Water and Sewage Treatment: Expertise Unlimited

The call-out didn't come at 3AM Sunday morning as predicted, but at noon the previous day. Frost damage had shattered many pipes, several pumps were air-locked, and there were unexpected foreign bodies in the feed which were causing blockages-and of course the buffer tanks were completely full at both sites, and the generators, instrumentation and SCADA system were also misbehaving.

It took half a day to patch things up, clear the blockages and airlocks, and get both plants running at top speed again to shift the melt-water.

Labels: emergency callout, groundwater, plant, treatment

I've been quite busy with learning to teach, but I went down to see a plant I upgraded about a year ago last Friday for a "health check".

As it took the operators three-quarters of an hour to even find the O+M manual, it looked as if it hadn't seen much use. The recommended daily checks had been reduced to a quick look through the fence as they went past, and no checks at all on weekends or holidays. They had turned the coagulant dose right down and filled the plant with 32% acid and alkali to save on chemical costs, and unsupervised tanker drivers had been walking on the tray-work. Despite all of this, everything was still basically working.

I'm going to do a bit of lab-work this afternoon to see if they can use a cheaper coagulant than the fancy blend the original plant installers recommended. At £2 a litre, I can see how they want to turn the dose down, even if it does degrade plant performance.

I'm off to Nottingham this morning to see a few examples of good lecturing practice, and if I have time, I'm going to make a start on the anaerobic digestion course I'm doing for Loughborough.

Labels: effluent, industrial, plant, treatment, troubleshooting

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

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

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

More enquiries have come in from people with misbehaving small effluent treatment plants. I have covered some of the more interesting problems I have encountered previously with small plants on my website here.

Most of the non-compliant effluent treatment plants I see have been undersized, poorly maintained, and often worsened by the attention of unqualified "engineers" from maintenance companies.

From July of this year, BS EN 12566-3 replaces all national standards for sewage treatment plants for up to 50 population equivalent. Trading standards will enforce it, and it will require plants to have been tested to meet a set standard. The plants will therefore deliver a set standard at their rated population equivalent.

I have however only once been called out to a plant which was incapable of meeting its claimed standard by reason of incompetent basic design (that manufacturer shortly afterwards started to offer someone else's design, whilst not admitting that theirs was incapable of performing as claimed). The problem is more commonly poor specification, installation or maintenance.

What we therefore need now if for someone to make the specifier comply with the British Water Code of Practice in setting a conservative population equivalent for their development, and for someone to explain to the monkeys who work for maintenance companies that no amount of sucking sludge into a tanker makes you an engineer, and I'll be out of a job. I'm not losing any sleep about it. You can go to jail for claiming to be a Doctor, but anyone can claim to be an Engineer.

Labels: BS EN 12566-3, effluent, package, plant, sewage, treatment

It's been a quiet week in the office. I've mostly been attempting to teach my French work experience student (Cyril) how to use a library to research an area of scientific interest. In this case, the subject of interest is PCB contaminated groundwater. He is looking as some problems with floating oily sludges on a treatment plant I look after.

It turns out that the French-speaking world have never heard of the Science Citation Index and Chemical Abstracts. I'm waiting to find out what their librarians recommend as an alternative.

Just as I write that things are quiet, I have received a call from some people I quoted six months ago to look at a problem on a pharmaceutical effluent treatment plant...

Labels: effluent, groundwater, PCB, plant, treatment

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