36 / June 2016 / Indian Plumbing Today

PORTABLE ZERO DISCHARGE (ZERO-D) TOILETS AND URINALS

AMRIT F. SANGHAI

Today, domestic and industrial sewage treatment is of utmost importance; in fact, as important as industrial effluent treatment because one of the major concerns of water pollution is sewage. Sewage introduces pathogenic microorganisms which can cause various water borne diseases, some of which could be fatal. Therefore, there is a need for environmentally sound management of sewage related issues to regulate discharge of sewage and reduce the health risk associated with it. Several physical, chemical and physico-chemical treatment technologies have been de-veloped for the treatment of sewage. However, their use is constrained by key factors such as space, cost and efficacy. A new Zero-D Sus-tainable Portable Toilet System based on most advanced hydrolysis and oxidation technology has been developed. This process breaks the molecular linkages of pollutant for easy oxida-tion/mineralization and helps to reduce its COD, BOD, TDS, color and odor. The system solves the problem associated with sewage treatment and converts sewage into clear and odorless water, meeting discharge specifications. The treated water can be recycled back into the flush tank and becomes a Zero-discharge (Zero-D) system. During the annual maintenance, a small amount of odorless inorganic substance needs to be cleaned.

These advanced Zero-D toilets and urinals are eco-friendly as the process does not use harm-ful external chemicals, UV or electro-chemicals. They do not produce harmful by-products, are energy efficient, economical, and are alterna-tives to current technologies. They are easily installed on site with minimum foot print area as filtration, sedimentation, hydrolysis, oxidation and disinfection happen in single compact unit.

Zero-D green portable toilet - advanced hydrolysis and oxidation technology. This pro-cess breaks down fecal waste into clear, odor-less and pathogen free water with some gases released by using Magikit which contains nat-ural concentrated enzymes. In the Magitank a five step treatment process has been installed in which sewage is treated by liquefaction, hy-drolysis, oxidation, de-nitrification and disin-fection. The treated water becomes colorless, odorless and pathogen free which can be recy-cled into the flush tank as shown in figure 1. The treated water quality complies with discharge and recycling standards of central pollution board. During the annual maintenance, a small amount of odorless, non hazardous inorganic substance needs to be cleaned and can be used as fertilizers.

Figure 1: Schematic diagram of Zero-D green portable toilet

SN examining the Prototype of the Zero-D Toilet at IPA Seminar, Jaipur

1. Figure 1: Schematic diagram of Zero-D green portable toilet

2. SN examining the Proto-type of the Zero-D Toilet at IPA Seminar, Jaipur

1. 2.

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Enzymatic Treatment Technology:

An enzyme is a chemical catalyst that breaks up long, complex waste molecules (hydrolytic reac-tion) into smaller molecules which can then be oxidized or digested directly by other enzymes and bacteria. Enzymes are manufactured and used by bacteria in order to digest or mineralize the waste. Magikit is a dry free flowing powder and is a concentrated source of hydrolytic, oxi-dative, denitrifying enzymes and eight strains of natural bacteria that are genetically capable of producing concentrations of enzymes in waste treatment systems under aerobic conditions. Magikit is used for reducing the BOD, COD lev-els as well as reducing the sludge volumes odor and color in the effluent and sewage treatment plants. With use of Magikit, organic compounds get converted into volatile fatty acids and then into CO2 and H2O, and organically bound ni-trogen, sulfur and phosphorus get transformed from organic forms to mineralized forms (i.e., NH3, NH4, NO3, SO4, and PO4).

Enzymatic Treatment Process:

The purification works provide primary, sec-ondary and tertiary treatment processes viz. five steps –liquefaction, hydrolysis, oxidation, de-ni-trification and disinfection

Liquefaction of sewage

Primary treatment consists of liquefaction or dissolving of solid or semi solid fecal matter into liquid. This enables the hydrolytic enzymes to act very efficiently on the soluble organic and inorganic compounds.

Hydrolysis

Secondary treatment uses enzymes for hydroly-sis, oxidation and denitrification to convert or-ganics into simple compounds and mineralized inorganic compounds with release of CO2 and N2 gas.

Stepwise depolymerisation (hydrolysis) of high-ly polymeric substrates is usually the first and overall rate-limiting step for the mineralization

of organic matter in activated sludge and an-aerobic digested sludge treatment systems. The removal of organic matter by enzymatic and biological oxidation depends on the molecular weight and surface area of pollutant to easily add either oxygen or to remove nitrate. The target pollutants to be destroyed must undergo mass transfer into the monomeric and oligomeric sub-strates (< 1000 Da molecular weight). The pro-prietary hydrolytic enzymes (Magikit) in sludge degrade the complex organic matter (polymeric substrates such as proteins, lipids and carbohy-drates) into low molecular-weight intermediates by the action of extracellular hydrolases. These low molecular weight compounds are in turn easily oxidized or assimilated by the cells and used as a source of energy and carbon.

Oxidation

Enzymatic oxidation treatment is one of the im-portant sewage treatment steps. The sewage is treated using Magikit which is blend of green different oxidase and peroxidase enzymes. Some enzymes also do the symmetric break down of some of the water molecules and pro-duces OH° free radicals which is utilized as a strong oxidizing agent for the oxidation and mineralization of the sewage. With this step upto 80% COD and BOD of the sewage goes down. And, organic molecules get converted into CO2, H2O and energy.

Denitrification

The majority of nitrogen in fresh urine is urea. Urea dissociates to ammonium in a reaction catalysed by MAGIKIT (Equation 1). Ammo-nium is in equilibrium with dissolved ammonia (Equation 2); and dissolved ammonia is in equi-librium with gaseous ammonia (Equation 3).

There needs to be sufficient alkalinity, oxygen and biomass present to effectively convert all ammonia and our MAGIKIT provides suffi-cient oxygen to covert ammonia into first nitrite (Equation 4) and then nitrate (Equation 5) by two steps and finally helps to intensify denitri-fication process by which nitrate get converted into nitrogen gas which will escape from the system (Equation 6)

CO(NH2)2 +3 H2O → 2NH4+ + HCO3 + OH- 1

NH4+ + OH- ←→ NH3 (aq) + H2O 2

NH3 (aq) ←→ NH3 (g) 3

NH3 + O2 → NO2 4

NO2 + O2 → NO3 5

2NO3 → N2 + 3 O2 6

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Disinfection

In tertiary treatment, the technology uses residu-al OH° free radicals generated during oxidation for the disinfection of pathogens. Also, if site conditions permit, the energy from the sun is uti-lized to destroy pathogens further. The effluent is then safe to be discharged or recycled.

The treated water becomes colorless, odorless and pathogen free, which can be recycled for flushing or for gardening/landscaping. The treat-ed water quality complies with discharge and re-cycling standards of pollution board.

Amritlal F. Sanghai is Founder Director of Everlast Composites Pvt Ltd. and Director, House of Doors, Mumbai

Editorial Note:The views expressed in this article are of the author and not of IPT. He can be contacted on +91 9323657415.

Possible applications - homes, farms, farm-houses, pre-fabricated structures, construction sites, warehouses, cottages, cabins, grounds and exhibitions, gardens and forest, golf courses, public facilities, etc.

Advantages of Zero-D green toilet-

• A (patent pending) clean technology. • Zero discharge system - no waste generat- ed from the toilets after treatment • Green rated product - no need to add ex- ternal chemicals/aids. • Efficient - treat the waste in just hours in- stead of days or months. • Eco friendly - works effectively on human waste without producing pathogens. • Economical - cost effective solution for sewage water treatment. • Treats the waste in the first place (treat- ment at source itself). • Clean tech system - treated water will be colorless, odorless, free from pathogen, and can be recycled for flushing and clea- ning purpose. This saves water. • Standalone - does not require any sewage line connection or additional septic tanks for waste treatment. • Scalable - can be designed for all sizes. • Maintenance free - works on fit and for- get principle. • Retrofitted - can be fitted without any sig- nificant modification. • Less footprint - compact and can be in- stalled anywhere on site. • Portable - light weight, easily transport- able. • Durable - weather proof and long func- tional life. • Precision engineered - saves space, energy, time and environment. • Developed in collaboration with world’s renowned university and consultants. • Tested in recognized lab. • No need of any approval - since the whole waste stream is recycled, approvals are not normally required. • Treated water matches pollution control board’s standards.

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AMRITLAL F. SANGHAI