Perspectives of phytoremediation using water hyacinth for removal of heavy metals, organic and inorganic pollutants in wastewater

Highlights

• Removal of nutrient and heavy metals using water hyacinth are reviewed.

• Water hyacinth can efficiently treat different types of wastewater.

• Pollutant removal efficiency was higher compared to other aquatic plants.

• After waste water remediation can be used for wide range of applications.

Abstract

The development of eco-friendly and efficient technologies for treating wastewater is one of the attractive research area. Phytoremediation is considered to be a possible method for the removal of pollutants present in wastewater and recognized as a better green remediation technology. Nowadays the focus is to look for a sustainable approach in developing wastewater treatment capability. Water hyacinth is one of the ancient technology that has been still used in the modern era. Although, many papers in relation to wastewater treatment using water hyacinth have been published, recently removal of organic, inorganic and heavy metal have not been reviewed extensively. The main objective of this paper is to review the possibility of using water hyacinth for the removal of pollutants present in different types of wastewater. Water hyacinth is although reported to be as one of the most problematic plants worldwide due to its uncontrollable growth in water bodies but its quest for nutrient absorption has provided way for its usage in phytoremediation, along with the combination of herbicidal control, integratated biological control and watershed management controlling nutrient supply to control its growth. Moreover as a part of solving wastewater treatment problems in urban or industrial areas using this plant, a large number of useful byproducts can be developed like animal and fish feed, power plant energy (briquette), ethanol, biogas, composting and fiber board making. In focus to the future aspects of phytoremediation, the utilization of invasive plants in pollution abatement phytotechnologies can certainly assist for their sustainable management in treating waste water.

Introduction

Eichhornia crassipes also known as water hyacinth has gained significant attention as aquatic plant which has the ability to absorb pollutants from aquatic environments with rapid proliferation. As attempts for controlling it has not been completely successful, the best management strategy is to find some usage for them (Patel, 2012). The most possible usage of water hyacinth includes making of animal fodder/fish feed (Aboud et al., 2005), biosorbent for the removal of toxic metals (Malik, 2007), production of biogas and bioethanol (Mshandete et al., 2004), compost (Szczeck, 1999), paper manufacturing (De Groote et al., 2003), also as phytoremediation agent (Sajn-Slak et al., 2005). In addition, Indian scientists have suggested many formulation of medicines using water hyacinth for treating diseases (Oudhia, 1999).

Moreover, after the removal of pollutants from waste water, water hyacinth can be used for recovering some of the toxic and non-degradable materials like heavy metals (Isarankura-Na-Ayudhya et al., 2007). The abilities of water hyacinth such as higher growth rate, pollutant absorption efficiency, low operation cost and renewability shows that using this plant it can be considered as a suitable technology for the treatment of wastewater. Malik (2007) reported that naturally water hyacinth create serious challenges in the filed of navigation, irrigation, and power generation. Therefore, inorder to avoid these problems using of phytoremediation technology must be carried out along with the controlling of water hyacinth. Mahamadi (2011) found that some of the aquatic plants like water hyacinth can also be used for the production of biofuels. This technology to produce biofuels can overcome both environmental pollution and the depletion of energy sources worldwide. Rezania et al. (2015) have reported that dried water hyacinth can used for manufacturing briquette, which is used for co-firing in coal power plant.

The main reason for releasing huge amount of wastewater into the environment is because of increase in population, urbanization and industrialization, which mainly constitutes organic matters and heavy metals (Lalevic et al., 2012). That is why a reliable technology is needed to treat wastewater before it is being released into the water bodies (Talaie et al., 2011a). Although, wastewater treatment technologies are often costly, they are not always environmental friendly (Dixit et al., 2011, Talaie et al., 2011b). Therefore, environmental friendly technologies have been gaining attention among the researchers worldwide. Many researchers have reported the application of phytoremediation techniques for treating different types of wastewater. Water hyacinth, water lettuce and vetiver grass are plants that have been used for the removal of wide range of pollutants, which includes biochemical oxygen demand, heavy metals, total suspended solids, chemical oxygen demand, dissolved solids, nitrogen and phosphorous removal (Gupta et al., 2012). The different applications of water hyacinth have been illustrated in (Fig. 1).

Recently, only few review papers related to wastewater treatment using water hyacinth have been published (Mahamadi, 2011, Patel, 2012, Gupta et al., 2012, Rezania et al., 2015). Mostly this review emphasize the most recent studies during the past five years for the uptake and removal of organic, inorganic and heavy metal present in waster water using water hyacinth to make it as a suitable, inexpensive, effective and environmental friendly technology for treating wastewater. The main focus of this review is to compare how water hyacinth is effective in the removal of pollutants from waste water in comparision to other aquatic plants and to provide insight for the development and new emerging technologies of phytoremediation.