Role of Macrophytes in improving water quality of an aquatic eco-system

Macrophytes plays important role in balancing Lake Ecosystem. They have capacity to improve the water quality by absorbing nutrients, with their effective root system. At the same time death & decay of the macrophytes increases nutrient concentration, this leads to eutrophication. A rational setup between these two simultaneous activities is required to maintain the water quality of an aquatic ecosystem. The objective of the study is to evaluate the usefulness of different macrophytic species (Bio-filters) in reducing the nutrient content of the water i.e. to reduce the pollution level of water. The paper is the outcome of ex–situ experiments conducted on samples collected from Shahpura Lake, Bhopal. Two macrophyteic Species Eicchornia crassipes & Hydrilla verticillata were selected for ex-situ study. Both the plant species indicates that macrophytes are capable in improving water quality by reducing nutrient concentration. @ JASEM Macrophytes are the common features of an aquatic ecosystem. Accumulation of nutrients in an aquatic ecosystem leads to eutrophication resulting into massive growth of the macrophytes and weeds. Main cause of nutrient accumulation is rapid urbanization and anthropogenic pressure. Storm water runoff and discharge of sewage into the lakes are two common ways that various nutrients enter the aquatic ecosystem, resulting into the death of those systems (Sudhira & Kumar 2000). The washing of large amount of clothes by dhobis, laundry workers, and continued entry of domestic sewage in some area death & decay of macrophytes are posing pollution problems. Of all the water quality issues regarding lakes everywhere, eutrophication is of great concern. Eutrophication of a water body signifies the aging of a lake. It is caused by the accumulation of nutrients, sediments, silt and organic matter in the lake from the surrounding watershed. Macrophytic vegetation plays an important role in maintaining the ecosystem of a lake. Various types of macrophytes emergent, free floating, submerged are generally observed in an aquatic ecosystem. Freefloating macrophytes leaves & roots are floating; roots are not attached in sediment. Eichhornia crassipes is free floating aquatic plant in which roots play important role in removing nutrients (Reed crites and Middle brooks 1995). It has tremendous capacity of absorbing nutrients and other substances from the water (Boyed, 1970) and hence brings the pollution load down. It is found to be most effective in removal of BOD, COD, nitrogen, phosphorus, organic carbon, suspended solids, phenols, pesticides, heavy metals etc from waste water (Gupta 1982). In Hydrilla verticillata (submerged macrophyte) the whole plant plays an important role in absorbing nutrients. Submerged plants grow well in oxygenated water and therefore cannot be used in treating wastewater high in the BOD. They have more area for attachment for denitrifying bacteria then emergent macrophytes (Weisner et al. 1994). In India, all most all the water resources are occupied with various types of macrophytes viz. rooted shoreline, free floating and submerged etc, which are an integral part of the ecosystem and acts as biofilters. As we know conventional treatment process is very costly with high operational and maintenances cost therefore efforts are for the use of natural devices, which can be used as an eco-friendly and effective source of treatment. The need of the study is because of the deterioration of water quality of Shahapura Lake day by day. Accumulation of residential waste, toxic chemicals and sediments are very common (Suchi Tiwari, 2005). Due to excessive pollution load massive growth of macrophytes are commonly seen. Commonly found macrophytes are Eichhornia crassipes., Hydrilla verticillata. & Phragmities sp. The purpose of the study is to utilize these macrophytes as bio-filters & to observe efficiency of various macrophytes to remove pollutants available in lake. MATERIALS AND METHODS The present study was conducted in water of Shahapura Lake (Mansarover Lake) of Bhopal city. The Lake is situated in the center of Bhopal city, the state capital of Madhya Pradesh India (latitude 2312’00’’E and longitude 7725’30’’N). The lake is a shallow aquatic ecosystem mostly muddy due to accumulation of silt. The main inlet joins at northern end, through which maximum sewage inflows into the lake. Two Ex-situ studies were also conducted by taking two Macrophytes Eicchornia Crassipes & Hydrilla verticillata. For observing the rate of nutrient uptake water container (approx. 5.0 liters) is required. Add 2.0 liters of raw water from inlet and introduce 100.0 grams of Eicchornia crassipes. Observe initial Role of Macrophytes in improving water quality of an aquatic eco-system. * Corresponding author: Sangeeta Dhote 134 concentration of nutrients in raw inlet sample. Collect the samples at regular intervals of one week and observe nutrient concentration. Similar experiment was also conducted by taking macrophytes Hydrilla Verticillata (Submerged macrophytes) as a bio-filter. Samples at regular interval were collected from exsitu experiment set-ups. RESULTS & DISCUSSION