Abstract
A survey was established to study the mobility of metals (Cr, Mo, Cu, and Zn) from soils amended with municipal sewage sludge (SS) into plants grown at three locations in Kentucky and compare metal concentrations in plants to their permissible standard limits. The field experiments were established at Meade, Adair, and Franklin Counties in Kentucky areas where commercial growers use SS as alternative to inorganic fertilizers. Metals in soil and plant tissue were quantified using Inductively Coupled Plasma (ICP) spectrometer. Results revealed that different trace metals had different uptake pattern by different plants. Cr concentrations in beans has shown very little accumulation in bean seeds. Cr and Mo concentrations in plants grown at the three locations were below the permissible level of 1.3 µg g<sup>-1</sup> tissue. Other than onion bulbs, Cu concentrations were above the permissible level of 10 µg g<sup>-1</sup> tissue in plants grown at Meade site. At the Adair site, Cu was above the limit only in tobacco leaves. Whereas at Franklin site, Cu was above the limit in potato tubers, onion bulbs, and tomato fruits. Zn concentration in all plants tested never exceeded the permissible level of 0.6 µg g<sup>-1</sup> tissue.
Highlights
Municipal sewage sludge (SS) is processed at the Wastewater Treatment Plant (Metropolitan Sewage Facility, Louisville, Kentucky) to eliminate their odor, pathogens, and reduce its volume by drying to make it easier to handle and transport to agricultural lands
Cu concentrations were above the permissible level of 10 μg g-1 tissue in all plants grown in Meade site
Whereas at Franklin site, Cu was above the limit in potato tubers, onion bulbs, and tomato fruits
Summary
Municipal sewage sludge (SS) is processed at the Wastewater Treatment Plant (Metropolitan Sewage Facility, Louisville, Kentucky) to eliminate their odor, pathogens, and reduce its volume by drying to make it easier to handle and transport to agricultural lands. In agricultural production systems soil microorganisms need certain metals for their existence and survivals. Metals are toxic to soil microorganisms when present above certain concentrations [1] as indicated by diminished activities of the enzymes they release. Risks of soil contamination when waste materials such as SS are used as organic fertilizer have been a matter of frequent concern [4]. Some of these metals can be detrimental to human and plants when present above certain limits. Thuy et al [5] indicated that some metals are toxic pollutants of most concern around the world. Elevated concentrations of trace metals in plants could expose consumers to excessive levels of potentially hazardous chemicals [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
