Research Article
Muhammad Asif and Salman Sa
Abstract
Plant species such as Thlaspi caerulescens Viola calaminaria, Euphorbia prostrata, Arundo donax, Brassicajuncea, Helianthus annuus, Festuca arundinacea, Populus species etc. are long known for their ability to extractheavy metals from soil and waste water. Various attempts at increasing efficiency of extraction by phytoremediationinclude adding micro- organisms, co-cropping various species and using genetically engineered species. So far, theeffect of levels of concentration of heavy metals on extraction efficiency of these plants has not been investigated.The purpose of this study is to test for the hypothesis that the concentration of heavy metals in soils affects theefficiency of phytoremediation. Nine samples of Typha latifolia were planted under controlled environment. Plantswere irrigated by wastewater of industrial effluents diluted with different amounts of clean water, while providingprotection from rainwater. The soil in the planters was tested for heavy metals to obtain levels of contaminationalready present in the soil and after plants was fully grown, using X-Ray Fluorescence Spectrometry, while thewastewater used for irrigation was tested using Atomic Absorption Spectrometry. The amount of heavy metalsalready present in the soil and that introduced by irrigation was compared to the amount left behind in the soilafter maturity of plants, were compared to test the hypothesis. The results suggested that rate of extraction ofheavy metals using phytoremediation was indeed affected by the level of concentration of heavy metals in the soiland irrigation water, however, owing to the small number of samples, the relationship between extraction rate andconcentration levels could not be established. The study provides enough evidence to support the stated hypothesisand opens a new avenue of research to optimize the extraction efficiency of Typha latifolia and other species.