively consume the suspended organic material found in the decanted liquid from the primary process. The aerated cells are equipped with a fine-bubble aeration system distributing the oxygen required for a healthy and stable population of heterotrophic bacteria. Oxygen is supplied to the air diffuser system by a side channel blower that requires minimum maintenance.
The module is a series of aerated cells and anoxic zones. The aerated cells are also furnished with fully submerged bio-film growth media to ensure that the microorganisms have a substantial area for growth and a stable environment. In addition, full floor coverage with the aeration diffusers ensures maximum oxygen transfer and no ‘unaerated’ dead zones as in circular tank designs.
Final Settlement – Clarifier. Any remaining solids (Humus) are settled out of the biologically treated effluent with a lamella pack and returned upstream as enriched activated sludge (RAS) to be absorbed in fresh wastewater. The lamella pack increases the active area and therefore improves the settling ability of the sludge within a small footprint.
The Eco-SAF system was selected for the following reasons:
Predictable performance
Lower operation and maintenance costs
No interruption to the process whilst servicing the aeration system
Modular design that can be added if production is increased
Better whole life cost
Easy installation with minimum excavation required
Life expectancy of over 30 years with minimum maintenance
No internal moving parts
Easy to de-sludge
Manufactured to Quality Management System ISO 9001