Water quality mix model - Essay Example

3. (1/2 mark) Convert the concentrations to meq/L and calculate the total meq/L of cations (positive) and anions (negative) and calculate the “Charge balance error”. Does the CBE indicate an accurate analysis or should another sample be analysed by the laboratory? 4. (3 marks) Assume that the “mine void” or V water is a mix of water from the coal seam C and an unknown source X. In the example with available data from a long wall coal mine, water X could be S (sandstone roof) or water X could be F (freshwater).

The mix proportion M could be from 0.01 to 0.99. Several water mix scenarios might be physically possible. 6. (1/2 mark) Using the ANZECC guidelines, find the guideline value for Zinc for 95% protection of fresh water aquatic species. Which of the above mix scenarios complies with this guideline value if the waters from the coal seam void were to be pumped and discharged to a river? The following geochemical model results are presented for a PHREEQC model of a water mix from 19% fresh rain and 81% of “C” coal seam.

PHREEQC predicts that the pH of the mixed water is 7.2. Examine these extracts from the output file and answer the questions following. 5. (2 marks) Install PHREEQC following instructions in the appendix that follows. Run PHREEQC using the mix input file provided and then edit the mix input file for the scenario in Question 4b) above where X = F (freshwater) based on TDS. For the mixed water result, what is the pH, major ion, zinc concentration and zinc speciation? Prepare a brief critical review that describes options for mitigating the effects of discharging salt and metals on the river using a variety management options.

Concentrations for example may involve source and discharge controls, geochemical attenuation, physical structures and treatment. It is vital to maintain the rain water with the aid of the LID (Low Impact Development techniques) like ‘green roof’. These assist in the jurisdiction of