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Aesthetic look of treatment system

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Bio diversity at one of the ecologically restored lakes

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Ecologically restored Ahar river

Soil Scape Filters

STP for Industry - the Soil Scape Filter in action

Ecotechnological Systems PDF Print E-mail

Ecotechnological Systems
Applications of ecological engineering principles, environmental chemistry, microbiology, interactions of organisms and succession of biological communities are very useful to consume organic and inorganic pollutants from the wastewaters and bioconvert them into non-toxic form, finally transferring the elements in the ecological cycles. These eco-transformations, eco-conversions and degradation or bio-utilization of pollutants - nutrients are the part of ecological cycles - biogeochemical cycles. In the ecotechnology, attempt has been made to apply natural flora and fauna in well-designed manner to develop technologies like Green Bridge, Green Lake Eco-Systems, Green channel, biox (biological oxidation) and Stream Eco-Systems.
•    Effective removal of dense colour and foul smell from the wastewater stream.
•    Decontamination of the organic and inorganic pollutants present in the stream.
•    To achieve the stream flow rate constant throughout by maintaining the nalla basin and bed slope.
•    Implementation of the treatment process prioritizing the ecological and economical aspect. 
•    Effective use of the treated water for the further beneficial use.

Soil Scape Filter
It is the simulation of natural filtration process of water through the good vegetated soils and fragmented rock materials below which purified water percolates down in the form of groundwater. Soil Scape filter contains layers of bio-active (i.e. biologically activated) soil - ECOFERT - developed from non-toxic and non-hazardous wastes. The process harnesses ecological principles of interactions and interrelationships of biota with their environment and eco-transformations of substrates into assimilable form by treating, transforming and detoxifying the pollutants using solar energy.

soil scape
It has been experienced in school in Baroda that 50 cu m sewage without segregation of solids is being treated using Soil Scape filtration with use of 8 units electricity, since there is no gravity benefit. So, only pumping is needed. The treated BOD is less than 16 mg / L since from 2 years the plant became operational. By conventional method, they would have required at least 50 units of electricity every day with some additional cost for consumables.

In one food processing unit about 50 km from Pune, 30 cu m industrial wastewater having COD more than 1000 mg / L and BOD more than 440 mg /L is being treated from last 4 years with consistent outlet COD and BOD less than 80 mg / L and 32 mg / L respectively. They have found it very cost effective as far as electrical consumption is required for conventional mechanistic systems.

The coloured effluents from the textile units are also treated using Soil Scape filtration system. The colour reduction in two stage filtration system is consistently is more than 90%. These plants are successfully running in Baroda and Jaipur from last 3 years. The precursors of dyes and pigments are also treated considerably - upto 95% COD reduction – the biological system found to be adapted to such difficult pollutants.

Hydrasch Succession Pond
It applies ecological successions of aquatic plants depending on characteristics of incoming effluents. Various green plants are successfully employed to treat organic and inorganic pollution using phytofiltration and phytoremediation processes. It is open water system, confined by rooting plants, surface covered by floating plants with various trophic levels flourishing depending on the limiting factor of incoming nutrients.

succession pond
his was found to be very effective for the treatment of metallic waste with domestic wastewaters. Mixed wastewater contained heavy metals like hexavalent chromium, nickel and copper etc. The natural phenomenon of adsorption of positively charged metals on negatively charged organic is one of the key processes in this treatment system. The metal reduction is noted upto 99% in the system.

Stream Ecosystem
It uses natural slopes of polluted drains, beds, banks of streams or pond to augment the aerobic activity in water by creating turbulence and providing shallow depths to allow sun – light to penetrate the water column. This is a simulation of stream flow in the wilderness. It facilitates the free flow of water splashing due to stones and cascades.  It is observed in nalla treatment project in Pune installed in 2004 that the dissolved oxygen in the water increases multifold – in some already installed systems. This increase is upto 90 – 120 times i. e. (from 0.1 to 8 – 12 ppm)9.
Natural streams, rivers and lakes have their own in - built purification system, the winds, natural slopes, stones, sand, biological growth and complex food web help in the purification process. The basis of food web is nothing but utilization of one's waste by another as it's food. Nature has her own living machinery of detritivorous microbes and other living species to consume wastes. These principles have been harnessed in the Stream Eco-System Technology.

stream ecosystem

Phytofiltration and Biox Process
It involves the use of plant fibres, roots to remove suspended solids from wastewater effectively in a well designed tank. In this techniques normally, the floating plants are used to facilitate the removal of solids by biosorption methods.
Biological oxygenation process is defined as the transfer and dissolution of oxygen with the help of certain green plants and algae. It has been observed that in the unpolluted mountain streams the oxygen content in the water rises up to 19 ppm.

Green Bridge Technology
The Green Bridge ecotechnology applies filtration power of biologically originated cellulosic / fibrous material in combination with sand and gravels and root systems of green plants.

green bridge

It’s an innovative approach to minimize the cost of pollution treatment when the cellulosic / fibrous materials like coconut coir or dried water hyacinth or aquatic grasses are compacted and woven to form a bridge / porous wall like structure strengthened by stones and sand. All the floatable and suspended solids are trapped in this biological bridge and the turbidity of flowing water is reduced substantially. The green plants growing there help in absorption of soluble substances including heavy metals.

First of such innovative system was developed in College of Military Engineering (CME), Pune in 2003. The system was installed on highly polluted with industrial and domestic wastewater having flow more than 70 MLD. It was joint efforts of SERI with CME, Clean River Committee and Cummins Foundation. Then two more such projects were developed on another highly polluted nallas in Pune. The advantage of this technology is that it takes 1/5 time that of conventional systems to install and commission. It does not require any additional land or electricity or cement. It developed with locally available material only. Even after 4 years of installation, the parameters of treated water found to less than that of receiving river Mula.

Green Lake Technologies
It can be integrated with Green Bridges. Green Lake system uses floating, submerged or emergent aquatic plant species. These can be termed as macrophyte ponds also. Macrophytes are capable to absorb large amounts of inorganic nutrients such as N and P, and heavy metals such as Cd, Cu, Hg and Zn etc and to engineer the growth microbes to facilitate the degradation of organic matter and toxicants.

green lake

Wastes in the water bodies undergo anaerobic degradation and generate methane gas. This is common scenario in Indian rivers flowing through the densely populated areas. It can be said that the pollution of water bodies is one of the causative factors in India to release the greenhouse gases which are responsible for climate change. Therefore, tackling the issue of water pollution with proper preventive measures and appropriate pollution control technologies will improve the conditions in India.

Conventional technologies inclusive of mechanistic systems for degradation of pollutants aerobically or anaerobically are normally employed to treat the pollution from point sources. They are not that much effective against non-point sources of the pollution. It has been estimated that Pune city will need about 3000 MW electricity per day to run its sewage treatment plants based on conventional energy intensive technologies7. In other words, to generate that much electricity daily 3000 tons of carbon dioxide will be released into the environment. This CO2 emission factor is based on the data generated by Department of Energy of USA in association with Environment Protection Agency.

If the same logic is applied for the whole Country, then it will be a huge addition to GHGs by India for the treatment of sewage. Otherwise, the untreated wastes will be left in the water body’s leading to increase of GHGs mostly due to generation of methane gas in enormous quantities. So, there is need of radical change in the application of waste treatment techniques so that the electricity requirement is reduced substantially without compromising in the quality of outputs. Use of living systems i. e. components of detritus food chain would be beneficial in such circumstances as the source of energy for them is the Sun.

Benefits of Living Systems in the Treatment of Pollution
It is a three prong action – detritus feeding organisms consume the pollutants because it is a nutrient for them. Secondly, wastes generated from this process are useful for green plants and thirdly, the green plants absorb carbon dioxide from the atmosphere. Thus, the pollutants get transferred to the natural cycles, i.e. biogeochemical cycles of carbon and other elements. Carbon gets stored in vegetation and subsequently in the soil. Plants store carbon in the forms of live biomass. Once they die, the biomass becomes a part of the food chain again and eventually enters the soil as soil carbon. This is a natural process which doesn’t need electricity at all. Hence, the ecotechnologies – using ecological engineering principles to treat pollution – have incalculable advantage over energy intensive technologies.
The role of vegetation in carbon deposition is the suitable option which offers the potential in human systems to function as a carbon sink.