ARTICLE

New International Centre for Ecological Engineering at the University of Kalyani, India

By Prof. Dr. B.B. Jana

International Center for Ecological Engineering
University of Kalyani
Kalyani 741 235
West Bengal
India

Dr. B. B. Jana is professor of Aquaculture & Zoology at the University of Kalyani, West Bengal India. His major interests are in wastewater aquaculture, eco-restoration, aquatic microbiology, applied limnology and fish biology. Prof. Jana and his team are committed to develop the wastewater aquaculture - the main source of income to the fish farmers in West Bengal - in developing countries by upscaling and integrating it in different ways.

On March 13, the University of Kalyani has launched the International Center of Ecological engineering in collaboration with the International Ecological Engineering Society, Switzerland with the initiatives from Professor B. B. Jana, Coordinator and Convener of the center and the International Board Member of the IEES.

The programme consisted of two sessions: in the first morning session, the inauguration of the center was done, whereas an international seminar on Ecological Engineering was organized in the second post lunch session. The meeting was attended by more than 150 participants.

Fig. 1: Laying of the foundation stone in the International Centre of Ecological Engineering

The foundation stone of the center was laid by Higher Education Minister-in-Charge of the State of West Bengal, Professor Satyasadhan Chakraborti in presence of Professor N. Saha, Vice Chancellor of the University, Dr. Johannes Heeb, President, International Ecological Engineering Society, Switzerland, Professor B. B. Jana, Coordinator and Convener of the Centre, Professor M. K. Banerjee, Secretary, Department of Science and Technology, Government of West Bengal, Professor R. N. Poddar, former Vice Chancellor of Calcutta University, University Registrar, Finance Officer, Faculty members, officers, research scholars, students of the University and many distinguished guests from different Universities and Institutes and media people.

Fig. 2. One day seminar on Ecological Engineering and inauguration of International Centre of Ecological Engineering in the University of Kalyani, Kalyani , India, on March 13, 2003

At the outset, Prof. B. B. Jana welcomed all the delegates and briefly mentioned the genesis of the International Centre in this University. He spoke on the grand success of the International Conference on Ecological Engineering the university organized in 1998. Such an endeavor can be successful only through support and cooperation from various organizations. He appealed to all scientific communities of the world and Government Agencies for all possible help and support for the development of the International Centre in its true sense.

Dr. Johannes Heeb emphasized the role of Ecological Engineering and its importance in the developing countries. He appreciated the University for taking interest for the establishment of the centre. In the second session, he also delivered a key note address on Ecological Engineering and its relevance in the Developing Countries, emphasizing the utilization of composting toilets and its use in the cultivation of medicinal plants in Bangalore.

The Minister of Higher Education in the State of West Bengal appreciated the University for initiating such an important centre for sustainable development, and he assured all possible help for the development of the centre.

Prof. M. K. Banerjee, Secretary, Department of Science & Technology, Govt. of West Bengal, spoke on industrial mapping in the State of West Bengal for expansion of right industries in the right place. He also assured for collaboration through research projects.

Prof. N. Saha, Vice Chancellor of the University spoke on all kinds of support from the University despite financial limitations.

Professor B. B. Jana and his school from the International Centre of Ecological Engineering have been working on different aspects as follows:

1.

Eco-tech approaches towards reclamation of eutrophic waters using certain macrophytes

The nutrient removal capacity of water hyacinth under simulated eutrophic conditions was significantly higher in the mixed enrichment with N and P than either with N or P separately. Further, density dependent removal of P and N was more pronounced at low nutrient levels than at high nutrient level.

Lemna, another floating macrophyte, removed nutrients mainly from the water phase, whereas an emergent macrophyte, Scirpus, utilised P exclusively from the sediment. Plant recovery of both N and P was higher in emergent macrophyte than in the floating macrophyte.

Comparison of the nutrient removal capacity of floating and submerged macrophytes revealed that Hydrilla was more efficient than Trapa. The latter removed nutrients from the water phase, whereas the former removed both from water and from sediment. Plant recovery of both N and P was higher in the submerged macrophyte than in the floating one.

Introduction of macrophytes resulted in a decline of denitrifying bacteria but in an increase in heterotrophic bacterial populations. The floating macrophytes (Lemna and Pistia) were also responsible for controlling algal bloom (Microcystis) through shading effects. The effect was more pronounced in the case of Lemna compared to Pistia. As a consequence, species diversity of phytoplankton was significantly altered due to the presence of both macrophytes. The diversity index was higher in Pistia than in Lemna.

Introduction of fish caused nutrient mobilization from the sediment to the water phase by the bioturbation activities of fish. Periodic harvesting of macrophytes and mid-term introduction of fish has a profound role in the reclamation process of eutrophic system by macrophytes. These increased the efficacy of the system.

2.

Food chain management for controlling algal bloom

Our experimental studies proved that herbivorous fishes such as silver carp, bighead and tilapia were highly efficient in controlling permanent Microcystis bloom (60 - 93%) in an eutrophic lake. Silver carp performed the greatest gross and net clearance of Microcystis, followed by bighead and tilapia.

Regarding the ichthyoeutrophication potentials, the test fishes showed following order: tilapia > bighead > silver carp. It is concluded that silver carp is more suitable for cleaning Microcystis in lakes because of its minimal ichthyoeutrophication effects.

On the basis of experimental findings it may be recommended that Microcystis blooms in the tropics can be profitably utilized for enhancement of fish production by culturing silver carp of above six months age group. Catla and bighead of above two months age group can also be used.

3.

Use of some benthic animals towards reclamation of contaminated water bodies

The results of reclamation studies of heavy metal contaminated water bodies show that the freshwater mussel, Lamellidens marginalis, is the most suitable candidate for removal of cadmium from cadmium intoxicated environments.

It is observed that bivalves (Lamellidens marginalis) as well as gastropods (Pila globosa, Lymnaea stagnalis) are able to accumulate cadmium in considerable amounts in their different tissues, and the rate of accumulation is both dose and time dependent.

Small animals are more sensitive to cadmium accumulation than large ones.

Animals can be brought back to their normal state after exposing them to suitable depuration treatment for metal elimination from their body.

Thus, the same animal can be used again and again as biofilter if they are normalised to normal state by depuration and cadmium can be removed from the system by harvesting macrophytes.

It is demonstrated that presence of Eichhornia in the system induced the depuration of cadmium at a much faster rate compared to a chelating agent EDTA.

Eichhornia, an efficient absorber for heavy metal and other toxic substance induced fish cadmium depuration because of high rates of cadmium accumulation from ambient water by the macrophyte, resulting in a clear-cut concentration gradient between fish and water. This, in turn, enhanced cadmium depuration possibly by the mechanism of leaching of metal-rich residuals from permeable body surface.

Marketable live fishes are to be kept in a treatment tank containing clean water and Eichhornia for a few weeks prior to marketing. Further research is in progress for examining different aspects of depuration and to make fish safe for human consumption.

4.

Wastewater fed aquaculture as a reclamation strategy

Wastewater reclamation using the principles of Ecological Engineering and operating through integrated actions (living machines) and fish biomass as the final output is of great significance in tropical developing countries because of use of energy-saving biological sewage treatment systems mitigating the energy intensive mechanical systems. The extent of pond fertilization by sewage depends upon sewage characteristics, climatic conditions, physical features of the pond and the species of fish culture. Basically the culture system has been evolved based on local experiences.

A study was carried out in the Kalyani sewage fed fish farm for a period of two years. The farm receives about 17 mld of domestic sewage from about 82,000 inhabitants of the Kalyani township in West Bengal. Of the total of 17 mld sewage, 11 mld is treated through conventional systems before being discharged into the river Ganga. Only about 6 mld is treated through biological system using a three-step biological treatment system consisting of two anaerobic ponds in the first step, two facultative ponds in the second step and four stocking ponds in the third step.

The facultative pond or the waste stabilization system has been proven to be most dynamic in the reclamation process. It is accounting for 22-69% of the total reclamation. This is due to its enhanced microbial activity and to the development of intense algal bloom, which triggered further reclamation of effluents by providing aerobic condition.

The next subsystem of fish growing ponds was primarily responsible for converting organic wastes into fish biomass through the grazing-detritus-food-chain mechanism using the well known ecological principle of recycling through microbial biogeochemical nutrient cycle and grazing and detrital food webs.

The reclamation of the wastewater has been studied using certain biogeochemical cycling bacteria as indices. It may be stated that there was a scope for further reclamation of the existing final effluent by increasing the length of the treatment system by 200 m, implying the scope for construction of 1-2 more stocking fish ponds for aquaculture. This would ensure much more environmental protection from the sewage effluents and may meet more the stringent standards which may be imposed in future.

However, a permissible limit of water quality has been achieved with the existing practices. Further studies are necessary to examine the efficacy of the biological treatment system. The mechanism and quantification of the microbial reclamation process through organic matter decomposition in wastewater aquaculture systems have also to be elucidated.