Faculty of Biology, Moscow State University; EAWAG, Switzerland; University of Georgia, Athens, USA; Jizzak State Pedagogical Institute, Uzbekistan
Water streams are under strong man-made impact. By 2000, over 45 thousand large dams in over 140 countries were constructed (WCD, 2000). Pollution and canalizing impacted many rivers.
In Europe, as in the whole world, many water streams changed as a result of man-made activities, including changes of the morphology of river beds and banks, pollution, and using hydropower (Bratrich et al., 2004). 37 out of 55 major European rivers are strongly affected by dams and other engineering schemes (Hygum, 2001).Therefore there is an urgent need for developing basic principles for ecologically sound restoration and rehabilitation of the ecological systems associated with water streams.
Among the top-priority principles for restoration the water streams and associated ecosystems, we consider as relevant to mention the following.
1. Restoring the natural type of the morphology of the river beds including the terrestrial ecosystems surrounding the river. Special attention should be given to restoring the heterogeneity of habitats and giving some space for the river seasonal floods.
2. Quantity of water. The problem to be addressed is the rapid and high-amplitude changes of the level of water when the water discharge from hydrotechnical facilities is manipulated in the hours of the maximal demand for hydroelectricity. High cost of electricity at those hours makes it profitable for the hydropower owners to sharply increase and decrease the discharge of water. Such peak production occurs at the expense of destruction of habitats of some aquatic species. The ecological goal is to lessen those drastic changes in the level of water or to mitigate the negative consequences of them (Fette et al. 2003).
There are at least two options to achieve those goals.
Option 1 is to lawfully regulate and eventually to limit the degree of ecological degradation by the drastic changes of water discharge affecting habitats and ecosystems, and destroying biodiversity.
Option 2 is to lawfully regulate the allocation of the profit extracted at the period of the rapid changes of the discharge of water during the hours of the maximal demand for electricity requiring the allocation of a part of the profit to restore and protect habitats and biodiversity.
3. Quality of water. One of the facts about water relatively less known to non-specialists is the impressive amplitude of the interval of variability of many parameters that characterize water quality – e.g., concentrations of individual dissolved organic substances, concentrations of suspended particles etc. Depending on the parameters, the cost of treatment of water in the process of making it drinkable or proper for industrial use may vary significantly. The better the quality of the natural water, the cheaper is the treatment. Therefore there is a strong economic reason to care about the restoration of the natural ecological mechanism for maintaining and upgrading water quality. That mechanism was described and analyzed in (Ostroumov, 2004). As a result of the analysis, it was concluded that virtually all aquatic biodiversity is involved into the proper functioning of that mechanism. Moreover, not only the aquatic biodiversity, but also some of the terrestrial species that inhabit the areas of land adjacent to the aquatic body or stream are also involved in certain ecological and geochemical processes towards maintaining water quality (Ostroumov, 2005). Therefore the practical steps towards protecting the biodiversity of the streams and adjacent ecosystems are necessary.
1. The system of principles of the ecologically well-thought program to restore the streams that suffer from man-made impact must include 3 parts: ecologically-oriented measures regarding (1) the morphology of the area; (2) the quantity of water in terms of hydrological regime and man-regulated discharge of water; (3) quality of water that is closely associated with the ecological mechanism for maintaining water quality.
2. The specific goals that underline the abovementioned strategic principles are restoring and protecting heterogeneity of habitats and biological diversity of species.
3. To attain the goals mentioned in the preceding items above (items 1 and 2), in practical work it is necessary to restore the heterogeneity of both aquatic and terrestrial habitats, as well as diversity of both aquatic and coastal organisms.
Bratrich C., Truffer B., Jorde K., Markard J., Meier W., Peter A., Schneider M., Wehrli B., 2004, Green hydropower: a new assessment procedure for river management. River Research and Applications. 20: 865-882.
Fette M., Wehrli B., Pätzsold A., Tockner K. 2003, The third Rhone correction, rehabilitation despite operation of a power plant? EAWAG news 55, 21-23. http://www.eawag.ch/ publications_e/eawagnews/e_issues.htm.
Hygum B. 2001. Water and Wetland Index: assessment of 16 European countries – Phase 1 Results, WWF European Freshwater Programme. http:// www.wef.ch/ images/progneut/upload/report.pdf [March 2003].
Ostroumov S.A. Biological mechanism of self-purification in natural water bodies and streams: theory and applications // Advances of Modern Biology. 2004. 124 (5): 429-442.
Idem. Pollution, self-purification and restoration of aquatic ecosystems. Мoscow: МAX Press. 2005. 100 p.
WCD. 2000. World Commission on Dams: Dams and Development – A New Framework for Decision-Making. Earthscan: London.
PHYTOREMEDIATION OF PERCHLORATE USING AQUATIC PLANT MYRIOPHYLLUM AQUATICUM. p.25-27.
S.A. Ostroumov, D. Yifru, V. Nzengung, S. McCutcheon
Moscow State University, Moscow, Russia; University of Georgia, Athens, USA
Introduction. In previous work, we have started doing research of how plants may contribute to remediation of the polluted environment (Ostroumov et al., 2005).
The goal of this presentation is to report some new results on studying the potential of aquatic plant ^ to remediate aquatic environment. The question to answer was whether that species can be used in a simple 6-L bioreactor to decrease the concentration of perchlorate (starting with a significant concentration ca. 20 mg/L).
Square glass aquaria in the role of bioreactors were used. The inner dimentions: 29 cm (length) by 19 cm (width) by 19 cm (height).
Biomass of plants of Myriophyllum aquaticum in the bioreactors (wet biomass with roots): No.1: 226.3 g; No.2: 285.7 g; No.3: 230.3 g; No. 4, 5, 6: 0 g (no plant biomass in the aquaria No.4, No.5 and No.6).
Miracle Gro (all purpose plant food, produced by Scotts Miracle-Gro Products, Inc, 14111 Scottslawn Road, Marysville, OH 43041) was added: aquaria No. 1, 2, 3, 5 and 6: 0.5 g into each of the five aquaria; to aquarium No.4, 2g of Miracle Gro was added.
Each of the aquaria contained 6 L of water.
The composition of Miracle Gro is given in Table 1.
Table 1. The nutrient components and their concentrations in Miracle Gro
The perchlorate was added so that the expected concentration in the aquaria was 16.7 mg/L. The experiment was started April 6, 2005.
Water used in bioreactors. Water was deionized using equipment produced by U.S.Filter (Service Deionization). The details of the water treatment: mixed bed - Type 1; batch number: 03305111; install date 4-15-05; tank R004011.
Sample Preparation and Ion Chromatography. Water samples taken from the bioreactors (aquaria) were diluted as needed to the working perchlorate concentration range of 0.002 – 1.5 mg L-1. Each prepared sample was placed in two 5 mL Dionex autosampling vials. All samples were stored at 4oC between preparation steps and until the samples were analyzed.
The samples tested for perchlorate were analyzed on a Dionex DX-500 Ion Chromatograph (IC) outfitted with an IONPAC AG16 guard column (4 x 50 mm) and an IONPAC AS16 analytical column (4 x 250 mm). The IC was equipped with a Dionex AI-450 Chromatography Automation System and the Advanced Computer Interface Module (ACI). An autosampler with a holding capacity of sixty 5-mL vials was used. The system was run using an ASRS-ULTRA II Self-Regenerating Suppressor (4 mm) at a 300 mA setting. A 100 mM and 50 mM sodium hydroxide (NaOH) eluent at a flow rate of 1 mLmin-1 and a 500 L sample loop were used to measure perchlorate in mgL-1 and gL-1 levels respectively. The eluent was made using J. T. Baker® 50 % (w/w) solution and deionized, degassed (in the VWR Scientific Aqusonic, model 150D) water. Calibration and check standards were made by diluting 1000 g mL-1 perchlorate anion standard (SPEX CertiPrep, Inc.) and 0.5 g mL-1 and 1 gmL-1 standards (AccuStandard, Inc.). A new calibration curve was created each time the ion chromatograph was turned on, or after the eluent had been changed (every 1-2 days). For quality control, all samples were run in duplicate, and an external standard and a blank were run after every two samples. The standard was used to ensure that the percent error remained below 5%, and to monitor any instrumental drift, while the blank checked for any carry-over from the previous sample.
Results. Results are presented in table 2.
Table 2. The concentrations of perchlorate measured in the bioreactors
It is seen that the aquaria with plants demonstrated the rapid decrease in perchlorate. Within less than 20 days the the concentration of perchlorate decreased by the factor of more than 2.
The decrease was rapid also in the aquarium with a high concentration of nutrients.
The authors thanks University of Georgia and the Contemporary Issues program (IREX) for providing support for those studies.