disinfection, storage

sedimentation, filteration

controlled parameters

2 hourly and 4 hourly for raw, coagulated, settled and treated

wsp workshop - june 09

- identification of hazards

(to be continued...)

WATER SAFETY PLAN

-originated in australia
-the objective is to ensure safe drinking water through good water supply practice.
-to prevent contimination of raw water sources
-treating water to reduce contimination
-to prevent re-contimination of treated water in storages, distribution and network system
-proactive control of hazards and risk
-to provide quality trusted product for both suppliers and consumers

instrumentation hand-on workshop

jar test, dosing, coagulation, flocculation

raw water parameters are to be recorded, jar test is carried out to determine the optimum dosage for coagulation

hyrated lime is used for pH adjustment than aluminium sulphate is added, graph is plotted to get the optimum dosage of those chemicals which will be used later on in this process



silos where hydrated lime is stored

slurry tank where hydrated lime solution is prepared

metering pump for hydrated lime and aluminium sulphate

dosing points




a good jar test should by right represents a correct / optimum dosage and adequate coagulation for flocculation, resulting a good end product.

AL₂(SO4)₃.14H₂O + 3Ca(OH) ₂ → 2Al(OH) ₃ ↓+ 3CaSO₄ + 14H₂O

aeration (or aerification)

Adding oxygen to remove dissolved gases in water , to oxidized and convert undesirable substances (i.e Iron and Manganese ) to a more manageable form.

4Fe²⁺ + O₂ + 10H₂O → 4Fe(OH)₃ ↓ + 8H⁺

2Mn²⁺ + O₂ + 2H₂O → 2MnO₂ ↓ + 4H⁺

these reaction may be happened in this stage where both ferrous iron and manganese are oxidized forming a non-soluble substances and removed after aeration.