Ecology, Environment and Conservation Paper

CHANGING WETLANDS DUE TO DISCHARGE OF EFFLUENTS FROM SMALL SCALE INDUSTRIES AROUND VARUNA RIVER CORRIDOR

A.K.Gupta & S.K.Singh

Abstract

River banks are among the most stressed ecosystems because of periodic erosion, floods, silting and a variety of anthropogenic pressures. Riparian lands are important in buffering nutrient flow from upland watersheds to waterbodies. River corridors face a lot of biotic activities causing soil erosion and loss of nutrients. Due to various human activities, the number of river corridor wetlands are changing day by day. For the present study, river Varuna has been chosen which is a main tributary of famous river Ganga in Varanasi. It has extensive marginal wetlands. Four distinct regions at Varuna river corridor, were selected along the river course in Varanasi, facing variety of effluents discharged from various small scale industries viz. carpet-dying, soap, fertilizers, fireworks, agarbatti, metal-utensils, battery making industries, iron foundaries and ayurvedic medicine's units. The effluents of these industries are, either being discharged directly into the river or at the river corridor.The soil analysis shows following variation in its important characteristics such as pH - 7.3-8.9, EC - 359-981 ps cm-1, nitrogen-0.038-0.998%, phosphorus - 0.049-0.091, and potassium - 0.38-0.81% at the study sites. The heavy metal content at four regions for Cd, Cu, Cr and Fe, ranged in between 2.0-15.0, 9.0-57.0, 2.0-113.0 and 4.0-72.0 pg/g respectively.The most dominant riparian herb found at four different regions was Polygon urn amphibium, Cyperus rotundus,Aponogeton pectinatus and Ageratum con yzoides respectively.The water analysis of river at four different regions of the corridor, shows following range - pH - 7.183, transparency - I 7.3-51.2 cm, total solids - 56.0-141.0 mg/I, BOD - 6.1-62.3 mg/I, COD - 5.9-91.0 mg/ 1, nitrate - N, phosphate-P, Sulphate-S and chloride (mg/1) varies from 0.09-0.27, 0.01-0.09, 17.9-38.3 and 0.10-0.26 respectively.The results of Table 1 and 2 indicate that the first region (Rameshwar) shows least pollution but as the river moves ahead towards the city, due to increasing pollution load, especially of small scale industries situated at the river corridor, the soil and water gets more polluted and the physico-chemical characteristics indicate that, wetlands show drastic change in its quality and nature.