Water and Sewage Treatment: Expertise Unlimited

The overly complex PLC based controls of the original plant were replaced by a dedicated pH controller, and these three boxes.

These are a distribution board, an ultrasonic controller, and an inverter.

These replace the plc without a human interface which the original installers used.

Since at least monthly intervention is required to calibrate the pH probe, this might be viewed as a design weakness, or an attempt to prevent the purchaser from using another plant maintenace company.

Labels: Controls, effluent, pharmaceutical, plant, treatment

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.

Labels: alum, chemical, design, dosing, effluent, engineer, environment, etp, industrial, pharmaceutical, plant, problem, pump, treatment, troubleshooting, wastewater, water

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.

Labels: chemical, design, dosing, effluent, engineer, environment, etp, pH, pH dosing, pharmaceutical, plant, pump, treatment, waste, wastewater, water

We have added some new content to the website, in the form of a collection of recent publications:
some book reviews, a water feature design manual, an article on packaged waste water treatment plant problems, and a literature review on PCB water treatment technologies.

Things are proceeding well in other areas, getting ready for the pharma. plant upgrade in November, and picking up a few new clients.

Labels: book, design, effluent, feature, literature, manual, package, PCB, pharmaceutical, plant, review, treatment, waste, water

So it turned out that the heating and aeration of the oily sludges as part of the test for aerobic degradation broke the emulsion, where all other attempts had failed. Investigations continue.

I got an interesting email from South Africa this week, prompted by my page on package plant failures.

Steve Nicol of Wastewater Watch in SA produces an amusing name and shame newsletter for those he considers to be rogue package plant manufacturers in his country.

Design is proceeding on the upgrading of the failing pharma effluent treatment plant. We should be on-site in October/November to carry out the work.

Labels: aerobic, africa, degradation, effluent, industrial, oil, package, PCB, pharmaceutical, plant south, sludge, waste, water

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.

Labels: agency, alum, COD, dosing, environment, pH, pharmaceutical, plant, problem, sewage, solids, suspended, treatment, troubleshooting, water

Things not looking too promising for the experiment set up on Monday to test anaerobic digestion of PCB containing oily sludges in Manchester. No evidence of any gas generation as yet.

Awaiting the order for starting sampling work to establish the bast way forward for the pharma client.

Continuing to review "Elements of Environmental Chemistry". Can't see a thing wrong with it so far...

Labels: book, PCB, pharmaceutical, review, sludge, waste, wastewater, water

Other than designing a solution to the problems of our new pharmaceutical client, I have been reviewing a book for The Chemical Engineer magazine, and looking at carrying out an experiment to determine how well anaerobic digestion might reduce PCB levels in oily sludges.

I am having difficulty at present sourcing a small chopper pump which can be controlled by inverter to provide a better, smoother feed to the pharma client's plant without blocking concerns. No problem getting one with 75mm discharge size or above, but the small ones don't have an over-rated motor, which is recommended for variable speed drive.

The book I am reviewing is "Elements of Environmental Chemistry" by Ronald Hites. Seems like a pretty good little textbook.

The oily sludges I hope to treat with AD have been a problem at a couple of sites I provide technical cover for for years now, and it is getting increasingly difficult and expensive to dispose of them. It would be nice if we can get PCB levels down to non-hazardous numbers by this process. The experiment is fairly quick and dirty, so we should have a rough answer by August.

Something amusing I saw today on the quackery front: truth in alternative medicine at last...

Labels: anaerobic, chemical, chemistry, chopper, degradation, digestion, engineer, environment, oil, PCB, pharmaceutical, pump, sludge

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.

Labels: design, dosing, effluent, error, groundwater, mixer, pharmaceutical, plant, static, waste, wastewater, water

I've decided to start a blog on the company website, covering things which interest me professionally.

I'm a Chemical Engineer and Environmental Scientist, working mainly in the field of Water Engineering, though I do also deal in more general environmental advice, mostly on behalf of a government funded scheme called Envirowise.

I used to work for water contractors who you will not now have heard of, because it is seemingly a rule in the water industry that companies have to change the name of their company from time to time, for a number of reasons. For good companies, this is usually something to do with the marketing department. For bad companies, the reasons may be less honourable. None of the people I used to work for went bust by bidding jobs at less than cost and then came back one month later as "(old company name) 2008 Limited", but this is far from uncommon in the industry.

I do quite a bit of work of packaged sewage treatment plants which are misbehaving, look after some groundwater treatment plants, and am also presently involved in something I do a bit of from time to time, water feature design. I am helping with the design of water features in the Parc1 development in Korea. Don't click on the link unless you have broadband, the graphic designers have gone nuts on the website.

I'm also interested in water quackery, and will post some stuff on this as I come across new examples.

Labels: chemical, design, effluent, engineer, environment, etp, groundwater, industrial, package, PCB, pharmaceutical, plant, problem, sewage, sludge, treatment, troubleshooting, wastewater