Sewage Treatment Plants



Sewage Treatment, or Domestic Wastewater Treatment, is the process of removing contaminants from wastewater and household sewage, both runoff (effluents) and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants.

Its objective is to produce a waste stream (or treated effluent) and a solid waste or sludge suitable for discharge or reuse back into the environment. This material is often inadvertently contaminated with many toxic organic and inorganic compounds.

HydromagxTM employs proven European designs for treating Sewage and an exhaustive range of Industrial Effluent. The system achieves the dual goals of meeting the regulatory norms of Effluent Discharge as well as Recycling of Treated Effluent for reuse for auxiliary or process needs.

Over the years, HydromagxTM R&D and Application Development Teams have also developed the following technologies to treat wastewater and convert them fit for reuse, in line with our commitment to offering leading edge ZERO LIQUID DISCHARGE Treatment of Wastewaters.

SAFF (Submerged Aerobic Fixed Film Reactor)
FMBR (Fluidized Media Bio Reactor)
SBR (Sequential Batch Reactor)
MBR (Membrane Bio Reactor)


SAFF System

The HydromagxTM SAFF (Submerged Aerobic Fixed Film Reactor) incorporate the advantages of fixed film technologies and combines with them the fine bubble diffused aeration techniques, to get a highly efficient biological treatment unit. It has as its main components, the bio media and fine bubble diffused aeration grid. With the higher surface area of bio media, higher organic loading rates are enabled, thus reducing the overall size required of the aeration tank. This leads to a considerable reduction in civil and fabrication costs.

The system configuration enables better oxygen transfer efficiency with plug flow conditions. Submerged fixed film growth in SAFF reactors sustain good microbial growth even in adverse conditions and also handles shock loads very well. Sludge production is low; no sludge recirculations is required and mean cell residence time is enhanced. Air requirement is based only on the organic load and mixing requirements are not called for, as this system is primarily an attached growth system. The media is a randomly packed polypropylene filter media and has wide application in biological treatment systems. The reactors are up-flow or down-flow fixed film type, based on either anaerobic or aerobic treatment processes.

The media provides optimum effective surface area for biological growth. The three dimensional liquid distribution due to unique dimensional design, increases hydraulic retention time and ensures excellent gas-liquid distribution within packed bed reactors, thus enhancing the treatment efficiency.

Features:

• Handles wide range of hydraulic and organic loads.
• Media is designed to orient within the filter so that no surface generates a continuous vertical or horizontal position.
• Random dumping with simple structural supports helps in easy installation in reactors of varied geometric shapes.
• Polypropylene, a recyclable material of construction, has a high resistance to chemical attack and ensures longer operational life.
• Easy upgradability for the rock/mineral filters.


SAFF media is having a cylindrical configuration with a diameter to height ratio ~2.50. It has four continuous internal radial ribs and two concentric circular sections. The external surface with unique etching design can hold the attached film withstand normal sheering forces.

When installed in random configuration, it maintains uniform passage of air and waste water in all direction, throughout a 360° field.

SAFF media is a randomly packed polypropylene filter media and has wide application in biological treatment systems. The reactors are up-flow or down-flow fixed film type, based on either anaerobic or aerobic treatment processes.

The media provides optimum effective surface area for biological growth. The three dimensional liquid distribution due to unique dimensional design, increases hydraulic retention time and ensures excellent gas-liquid distribution within packed bed reactor, thus enhancing the treatment efficiency.

Features:

• Handles wide range of hydraulic and organic loads.
• Media is designed to orient within the filter so that no surface generates a continuous vertical or horizontal position.
• Random dumping with simple structural supports helps in easy installation in reactors of varied geometric shapes.
• Polypropylene, a recyclable material of construction, has a high resistance to chemical attack and ensures longer operational life.
• Easy upgradability for the rock/mineral filters.

SAFF media is having a cylindrical configuration with a diameter to height ratio ~2.50. It has four continuous internal radial ribs and two concentric circular sections. The external surface with unique etching design can hold the attached film withstand normal sheering forces. When installed in random configuration, it maintains uniform passage of air and waste water in all direction, throughout a 360° field.

The formulation adopted is resistant to ultra-violet degradation, aging and erosion and comply with all material test standards

Advantages of SAFF System

• No foul smell from the treatment plant area.
• Less sludge production.
• Easy operation & maintenance.
• Low operating cost.
• Less Space

FMBR System

The Fluidized Media Bio Reactor (FMBR) technology is based on a proprietary media and a unique air distribution system. This media provides a large protected surface area for biological attached-growth. In the FBBR tanks and reactors, the media is subjected to an aeration process for maximum oxygen and mass transfer. The result is a very high rate of Biochemical Oxygen Demand (BOD) reduction per volume. The high density of attached living biomass makes the process much more resistant to toxic shock, sludge bulking, and other problems that can plague pure suspended growth systems. FMBR technology allows for biological treatment in much less time and space required than for conventional bio-treatment systems currently utilized.

A typical configuration is depicted below. Air generated from air blower is diffused into the bottom of the reactor vessel. The oxygen supply is automatically adjusted to maintain the proper dissolved oxygen level in the vessel. A high concentration of biomass develops because of the large media surface area, abundant oxygen and optimized mass transfer conditions. Excess biomass is automatically sheared at the discharge point for removal.

BENEFITS

• Compact design.
• High throughput-to-size ratio
• 95% BOD reduction achievable
• Low operator attention
• Low capital and operating cost, and virtually odor-free
• Customization is easy
• Easy and quick installation
• Continuous uniform growth of biomass
• Continuous uniform sloughing of excess biomass
• Continuous uniform liquid distribution
• Resistant to clogging
• Eliminates dead spots

SBR – An Overview


• Sewage Treatment Plant using various technologies has progressed steadily over recent years out of which continuous feed; batch discharge reactors provide an important option in treatment selection. Only now are the advantages and potential of continuous feed, batch discharge technology becoming apparent to the general market.

• Continuous Feed, Batch Discharge are not the Sanitary Engineers panacea. They are however, uniquely suited to many wastewater applications. The reactors have been applied with success in both industrial and municipal applications. A practical understanding of what batch reactors are and how, when, where and why they work best is mandatory in today’s market to select the most practical and cost effective treatment process for a given application. Proper process design and equipment selection can achieve capital and energy savings of up to 60% compared to conventional activated sludge designs.

• Continuous Feed, Batch Discharge termed as Intermittently Decanted Extended Aeration or SBR for short is an innovative sewage treatment plant that is operating at various sites in India and Bhutan. A few examples of these innovative sewage treatment plants are outlined below. Unlike conventional sewage treatment plants, which take up large open spaces and are rather odorous, these new innovative sewage plants use the latest biodegrading technologies requiring very little operating space, are free from odors and can provide a town with an added supply of clean water.

PURPOSE

• These innovative sewage treatment plants are based on biological processing utilizing repetitive sequence of aeration and non-aeration followed by a period of settling and decanting. Aeration is achieved by pumping air through the sewage at a very high rate. During the settling period, the solids settles out as sludge and the treated water is removed (decanted) where it then undergoes a final treatment step to ensure the destruction of harmful micro-organisms by using Filtration and Ultraviolet Light. Because sewage is mostly water, very little sludge is actually produced and therefore, depending on the size of the plant and its throughput, the sludge need be removed once every couple of months. The treated sludge can then be used as fertilizer after treatment.

• Properly applied, aeration ensures that little or no odors are produced. This is due to the fact that aeration encourages the growth of aerobic bacteria (i.e. oxygen consuming bacteria) instead of anaerobic bacteria that produce smelly byproducts resulting from the breakdown of nutrients in the sewage.

• The big advantage that this technology has over conventional systems is its ability to treat sewage within a short period of time at a reasonable cost. These systems use only minimal operator attention, often requiring only one person to operate the system and can be operated by a member of the community. Furthermore, these plants take up very little space and we provide routine maintenance and operator assistance at a very low cost to the community.

SBR Operation Philosophy

• SBR actually represents a very elementary form of treatment process known as FILL and DRAW. Wastewater added to a reactor is treated to remove undesirable components, and is subsequently discharged. The SBR reactor is a self- contained system incorporating equalization, aeration and clarification, within the confines of a SINGLE basin.

OPERATION

• Normally the process follows the basic steps of AERATE, SETTLE and DECANT. The actual cycle time will vary with the sewage results desired. If only BOD reduction is desired, a cycle time as 3 hours may be used. If further treatment, to obtain nitrification/Denitrification/f.e is required, the cycle time can be extended to accommodate the process requirements.

• The AERATE phase in the SBR system is typically time/level controlled and can be adjusted depending on the required removal efficiency. The AERATE phase is followed by the SETTLING PHASE. The settling represents the quiescent phase during which no aeration or mixing occurs and is also time\level controlled. The last step is the decant step representing the discharge of clarified sewage controlled by level in the reactor.

• Aeration Phase : Depending on capacity (max 4 Hrs).
• Settling Phase : Normally 45 to 60 minutes.
• Decant phase level within 15-30 min : Reduction from maximum to minimum.
• Disinfection of treated water will be done using Hypo chlorite solution. For this hypo chlorite tank and dosing pump will be provided.
• Sludge removal is less and is totally digested and hence has no odor. The sludge is removed by means of submersible pump in the SBR reactor. The frequency of sludge removal will be once in a month (minimum) to a maximum of 3 months. The sludge can be dewatered using sludge drying beds or other dewatering device or can be directly applied as manure.

MBR System

Membrane Bio Reactor (MBR) process is a combination of biological wastewater treatment and a membrane filtration process using submersed flat sheet membranes. The Hydromagx™ MEMBROC MBR System is a compact wastewater degradation solution combining a biological decay step with a next step polishing by High Performance Membranes. The untreated wastewater is fed to an aerated tank - the bio-reactor where the organics are oxidized by the activated sludge. The activated sludge solution then enters a membrane filtration unit where water separates from the sludge. The sludge retains in the bio-reactor, while the permeate is of a grade ready for instant re-use or of RO Feed Quality.

A combination of biological treatment with membrane treatment has additional benefits compared to the conventional activated sludge system in municipal wastewater treatment - high biological mass concentration; instant re-use grade treated effluent and less sludge creation and handling.

The above advantages results in a low footprint-high efficiency system that is increasingly being viewed as a major superiority point in regions with population pressures while simultaneously addressing the concerns of a sustainable environment!


For high MLSS streams > 15,000 mg/l including applications in treating Municipal & Industrial Sewage - in Community Developments, Hotels, Labor Camps and as well in many other Industrial Process Wastewater Treatment applications.



Advantages of the High Performance Submersed Flat Sheet Membranes used in Hydromagx™ MEMBROC MBR Systems:-

1. High water permeation rate per unit area of membrane in sewage treatment
2. Resistant to stain
3. High chemical resistance
4. Consumes less energy

HYDROMAGX™ MEMBROC MBR Treatment System - Typical Results

BOD : < 5 ppm.

COD : < 30 ppm.

TSS : <1 ppm.