INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 3, ISSUE 7, JULY 2014 ISSN 2277-8616 47 IJSTR©2014 www.ijstr.org Laboratory Study Of Arsenic Uptake And Phytoremediation Potential Of Three Aquatic Macrophytes Of Meghalaya, India Marbaniang D., Chaturvedi S.S. Abstract: Laboratory experiments were performed to evaluate the As uptake capacity by three aquatic macrophytes (Scripus mucronatus, Rotala rotundifolia and Myriophyllum intermedium). The selected macrophytes were transferred to the laboratory containing nutrient solution and working As standard solutions of different concentrations (1.0, 2.0, 4.0, 8.0 and 16 mg L -1 ) and harvested at regular time interval of 2, 4, 6, 8 and 10 days. The As uptake by these macrophytes showed a linear relationship for S. mucronatus, R. rotundifolia and M. intermedium with the exposure time period (2–10 d). As accumulation in the plant parts was higher in the roots for S. mucronatus but reverse in the case of R. rotundifolia and M. intermedium. The maximum bioconcentration factor (BCF) values were found at the 8 th day in all the three aquatic macrophytes and translocation factor (TF) was at the 8 th day for S. mucronatus and R. rotundifolia and at the 6 th day for M. intermedium respectively. The experimental results demonstrated that these three aquatic macrophytes have a phytoremediation potential for removing As from As -contaminated water. Keywords: Scripus mucronatus, Rotala rotundifolia, Myriophyllum intermedium, Arsenic uptake, Bioconcentration (BCF), Translocation Factor (TF). ———————————————————— 1. Introduction Water though an indispensable resource for human life is yet one of the most badly abused resources. For centuries, especially in urban areas, water has been polluted and used as dumping places for all sorts of domestic and industrial waste as well as sewage. Over 75 to 90 percent of people in developing countries are exposed to unsafe drinking water [1], hence proper water treatment is inevitable in order to ensure healthy life. Nowadays, apart from other common pollutants, heavy metals are considered as one of the most important water pollutants which may have a severe health problem. As contaminations from natural and anthropogenic sources has been reported in number of sites worldwide [2]. The extensive arsenic contamination in the groundwater have been reported in many countries, especially Taiwan, Argentina, India, Bangladesh, Mexico, Hungary, and Chile [3]. Arsenic is the 20 th abundant element in earth crust [4], As is a semi-metallic element (atomic number 33, atomic mass 74.9) belonging to group V. The occurrence of As naturally in the environment is mainly from minerals and geogenic sources, but however extensive anthropogenic activities such as mining, burning of fossil fuels, use of arsenic containing chemicals in agriculture increases the As distribution in the environment [5]. As has been widely used in the fields of medicine, electronics, agriculture (pesticides, herbicide, insecticides, fertilizer, etc.), livestock (cattle and sheep dips), and as wood preservatives [6]. A variety of techniques which includes chemical, physical and biological technology have been used to remediate heavy metal contamination from soil or water. Toxic metals from industrial effluents have been remove by various other techniques such as precipitation, reduction, artificial membranes, and ion exchange, but however these techniques generate a huge amount of waste e.g., sludge, metal rich waste, etc which is difficult to dispose of and therefore, dangerous to the environment and they are also generally expensive, relatively inefficient [7]. Phytoaccumulation, one of the biological indicators which indicate the degree of absorption of heavy metals in plants has lately gained its applicability because its cost- effectiveness, long-term and ecological aspect [8]. Aquatic macrophytes have received great attention and have shown to be one of the candidates in the aquatic system for pollutant uptake and biological indicators of heavy metal [9]. The objective of the present study was to assess the uptake of As and phytoremediation potential of S. mucronatus R. rotundifolia and M. intermedium for As under laboratory conditions. The experiments were performed in a contained environmental set up inorder to eliminate all external environmental factors. 2. Materials and Methods S. mucronatus an emergent and R. rotundifolia and M. intermedium are submerged macrophytes and they are one of the major natural constituent of wetland and riverside vegetation. They are sampled as shown in fig 1 from water body of Mawlai Umshing, (Lat 25 0 36’36.76N Long 91 0 54’05.11E), Cherrapunjee (Lat 25 0 19’01.38‖N Long 91 0 48’36.51‖E) and Pongkung (25°21’47.69‖ N 91°40’03.34‖ E), Meghalaya, India in the month of October 2012 and collected in polyethylene bags and transferred to the laboratory. Plants were washed several times with tap and distilled water in order to remove any adhering soils and plants of similar size, shape and height were selected and kept separately in a 40L capacity tank which contained half strength Hoagland’s solution of pH = 7 [10] and kept for 15 days prior to experimentation for. The Hoagland solution was modified by omitting ferrous sulfate in order to prevent the As precipitation by iron. Nevertheless, high level of phosphorus in the nutrient medium may influence arsenic uptake by plants. After 15 days the acclimatized plants were transferred and maintained in 5% Hoagland’s solution containing working As standard solutions of different concentrations 1.0, 2.0, 4.0, 8.0 and 16.0 mg L -1 and then they were exposed to As concentrations at a time interval of 2, 4, 6, 8 and 10 days. As of analytical grade, were supplied as As 2 O 3 (Himedia) were used as the source of As. Experiments were carried out separately for the three aquatic macrophytes under controlled temperature (24±1 0 C) and light (3500 Lux) conditions. After each time interval the plants were collected and washed with deionised water to remove any metal adhering to its surface. The washed plant samples were carefully dried the