Plant algae method for arsenic removal from arsenic contaminated groundwater Mupenzi Jean de la Paix, Li Lanhai, Habumugisha Jean de Dieu and Maina Nyongesah John ABSTRACT Field studies were carried out in Urumqi River Basin in Northwest China. The study focused on experimentation on a plant algae method that was tested by taking various water chemistries into consideration. The results from a greenhouse experiment evaluated for four doses of P (0, 100, 200, and 300 μmol/L) using two ferns (30 and 60 day old) on 15 L of contaminated groundwater per plant revealed that the biomass of 30-day old ferns gained was higher than 60-day fern. As solution-P increased from 0 to 450 μmol/L, Phosphorus concentration in the fronds increased from 1.9 to 3.9 mg/kg and 1.95 to 4.0 mg/kg for 30-d and 60-d ferns respectively. This study showed that the plant algae method may be a good solution to maximize arsenic uptake in the short term under normal climatic conditions. Mupenzi Jean de la Paix (corresponding author) Li Lanhai Maina Nyongesah John State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 818 Beijing Road South, Urumqi, Xinjiang, 830011, China E-mail: mupenzi2ms.xjb.ac.cn/lilh@ms.xjb.ac.cn Mupenzi Jean de la Paix Habumugisha Jean de Dieu Institut Politechinique de Byumba (IPB), 25 Byumba, Gicumbi, Rwanda Mupenzi Jean de la Paix Independent Institute of Lay Adventists of Kigali (INILAK), PO Box 6392 Kigali, Rwanda Key words | arsenic, groundwater, plant algae, water contamination INTRODUCTION Occurrence of arsenic in drinking water is problematic in some parts of the world especially in China due to rapid industrialization in recent years. Like phosphorus, arsenic exhibits allotropy, although only the gray allotrope is important under normal conditions; it can lead to death in chronic intakes (Daneshvar et al. ). Several studies have revealed that arsenic and its compounds are poiso- nous, highly toxic and carcinogenic to humans. Plant biomass and other methods have been proven to be able to treat wastewaters from different sources such as textile industries, food and protein production, soluble oil wastes, restaurants, metal finishing and lately arsenic containing wastewater and groundwater (Beck et al. ; NRC ; Mills ; Smedley & Kinniburgh ; Gomes et al. ; Park et al. ; Ghosh et al. ; Balasubramanian et al. ). Arsenic in water can be removed by microbiological processes and two main types of metal–microbe interactions can be potentially used for the removal of arsenic from groundwater, which are: (a) microbial oxidation of arsenic(III) to arsenic(V) to facilitate its removal by conventional arsenic removal processes, and (b) bioaccumulation of arsenic by microbial biomass (Sutton et al. ; Chen et al. ; Rahman & Ravenscroft ; Kumar et al. ; Parga et al. ). In China, acute scarcity of safe water supply and improper water resource management has resulted in the consumption of high arsenic-contaminated groundwater. More than half a billion of its population is exposed to dangerously high-arsenic poisoning emanating from the use of arsenic-contaminated groundwater for drinking and irrigation purposes (Guo & Wang ; Li et al. ). For a long time, groundwater has been the major source of water supply in this country. Through investigations in Xinjiang autonomous regions in North- west China, a 1,900 μg/L rise in arsenic concentration was identified in groundwater, with an average concen- tration of 350 μg/L and these exceeded the standard of 10 μg/L as revealed by the World Health Organization (WHO) (Matteson et al. ; Chen et al. ; Holt et al. ; Jiang et al. ; Tu et al. ; Wachinski et al. ). The main goal of this investigation was to ameliorate the As(III and V) removal from groundwater using a plant algae method, which is believed to be among the most simple, efficient and promising technol- ogies for the removal of the two forms of As from contaminated water. It has been proven to be very 927 © IWA Publishing 2012 Water Science & Technology | 65.5 | 2012 doi: 10.2166/wst.2012.875