Biofilter>>

Principle:

McWong's Biofilter is composed of a filter bed, aerator system, impulse backwash sludge draining system, distribution system and and effluent collection system.
The raw water enters the base of the biofilter through an influent distribution trough. Air distribution equipment is also installed at the base of the unit. The air/water mixture is equally distributed through the unit as it rises through the filtering materials. Large quantities of organisms adsorbed to the surface of the filtering materials degrade the dissovled organics and NH3 in the influent stream. The effluent from the unit is drained from the top of the system. During the filtering process, the biofilm layer increases, therefore backwashing is periodically required.

Characteristics:

Large surface area to volume ratio, high activity of biofilm;
Concurrent flow of air and water, low filtering resistance and high filtering velocity;
Superior desing makes is extremely clog resistant, high rate of oxygen utilization;
A unique backwashing process provides a high dregree of automatization.

Application areas:

Raw wastewater pretreatment for streams with low COD levels.

Raw wastewater that requires ammonia removal.

Raw wastewater that requires phosphate removal.

Recycled water that requires additional ammonia removal or suspended solids removal in order to meet landscape water quality standards.

EGSB>>

Component part

(l) Influent distributor
(2) Reaction area
(3) Three-phase separator
(4) Effluent circulation system and drainage system
(5) Air chamber
(6) Scum skimming system
(7) Sludge drainage system

Principle:

The EGSB (Expanded Granular Sludge Bed) reactor is an application of solid fluidization technology in the organic wastewater bio-treatment field.

In the EGSB reactor, granulated sludge is used as a carrier for active biological growth with a very high surface area to volume ratio. This provides excellent BOD removal through the EGSB unit. When the organic wastewater and the produced methane flows through the bed from the base of the unit to the top of the unit, a different relative movement between the granulated sludge and the wastewater occurs, which will result in different work states of the sludge bed. When the upflow velocity is relatively low, the granular sludge in the tank stays relatively static. But when the upflow velocity reaches a certain level, the pressure becomes equal to the weight of the granulated sludge per unit bed. Then the bed begins to expand and the bed is considered to be fluidized.

McWongs EGSB operated within a tight velocity and pressure range to keep the volume expansion between 10 to 30%. Within this operating parameters, the influent flow rate is relatively low, which not only ensures the contact between water and the granular sludge to accelerate the biological reaction but also decreases or eliminates the condition of bottom overload that often occurs in a static bed such as a UASB, which will increase the capacity of organic load or poisonous materials.

Characteristics:

The anaerobic EGSB process is a relatively new technology that was developed based on the anaerobic UASB process. It has many advantages such as a high sludge concentration, high loading rates and high COD removal rates (>85%). Additional advantages are:

Good ability to resist impulse loadings. It is very suitable to fit situations where there is a great fluctuation both in quantity and quality.

Low floor space and a high gas production volume.

Application areas:

High COD wastewaters

In most locations where UASB reactors can be used

Wastewaters from the many food industries

Wastewaters containing alcohol