The expertise of Jyväskylä-based watercourse researchers and environmental technology enterprises is being used to clean up a polluted Chinese lake. The improvement in the state of Lake Jyväsjärvi is an excellent local example of what can be achieved.
Lake Jyväsjärvi, located just south of the city of Jyväskylä, has undergone a complete transformation in recent decades. The water in the badly eutrophied and polluted lake is nowadays clean and the lakes ecological state is improving all the time: even game fish are occasionally to be had from it.
Behind the radical improvement in the condition of the lake are research studies conducted by the University of Jyväskyläs Institute for Environmental Research as well as various schemes for treating and rehabilitating the lake which these have spawned. Environmental legislation and work by the authorities have also played a major role in the clean-up operation.
Researchers and firms from Jyväskylä will be lending their expertise in the future, too, in the clean-up of badly polluted Lake Dianchi in China.
According to Jarmo Meriläinen, director of the universitys Institute for Environmental Research, only a third of domestic wastewater in the Dianchi area is treated. The lake is also burdened by agricultural wastewater and run-off. The area is one of the worlds largest centres of the cut flower industry, and in the region theres also extensive tobacco and vegetable farming. Meriläinen suggests that the pollution of the lake can be ascribed to a combination of factors.
The region has not had the resources or the methods for treating wastewater, nor until recently has the value of the lake been recognised.
The planned collaboration between the universities of Jyväskylä and Yunnan would include bilateral exchange of both researchers and students. Also in the pipeline is a development project which would concentrate on reducing the load that ends up in the lake. In this task environmental technology enterprises in the Jyväskylä Region would play a crucial role.
Theres a need in the area for a variety of small-scale sewage treatment plants, sanitary and waste management systems as well as solutions aimed at local production of energy, reveals project manager Annimari Lehtomäki from Jyväskylä Innovation Oy, which is collaborating in this matter with Jyväskylä Regional Development Company Jykes Ltd.
Specialists from Jykes have a strong acquaintance with the Chinese market and a representative office in Shanghai. Jyväskylä Innovation, in turn, possesses expertise in environmental and energy technology.
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Around Lake Dianchi there are six sewage treatment plants which transport sludge to a landfill or straight onto the fields. The untreated sludge causes odour problems and the sludge which runs off into the lake eutrophies water which is already polluted. The sludge could be utilized by means of anaerobic digestion, which produces bio-gas. The bio-gas obtainable from the quantity of waste in question would correspond to as much as 9 megawatts of power each year.
MK Protech Oy, a Jyväskylä-based company specialized in environmental technology, particularly water and waste management and process industry, has been involved in negotiations for a couple of years now regarding the building of a sludge digestion plant in the Kunming area. Project manager Heikki Kutinlahti believes the final agreement will take shape during the spring of 2008. Mechanically dewatered sludge can be transported without odour problems to a central plant for further treatment. The central plant shared by the six sewage treatment plants could handle as much as 250 000 cubic metres of sludge each year. Alongside the plant were hoping to build five 3 900 cubic metre reactors, which would produce over 11 million cubic metres of bio-gas, Kutinlahti says of the envisaged complex.
When a decision to build the sludge processing plant is taken MK Protechs network of planners will be responsible for the plants basic design while the Chinese will take care of construction and other implementation. The same partners are being used in this project as were involved in planning the sludge treatment plant for Rayong in Thailand which was implemented in 2002. Also where the procurement of equipment is concerned Finnish companies will enjoy preference. Some key items of equipment such as the homogenizer, bioreactor agitator and thermal dryer for the sludge will be designed and supplied in Finland.
MK Protech will also be responsible for training the personnel and supervising the start-up of the plant. According to Project Manager Heikki Kutinlahti the plants operating principle is relatively simple, so personnel can be quickly prepared for their tasks.
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Photo (below): On the shores of Lake Dianchi there is extensive cultivation of flowers and vegetables. Wastewater from agriculture, as well as that from industrial and domestic sources, means the lake is badly eutrophied.
Pia Tervoja Photos by Annimari Lehtomäki Graphics by Martti Hänninen