1

RUHWAYA DOUGLAS A MC14124213A

CUHCHE 2104

Determination of trace metals concentration and microbiological

quality of spring water

2

Scope of research

The research was limited to Eureka Farm in Macheke, Mashonaland East.

The farm is located in the watershed area of the Macheke sub-catchment area of the Save catchment area.

The following parameters were assessed: Microbiological qualities: Total Coliform, Biological Oxygen Demand

and Chemical Oxygen Demand. Trace metals: Chromium (Cr), Nickel (Ni), Zinc (Zn), Copper (Cu)

Mupindu , s., Murimirudzombo, N. & Changunda, P., 2004. Sida Support to Save Catchment Council, Stockholm: Sweddish International Cooperation Agency.

3

INTRODUCTION

Population increase has increased pressure on the water resources of the developing and developed countries

Hence, the need to carry out microbiological and chemical evaluation of the spring water supplies.

Water quality refers to the chemical, physical and biological characteristics of water, it is not static

Balogun, S. A., Ejelonu, B. C., Lasisi, A. A. & Adeogun, A. I., 2013. Microbiological and chemical assessment of spring water from a rural setting in Ondo State Southwest, Nigeria. Africa Journal Of Environmental Science and Tchnology, 7(6), pp. 555 - 559.Okechukwu, M. E. et al., 2013. Water quality evaluation of spring waters in nsukka, Nigeria. Nigerian Journal of Technology, 32(2), pp. 233 - 240.

4

Objectives

Main objectives:To determine concentration of trace

metal contaminants in spring water.

To determine the levels of microbiological contaminants in spring water.

5

Other objectives

To identify activities that contaminate the spring water.

To determine quality of the spring water for domestic use.

To recommend ways of remediation of the spring water incase of contamination.

6

Literature review

Springs are a naturally occurring outcrop of ground water to the earth’s surface, either from the force of gravity or hydrostatic pressure or recharge of surface water.

Springs are naturally safe but pollution is possible from leaching (organic matter and nutrients) from soil, hydrological factors (runoff) and biological factors.

Microbiological contamination can culminate into gastrointestinal illness

Forstner, U., 1977. Arch. Hydrobiology, Volume 98, pp. 172-191.

7

METHODOLOGY

Total coliform was determined using the Most Probable Number method.

BOD and DO were both measured using a DO meter. BOD5 is measurement taken within 5 days.

COD was measured using the dichromate COD test.

Trace metal elements are determined by ICP-OES

8

SUMMARY OF METHOD PRINCIPLES

BOD5 – mass of dissolved oxygen required by specified volume of liquid for the process of biochemical oxidation.

Multiple Tube Fermentation Technique – uses presumptive, confirmed and completed tests to determine Most Probable Number of coliforms in the water sample.

9

SUMMARY OF METHOD PRINCIPLES

COD – Open Reflux Technique – most types of organic matter are oxidized by boiling the mixture of chromic and sulphuric acid.

The organic matter was oxidized completely by potassium dichromate (K2Cr2O7) with silver sulfate as catalyst in the presence of concentrated H2SO4 to produce CO2 and H2O.

Cr2O72- 14H+ 6 e 2 Cr3+ + 7 H2O+ +

10

The excess K2Cr2O7 remaining after the reaction was titrated with 0.145M ferrous ammonium sulfate [Fe (NH4)2(SO4)2], dichromate consumed gives the oxygen (O2) required for oxidation of the organic matter

Fe2+ Fe3+ + e-

11

ELEMNTAL ANALYSIS: ICP-OES

12

Expected Results

PARAMETER UNITS WHO standards

SAZ standards

BOD mg/L O2 5.0 6.0COD mg/L O2 10.0 10.0Total Coliform MPN/100mL 0 0Cr mg/L 0.05 0.05Zn mg/L 3.00 5.00Cu mg/L 1.00 2.00Ni mg/L 0.02 0.05

13

RESULTS: MICROBIO

TOTAL COLIFORMBOD5

COD Volume of sample in each bottle / mL

50 10 2  

Number of Bottles Used 1 5 5 MPN of coliforms in 100 mL of the original water

Bottles with positive results of Total Coliform

1 5 2 50

Sample Number

Volume of sample (mL)

Volume of dilution water (mL)

Decimal Volumetric Fraction used, p

Initial Dissolved Oxygen (ppm)

Final Dissolved Oxygen (ppm)

BOD5

SW 1 0 300 0.00 8.11 2.88 5.23

SW 2 50 250 0.17 7.00 3.43 0.52

SW 3 150 150 0.50 6.68 3.73 1.28

SW 4 200 100 0.67 5.84 3.74 1.22

SW 5 300 0 1.00 5.53 3.75 1.55

AVERAGE BOD5 1.96

SAMPLE Molarity of FAS / M

Volume of FAS used for sample / mL

Volume of FAS used as blank / mL

Volume of sample used / mL

COD / (mg/L)

SW1 0.145 0.733 0.000 100 8.50

SW2 0.145 0.750 0.000 100 8.70

SW3 0.145 0.741 0.000 100 8.60

AVERAGE COD /( mg/L) 8.60

14

RESULTS: TRACE METALS

METALS WHO/ ppm

MACHEKE/ ppm

SAZ/ ppm

ERROR

Zinc 3.000 0.03156 3.000 0.00286

Copper 1.000 -0.02220 b 2.000 0.00355

Nickel 0.020 3.29000 0.050 0.05132

Chromium 0.050 -0.03330 b 0.050 0.00053

Zinc Copper Nickel Chromium-0.500

0.000

0.500

1.000

1.500

2.000

2.500

3.000

3.500

3.000

1.000

0.020 0.050

3.000

2.000

0.050 0.050

TRACE METALS IN SPRING VS STANDARDS

WHO MACHEKE SAZ

CO

NC

ENTR

ATIO

N /

ppm

15

DISCUSSION AND RECOMMENDATIONS

Total coliform too high 50MPN/ 100mL – build embankment to prevent contamination.

Cu and Cr were recorded as blanksZn was recorded as 0.03156 ppm – SAZ

guidelines 3.0 ppm ≤ [Zn]Ni was recorded as too high than the SAZ

standards 3.29 ppm – SAZ guidelines 0.02 ppm ≤ [Ni]

16

CONCLUSION

The main objective of this study was to determine the concentration of the metals in the spring and microbiological quality of the spring water.

The spring had only two metals present of the four that were analysed and their concentrations were:

Zinc – 0.03156 ppmNickel – 3.29 ppmCopper – blankChromium – blank

The microbiological quality was defined by three tests:o Total coliform – 50 MPN/ 100mL BOD5 – 1.96 ppm COD – 8.60 mg/ L

17

THANK YOU