1.

0 INTRODUCTION AND OBJECTIVE

Introduction:

Water is a principle constituent of earth. Natural sources of fresh water are in the form
of rivers, lakes, glaciers and ample ground water system. Heavy metals like aluminium,
calcium, cadmium, chromium, copper, iron, lead, magnesium, manganese, zinc, etc. maybe
present in water sources due to geogenic reasons or due to anthropogenic activities such as
uncontrolled discharge of wastewaters of different industries into these water sources. While
some heavy metals may pose significant impact on the consumers, some may benefit from the
presence of these metals, under a certain level (Sharma & Tyagi, 2013).

Heavy metals are major toxic pollutants that severely limit the beneficial use of water
for domestic and industrial application. Their excessive release into the environment and their
determination in natural waters is a major concern and important task worldwide. They can
enter a water supply by industrial and urban waste or can be released from acidic rain into
natural water bodies causing deleterious effects. Land and water pollution with heavy metals
includes point sources (emission, effluents and solid discharge from industries) and nonpoint
sources (Fotio, Researcher, & Fontem, 2015).

Nowadays, several types of detection techniques for metal ions in drinking water
samples are available. Among the techniques are atomic absorption spectroscopy (AAS),
flame emission vapour generation accessory (VGA), graphite tube atomizer (GTA),
inductively couple plasma emission, ion chromatography, UV-Visible spectrophotometer,
high performance liquid chromatography (HPLC), etc, which are capable to detect the
concentration of metal ions up to parts per billion (ppb). The specification of metal ions in
drinking water samples can also be achieved by advanced instrumentation techniques
including chromatographic, capillary electrophoresis, spectroscopic and other techniques for
metal ion analysis in drinking water samples (Sharma & Tyagi, 2013).
Objective:

• To determine the concentration of Copper (Cu), Zinc (Zn) and Manganese (Mn)
in wastewater sample using AAS as common method of heavy metal detection.
2.0 PROCEDURE

Apparatus:
1. Beaker
2. Dropper
3. Watch glass
4. Conical flask
5. Filter funnel
6. Filter paper
7. pH meter
8. Magnetic hot plate stirrer (for heating)
9. DR900 equipment

Reagent:

1. 65% concentrated Nitric Acid (HNO3)

Preparation of Sample:
1. 50 ml of sample from D1 tank of Experiment 2 was taken.

2. The initial pH of the sample was measured.

3. 10 ml of 65% concentrated Nitric Acid (HNO3) was added to the sample and the
mixture was slowly heated until boiled.

4. Another 10 ml of 65% HNO3 was added.

*Colour of the sample must be clear during the heating procedure.

5. 5 ml 37% of Hydrochloric acid (HCl) was added to the sample.

6. The sample was filtered to 250 ml of conical flask.

7. The sample was then diluted with deionized water until mark.
8. The sample was then analysed by using DR900 equipment (for Cu, Zn and Mn
analysis).

* Fume hood and proper PPE were used throughout the experiment.
3.0 RESULTS AND DISCUSSIONS

Result:

Table 1: Analysis Data from Experiment

Heavy Metal Concentration of heavy metal (mg/L)

Manganese (Mn) 0.32

Copper (Cu) 0.97

Zinc (Zn) 1.75

Initial pH 9.77
Discussions:

Water pollution is contamination of water by foreign material that deteriorates

the quality of the water. Thus, wastewater quality detection was done to access the suitability
of wastewater to be disposed or re-use. The fresh water that available for drinking, household
and irrigation purpose gets contaminated with heavy metals, metal ions and harmful
microorganisms (Gupta et al., 2012). Heavy metals are important for all living organisms in
varying amounts, such as iron, copper, zinc and cobalt, for proper growth. However,
the excessive amount of these heavy metals can also produce toxic effects. The determination
of the amounts of heavy metals is especially important where there is a risk of having
anthropogenic influence on aquatic environment

In this experiment, the waste water quality detection of heavy metal was conducted to
determine concentration of Manganese (Mn), Copper (Cu) and Zinc (Zn) in waste water
sample by using Atomic Absorption Spectrophotometer (AAS). AAS is method of heavy
metal detection that commonly used to measure the concentration of heavy metal in
wastewater. The experiment was started by perform the digestion method of heavy metal
whereby the wastewater sample was collected from tank D1 for 50mL. The wastewater
sample was heated up inside the 100mL beaker and added together with 10mL of nitric acid
(HNO3) until it nearly to dry for about ±5mL. The experiment was repeated by adding
another 10mL more HNO3 until it the wastewater sample see-through clear. As it see-through
clear, 5mL of HCL was added until the solution was clear. The sample was removed from the
heating source to allow it to cool down before it was filtered and dilute with distilled water
inside the 100mL of conical flask. Then, the sample was measured by using DR900 to obtain
the concentration of heavy metal in wastewater for Mn, Cu and Zn.

From the result, the initial pH was obtained is 9.77 which is polluted. Theoretically, the
pH value is the most important in wastewater parameter which were the pH value that less than
6 meaning corrosiveness in nature and those having pH more than 9 will cause some metal ions
to precipitate as carbonates or hydroxides. The concentration of manganese (Mn), copper (Cu)
and zinc (Zn) were 0.32, 0.97 and 1.75 respectively. According to Fifth Schedule of Acceptable
Conditions for Discharge of Industrial Effluent or Mixed Effluent of Standards A and B, the
concentration value of Mn, Cu and Zn in allowable limit for standard A and B
which were 0.2mg/L-1.0mg/L for Mn, 0.2mg/L-1.0mg/L for Cu and 2.0mg/L for Zn. Hence,
the wastewater from the tank D1 is safe to be disposed to the environment.

There were several errors when conducting this experiment. Firstly, solution inside
the beaker is left to dry that cause the sample turn to yellowish-solution when the HCl pour into
the sample of wastewater that already added with HNO3 for two times. Besides, the
misconduct of procedure for measurement by using DR900 causes the reading error. Finally,
the sample wastewater that heated is not covered properly by wash glass that caused
the evaporation process effect the sample wastewater.
4.0 CONCLUSION AND RECOMMENDATION

As a conclusion, the concentration of heavy metal of Mn, Cu and Zn of sample

wastewater in tank D1 was successfully analysed by using DR900. The measurement was
taken for different reading of heavy metal to identify the concentration of heavy metal inside
the wastewater after the digestion method of heavy metal. As result, the wastewater solution
that was analysed was in the range of Standard A and Standard B which was manganese
(Mn), copper (Cu) and zinc (Zn) were 0.32, 0.97 and 1.75. From this analysis, the sample of
wastewater in tank D1 was safe to be discharged since the heavy metal concentration was low
according to Environmental Quality (Industrial Effluent) Regulations 2009. As for the
pH value, it was suits to be discharge to the environment.

There were some recommendations that need to take into consideration so that there will
be no error occurred in the future. First was the experimenter must always monitor the
temperature used to heat up the solution so that the solution will not too dry. Next, ensure that
the analysis equipment was in good condition and read the manual thoroughly so that there will
be no error happened when the solution was being analysed. Lastly, labelled all the
solution of heavy metal that was being analysed so that it will not change with others.
5.0 ANALYSIS QUESTION

1. Analyze relationship of heavy metal concentration corresponding to the initial pH of

waste water?

Figure 3.1 Relationship between Heavy metal concentration and initial pH (Apiratikul
& Marhaba, 2004)

According to the figure 3.1 shown that the higher the concentration of the heavy metal
such as zinc in the water the lower the pH value of the water. Different type of heavy
metals has different initial pH value for 100 mg/l of the metal solubility such as for zinc
has pH 6.5, lead 5.5, copper 4.5 and cadmium is 4 (Apiratikul & Marhaba, 2004)

2. Compare result with parameters limits of heavy metal in effluent as IER 2009?

Heavy Metal Results Standard B IER 2009

Manganese 0.23 1.0
Copper 1.27 1.0
zinc 1.88 2.0

Table 3.1 Comparison between result and IER 2009

According to the result that had been obtained shown that UniKL MICET is followed
to the standard B because UniKL MICET is classified as a company. According to the
IER 2009 the amount of the manganese is 1.0, copper 1.0 and zinc is 2.0. All of the
heavy metal meets the requirement which are the level reading is below to the reading
IER 2009 except copper which is 1.27.
6.0 REFERENCES

1. Fotio, D., Researcher, I., & Fontem, D. A. (2015). Determination of Heavy Metal
Concentration in Surface Waters of the Western Determination of Heavy Metal
Concentration in Surface Waters of the Western Highlands of, (January).
https://doi.org/10.9734/JGEESI/2015/15726
2. Sharma, B., & Tyagi, S. (2013). Simplification of Metal Ion Analysis in Fresh Water
Samples by Atomic Absorption Spectroscopy for Laboratory Students, 1(3), 54–58.
https://doi.org/10.5923/j.jlce.20130103.04
3. Environmental Quality (Industrial Effluent) Regulations 2009
4. Gupta P, Sharma SK, Borauh M, Nisar KU (2012). A Specific Study of Drinking
Water Status in Term of Essential Characteristics Present in Rural and Urban Area of
Alwar District (Raj. India. Int. J. Res. Pharm. Sci. 2:123-129
5. Heavy metal water pollution-A case study. Available from:
https://www.researchgate.net/publication/303152384_Heavy_metal_water_pollution-
A_case_study [accessed Mar 4 2019].