Water and Sewage Treatment: Expertise Unlimited
Sean Moran, our Principal Engineer writes this occasional blog about his experiences. Our company (Expertise Limited) design, commission and troubleshoot Sewage, Industrial Effluent and Water Treatment Plant. We provide Process and Hydraulic Design, Staff Training, Review and Audit and Expert Witness Services.Saturday, 13 December 2008
Polymer Dosing: Pharma Effluent
This is the polymer dosing pump and storage tank, for dosing an aluminium based coagulant for colour removal.
We refitted the old polymer dosing pump to a reconditioned IBC, and new downpipe. We also replaced its outgoing line with new twinwall stock.
The polymer pump was rewired to the new control system and interlocked to feed pump operation from its inverter.
We refitted the old polymer dosing pump to a reconditioned IBC, and new downpipe. We also replaced its outgoing line with new twinwall stock.
The polymer pump was rewired to the new control system and interlocked to feed pump operation from its inverter.
Labels: alum, chemical, design, dosing, effluent, engineer, environment, etp, industrial, pharmaceutical, plant, problem, pump, treatment, troubleshooting, wastewater, water
pH Dosing Kit: Pharma Effluent
This is the pH correction system, dosing up to 32% HCl and 20% NaOH by means of dosing pumps controlled by the yellow unit in the foreground.
Chemical storage is 2 No. 1000 L reconditioned IBCs.
Dosing lines are twin-wall for safety.
Chemical dosing operation is interlocked to feed pump operation via a feed from the inverter.
Chemical storage is 2 No. 1000 L reconditioned IBCs.
Dosing lines are twin-wall for safety.
Chemical dosing operation is interlocked to feed pump operation via a feed from the inverter.
Labels: chemical, design, dosing, effluent, engineer, environment, etp, pH, pH dosing, pharmaceutical, plant, pump, treatment, waste, wastewater, water
Wednesday, 16 July 2008
Troubleshooting and Experiments
Spent a long day yesterday troubleshooting problems with the duff effluent treatment plant for the pharma client previously discussed. Managed to solve his excessive flow to sewer by simply restricting air flow to his diaphragm pumps. The client had not thought of this because he was convinced that his effluent flow rate was around five times its actual value. Always good to check your assumptions. Couldn't get his pH correction system online, due to problems with an injection lance, but increasing the alum dose brought the pH into spec. anyway. Just the problems with COD, suspended solids and heavy metals to solve now.
Also had a call from the Environment Agency yesterday about a former client who has tried to solve his own problems with an undersized effluent treatment plant. Like a lot of inexpert clients with such problems, he had been duped by a succession of snake-oil salesmen into trying all sorts of quick fixes, none of which had worked. He only carried out the cheaper of my recommendations, as cheaply as possible, and now it seems he is likely to get prosecuted.
The morals are:
1. All the magic bugs, fat dissolvers, swimming-pool filters and chemical dosing in the world will not save you if your plant is not the right size, installed, operated and maintained correctly. If it is correctly designed, installed, operated and maintained, you will not need these things.
2. If you spend money on a consultant, follow his suggestions. Waving a report whose suggestions you did not implement at the EA will not save you from prosecution.
Experiments on PCB containing oily sludges are going OK, in the strict scientific sense. That is, we have no growth yet of either anaerobic or aerobic organisms on the stuff. Of course, from a practical point of view, this disappoints.
Also had a call from the Environment Agency yesterday about a former client who has tried to solve his own problems with an undersized effluent treatment plant. Like a lot of inexpert clients with such problems, he had been duped by a succession of snake-oil salesmen into trying all sorts of quick fixes, none of which had worked. He only carried out the cheaper of my recommendations, as cheaply as possible, and now it seems he is likely to get prosecuted.
The morals are:
1. All the magic bugs, fat dissolvers, swimming-pool filters and chemical dosing in the world will not save you if your plant is not the right size, installed, operated and maintained correctly. If it is correctly designed, installed, operated and maintained, you will not need these things.
2. If you spend money on a consultant, follow his suggestions. Waving a report whose suggestions you did not implement at the EA will not save you from prosecution.
Experiments on PCB containing oily sludges are going OK, in the strict scientific sense. That is, we have no growth yet of either anaerobic or aerobic organisms on the stuff. Of course, from a practical point of view, this disappoints.
Labels: agency, alum, COD, dosing, environment, pH, pharmaceutical, plant, problem, sewage, solids, suspended, treatment, troubleshooting, water
Wednesday, 4 June 2008
Design Errors: Static Mixers
A quiet sort of a week in the main. Cyril continues his research into treatment of PCBs in groundwater. I have been engaged with the pharmaceutical client mentioned previously on here.
They have what must be one of the worst effluent treatment plants I have ever seen in terms of fundamental design flaws. One of the biggest of them was the use of static mixers to mix acid and coagulant with effluent, which was pumped by diaphragm pumps. This showed a fundamental misunderstanding of the nature of static mixers in the system designer. Static mixers blend fluids across the body of the mixer. If you feed them with a pulsating flow from a diaphragm pump, and an out-of synch. pulsating flow from a dosing pump, you end up with constantly varying degrees of mix in the outlet flow. The normal rule of sampling at least 10 pipe diameters downstream to get 95% degree of mix no longer applies. Your pH probe for example will see extreme variation in measures pH, and instead of gaining control to +/- 0.1pH units as you should from a system like this, you will be lucky to see +/- 0.5 pH units.
They have what must be one of the worst effluent treatment plants I have ever seen in terms of fundamental design flaws. One of the biggest of them was the use of static mixers to mix acid and coagulant with effluent, which was pumped by diaphragm pumps. This showed a fundamental misunderstanding of the nature of static mixers in the system designer. Static mixers blend fluids across the body of the mixer. If you feed them with a pulsating flow from a diaphragm pump, and an out-of synch. pulsating flow from a dosing pump, you end up with constantly varying degrees of mix in the outlet flow. The normal rule of sampling at least 10 pipe diameters downstream to get 95% degree of mix no longer applies. Your pH probe for example will see extreme variation in measures pH, and instead of gaining control to +/- 0.1pH units as you should from a system like this, you will be lucky to see +/- 0.5 pH units.
Labels: design, dosing, effluent, error, groundwater, mixer, pharmaceutical, plant, static, waste, wastewater, water
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