Next Article in Journal
Previous Article in Journal
Int. J. Environ. Res. Public Health 2014, 11(3), 2569-2579; doi:10.3390/ijerph110302569
Article

Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa

 and *
Received: 30 December 2013; in revised form: 29 January 2014 / Accepted: 13 February 2014 / Published: 3 March 2014
View Full-Text   |   Download PDF [401 KB, uploaded 19 June 2014]
Abstract: Heavy metals in high concentrations can cause health and environmental damage. Nanosilver is an emerging heavy metal which has a bright future of use in many applications. Here we report on the levels of silver and other heavy metals in municipal sewage sludge. Five towns in Limpopo province of South Africa were selected and the sludge from their wastewater treatment plants (WWTPs) was collected and analysed. The acid digested sewage sludge samples were analysed using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) methods. The concentrations of silver found were low, but significant, in the range 0.22 to 21.93 mg/kg dry mass. The highest concentration of silver was found in Louis Trichardt town with a concentration of 21.93 ± 0.38 mg/kg dry mass while the lowest was Thohoyandou with a concentration of 6.13 ± 0.12 mg/kg dry mass. A control sludge sample from a pit latrine had trace levels of silver at 0.22 ± 0.01 mg/kg dry mass. The result showed that silver was indeed present in the wastewater sewage sludge and at present there is no DWAF guideline standard. The average Cd concentration was 3.10 mg/kg dry mass for Polokwane municipality. Polokwane and Louis Trichardt municipalities exhibited high levels of Pb, in excess DWAF guidelines, in sludge at 102.83 and 171.87 mg/kg respectfully. In all the WWTPs the zinc and copper concentrations were in excess of DWAF guidelines. The presence of heavy metals in the sewage sludge in excess of DWAF guidelines presents environmental hazards should the sludge be applied as a soil ameliorant.
Keywords: heavy metals; sewage sludge; effluent; silver heavy metals; sewage sludge; effluent; silver
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Shamuyarira, K.K.; Gumbo, J.R. Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa. Int. J. Environ. Res. Public Health 2014, 11, 2569-2579.

AMA Style

Shamuyarira KK, Gumbo JR. Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa. International Journal of Environmental Research and Public Health. 2014; 11(3):2569-2579.

Chicago/Turabian Style

Shamuyarira, Kudakwashe K.; Gumbo, Jabulani R. 2014. "Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa." Int. J. Environ. Res. Public Health 11, no. 3: 2569-2579.


Int. J. Environ. Res. Public Health EISSN 1660-4601 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert