Waste Water Treatment Plants (WWTP)

General Features and Technical Information

MORF INDIA offers a wide range sewage treatment plants (STP), sullage treatment plants (SuTP) and kitchen effluent treatment plants (KETP) by deploying divergent technologies chosen based on the site conditions and the customers' preference for technologies. However, we do not deal with industrial effluent treatment plants (IETP).

The treated water meets the permissible discharge standards stipulated by the pollution control board. This water can be safely used for specific applications as recommended by us.

MORF INDIA designs WWTP for reduced ownership cost, user-friendly operation, easy maintenance and lower foot print. All the WWTP systems are custom-built and manually operated. Membrane Bio Reactor (MBR) plants can be provided with fully automatic provisions.

These plants can be installed in individual houses, apartments, townships, hotels, restaurants, colleges, schools, hostels, factories and municipalities.

The common technologies adopted and efficiently used by us to aerobically treat the waste water are Activated Sludge Process (Extended Aeration System), Fluidized Bio Bed Reactor(FBBR), Submerged Aerobic Fixed Film Bio Reactor (SAFF)and Membrane Bio Reactor (MBR).

Activated Sludge Process (ASP)

The conventional ASP is a time-tested methodology and works well in the treatment of waste water with high volume flow rates. The extended aeration process is economical for larger flow rates compared to media based reactors. In this process, different types of aeration equipment are used. viz., High-speed floating aerators, fixed aerators and diffusers. The choice of aeration techniques depends on factors like tank height, flow rates, space availability and possible augmentation of the system in future.

Fixed aerators come with a customized impeller connected to a gear reduction system with drive. The impeller provides optimal agitation to facilitate rapid oxygen transfer and the technology results in lower power consumption. Fixed aeration systems are erected with proper access for routine maintenance and adhering to all safety aspects.

Diffused aeration system is used to provide highly efficient biological treatment. Twin lobe type air blowers provide the oxygen required for the oxidation of organic pollutants. The air is distributed through fine bubble membrane type diffusers. The MLSS concentration in the aeration tank is maintained at 3000 - 4000 mg / ltr by re-circulating the biomass. Diffused aeration systems provide several advantages over the surface aeration techniques.

Since oxygen transfer is done by means of diffusers placed at the bottom to ensure uniform flow of dense fine bubbles of air, the aeration tank can be designed into any shape to suit site requirement. Diffused aeration systems can operate up to a maximum of 4 mtrs liquid depth which in turn translates to smaller tank size and smaller foot print for the WWTP.

Diffused aeration systems are also highly flexible to site location (i.e.) the system can be located in a building basement or below ground level where there is space constraint.

However, activated sludge process has certain limitation like large foot print, extensive civil works and longer hydraulic retention time.

Submerged Aerobic Fixed Film Bio-Reactors (SAFF)

This process involves the utilization of a specifically developed fixed film media in UV-stabilized polypropylene. The UV-stabilized and chemically compatible propylene media is immersed in the aeration tank and enhances the biological degradation process. The media surface provides an ideal condition for the growth of micro organisms which in turn rapidly degrade the incoming organic contaminants. The sludge built on the surface is detached by the rising mass of fine air bubbles through the media. The use of this special media also reduces the size of the aeration tank substantially thereby reducing the overall footprint of STP.

Air required for the process is provided by means of twin lobe type air blowers which maintain the required flow of air through fine bubble diffusers made up of either EPDM / silicon rubber. The diffusers are located at the bottom of the aeration tank and are placed in such a manner as to ensure a uniform flow of dense fine bubbles of air from the bottom to top. The generated biomass is settled in the downstream clarifiers.

Fluidized Bed Bio Reactor (FBBR)

FBBR is also known as Moving Bed Bio-Reactor (MBBR) and Dynamic Bio-Bed Reactor (DBBR).

The FBBR also utilizes a similar media based aeration. In FBBR, custom-designed media in the shape of small cylindrical wheels is used. The density of the media is maintained in a manner where it remains floating at all times and easily moves around within the aeration tank. The small size of the media and its random movement within the tank provides better sludge dispersion and enhances the bio-degradation rate of organics present. FBBR reduces the hydraulic retention time, can handle higher BOD loads and tolerates fluctuations in inlet BOD and COD load.

FBBR media is manufactured of rigid and high quality UV stabilized polypropylene thus giving the media high strength and good durability. Air dispersion is carried out by providing twin lobe type air blowers to maintain the required flow of air through special piped air grids.

FBBR technology helps in reducing the plant footprint, civil works and hydraulic retention time by over 50%. The quality of treated sewage is significantly better than the activated sludge process.

Membrane Bio Reactors (MBR)

The Membrane Bio-Reactor (MBR) technology combines ASP with a membrane based liquid-solid separation process. This process incorporates reinforced hollow fibre Ultra Filtration (UF) membranes specifically designed to meet the requirements of waste water treatment. MBR systems combine aeration, clarification and tertiary filtration into a simple and cost-effective process that reduces capital and operating costs. These membranes are either immersed in the aeration tank (also may use a separate membrane tank) or mounted next to the aeration tank. The result is consistent, high quality effluent suitable for any discharge or reuse application.

MBR is the latest, most advanced and globally acclaimed waste water treatment technology. In this technology, the foot print of the system is significantly reduced and the quality of the effluent is far better than all other processes. The quantity of sludge generated in MBRs is only 1/4th of the conventional systems on account of better bacterial digestion. MBRs produce superior quality effluent by using a combination of low-pressure UF membranes and a suspended growth biological reactor. With absolute and nominal pore sizes of 0.04 and 0.10 microns respectively, these MBRs ensure a virtually particulate-free effluent. These UF membranes replace the solid separation function of secondary clarifier and the polishing function of the granular activated carbon that are found in conventional treatment plants. By eliminating the need for sludge settling, MBRs can operate at very high MLSS (Mixed Liquor Suspended Solids) concentrations in the range of 10,000 to 14,000 mg/litre which is three to five times greater than conventional plants resulting in more compact (lesser footprint) units. This enhanced biomass concentration in the membrane bio-reactor process allows for very effective removal of both soluble and particulate bio-degradable materials at higher loading rates. The increased sludge retention time (SRT) ensures complete nitrification even under extreme cold weather operating conditions.

MBR requires very short hydraulic retention time (HRT) and considerably less civil works. Highly automated PLC operations make the plant operation less labour intensive and more consistent.

The cost of building and operating an MBR is usually higher than conventional waste water treatment. However, this technology has become increasingly popular and has gained wider acceptance throughout the industry. In developed urban areas where the footprint of the treatment plant is considered a limiting factor, MBR is considered a desirable option.

MORF INDIA offers the latest generation state-of-the-art tubular membrane modules located externally and also the submerged hollow fibre-based modules.