LUCAS®, Leuven University Cyclic Activated Sludge system

LUCAS® is the family name of a complete range of wastewater treatment processes developed by WATERLEAU.

LUCAS® stands for Leuven University Cyclic Activated Sludge and, as this name suggests, it is a cyclically opera ting activated sludge system with a compact and modular design.

LUCAS® also stands for Low-cost Unobtrusive Compact Advanced Sustainable, summarising the advantages of this technology.

LUCAS® combines the advantages of the conventional technology and of the fill-and-draw/SBR technology. As in the conventional system, the reactor volume and the level in the tanks are always constant. It is a continuous system for both influent feed and effluent discharge. As in an SBR system, the reactor operates according to a time controlled process cycle that allows for the alternation of all essential processes (accumulation, regeneration, sedimentation) in a single compartment.

Over the years, the LUCAS® family of wastewater treatment systems has been extended with new members, each showing specific additional features. Combinations of these features are also possible:

LUCAS® NP : with biological nutrient removal

LUCAS® two-stage aerobic : 2 LUCAS® systems in series (high load - low load)

LUCAS® anaerobic-aerobic : anaerobic pre-treatment, followed by an aerobic post-treatment

multiple-lane LUCAS®

undercover LUCAS® : zero-emission WWTP

chameleon LUCAS® : zero environmental impact WWTP

closing-the-loop LUCAS® : with effluent recycling

LUCAS® lagoon

Click here for the different LUCAS®-systems

How it works

The typical features of the LUCAS® system are:

the aerobic biological reactor consists of 1, 2, 3, or 4 units.

constant reactor volume and level.

influent can be directed to every unit.

effluent can be discharged from every unit.

every unit can be aerated.

sludge can be wasted from every unit.

hydraulically interconnected units which can be separated by closing the common gate valves.

all the equipment follows an operational sequence controlled by a PLC

completely redundant system Scheme of a LUCAS®-3 system

The following illustrations show how the LUCAS®-3 system alternates between 3 phases in such a way that in every reactor unit there is a succession of the 3 processes accumulation, regeneration and sedimentation. Effluent is discharged from the current sedimentation unit. Sludge is wasted from the bottom of the current sedimentation unit. Between each main phase there is an intermediate phase to allow a smooth transition from one main phase to the other.

Hydraulic flow scheme of a LUCAS®-3 system

Advantages

Compact and modular: common walls, easy to extend, easy to cover.

Continuous operation, continuous inflow, continuous outflow: allows for use of smaller pump capacities and piping diameters.

Constant reactor level: no need for moving weirs, simple construction.

Constant reactor volume: 100% use of the volume, no changing pressures on walls.

Identical reactor configuration: every compartment has the same size and the same equipment.

Symmetrical cyclic operation: every compartment follows the same process cycle, which gives a very equal sludge distribution and an equal oxygen demand in every compartment. The optimal alternation of phases allows for the selection of well settling sludge flocs.

Complete control flexibility and the optimal circumstances for all essential biological and physical ­processes.

As in SBR systems LUCAS® favours well settling sludge formation ('integrated selector effect').

Applications

Municipal wastewater treatment

Industrial wastewater treatment

The selection of the type of LUCAS® system depends mainly on the wastewater characteristics, the discharge limits and the surrounding environment.