labreport-graham_fin Essay

Graham Fallon – 20083726

Lab report – Chemistry

Environmental water analysis

Lab report Water Quality Analysis Graham Fallon – 20083726

Analysis of the water quality of

St. Johns river, Waterford

Aims:

(1) To estimate the total weight of suspended solids in a water sample.

(2) To estimate the total weight of dissolved solids in a water sample.

(3) To calibrate a pH meter and use it to determine the Ph of a water sample.

(4) Buffering capacity of water sample.

(5) To determine the acidity of the water sample .

(6) To d etermine the alkalinity of the water sample.

Introduction:

The European council have set out directives, Council directive 98/83 EC of November 1998

on the quality of water intended for Human consumption and The Nitrates directive

(91/676/EEC). Both of which outline the standards for water quality across the entire

region. These directives set out guidelines for the minimum requirements for water quality

to ensure the public health is protected (Eur -lex.europa.eu, 2019) . It is up to each member

state to monitor water quality by sampling throughout the year, this obligation also requires

that all sterilization techniques are valid (Eur -lex.

europa.eu, 2019) . As for the Nitrates

directive, this directive also defines the parameters for the use of fertilizers at during certain

periods of the year (Department of Housing, Planning and Local Government, 2019) . According

to Howard Perlman of the USGS water science school, improper timing and use of fertilizers/

slurry can cause severe algal b looms, which contribute to fish kills and the degradation of

ecosystems (H. Perlman, 2019).

The water samples taken in Ireland are usually carried out by the EPA and report findings

back to county councils and group water schemes, these reports must includ e

concentrations and account for each of the following;

• Microorganisms and parasites

• Suspended organic/inorganic materials

• Dissolved organic materials

• Dissolved inorganic materials

• Taste and odor

• Temperature

• Chlorides

• Nitrates

• Algae

• pH

Lab report Water Quality Analysis Graham Fallon – 20083726

The sample provided was taken from the St John river, which runs through Waterford city,

of which most of the river is tidal and according to a report published by the EPA in 2011

ammonia, o -phosphate, nitrite and nitrate are frequently elevated. This river was said to be

seriously polluted (Report on the River Water Quality in Waterford city & County, 2011).

Method:

Apparatus used:

250ml graduated cylinders, 250ml conical flasks, 250ml Beakers, 50ml Burettes, filter

paper, oven, pipettes, pH meter, Analytical balance, Top -pan balance, tongs, funnel.

Chemicals used:

pH buffer solutions 7&10, Phenolphthalein, Methyl Orange indicator, 0.02M HCL solution,

deionized water, St Johns river sample.

(1) Suspended solids

• Filter paper was removed from packaging and weighed on Analytical balance,

ensuring door was closed for an accurate reading. Reading recorded to four decimal

places.

• 100ml of sample water was allowed to drain through filter paper into a 250ml

beaker, the water that filtered through was kept for a later test.

• After filtration, filter paper was placed into the oven for 30 minutes at 100 degrees

Celsius until filter paper was completely dry.

• The filter paper was reweighed on the Analytical balance and the figures recorded.

• A weighted was d etermined in g/ml.

(2) Dissolved solids

• Water from the suspended solids test were kept and used to determine the total

concentration of dissolved solids.

• A clean/dry beaker was weighed on the Top pan balance to determine the beakers

dry weight and measured in grams, to two decimal places.

• 100ml of sample water was allowed to filter through the filter paper into the 250ml

beaker.

• The beaker was weighed along with the sample water using the Top pan balance.

• The beaker was then placed into the oven at 200 degrees Celsius until the water had

been driven off.

• The beaker was allowed to cool and reweighed and readings recorded.

Lab report Water Quality Analysis Graham Fallon – 20083726

(3) pH test of water sample

• The pH meter was unpacked and the probe cleaned using deionized water and a soft

piece of cloth. A small beaker was filled with deionized water for cleaning after buffer

solutions.

• The pH meter was calibrated using two buffer solutions of known pH, the meter must

be in calibration mode while using the buffer solutions.

• First using the buffer solution of 10, waiting for a stable reading then calibrating.

• Rinse probe.

• Use the second buffer solution of 7, wait for a stable reading then calibrate.

• Rinse probe.

• The sample was inserted i nto a small beaker, agitated and probe inserted.

• Readings were measured and recorded.

(4) Buffering capacity

• 50.0ml of water sample was placed into a clean/dry 250ml Beaker.

• The pH was measured and recorded.

• Using a disposable pipette, 1ml of 0.01M HCL was added to the sample one drop at a

time, monitoring the pH as each drop was added.

• Continuously stir sample.

• This process was carried out repeatedly until the pH had changed by

one entire unit.

• The Buffering capacity was then calculat ed

(5) Acidity of a water sample

• Using a pipette 50.0ml of sample water was placed into clean/dry

250ml conical flask.

• Two drops of Methyl Orange indicator were added to this sample.

• After two drops of Methyl Orange were added, the samp le went a bright red.

• A decision was made to titrate back using 0.02M NaOH in a 50ml burette to reach a

yellow end point. Colour change should take place at around 4.5pH (Graham, 1999).

• No end point could be established after 25ml of 0.02M NaOH as sample o r beaker

may have been contaminated.

• The test had to be abandoned due to time constraints and working alone.

(6) Alkalinity of a water sample

• Using the same apparatus and set up as the test for acidity in a water sample.

• 50.0ml of sample water used and 2 drops of phenolphthalein indicator added to

sample. Pink colour observed.

• 0.02M HCl used in titration back to a colourless solution.

• Titre value recorded

• Due to time constraints, test could not be replicated or repeated .

Lab report Water Quality Analysis Graham Fallon – 20083726

Calculations:

2HCl + CaCO3 — CaCL 2 + H 2O + CO 2

MaVa/n1 = MbVb/n2

a = CaCO 3 b = HCl

Ma = ? Mb = 0.02M

Va = 50ml Vb = 11.6ml

n1= 1 b1 = 1

(? x 50)/1 = (0.02 x 11.6)/1

? = (0.02 x 11.6)/50

= 0.00464

0.00464 x 100 = 0.464 g/L

= 464 mg/L

Lab report Water Quality Analysis Graham Fallon – 20083726

Table of results

Table A: Suspended Solids

Sample Filter

Paper

Mass (g)

Filter

Paper +

Solids

(Dried) (g)

Mass of

Solids in

100ml/ (g)

100ml of St.

Johns river

water

1.2885g 1.3018g 0.0133g

Table B: Dissolved Solids

Sample Beaker

Weight Dry

(g)

Beaker &

Dissolved

Solid

(wet)(g)

Beaker &

Dissolved

solids

(dry)(g)

Dissolved

Solids

(100ml)

Total

Dissolved

Solids (mg

L)

100ml

Sample

water

165.11g 256.182g 165.18g 0.07g 0.0007mg L

Table C: pH Results

Sample pH

St. Johns River 6.86

Distilled Water 6.6

Results D: Acidity/Alkalinity Titration

Sample Methyl Orange Phenolphthalein

50.0ml Sample water N/A 11.6cm 3

Lab report Water Quality Analysis Graham Fallon – 20083726

Discussion

When considering water quality, guidelines provided by the EC in the Council directive 98/83

EC of November 1998 on the quality of water intended for Human consumption and the

EEC, No.L229 of July,1980 must be considered, although these experiments were no t

testing for human consumption.

The outlined total suspended solids (dry residues) must be under 1500mg/dm 3 (Eur –

lex.europa.eu, 2019) . Measurements of 0.07g can be seen in table (B) and this

measurement is within the standards set out by the EC &EEC.

As with current standards on pH, the Freshwater Fish directive (78/659/EEC) of 1978 on the

quality of fresh waters needing protection, co mments on the recommended pH being from 6

to 9 for both Salmoid and Cyprinid waters. Test results obtained were 6.86pH and are within

the parameters set out.

The current directive also outlines for suspended solids and Nitrates among other things.

These re adings are all within current parameters as can be seen in Tables (A) through (D).

These findings could be false, figures recorded are all below recommended guidelines. The

EPA define St Johns river as being treated for sewage and affluent run off, that th e river is

‘of concern ’ and ‘seriously polluted’ (Report on the River Water Quality in Waterford city &

County 2011, 2011).

Errors and false results

• The lab manual was difficult to follow at times and this was compounded by my change of

partners week to week. A lab practical on this topic would have been beneficial. All

figures could have been tabulated across the group to find more precise results.

• Glassware contaminated with unknown material thus making one experiment invalid.

• Door would not close on the analytical balance after drying filter paper, this may have led

to inaccurate results as the filter paper was absorbing environmental moisture.

Con clusion

Water quality standards across Ireland have fluctuated throughout the years from an all –

time low (14.5%) in moderate water quality rivers and estuaries (2007 to 2009), into the

present day where the figure stands at 16.7% (O’Boyle and Tierney, 2016). There was also

an increase in sites where phosphate damage had been decreased, from 28% in 2007 to

37% in 2017 (O’Donnell et al., 2017) . These decreases are a reflection of directives and the

willingness of governments to follo w through.

As the results obtained were in line with recommended standards on water quality, the

results may be incorrect due to previously outlined errors. As the Environmental protection

agency has stated in the report on Water Quality in Waterford city & county, there has been

no substantial change in the water quality of St. Johns river (Report on the River Water

Quality in Waterford city & County 2011, 2012)

Lab report Water Quality Analysis Graham Fallon – 20083726

Refernces

Bristow, A., Whitehead, D. and Cockburn, J. (1992). Nitrogenous constituents in the urine of

cattle, sheep and goats. Journal of the Science of Food and Agriculture , 59(3), pp.387 -394.

Department of Housing, Planning and Local Government. (2019). Nitrates Directive . [online]

Available at: -quality/nitrates/n itrates -directive

[Accessed 27 Mar. 2019].

Eur -lex.europa.eu. (2019). EUR -Lex – 01998L0083 -20151027 – EN – EUR -Lex . [online]

Available at: -lex.euro pa.eu/legal -content/EN/TXT/?uri=CELEX:01998L0083 –

20151027 [Accessed 28 Mar. 2019].

Graham, N. (1999). Guidelines for Drinking -Water Quality, 2nd edition, Addendum to

Volume 1 – Recommendations, World Health Organisation, Geneva, 1998, 36 pages. Urban

Water , [online] 1(2), p.17. Available at:

[Accessed 27 Mar. 2019].

Howard Perlman, U. (2019). What causes fish kills? Water science questions and answers,

from the USGS Water Science School . [online] Water.usgs.gov. Available at:

-chemical -fishkills.html [Accessed 31 Mar. 2019].

O’Boyle, S. and Tierney, D. (2016). Indicator 2 – High Quality water sites . [online] Available at:

-in-the -percentage -of-high -quality -river -sites -Q5 -Q4 –

5-since -1987_fig2_325877817 [Accessed 29 Mar. 2019].

O’Donnell, G., Stephens, A., Free, G. and Tierney, D. (2017). Phosphorus (mg/L) in Lakes .

[online] researchgate. Available at: -three -year –

averages -of-total -phosphorus -concentrations -at-monitored -lakes -2007 -2016_fig4_325877817

[Accessed 30 Mar. 2019].

Report on the River Water Quality in Waterford city & County 2011. (2011). [online] pp.1 -4.

Available at:

WaterfordCityandCounty.pdf [Accessed 27 Mar. 2019].