43

Table 1.2 Basic Data Relating to Pulp
Table 2.2.1A Aqueous Emissions
Table 2.2.1B Examples of Quantitative Emission Values
Table 2.2.2A Emissions into the Air
Table 2.2.2B Emissions into the Air, Typical for the Sector, State-of-the-Art, Limit Values
Table 2.2.3 Solid Waste
Table 3.1.1 Methods of Wastewater Analysis
Table 3.1.2A Minimum Wastewater Requirements
Table 3.1.2B Pollutant Units for the Measurement of Wastewater Discharges in Germany

Appendix B: Glossary

1. Scope

1.1 Introduction/general information/terminology

· Pulp

- Pulp (in the context of this brief) is the common name for vegetable cellulose in the form of fibres or bundles of fibres, more or less free of residual plant parts.

Cellulose is the principal supporting component of all plants and thus in theory, pulp can be obtained from any type of plant. However, as the various fibre properties and also the fibre content can differ widely, in practice only relatively few types of plant are used for pulp production.

- Wood is the chief raw material used in pulp production. Generally speaking, softwood has longer fibres and hardwood shorter ones.
- In addition to wood, annual plants are used for pulp production, mainly in countries with scarce wood resources (China, India etc.).
- Pulp is produced for mechanical processing into board, paper etc. and for chemical processing to films, synthetic fibres etc.
- Pulp is produced from the stated raw materials by means of chemical, chemical-mechanical or mechanical processes.
- Pulp can also be obtained from waste paper (recycling) although in this case it can only be used for paper and board production.
- The auxiliary materials used are water, steam, mechanical and electric energy and chemicals.
- By-products and waste are produced which can cause direct or indirect atmospheric and water pollution, but which can be reduced by measures within the production plant (internal means) and by installations downstream from them (external means).

· Paper and board

- In the context of this brief, paper is a thin fibrous mat made principally from pulp, with or without surface treatment, manufactured from the above-mentioned types of cellulose.
- Board is thick (stiff) paper.
- Cardboard is strong board (thickness), made by a special process.
- Depending on the type of pulp or waste paper and how they are pretreated, the properties of the paper, board or cardboard can be adapted for their intended uses, thus the range of different paper and board types is manifold.
- The wastewater produced during paper and board manufacture contains pollutants which can be removed by appropriate cleaning processes.

1.2 Pulp production

Table 1.2 summarises the basic data on pulp, such as yield, specific energy consumption, relative consumption of chemicals, relative pollutant quantities and relative environmental pollution. Some basic terms are also defined below:

1.2.1 Raw materials

· Wood

a) Softwood: Mainly pine, fir and spruce varieties, for pulp with long fibres (high strength).

b) Hardwood: Mainly beech, birch, eucalyptus, poplar, other types and mixtures (medium strength) too, depending on the location.

· Annual plants

a) Agricultural by-products: Various types of straw (wheat, rice etc.), bagasse, i.e. sugar cane following extraction (low strength). For special papers: linters, i.e. by-product from the cotton oil industry (high purity and strength).

b) Others: Reed, bamboo, jute, kenaf etc. (less commonly used).

· Waste paper

Different grades, sorted into unprinted clippings from paper-processing (e.g. printing) through to mixes from domestic collections.

1.2.2 Products and processes

Apart from the hygiene sector (e.g. for nappies) pulp is not an end product but an intermediate product for paper manufacture, and as chemical conversion pulp, is the raw material for the chemical industry (fibres, films, plastics).

Pulp is available in a number of different forms, the most important of which are:

· Groundwood (Mechanical wood pulp)

Groundwood fibers produced mainly from softwood with a grinding stone and containing practically the same constituents as the original wood, except for some extractives. It provides the highest yield and generally is not bleached or only to a low to medium brightness.

Applications: For mass-produced papers at the lower end of the quality scale. Typically: newsprint, writing and printing paper containing wood, duplex board.

Characteristics: Products are of low strength, they yellow in daylight and are not very resistant to ageing.

The chemicals most frequently used (for bleaching): sodium didithionite, peroxides - peroxide being the least polluting bleach.

Plant sizes: 50 - 600 t/day.

· TMP - thermomechanical pulp

Comparable with groundwood, but defiberation between rotating discs. Slightly lower yield but better strength properties. Is bleached like groundwood.

Applications: as for groundwood.
Characteristics: as for groundwood.
Plant sizes: 300 - 600 t/day.

· CTMP - chemi-thermomechanical pulp (includes APMP)

In contrast to TMP, pulping is facilitated by a chemical pretreatment. The yield is slightly lower, but despite this the mechanical properties of the fibres are improved. Is usually bleached to medium or high brightness.

Applications: As absorbent in the field of hygiene products (nappies etc.), for mass produced printing and writing paper midway along the quality scale.

Characteristics: Depending on the raw material, products are medium to low strength; they yellow quite readily and are not particularly age-resistant.

· SC (or NSSC) - semichemical pulp

Still contains considerable quantities of non-cellulose substances. Wood chips or other fibrous raw materials are pretreated with chemicals in pressure vessels and with steam under pressure. Pulping is then carried out in refiners with a relatively low power consumption. Is not usually bleached.

Applications: Packaging papers, particularly corrugated medium in corrugated board.

Characteristics: Produces fairly stiff paper and board, depending on the raw material used.

Chemicals most often used: sodium sulphite, sodium hydroxide and/or sodium carbonate. Recycling or disposal within the mill is necessary.

Plant sizes: 50 - 500 t/day.

· Chemically produced pulp

Contains only low to very low quantities of non-cellulosic substances, low yields due to the removal non-cellulosic materials. Wood chips or other fibrous raw materials are pulped with chemicals and steam under pressure. This is usually followed by bleaching and then either drying and pressing into bales as commercial pulp or, in an integrated plant, further processing into paper products.

Applications:

- Unbleached: mostly as packaging paper, also added to lower strength pulps (reinforcing).
- Bleached: mostly for writing and printing papers, also as an additive to lower strength pulps, cellulose for chemical feedstock (dissolving pulp), mostly produced from hardwood.

Characteristics: High strength in the case of softwood products. Bleached substances yellow only slightly and are highly age resistant. High purity for chemical raw materials.

Pulping chemicals: Sodium hydroxide, Na₂S (alkaline processes: "soda", "sulphate") and Ca, Mg, Na and NH₄ bisulphite (acid processes: "sulphite"). Recovery and regeneration of chemicals is a precondition for economic and non-polluting operation. Some of the spent liquor from the sulphite process can be processed by fermentation to form yeast and alcohol or, in its dried form, can be sold as a binding agent.

Bleaching chemicals: Chlorine (the use of which is on the decline), sodium hypochlorite, chlorine dioxide, oxygen, sodium and hydrogen peroxide.

Plant sizes: softwood as raw material: 500 - 1300 t/day; annual plants as raw material: 50 - 250 nnt/day.

· Waste paper pulp

Waste paper contains a mixture of pulps from various sources, depending on the composition and sorting of waste paper, and is a substitute for fresh pulp (cheaper, energy-saving). It is pulped mechanically. May be de-inked and bleached following removal of non-paper fibres and other impurities.

Applications: In principle, for all paper and board types, with or without the addition of fresh pulp.

Characteristics: Quality slightly or moderately inferior to fresh pulp, depending on the quality, sorting, cleanliness etc. Chemicals for de-inking and bleaching are detergents, fatty acids, dispersants, dithionite, peroxide.

Plant sizes: 50 - 400 t/day.

1.3 Paper and board production

1.3.1 Basic fibrous material, pulp (raw materials for paper and card production)

All the products listed under 1.2.2 are basic materials for the paper industry. In most cases a mixture of two or more of them are used to give the paper the required characteristics or for reasons of economy.

1.3.2 Products and processes

Paper and board types are usually classified into the following main groups on the basis of intended use:

- printing and writing (graphic) papers
- industrial papers
- special papers.

Practically all papers and boards are produced on continuously (or in the case of boards sometimes semi-continuously) operating machines, the principle of which is the dewatering of the aqueous fiber suspension on a wire to form a fibrous mat which is then pressed and dried. The sheet of paper thus produced is packed in the form of rolls or packs of sheets. The pulp fibres are pretreated in "beating" machines (refiners) to give them the properties required for the individual type of paper, and additives are used to give properties such as ink absorbance, water-resistance, stiffness, colour. Fillers such as kaolin (alumina), and more recently calcium carbonate and sulphate improve the paper surface for certain printing processes.

The product groups are characterised as follows:

· Printing and writing (graphic) papers

These writing and printing papers are basically subdivided into those containing wood¹ (coated and uncoated)2 and those not containing wood pulp (likewise coated and uncoated), the former mainly as mass-produced papers, the latter for high quality and special applications. Today, both kinds contain increasing quantities (in some cases up to 100%) of waste paper.

¹"wood containing": containing not only pure, chemically produced pulp but also groundwood, CMP etc.
"wood free": containing only chemically produced material.
² coated: surface treated with dominatingly inorganic pastes.

· Industrial papers

These include mainly packaging papers and boards, comprising many brands of grey common wrapping papers (made from recycled paper) through to high-quality packaging materials for food and luxury goods, in some cases surface treated, multi-layer or coated for costly print processes. Corrugated board, made from fresh unbleached pulp or recycled corrugated board (a rising trend) depending on quality, accounts for a portion of industrial papers in quantity terms.

· Special papers

These cover a wide range of paper types which cannot be specifically allocated to the two product groups described above, e.g.:

- papers for hygiene applications (tissues, kitchen rolls, toilet paper)
- filter papers for use in industry, the home, the laboratory etc.
- transparent papers for drawing
- photographic papers
- base paper for parchment, vulcanized fibre
- cigarette paper
- capacitor paper etc.

1.4 Secondary and auxiliary installations

· Energy supply

Energy is required in the form of mechanical energy (electricity) and heat (steam). Where no hydraulic power is available, electrical energy is obtained either from the national grid or generated by a power plant inside the mill (steam or gas turbines). Fossil fuels (heating oil, natural gas, coal), and also wood and wood waste (bark) or other waste substances are used for steam production.

The spent liquor from chemical pulp production is an important "waste" product in terms of energy. It is burnt in special boilers ("recovery boilers")to produce steam to cover process energy needs.

· Water

The availability of fresh water is a basic requirement for pulp and paper production. The water demand may exceed 150 m³/t of product, but in very modern mills it may be no more than 2 m³/t, although this also depends on the quality of the process management.

· Wastewater treatment

Mechanical, biological and/or chemical wastewater treatment are now standard in any pulp and/or paper mill.

2. Environmental impacts and protective measures

2.1 Area: Raw and auxiliary materials

2.1.1 Fibrous raw material

· Wood

The afforestation and reforestation of suitable areas for the raw materials supply of paper and pulp mills are advantages in terms of climate, water resources and the labour market.

The use of timber must be planned with a view to maintaining a balance between the cutting and growth rates.

Vegetable fiber resources are renewable - in the case of wood by reforestation. Special measures are essential for such single-crop agriculture; in-depth studies of cultivation measures as well as socio-economic aspects (e.g. competition for land usage) are essential.

· Annual plants

Agricultural products used as raw materials should not automatically be regarded as environmentally advantageous. For example, if straw is not ploughed back into the soil, increased fertiliser use is necessary, whilst the humus content in the soil will drop. The widespread burning of straw is also undesirable and the collection of straw is relatively energy intensive (pressing in bales for transport, yet still bulky, truck capacities by no means fully utilised). Furthermore, the large stocks which have to be held because of the relatively short harvest period create a fire risk.

In the case of bagasse (waste from cane sugar production) used as a fibrous raw material for paper, conditions are more favourable in that it does not have to be collected separately, but nonetheless large stocks need to be held to cover periods when the sugar factory is closed. The competition between raw material for paper and fuel in the sugar factory is described in the environmental brief Sugar.

In short, the use of annual plants is only environmentally positive under certain conditions. It is generally insignificant and only relevant in special cases.

· Waste paper

This raw material enables significant savings to be made on energy compared to fresh pulp, with the exception of fully chemical pulp as modern pulp mills are energy selfsufficent. However, paper cannot be recirculated ad infinitum. For every circuit there is a sacrifice in quality due to fibre damage. However, the use of waste paper must be regarded positively from the environmental viewpoint, in most of today's cases of application.

2.1.2 Water

Production water (river and well water) is required in relatively large quantities (see 1.4 above) and must meet certain minimum purity criteria. It must be processed, but can be recycled in internal circuits a number of times. In less favourable instances the use of wells can result in a long-term change in the groundwater table. As far as water requirements are concerned detailed analyses with a view to meeting the needs of competing usages are essential at the paper mill design stage.

2.1.3 Energy

The environmental impacts of electricity generation and the use of fossil fuels, also used in pulp and paper mills, are known and can be found in the environmental briefs on Thermal Power Stations and Power Transmission and Distribution.

Sector-specific fuels arising in mills during pulp production or in the wood-processing industry are

- spent liquor from the cooking and impregnation process
- bark, sawdust, splinters.

Concentrated spent liquors are burned in recovery boilers specially designed for this purpose, thereby releasing the pulping chemicals in the form of molten ash for regeneration. Spent liquors replaces some, and in modern chemical pulp mills all, of the fossil fuels.

Wood waste is likewise burned in special boilers and thereby replaces fossil fuels. (For relevance of emissions, see 2.2). Typical specific energy consumptions are listed in table 1.2.

2.1.4 Chemicals, auxiliary materials

Although some of the chemicals to be added, particularly bleaching agents, such as chlorine, sodium chlorate, caustic soda and peroxides, are bought in by pulp and paper mills, their production requires considerable quantities of energy. A reduction in bleach consumption requires a generally greater acceptance of less bright paper on the part of the consumer, but would be a major environmental protection measure.

The production of other auxiliary materials, such as dyes, starch, clay and resin, is likewise heavy on energy, but is less significant because of the relatively small quantities used.

2.2 Emissions from pulp and paper mills

2.2.1 Aqueous emissions

Table 2.2.1A gives a detailed survey of sources, substances emitted, impacts, and reduction measures and the degree of reduction of aqueous emissions, while table 2.2.1B provides information on typical emission limits in terms of quantity.

Considered first are:

- emissions
- their impacts and
- reducing and protection measures

before the downstream treatment plant (wastewater treatment plant). This is followed by the effect of these reducing and protection measures.

A: Quantity

The quantity of wastewater is approximately the same as the quantity of fresh water used. Thus a reduction in fresh water consumption by creating internal circuits results in a reduction in wastewater quantities, which is also a major cost factor when designing wastewater treatment plants.

B: Quality

Quality factors in aqueous emissions are

- content of undissolved substances (settleable/filterable)
- content of dissolved substances, comprising

· reaction products from pulping and chemical recovery
· reaction products from pulp bleaching
· concentrated condensates from chemical recovery
· chemical residues and soluble content of waste paper cleaning
· dissolved substances from paper manufacture and coating
· dissolved substances from secondary installation wastewater.

In terms of impact they are all capable of:

changing pH, consuming O₂, causing discoloration or turbidity, they may be toxic, either individually or in combination.

Primary reduction measures are internal recirculation before the remaining wastewater and pollutants are transferred to the

C: Wastewater treatment plant

(secondary treatment, downstream plant) where they are purified to such a degree that they can be discharged into public sewage systems.

2.2.2 Emissions into the air

There is an wide variety of major sources in pulp mills and they are affected in some cases by highly complex technical factors. They range from dust produced in raw material crushing, through vapours and gases escaping from reaction vessels and liquor tanks to flue gases from recovery, bark, sludge and oil/coal boilers, the waste gases from lime burning and degassing systems of bleach tanks and bleaching towers.

In paper mills, the situation is less complex, with fewer factors involved, the main source being waste air from dryers.

Table 2.2.2A gives a detailed overview of source, substances emitted, impacts, reduction and protection measures which can be taken inside the mill and the degree of reduction in the most important departments, while table 2.2.2B provides quantity data relating to typical emissions in the sector, values currently achievable and limit values.

External plants are avoided wherever possible in the case of waste air cleaning plants; they are incorporated in the various process stages so that the media extracted can be recirculated.

The main emission components are carbon dioxide and monoxide, dust (wood and mineral), steam, sulphur dioxide, reduced sulphur compounds (mercaptans and the like), nitric oxides and hydrocarbon compounds.

Their most significant impacts are:

- they range from being hazardous to health to toxic, they present a fire risk, they give rise to odours and smog, they may be a contributory factor to acid rain and they reinforce the greenhouse effect.

Reduction or protection measures range from internal collection, recirculation, combustion or other chemical conversion processes to downstream (external) gas scrubbers, filters and absorbers.

2.2.3 Solid waste

Table 2.2.3 describes the sources, materials, impacts and possible countermeasures specific to solid waste.

The main sources are as varied as for gaseous emissions. They comprise for the most part wood waste such as sawdust, bark, fiber bundles, and also mineral waste such as lime sludge, sand and spent auxiliary materials such as screens, felts, plastic film, wire etc. The main impact is the dumping space requirement.

Reduction and protection measures involve essentially a reduction in volume by incineration and the return of recyclable materials to the manufacturer (metal parts, for example).

2.2.4 Noise

The principle sources of noise are:

raw material preparation, such as wood debarking and chopping, transport equipment, refiners, vacuum pumps, finishing machines, steam blow-off in the boiler house, drive units.

The impacts may range from nuisance and disturbance to nearby residential areas at night to physical health problems and hearing impairment.

Possible reduction measures are:

wood debarking and chopping and heavy goods transport in daytime only, since intermittent operation is possible. Also enclosure of machines, and if applicable sound-proofing materials, steam blow-off with silencers only, new plant sited a suitable distance from residential areas. (With few exceptions, machines are already being designed with noise reduction in mind). internal measures: prescription of hearing protection to be in the relevant departments.

3. Notes on the analysis and evaluation of environmental impacts

3.1 Aqueous emissions

The monitoring of these emissions demands continuous or semi-continuous sampling and appropriate equipment, both for the individual wastewater flows and for the combination of them.

Routine analyses can be confined to temperature, pH, settleable or filterable solids, biochemical oxygen demand (BOD₅), chemical oxygen demand (COD, measured as potassium chromate consumption), fish toxicity, adsorbable organic halogen compounds (AOX) in relevant cases (i.e. where chlorine or bleaching agents containing chlorine are used).

Special analyses include, inter alia, the determination of turbidity, colour, odour, conductivity, colloids, oils and fats.

Analysis methods for routine and special tests are listed in table 3.1.1.

Minimum requirements for the discharge of wastewater into public sewage systems have been established and have come into effect in a number of countries in order to assess the environmental impact of aqueous emissions.

For the German pulp and paper industry, the Wasserhaushaltsgesetz [WHG - Federal Water Act], the Abwasserabgabengesetz [AbwAG - Wastewater Charges Act] and the Bundesimmissionsschutzgesetz [BImSchG - Federal Immission Control Act] are of particular relevance. These laws and their enforcement ordinances lay down minimum requirements which must be observed following application of emission-reducing purification or cleaning processes (see in this regard tables 3.1.2A and 3.1.2B).

In Switzerland, assessment criteria are established in the ordinance on water discharge "Verordnung über Abwassereinleitung", in Austria the standards ÖNorm cover this area, and in the USA, the "Effluent Limitations Guidelines and New Source Performance Standard for the Bleached Kraft, Groundwood, Sulfite, Soda, Deink and Non-integrated Paper Mills Segment of the Pulp, Paper and Paperboard Mills" in the EPA (Environmental Protection Agency) programme apply.

In some other countries, although similar values exist, they are all too frequently in the form of guidelines, and compliance with them is seldom monitored.

Likewise, pollutant concentration data is often given as an assessment criterion, though it would be more correct to restrict the absolute quantity of the emission. The concentration assessment may well lead to a dilution of emissions to the limit values if adequate fresh water is available, but "dilution is no solution to pollution".

To obtain a reliable assessment of the expected emission situation for an extension or new-build project, consideration must be given not only to emission quantity and quality but also to the drainage situation. The essential determining factors here are:

- flow rates with seasonal minima and maxima
- initial loading of watercourses/rivers
- use of water downstream from the discharge point (drinking water, irrigation, fishing, industry).

3.2 Emissions into the air

As the major part of emissions into the air and the main emission components (dust, CO₂, CO, NOx) stem from the combustion plants for steam generation, the relevant environmental brief Thermal Power Stations should be consulted.

Typical sectoral emissions (particularly pulp mills) are:

sulphur dioxide (SO₂), reduced organic sulphur compounds (TRS), chlorine/chlorine dioxide gas (Cl₂, ClO₂), certain hydrocarbons (HC).

The routine monitoring of these emissions is in some cases carried out by continuous display and recording equipment, which must be inspected and calibrated by supervisory bodies at prescribed intervals.

Non-continuous inspections (special inspections) are carried out on intermittently collected samples by laboratory staff. The measuring methods for this are prescribed in Germany by the TA-Luft [Technical Instructions on Air Quality Control]. As with wastewater (see above), other countries have their own specific measuring methods which are defined in the relevant clean air regulations.

The substance-specific emission limits currently applicable in Germany, in accordance with the TA-Luft, are listed in table 2.2.2B. It should be noted in this regard that the TA-Luft does not contain a limit value for TRS compounds which are responsible for the odour nuisance generated by sulphate factories. For this reason, the limit values currently contained in the USE-EPA - which are largely in line with the state-of-the-art - are recommended as guidelines.

The limit values given in table 2.2.2B can be used as guidelines for extension and new-build projects in countries where provisions in this area are inadequate or do not yet exist yet.

3.3 Solid waste

There are only a limited number of analysis methods for the environmental impacts of solid waste; for example, there are none for bark, sawdust-type wood waste, bale wire, plastic bags and felt. Other solid waste (constituents of waste sludge, lime sludge, waste gas dust etc.) is routinely examined.

As solid waste cannot be described as altogether typical of the sector, the analysis methods described in the relevant environmental briefs (Solid Waste Disposal, Timber) should be consulted.

Limit values to assess the environmental impacts of the aforesaid substances in the form of ordinances are rarely prescribed. In Germany they exist in respect of the suitability of substances for disposal (see in this regard the environmental briefs Solid Waste Disposal and the Disposal of Hazardous Waste). The Compendium of Environmental Standards also contains information about substances which can be critical in waste sludge (heavy metals from printing inks, toxic compounds etc.).

3.4 Noise

Noise is measured and assessed as noise immission. The unit of measure used in Germany is the dB(A) to DIN standard 45 633.

Immission limits vary according to the type of area, ranging from 70 dB(A) for purely industrial zones to 35 dB(A) for health resort and residential areas as a night limit.

No special measures are required to comply with a noise immission level of around 50 dB(A) in the immediate surroundings of modern pulp and paper mills, provided that the mills are housed inside buildings and are fitted with state-of-the-art sound-proofing.

In Germany, for example, this means that a pulp and paper mill can only be built in industrial or principally industrial areas.

If the relatively large amount of land required to build a paper mill is available, the noise restrictions do not in many countries represent a major barrier to such projects. In fact, the noise immission values may be conformed to even outdoor design of mills, as is frequently the case in tropical countries, as long as it is at an adequate distance from neighbouring areas used for residential or other purposes requiring protection.

4. Interaction with other sectors

4.1 Areas typical of the sector

4.1.1 Raw materials

Pulp and paper mills are extremely capital intensive and have a very long service life (some are over 100 years old). For this reason, the long-term reliability of raw material supplies is of fundamental importance.

· Wood

Planned and organised cooperation with the forestry sector is essential. This collaboration can be structured in a number of ways: it ranges from the simple purchase of trunk timber, thinning timber or wood chips and sawmill waste through to the management of a mill's own forests. In view of the large time span between the planting and the felling of trees, long-term planning is required for new-build projects. Proper afforestation work is essential, along with the appropriate capital investment and the necessary organisation.

One important aspect of interaction with other sectors is that of competition in the standing timber and sawmill waste market (sawmills, plywood manufacture, the wood processing and wood product sector).

Interaction with the agricultural technology sector exists in the context of so-called "agro-forestry", in which trees are used to provide shade and as windbreaks. This could be interesting if the correct types of tree for paper production were chosen, and it could also be an additional source of income for farmers.

Other competition with pulp wood derives from use of wood as fuel (see the environmental brief Renewable Sources of Energies) or wood for charcoal or building.

· Annual plants

With few exceptions, the annual plants which can be used for pulp and paper production constitute waste or by-products from agriculturally based industries (e.g. sugar production).

In global terms this group is not significant as far as paper manufacture is concerned, but may be important locally if no wood is available. The raw material potential for pulp and paper production therefore depends on the market for the products of these other industries. Relatively short-term changes in farming programmes can greatly reduce raw material supplies or lead to arable land being withdrawn from production for reasons of pricing policy.

· Examples of annual plants

Straw:

Large quantities produced worldwide, but with low potential for use due to the costs incurred in its collection, transport and storage; significant emission problems in its processing to pulp. Change of crop programme, e.g. due to introduction of short-stemmed cereal varieties, could jeopardise projects. Competitive situations could arise with a demand for straw as bedding for cattle or as fuel for heating and cooking.

Bagasse:

The sugar cane residues following sugar extraction are traditionally used in the sugar factory itself as a fuel (energy self-sufficiency). It is therefore in competition with fossil fuels if it is to be used for paper manufacture, hence the interaction with the agro-industry.

Of minor importance in terms of quantity, but interesting in terms of fibre properties are raw materials such as:

Jute:

In the form of jute sticks, the waste from the ailing jute (textile) industry. Competition with fuel. Jute cuttings: competition with the textile industry.

Flax:

Flax straw as waste from the linseed oil industry. Transport and cleaning very costly. Competition with textile manufacture.

Sisal:

Since sisal is little used now for ship hawsers, efforts are being made to cultivate its use as a raw material for special papers. Very high transport and preliminary cleaning costs. Competition with sack and bag production.

Abaca:

Plays a (minor) role in special paper production (Philippines) alongside (minimal) use for textile purposes.

Linters:

Waste product from cottonseed oil factories. Is a raw material for special, chemically pure cellulose for the chemical and pharmaceutical industries, also for special papers and filter material. Advantage: produced centrally - at the oil mill. Competition on the product side from wood dissolving pulp.

Bamboo:

Important building material in all countries where it grows (in practice only a natural crop, cultivation difficult), therefore only limited quantities available for pulp and paper. Competition exists for use as a vegetable (bamboo shoots).

Esparto or alfa grass:

Like bamboo, it is not cultivated and is collected only for insignificant quantities of paper production (special papers) (North Africa and Spain). Competition exists with use as a braiding material.

· Waste paper

The potential for waste paper supply is directly dependent on paper consumption in the region or catchment area and on market price (determined by the economic climate). In countries with large stocks, lower qualities are most vulnerable to the economic climate.

Waste paper can be an important raw material in countries where a paper industry is to be established for a relatively low initial investment.

There are links here with the paper-processing industry.

In many countries, "competition" exists in the form of the recycling of paper which in the end is too dirty for reprocessing (e.g. newsprint which is used first as wrapping matter and finally as toilet paper).

4.1.2 Auxiliary materials and additives

· Water:

Since the pulp and paper industry requires large quantities of water, there is competition with other sectors, e.g.:

- water for domestic and industrial use,
- agriculture (irrigation),
- other industries which consume water.

This can have a direct effect (surface water) or an indirect and delayed effect (well water). The competitive situation vis-a-vis agricultural and other businesses can be mitigated by appropriate wastewater treatment so that the water can be reused to a greater or lesser extent. However, all aspects of the possible salination of the soil must be taken into account here.

The availability of water is one of the most important factors in selecting a suitable site for a new mill.

The environmental impacts of other auxiliary materials and additives are not typical of the sector (chemicals, energy).

4.2 Areas not typical of the sector

Areas which are not typical of the sector but which are essential for the operation of a pulp and paper mill and concern mainly the infrastructure are simply listed here as an addition to the information given in the various texts (although this list is not exhaustive):

- water supply
- chemical industry, for alkaline chemicals (caustic soda, soda, aluminium sulphate, sulphuric acid, chlorine, sodium and hydrogen peroxide, sulphurous acids etc.) (in this connection refer to the Compendium of Environmental Standards)
- mineral oil industry, for fuel oils, lubricating oils, natural gas, LPG
- mining, for coal and possibly clay, limestone
- power stations, electricity transmission
- transport, roads, railway connections, waterways

and:

- workshops for repair work and maintenance of mechanical and electrical machines and instruments
- general and technical colleges for the basic education of personnel
- hospitals, clinics, for medical care
- social areas.

There is therefore an interaction with many wider areas such as regional development, planning of locations, general energy planning, schools, health services, water supply and distribution planning, transport and traffic planning etc.

5. Summary assessment of environmental relevance

Given the state-of-the-art in the pulp and paper industry, and the technology developed or adapted for it in the field of recirculation, reduction or prevention of emissions which pollute the environment with proper operation monitoring, the following points can be made:

- With regard to wood as a renewable raw material, this industry is environmentally sustaining as long as the quantity of wood used is less, or possibly equal to the quantity growing to replace it. A further environmental protection feature arises with the processing of wood residues and waste (sawmill and brushwood) in pulp mills.
- In the case of annual plants the environmental impact is considerably less positive - the alternative use (fuel in the case of bagasse) involves replacement in the form of fossil fuels and therefore has negative impacts for the global CO₂ balance, among other things.
- The still increasing use of waste paper as a raw material has generally positive environmental impacts: the processing of waste paper consumes less primary energy than fresh pulp and, overall, reduces the wood consumption per tonne of paper.
- Chemically produced pulp merits particular mention: in terms of both raw materials and energy, a modern production plant uses renewable feedstock (wood) only and therefore has no impact on the global CO₂ balance.
- Aqueous emissions from pulp production are minimal in the case of unbleached pulp (as long as the mill is equipped with a recovery system), and the increasingly common replacement of chlorine and chlorine compounds as bleaching agents with chlorine-free media (oxygen and peroxide) already enables a large number of bleaching installations to comply with the relevant limit values.
- Aqueous emissions from paper manufacture can also be kept below the relevant limit values without difficulty by the use of water recirculation measures and highly efficient water treatment plants.
- Gaseous emissions from power station and recovery installations can be kept below limit values with the cleaning/scrubbing techniques developed. Odour emissions (mercaptans) are still a problem, particularly in the case of sulphate pulp factories. However, systematic collection and control measures in modern European plants are also achieving acceptable reductions below the (EPA) limit values in densely populated areas.
- Only a small quantity of solid waste is produced, and a large proportion of it can be used for energy (bark, wood waste). In the area of waste sludge disposal (incineration, dumping), attention must be paid to the problems of heavy metals from printing inks where mills use waste paper.
- The outdoor design of mills, normally applied in warmer climates, makes noise prevention measures more costly than in enclosed plants, thus noise nuisance can only be prevented by siting such mills further from residential areas.

In temperate and/or cold climates, the question of noise can easily be resolved by building design, insulation and process management (avoiding operating noise-emitting departments at night).

The early involvement of the population groups affected, particularly women, in the planning and decision-making process, means that their interests can be taken into account and helps reduce environmental problems (e.g. competition for the use of water, wood and land).

The implementation and monitoring of emission limit values and a generally environmentally oriented operation are only possible if the necessary control bodies are institutionalised and operate effectively. One option is to appoint industrial environmental protection officers, who should also be responsible for the training and further education of personnel and increasing the awareness of personnel for environmental matters.

6. References

W Brecht and H. L. Dalpke: "Wasser, Abwasser, Abwasserreinigung in der Papierindustrie".

Deutsches Wasserhaushaltsgesetz (WHG), Abwasserabgabengesetz (AbwAG) and the Bundesimmissionsschutzgesetz (BImSchG).

EPA (Environmental Protection Agency) "Effluent Limitations Guidelines and New Source Performance Standards for the Bleached Kraft, Groundwood, Sulfite, Soda, De-ink and Non-integrated Paper Mills Segment of the Pulp, Paper and Paperboard Mills".

NCASI, USA (National Council of the Paper Industry for Air and Stream Improvement), Bulletins (div.).

ÖNorm M 94 64.

Allan M. Springer: "Industrial Environmental Control, Pulp and Paper Industry".

SSVL Sweden (Sriftelsen Skogsindustriernas Vatten och Luftvardsforskning), The SSVL Environmental Care Project.

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