Assessment of physico-chemical qualities and heavy metal concentrations of Umgeni and Umdloti Rivers in Durban, South Africa

Abstract

We assessed the effects of seasonal dynamics on the physico-chemical qualities and heavy metals concentrations of the Umgeni and Umdloti Rivers in Durban, South Africa. Water samples were taken from nine different sampling points and analysed for the following parameters; temperature, pH, turbidity, electrical conductivity (EC), biological oxygen demand (BOD5), chemical oxygen demand (COD), phosphate (PO4(2-)), nitrate (NO3(2-)), ammonium (NH4(+)), sulphate (SO4(2-)), lead (Pb(2+)), mercury (Hg(2+)), cadmium (Cd(2+)), aluminium (Al(3+)), and copper (Cu(2+)) using standard methods. The data showed variations it terms of the seasonal fluctuations and sampling regime as follows: temperature 12-26.5 °C; pH 5.96-8.45; turbidity 0.53-18.8 NTU; EC 15.8-5180 mS m(-1); BOD5 0.60-7.32 mg L(-1); COD 10.5-72.9 mg L(-1); PO4 (2-) < 500-2,460 μg L(-1); NO3 (2-) <0.05-4.21 mg L(-1); NH4 (+) < 0.5-1.22 mg L(-1); SO4 (2-) 3.90-2,762 mg L(-1); Pb(2+) 0.023-0.135 mg L(-1); Hg(2+) 0.0122-0.1231 mg L(-1) Cd(2+) 0.068-0.416 mg L(-1); Al(3+) 0.037-1.875 mg L(-1), and Cu(2+)0.006-0.144 mg L(-1). The concentrations of most of the investigated parameters exceeded the recommended limit of the South African Guidelines and World Health Organization tolerance limits for freshwater quality. We conclude that these water bodies are potentially hazardous to public health and this highlights the need for implementation of improved management strategies of these river catchments for continued sustainability.

Occurrence and significance of polychlorinated biphenyls in water, sediment pore water and surface sediments of Umgeni River, KwaZulu-Natal, South Africa

“…Studies showed that more than 85 % of contaminants in the Umgeni River basin were from non-point sources (Pegram and Bath 1995). However, some metals have been found in this river (Olaniran et al 2014). In 2002, a survey of some persistent organic pollutants in major South African waters revealed the presence of some PCB congeners such as PCB 28, PCB 52, PCB 153, PCB 101 and PCB 138, in a sediment sample collected from the mouth of the Umgeni River (Vosloo and Bouwman 2005).…”

uMngeni Basin Water Quality Trend Analysis for River Health and Treatability Fitness

“…E. coli), physical parameters (e.g. conductivity), metals, organic pollutants, turbidity, total suspended solids and pH [32]. These parameters should fall within specified guideline values for the raw water to be deemed safe for use.…”

Development of a Universal Water Quality Index (UWQI) for South African River Catchments

“…Umgeni River catchment has a surface area nearly 4432 km 2 , with Umgeni River being the major water channel of the drainage basin [13,15,19,48]. The 232-kilometre-long river originates from the Drakensberg mountains and flows eastwards towards the Indian Ocean, with four main cardinal tributaries, namely Lions, Karkloof, Impolweni and Umsunduzi Rivers [19,47].…”

“…The river source is found in the Noodberg area and stretches for nearly 88 km, flowing eastwards toward the Indian Ocean. The river estuary is approximately 25 km northeast of central Durban [48,52]. A considerable portion of the catchment is utilized for commercial farming, dominated by sugarcane and banana plantations with minimal vegetable and citrus farming.…”