Short communication Fast green capping on coal fly ash basins through ecological engineering Vimal Chandra Pandey *, Nandita Singh Eco-Auditing Group, CSIR-National Botanical Research Institute, Lucknow 226001, Uttar Pradesh, India A R T I C L E I N F O Article history: Received 30 June 2014 Received in revised form 12 August 2014 Accepted 7 September 2014 Available online xxx Keywords: Coal fly ash basins Green capping Saccharum spontaneum L Enzyme activities Ecological engineering A B S T R A C T The present article describes the possibilities of the fast revegetation of coal fly ash (FA) basins through human interventions i.e., “ecological engineering” for green capping. The field results revealed that the Saccharum spontaneum L. is a suitable candidate for green capping of coal FA basins because of its higher survivability and abundance growth. The establishment of S. spontaneum L. on the fresh coal FA basins and significant change in chemical properties, microbial biomass carbon and enzymatic activities between non-rhizospheric and rhizospheric soil were studied. The analytical results proved that S. spontaneum L. is a potential green capping candidate of coal FA basins. Besides green capping of coal FA basins, it provides other hidden benefits such as substrate quality enhancement, aesthetically pleasant landscape and carbon sequestration. Such model of ecological engineering should be applied as an efficient tool for the fast green cover development on new coal FA basins. ã 2014 Elsevier B.V. All rights reserved. 1. Introduction Coal fly ash (FA) basins are the dumping sites of coal combustion by-products of thermal power plants, and have been recognized as an environmental nuisance (Pandey et al., 2011). Huge FA disposal requires thousands of hectare land nearby thermal power plants across the world. The main problems of FA are the presence of toxic metals i.e., As, Cr, Cd, Pb, Hg, Se, B etc., and its fine particles. Hence, there are two major problems of coal-based thermal power stations viz. (1) Land requirement for FA disposal and (2) FA pollution i.e., suspended particulate matter as well as the movement of toxic metals into ground water and food chain. Moreover, FA has been recognized as a soil ameliorant (Ram and Masto, 2010, 2014; Pandey and Singh, 2010) along with forestry and agricultural production (Pandey et al., 2009a,b; Singh et al., 2011; Singh and Pandey, 2013; Pandey and Kumar, 2012) because of the presence of plant’s micro and macro-nutrients. It is well reported that FA causes irritation of sensory organs, heart disease and respiratory disorders in human being (US EPA, 2007). The most serious problem of FA is its easy dispersibility by strong summer wind from the ash basins in the atmosphere over a large area, creating big health hazards to the people of the surrounding areas. Because of the negative impacts of FA on human health and the local environment (Pandey and Singh, 2012), holistic approaches must be used to restore coal FA basins. So, the development of green capping through ecological engineering on coal FA basins is vital and urgent need to control environmental menace. Phytoremediation of FA disposal sites has been investigated successfully, and is suitable for the remediation of coal FA basins (Pandey 2012a,b; Pandey et al., 2012; Pandey, 2013; Kumari et al., 2013). Furthermore, naturally growing plant species on coal FA basins response better and can survive easily in comparison to introduced species from other areas (Pandey and Singh, 2011). The hostile conditions (i.e., high pH, heavy metals toxicity, poor organic matter, lack of nitrogen and phosphorus) of FA inhibit the vegetation growth on coal FA basins. Besides these limitations, some plant species have potential to grow naturally on abandoned coal FA basins.Some spontaneously growing potential grasses like Saccharumspontaneum L., Saccharum bengalense Retz (syn. Saccharum munja), and Cynodon dactylon (L.) Pers. were observed on coal FA basins during the field survey. These all invader grasses colonize naturally on the early stages of succession of coal FA basins and remain occupied permanently. However, they show sparse cover on the FA deposits and take many years to cover the whole area of coal FA basins. Fortunately S. spontaneum L. (commonly known as “Kans”) is one of the most abundantly colonized grasses on coal FA basins in India. S. spontaneum L. can cover the entire surface area of coal FA basins, if it is introduced properly with ecological engineering on the fresh coal FA basinsto convert barren FA deposits into ecologically and * Corresponding author. Tel.: +91 9454287575. E-mail addresses: vimalcpandey@gmail.com, vimalcpandey@hotmail.com (V.C. Pandey). http://dx.doi.org/10.1016/j.ecoleng.2014.09.036 0925-8574/ ã 2014 Elsevier B.V. All rights reserved. Ecological Engineering 73 (2014) 671–675 Contents lists available at ScienceDirect Ecological Engineering journal homepage: www.else vie r.com/locat e/e coleng