Career summary for Leslie Webb

I am a chemist by education with a chemistry degree from the University of Reading in the UK back in 1968. My first job was not one of careful choice, but rather the first one that was offered to me in a convenient location. Ironically, I do remember having a job interview with a paper company at a mill (since closed) located on the River Thames, but I had little hesitation in expressing no real interest in the position as I found it hard to see where much real chemistry came into the process. How wrong can you be!

So my first job happened to be in North London with Diversey Ltd., a company involved in the development of all types of cleaning compounds, mainly for industrial applications. I did manage to develop an effective oven cleaner during my 15 months with Diversey, but the work was too much like "bucket" chemistry, so I soon moved elsewhere to try to find a more satisfying direction.

The organisation that I joined in early 1970 was Welwyn Hall Research Association, located in Welwyn village in Hertfordshire. This was one of many industrial research associations that had been set up to carry out collaborative research in the post-war years. The RA covered several inter-related areas centred around calcium compounds - calcium silicate bricks, calcium carbonate and lime plus a section specialising in general powder technology. The calcium carbonate division under R.R.Davidson (later to become Director of the RA) was heavily involved in the application of calcium carbonate filler in papermaking, but I joined the lime division to work on the use of calcium oxide/hydroxide in water and sewage treatment.

The use of lime for sludge conditioning was under threat from aluminium compounds and polymers, which achieved a comparable performance at much lower doses than the normal 10-20% doses of lime. I found this type of applied research, midway between what being done by academics and industry itself, very satisfying. These first steps into the environmental field coincided with an upsurge in general interest in green things through the 1972 Stockholm conference on the environment plus publications like the Ecologist Journal's Blueprint for Survival.

Sadly, the future of Welwyn Hall Research Association didn't look too healthy so I moved on and managed to get a job with consulting engineers, D.Balfour & Sons, running their new chemical laboratory that had just been set up at their South London office. This was at a time when water and waste management in the UK was set to change radically with the establishment of the 10 powerful Regional Water Authorities and new powers for water and waste management in the 1974 Control of Pollution Act. I consider myself lucky to have got this job because I had not performed even one BOD or COD analysis at the time, but I got plenty of practice in the next few years.

Over the 6½ years with Balfours, I received my grounding in water and wastewater treatment with a little on solid waste thrown in for good measure. I also managed to convince the then Institution of Water Pollution Control that I knew enough to become a member, despite the "handicap" of having the Institution's then President as my boss. The Institution has considerably widened in scope since that time, but membership of what is now the Chartered Institution of Water and Environmental Management is still valuable recognition of one's experience.

During the time I spent at Balfours, the profile of consultancy work changed from predominantly UK to predominantly overseas work and the need for an in-house laboratory declined. I had been looking around for a new position for a few months, during which time I found myself in the unusual position of being interviewed for a job with the UK Department of the Environment by a panel which included my existing boss! I don't know what he said about me, but I didn't get the job, which is just as well as I would probably not have otherwise been able to enjoy the pleasures of working in the paper industry for the last 20 or so years.

So, having turned down a graduate job at a paper mill ten years before, I joined the Paper Industry Research Association (Pira) in Leatherhead in 1978 to take charge of the Paper Division's environmental group. At that time, the major focus of research was into a very specific problem area for a number of UK mills, namely the control of sewage fungus growth in rivers receiving mill wastewaters. A side attraction of this project was that it was being conducted at mills located in my favourite parts of the UK, namely Devon, the English Lake District and the Highlands of Scotland, frequent visits to which were absolutely essential for the project leader.

This area of research was still a fascinating one despite the large amount of research carried out by Pira and others in the preceding 10 years or so. The research that we did over the next 2 years is described in four articles in Water Research 1985, 19, 8, 947-954, 955-959, 961-967 and 969-974. At this time, most UK mills discharged primary-treated effluents either indirectly to sewer or directly to surface waters as there were only about 10 mills (from a then total of about 140) with secondary biological treatment. This was a key factor in the incidence of sewage fungus, but not the only one, as its growth required the presence of not just any biodegradable substance with a BOD, just those in the right form.

In particular, the compounds had to be available directly to the bacteria (or fungus), so the majority of the BOD, which was in the form of undegraded carbohydrate polymers like starch, could not be utilised by the microbial community in the river. What determined the growth of sewage fungus was the level of low molecular weight compounds such as glucose and maltose. Consequently, partial biological breakdown of an effluent usually exacerbated sewage fungus growth, which could only be prevented by very efficient biological treatment, ie close to 100% BOD removal. Since that time, most direct-discharging UK mills have installed biological treatment and sewage fungus has disappeared as a problem.

The next few years were taken up with research into areas with application to any paper mill. Firstly, we looked at the potential for enhancing the treatability of mill wastewaters at the primary treatment stage to see whether it was possible to remove significant levels of dissolved BOD and COD as well as suspended solids by optimised chemical pre-treatment. For UK wastewaters, this was a tough challenge as the dissolved organics were largely composed of degraded starch fragments with no strong charge character. The work on a range of mill wastewater types showed that removal of genuine dissolved organics was possible, but very expensive (greater than by biological treatment). Removal of colloidal organics was cost-effective, but was not easy on certain wastewater types, ie those from recycled mills running highly closed water systems.

At this time (early 1980s), mills were beginning to install more biological treatment plants, but these were mainly of the conventional aerobic activated sludge type. Anaerobic bio-treatment had been around for a long time, but it had never taken off as an industrial wastewater treatment due to fears about toxicity and reactor size. The development and application of the upflow anaerobic sludge blanket (UASB) process in the 1970s began to change these impressions and, unknown to me at the time of research into this at Pira, the first full-scale system at Papierfrabrik Roermond in the Netherlands was already underway. Our research at Pira confirmed the findings of most other workers that this process looked very promising for stronger, warmer wastewaters that were being generated by some pulping processes and recycled liner/fluting mills. This process and its later variants have gone on to become the standard treatment for the latter type of mills.

During this period, I took over responsibility for the technical work on wet end chemistry, which has many similarities in terms of fundamental concepts and processes to effluent treatment. This saw the coming together of the two main areas in which I now work, the common material being water, which will continue to be the largest raw material used by all paper mills. Picking up the reins on wet end chemistry research coincided with an upsurge in one particular strand of this subject, namely the development of on-line sensors for real-time control of wet end chemistry. The early research on this at Pira fostered collaboration between sensor manufacturers and mills to demonstrate the mill benefits in terms of improved understanding and process runnability.

Projects were also carried out to bridge the gap between wet end chemistry and wastewater treatment. These centred on the use of clean technologies to improve the retention of substances responsible for wastewater BOD and COD, which, at many mills, comes down to better control and application of starch additions, particularly those at the size press.

Towards the end of the 1980s, Pira was facing a major restructuring exercise and I fancied doing more of what really satisfied me rather than doing more managing of others doing what satisfied them, ie to take the daunting step of leaving the life of salaried employment for the uncertainties of self-employed consultancy. This decision was helped on its way by the rising profile of activities under the heading of environmental management and its penetration into new areas of business life. Envirocell was thus born in April 1990 and continues to do very much what it set out to then in providing a mixture of consultancy, training and information services within the confines of environmental and chemical aspects of the paper industry.