Grass For Waste Water Treatment

Published on by in Academic

Grass For Waste Water Treatment

United Nations University Institute for Natural Resourcesin partnership withEbonyi State Universityin Nigeria. The project is assessing the potential of an African vetiver grass species,in treating industrial effluents and wastewater from domestic origins

In Africa wastewater is increasingly becoming an important resource for various uses including irrigation in urban and peri-urban agriculture. This wastewater is often high in toxic heavy metals including arsenic, cadmium and manganese as well as components of nutrient pollution such as phosphates and nitrates.

The general findings of this vetiver project reveal that Chrysopogon nigritana can reduce these contaminants in industrial effluents and domestic wastewater. For example, in one case, samples were taken of leachates from a dumpsite and treated with Chrysopogon nigritana for seven days. Laboratory analysis of the chemical properties of the treated leachate indicated that phosphate, which was at a pre-treatment level of 92.9, was reduced to 19.71 mgl-1, while Chemical Oxygen Demand (COD) dropped from 151.78 to 50.57 mgl-1. These levels are far below the United States Environmental Protection Agency's (USEPA) permissible limits of 50 and 75 mg l-1 for each of these respective chemical properties in water.

Similarly, laboratory results showed that arsenic and cadmium properties, which were both initially at pre-treatment levels of 0.2mg l-1, were completely removed from sample effluents taken from a fertilizer company after a six-day vetiver grass treatment. The absence of these chemical properties after treating the effluents with vetiver grass is very satisfactory because the World Health Organisation/Food and Agriculture Organisation's (WHO/FAO) acceptable levels for arsenic and cadmium in water are 0.10mg l-1and 0.005mg l-1 respectively. Additionally, analysis of a sample of slaughterhouse wastewater treated for seven days by vetiver showed an 88 percent reduction in manganese (from 1.03 mg l-1 to 0.12 mg l-1) — a reduction well below the WHO/FAO's safety standard of 0.20 mg l-1 for manganese in water.

Source: Resilience.com

Read More Content Related To This News Here



Media

Taxonomy