A clean piece of paper

John E.G. Sikes

John E.G. Sikes is senior process engineer with Beak Consultants Ltd., Vancouver, Canada. This article was a contribution to the United Nations Environment Programme workshop on the pulp and paper industry and the environment held in Paris in March 1974.

The author surveys the developments of the past decade in pollution control for pulp and paper mills, including legislation, and points out encouraging trends such as the development in the foreseeable future of closed water systems which will result in virtually no effluent discharge.

The pulp and paper industry probably felt relatively little compulsion in the past to cope with, or even acknowledge, the environmental ramifications of its manufacturing process. Profitability was paramount. Recently, the industry has been making rapid progress toward combating pollution, instigated by legislative pressure, social compulsion, or the basic need to become more efficient.

In undertaking pollution control programmes the logical area of initial endeavour is within the production process. It has been estimated, for example, that in the average mill one third of losses to the sewer occur as a result of leaks and spills. In many mills this proportion is certainly greater. As water, fibre, energy and chemicals become increasingly valuable, special attention is being given to the efficiency of the production process, and the recovery rate of materials and chemicals.

Many of the steps being undertaken by existing mills relate to modifying the process. Some examples are: conversion from wet to dry debarking, better washing of pulp and recovery of cooking chemicals; more complete utilization of rejected fibre; modification of bleaching sequences and more countercurrent washing in bleach plants; improved evaporator and recovery operations; stripping of condensates for re-use, closing up paper machine white-water systems, upgrading precipitators and scrubbers; installing spill control facilities; improving monitoring and instrumentation. Perhaps the most important innovation is the introduction of educational programmes to improve operator motivation.

The list is lengthy. During the past ten years the water use of new pulp and paper mills has been reduced by a factor of two or more. Similar reductions are possible for total losses of chemicals and fibre. Atmospheric emissions of mills constructed today are a fraction of those of a decade ago.

For existing mills it is frequently difficult to undertake extensive process modifications in one step, due to the interdependence of the many production components. A gradual programme is normally implemented.

It is probable that in industrialized countries no pulp and paper mill is being constructed today, or even considered, without environmental factors being taken into account. Again, a decade ago, such factors would have been considered only superficially.

Treatment

The methods used for external treatment of effluents from the industry are generally derived from municipal techniques: sedimentation, sometimes with chemical addition to improve performance, various biological treatments and efficient dilution in the receiving waters. Where irrigation is practiced, increasing consideration is being given to the acceptability of effluents for use as irrigants. Some countries pay particular attention to the eutrophication issue, and also to the colour of effluents, especially from bleached sulfate mills. To date, methods for removal of colour and nutrients generally involve chemical coagulation and precipitation.

The equipment being used to control pollution includes high efficiency precipitators, scrubbers, fabric filters, inertial separators and incinerators.

The pulp and paper industry is currently undergoing a stage of rapid change in its implementation of pollution control measures.

New mills, certainly those in industrialized nations, are required to achieve rigorous effluent and emission criteria, usually through the use of proven modern technology. The regulatory criteria are such that not only appropriate treatment systems must be installed, but the basic process must maximize water re-use and recovery of chemicals and fibre. Enormous strides have been taken in the last few years to achieve the ultimate goal of a pulp and paper mill having no effluent discharge.

New mills in developing countries are usually subject to some form of environmental assessment, with process, treatment and disposal schemes specific to their own needs. While perhaps not as advanced as in industrialized nations, the approach is nevertheless similar. Developing nations may decide that it is better to forego technical innovations which entail some risk, in favour of reliability.

For existing mills in all countries, but more especially in industrialized nations where legislative machinery reacts more quickly to the public's demands, and where the major technical expertise exists, the situation is changing rapidly.

Saving water

With few exceptions, all mills have in recent years undertaken programmes to economize on water use and to control obvious sources of loss of fibre and chemicals. These are normally evaluated and undertaken by mill personnel, and usually represent an economic benefit.

A further step which is under way in many mills is one which involves the use of advanced proven technology, such as improving washing efficiency, closing up screening systems, reducing bleach plant water use, stripping condensates, and installing equipment to reduce atmospheric emissions and external treatment plants.

The most advanced companies are now entering a third stage: the use of technology not yet commercially proven. Examples include new pulping and bleaching processes, totally new equipment and radically different treatment technology. Some of these schemes are entering the pilot or demonstration plant phase. They are motivated by government or industry grants, concern for the environment, improvement of product quality, economic advantage or sheer inventive drive.

REDUCTION OF POLLUTANTS AS PROJECTED FOR 1970-75 (Table 1)

Country	Suspended solids	BOD5
	Percent
Canada	55	24
Finland	57	16
France	47	16
Germany, Fed. Rep	13	17
Japan	47	37
Norway	18	10
Sweden	51	50
Switzerland	55	77
United Kingdom	33	17
United States	47	66

SOURCE: Pollution by the pulp and paper industry - present situation and trends. Organisation for Economic Co-operation and Development, Paris, 1973.

Other broad environmental factors associated with the industry must not be ignored. Much is being done to improve forestry management; increasing attention is being given to the health and well-being of personnel; there is greater cooperation with the public sector.

A major difficulty in the analysis of quantitative trends in the discarge of pollutants by the industry is the dearth of statistical data from many countries and the lack of a mechanism for national or even international comparison. This problem is compounded by the assorted monitoring and analytical techniques used.

There is no question that the quantity of pollutants discharged by the industry, per unit of production, has been progressively reduced over the years. It is possible to construct a modern pulp and paper mill with a water use of one fifth to one tenth of that of an older mill, with a concurrent reduction of pollutants.

In terms of total quantity of pollutants discharged, it is probable that there was a progressive increase up until about 1970 due to increased production All major pulp and paper producing countries have projected a systematic reduction from 1970 onward, despite augmented productive capacity. Table 1 summarizes projections of a study by the Organisation for Economic Cooperation and Development (OECD) of the estimated reduction of Biochemical Oxygen Demand (BOD) and suspended solids between 1970 and 1975 for selected major producing countries, notwithstanding increased production.

National variations

These projections were made in 1971, when the data base was limited and, more important, at a time of rapid evolution in the formulation of national environment policies. The data are not strictly comparable, as during the reference year, 1970, the programmes in some countries were significantly more advanced than in others. Also, the definition of the parameters BOD and suspended solids varies from country to country.

Little information is available regarding the achievement of these objectives. Factors which affect the actual timing of individual programmes include market conditions, profit, regulatory agency attitudes, money supply and technological developments. Without firm statistical data, it would seem that the OECD projections remain generally valid, although in some countries the 1975 target may have been postponed.

Not enough basic data were available to the OECD group to make predictions on pollutant emissions to the atmosphere, but the same declining trend is apparent.

For the developing countries, the situation is even less clear. It might be hypothesized that in view of the ever-increasing need for improved efficiency, discharges and emissions are being reduced accordingly.

AERATION PONDS FOR EFFLUENT TREATMENT AT A SWEDISH PULP MILL not a luxury, a necessity

Measures so far taken by the industry to combat pollution have generally involved the application of proven technology. These methods have evolved gradually and, once proven, have been increasingly accepted. Even so, some techniques commonly practiced today would have been deemed unfeasible a decade ago. There are several mills, most of them manufacturing board products, that operate on almost totally closed water systems. One can foresee, in the not too distant future, paper mills making low-grade products having an essentially zero effluent discharge.

In the chemical pulp industry the same goals, considered futile only a -few years ago, are thought by some to be now on the horizon. Several sulfate pulp mills operate with almost totally closed water systems in the washing and screening areas, and bleaching technology is approaching the stage where water can be reduced to levels whereby the bleach plant effluent may be returned to the recovery cycle. At the same time new problems arise, such as a build-up of impurities in the various liquor systems. Methods are being developed to overcome these.

Increasing attention is being given to the development of less polluting pulping and bleaching techniques: some new pulping methods eliminate the use of sulfur, for groundwood, generally used in the manufacture of newsprint, new systems are being tried to improve pulp strength characteristics, and thus reduce and possibly eliminate the chemical pulp addition now required for quality considerations.

AVERAGE WATER POLLUTION CONTROL COSTS AS PROJECTED FOR OECD
COUNTRIES ¹ (Table 2)

Industry sector	Estimated costs
	1970	1975
	U.S. dollars/ton
Semichemical	2.34	8.89
Sulfite pulp and paper	2.48	11.70
Nonintegrated sulfate pulp	0.86	3.16
Integrated sulfate pulp and paper	1.31	5.52
Newsprint	0.64	2.63
Paper and board	1.08	3.04
Fibre building board	0.64	2.12

¹ OECD data were projected for mills in operation in 1970 Air pollution control costs were also displayed for some countries and, although obviously varying by production category, were significant. Estimated cost are based on 1970 level.

In bleaching technology, sequences are being researched to reduce or eliminate the traditional bleaching chemical used, and at the same time improve the quality of the bleachery effluent. Gas-phase bleaching and various forms of dynamic bleaching are also receiving consideration.

Air pollution control techniques under study include various process changes, and improved scrubbers and precipitators.

In the waste-water treatment field, methods being developed include chemical treatment of effluents, alternative means of dewatering sludges, biological treatment variations, absorption, reverse osmosis, and ion exchange.

While these efforts in pollution control research and development are being made, it is regrettable indeed that no mechanism for the exchange of information among countries should have been established. This situation will almost certainly result in duplication of effort and some inefficiency in application.

It must be admitted that it is becoming increasingly difficult to estimate the cost of pollution control systems. Traditionally, control costs were those "over and above" those required for the normal operation of a mill. Today, when control measures are becoming increasingly integrated with the production process, cost distinctions are becoming vague.

Despite this, environmental costs are a growing economic burden on the industry. In addition to water and air pollution control expenses, others, involving modifications to forest management practices, improved working conditions, and so on, must also be recognized. The OECD report gave cost estimates for 1970 and 1975, expressed as 1970 costs, for water pollution control. These estimates were averaged over those countries where reasonable projections were available for various sectors of the industry.

TYPICAL COSTS OF WATER POLLUTION CONTROL ¹ (Table 3)

	BOD5 removal
	60%	85%	90%	98%
	U.S. dollars/ton
300 TPD bleached sulfate	3.6	5.0	9.2	14.6
750 TPD bleached sulfate	3.1	3.6	7.4	12.0
750 TPD unbleached sulfate and sack paper	2.5	3.4	5.8	8.4
300 TPD coated fine paper	1.5	2.6	7.3	6.5
300 TPD bleached sulfate and coated fine paper	4.2	5.2	10.0	16.2
350 TPD groundwood-newsprint	1.9	3.6	5.6	7.7

SOURCE: A study of pulp and paper industry's effluent treatment, prepared by EKONO Consulting Engineers for FAO Advisory committee on Pulp and Paper, 13th session, Rome, 15-16 May 1972. (Available from FAO.)

¹ Costs are based on 1971 level. The EKONO report stressed that the cost estimates were for typical new mills only It is probable that to achieve the same level of treatment in different countries somewhat different costs are involved. In individual instances, the difference would be substantial.

The cost

The capital investment required by industry to install protection facilities is substantial. 'The OECD report estimated that during the period 1971-75 approximately US$3000 million, at the 1970 cost level, would be required by the pulp and paper industry in OECD member countries to finance pollution control facilities for those mills that were operating in 1970. The information, where available, indicated that approximately the same funds would be required for the second half of the decade.

When allowance is made for cost escalation, and for non-OECD countries, it may be calculated that the capital requirement for the worldwide pulp and paper industry to finance pollution control installations in this decade is about $10000 million.

A pertinent estimate made by OECD for its member countries was that the pulp industry would need some 43% more capital to finance pollution control, in addition to that needed for increased production capacity, between 1970 and 1980, The corresponding figure for newsprint was 20%, and for paper and board, 10%.

Many governments have adopted measures to help industry meet the cost of environmental control programmes, at least in the transition phase. Such measures include:

- Direct subsidies or grants.
- Tax reliefs, mainly in the form of accelerated write-offs.
- Loans from public funds, usually with a preferential rate of interest.

The OECD report emphasized that benefits from subsidies vary widely among countries. The effect of these benefits may be increased by freeing additional funds for productive investment purposes.

The structure of the pulp and paper industry is such that normal market forces generate considerable effect on the short-term outlook. The industry is capital intensive, and thus cannot easily trim production during times of low demand. When demand exceeds capacity it is possible to raise prices considerably, due to the low price elasticity of demand of paper products. Thus, unless demand and capacity are balanced, swings in product price can be anticipated.

Certain sectors of the industry are more vulnerable than others to adverse market conditions. When the market is slack, older, less efficient mills have disproportionate difficulty in competing economically. This applies especially to the sulfite pulp industry, which may largely be substituted by sulfate pulp. Environmental control requirements merely add to this burden, and may be accelerating the closure of inefficient mills. In areas where the mill is the sole employer, local social disruptions are great.

PULP SLOSHING, FIRST STAGE IN A PAPER MILL don't spill it!

Differing views

Since environmental costs vary from country to country, and even from mill to mill, it is difficult to define the point at which cost and ultimately price disparities become relevent in broad economic or social terms.

There seems to be wide disagreement as to whether these costs are significant to industry, as evidenced by the following arguments:

- Since the pulp and paper industry is so vulnerable to market forces, and some sectors of the industry are less stable than others, added environmental costs can only compound already difficult situations, particularly in the short term.

- It is becoming increasingly difficult for the industry to attract outside capital for productive investment, let alone environmental expenditure. Pollution control requirements have thus taken internal capital for non-productive investments, resulting in decreased new production and hence better market conditions and greater profitability.

- The cost increases are relatively small, and spread over a long period, and in any event environmental costs should not be viewed in isolation: there are many other factors, some of them flexible, which determine the selling cost - raw materials and chemicals, transportation, energy, labour, capital charges, taxes, duties, etc., several of which are widely different between and within countries. Pollution control costs are merely additional manufacturing costs, and their impact is indefinable.

There seems to be some validity in each of these arguments, the first saying that environmental expenditures have hurt the industry, the second, that they have helped it; the third, that there is no noticeable change.

It may be suggested that those countries or mills which have less stringent pollution programmes, or, alternatively, receive greater subsidies, enjoy a relative economic advantage, either through increased profitability or through the release of more funds for productive expenditure.

On the other hand, it can be argued that these countries will be placed in a less advantageous position if they have to increase the impetus of their programmer. Conversely, the countries which have the most stringent requirements may be undertaking more than is strictly necessary to create a harmonious environment.

In developing countries with pulp and paper mills, where production is generally for the domestic market, the problem of environmental protection is mainly an internal question, with curtailment of gross pollution the prime objective. However, these countries tend to be net importers of chemical pulp, and have to absorb any additional pollution control costs which have been included in the product price.

In the future, the pulp and paper industry in developing countries is likely to reach a point where its products are marketed internationally. In the absence of specific legislation, an environmental impact assessment may be undertaken for each industrial complex, and the most suitable control measures developed. Pollution control costs are therefore likely to be lower than those of most developed countries, where blanket control legislation exists for the industry.

The consumer

The costs of pollution control are becoming increasingly significant, to the consumer as well as the industry, as they are eventually reflected in the product price. The resulting higher product prices give the consumer the choice of accepting them and suffering some financial hardship or of reducing his consumption of the product. In either case it is necessary that the consumer make some sacrifice. The benefits, both direct and indirect, of application of environmental control measures are still poorly understood.

It is apparent that the approaches to environmental problems in the pulp and paper industry vary widely from country to country. As many countries are still evolving legislative methodology and control techniques, while others are only considering them, the issue of closer international participation should be explored. As a basis for consideration, the following points may be useful.

- Monitoring techniques and analytical procedures vary widely among nations. Since many countries have yet to establish uniform procedures, it would be desirable to develop standardized testing methods.

- There is at present no formal mechanism for the international exchange of environmental statistical data for the industry. In most countries data collection methodology is only just being developed. If more exchange of statistical data is desirable, it may be useful to develop consistent procedures.

- Pollution control techniques vary, and there seems to be some duplication of research and development effort. A formal means of sharing technological information would be practical.

- It would be helpful for those nations which have yet to develop specific environmental legislation to have better knowledge of the rationale behind the various enactments in other countries.

- The impact on society of increased costs for pollution control is still poorly understood, and it may be questioned whether society is aware of the implications of certain environmental programmes. Informing the public of these could thus be advantageous.

There is an aspect of the pulp and paper industry that has received little attention: from the environmental standpoint its technology is highly advanced. Usually when countries draft specific environmental legislation, this industry is among the first to receive attention. Credit should be given to the industry for developing antipollution technology. It is important that the dialogue with it be encouraged.

THE DIRECTION OF LEGISLATION The philosophical approaches used by various countries. In developing environmental legislation for the pulp and paper industry vary widely. They range from the use of the assimilative capacity of the environment to the application of practical control technology. These approaches are translated into legislation through the following systems: - Discharge fee: this is a tax, based on the quantity of specific pollutants in the effluents, sometimes on an increasing scale with respect to time. The revenue collected is usually used for the construction of treatment plants. This system is used in several European countries. - Case-by-case analysis: the discharge of effluent is assessed individually, based on the assimilative capacity of the receiving waters. In some countries, this system is simplified by classifying waters into various categories, and relating allowable discharges to these categories. - Uniform standards: all discharges must comply with uniform minimum standards, applied nationally or regionally. In some instances local environmental circumstances may override these standards and require more stringent effluent criteria. In most countries the trend is for new mills to be required to conform to the regulations from the start of operations, and for existing mills to conform either by a specified date or by a phased programme of improvements on a schedule negotiated with the regulatory agency. In developing countries In the developing countries, as well as in those countries without legislation specific to the pulp and paper industry, the environmental issue is generally recognized. When new production is being planned, and particularly when international agencies are involved in the planning process, some form of environmental impact assessment is usually required. This forms the basis for determining not only acceptable process and treatment criteria, but also the overall environmental implications of the protect.