P8.2.1.9 From time to time Manganese. Manganese Re-calculate have a second person concentration is chemical dosing check calculations more than 50% quantities solution used for preparation of the MAV. required for concentration of KMnO4 dosing the dosing incorrect, or in dosing No sign of solution. solution, and prepared with solution. insoluble prepare a new incorrect Check KMnO4 manganese Supplier’s solution. chemical. concentration in each formation certification new batch of dosing directly after Provide for of analysis. solution prepared. oxidation staff additional (metals must be training in Ensure that chemicals insoluble to be calculations are delivered to the removed). for solution correct bin, that bins preparation. are labelled, and that Checks show an operator is there to frequent Ensure that supervise chemical incorrect chemical delivery. calculations. supplier is of the need for Check quality of the operator to KMnO4 delivered. be present when chemicals are delivered. Obtain a new batch of chemical from the supplier, if quality P8.2.1.10 Do calculations and Manganese. Manganese If aerator during design to concentration is relies on Poor air ensure air circulation more than 50% natural draft, circulation for will allow enough of the MAV. consider droplet, or oxygen to dissolve in installation of thin-film, No sign of the water. blowers to aerator. insoluble provide forced manganese draft. formation directly after Modify the oxidation aerator to (metals must be minimise insoluble to be obstructions removed). to air flow. Calculations show air circulation too low. P8.2.1.11 Design to ensure Manganese. Manganese Replace droplets are given concentration is nozzles. Poor nozzle longest possible time more than 50% design in Modify spray in the air to allow of the MAV. spray aerator. trajectory. oxygen exchange No sign of (nozzle design and insoluble trajectory are manganese important). formation directly after oxidation (metals must be insoluble to be removed).
P8.2.1.9 dosing solution concentration incorrect, or prepared with incorrect chemical. From time to time have a second person check calculations used for preparation of KMnO4 dosing solution. Check KMnO4 concentration in each new batch of dosing solution prepared. Ensure that chemicals are delivered to the correct bin, that bins are labelled, and that an operator is there to supervise chemical delivery. Check quality of KMnO4 delivered. Manganese. in dosing solution. Supplier’s certification of analysis. Manganese concentration is more than 50% of the MAV. No sign of insoluble manganese formation directly after oxidation (metals must be insoluble to be removed). Checks show frequent incorrect calculations. Re-calculate chemical quantities required for the dosing solution, and prepare a new solution. Provide for staff additional training in calculations for solution preparation. Ensure that chemical supplier is of the need for the operator to be present when chemicals are delivered. Obtain a new batch of chemical from the supplier, if quality P8.2.1.10 Poor air circulation for droplet, or thin-film, aerator. Do calculations and during design to ensure air circulation will allow enough oxygen to dissolve in the water. Manganese. Manganese concentration is more than 50% of the MAV. No sign of insoluble manganese formation directly after oxidation (metals must be insoluble to be removed). Calculations show air circulation too low. If aerator relies on natural draft, consider installation of blowers to provide forced draft. Modify the aerator to minimise obstructions to air flow. P8.2.1.11 Poor nozzle design in spray aerator. Design to ensure droplets are given longest possible time in the air to allow oxygen exchange (nozzle design and trajectory are important). Manganese. Manganese concentration is more than 50% of the MAV. No sign of insoluble manganese formation directly after oxidation (metals must be insoluble to be removed). Replace nozzles. Modify spray trajectory.
treatment-iron-manganese-removal-feb14-v2.docx