WATER AND WASTE-WATER MANAGEMENT IN …

1 NATSURV12 WATER ANDWASTE-WATERMANAGEMENT IN THEPAPER AND PULPINDUSTRYNATSURV 12 WATER AND waste -WATERMANAGEMENTIN THEPAPER AND pulp INDUSTRYPREPARED FORTHEWATER RESEARCH COMMISSIONBYSTEFFEN, ROBERTSON AND KIRSTENCONSULTING ENGINEERSWRC PROJECT No. 145TT 49/90 DECEMBER 1990 Steffen, Robertson and Kirsten Inc P O Box 8S5616th Floor JOHANNESBURG20 Anderson Street 2000 JOHANNESBURG Tel : (Oil) 492-13162001 Available from: WATER Research CommissionP O Box 824 PRETORIA0001 Republic of South AfricaISBN 0 947447 83 0 This publication stems from a research project entitled:"National Industrial WATER and WASTE-WATER Survey"that was carried out by.

2 Steffen, Robertson and Kirsten IncConsultinn EngineersDISCLAIMERThis report has been reviewed by the WATER Research Commission and approved for does not signify that the contents necessarily reflect the views and policies of the WaterResearch Commission, nor does mention of trade names or commercial products constituteendorsement or recommendation for use.(iii)FOREWORDThe need for guidelines to reduce WATER intake and WASTE-WATER disposal by industry is ofnational concern in view of South Africa's WATER establish norms for WATER intake and WASTE-WATER disposal, the WATER Research Commission(WRC) in collaboration with the Department of WATER Affairs (DWA), contracted Steffen,Robertson and Kirsten, a firm of consulting engineers, to undertake a National Industrial Waterand WASTE-WATER Survey (NATSURV) of all classes of industry.

3 The consultants identified 75industrial groupings in South Africa, one of which is the paper and pulp industry. The resultsobtained in the survey of the paper and pulp industry form the basis of the Guide on WATER andWaste- WATER MANAGEMENT in the paper and pulp is hoped that this guide will be of value to the industry itself, and to other interested partiessuch as municipalities, administrators, researchers and consultants in the WATER and waste -waterfields.(iv)ACKNOWLEDGEMENTSTh e work was co-ordinated by a committee established under the chairmanship of the WaterResearch Commission, comprising representatives of the paper Industry, the Department ofWater Affairs, and Steffen, Robertson & CommitteeDr O O Mart (Chairman) WATER Research CommissionMr D F Sutton Department of WATER AffairsMr V Bohmer Sappi Research & DevelopmentDr A Wood Steffen, Robertson & KirstenMr P Skivinaton Steffen, Robertson & KirstenInformation has also been provided from literature searches by Waterlft of the library serviceof the CSIR.

4 The Timber Research Institute of the CSIR and the following representatives of thepulp and paper industry:Mr V Bohmer Sappi Research and DevelopmentMr H Jacobs Sappi EnstraMr C Gonin Sappi NgodwanaMr R Strcatfield Sappi StangerMr N Dhavraj Sappi MandiniMr J W'allis Sappi MandiniMr J Thubron Saiccor UmkomaasMr V Naidoo Nampak RosslynMr D Coetzee Nampak KliprivierMr H Wilkenson Nampak SpringsMr Bosveld Mondi SpringsMr E Durgveil Mondi MeerbankMr P Reid Van LeerMr G Horman Carlton(v)SUMMARYT here are 21 mill sites in the Republic of South Africa ranging from small household tissue millsto the most modern integrated pulp and paper mills, producing approximately 3 million tonnesper annum of pulp and paper products.

5 Specific WATER intake (SWI) varied between 33 and 136m3/t for integrated pulp and paper mills and between 1 and 49 m3/* for pulp and paper productsplants. Specific pollution load (SPL) was found to vary between 9 and 80 kg COD/t and 21 and1S3 kg TDS/t for integrated pulp and paper mills, and between 4 and 10 kg COD/t and 2 and110 kg TDS/t for non-integrated variation in WATER intake and WASTE-WATER quality is dependent upon the tree species or pulpmaterial utilized, the efficiency of the mill in terms of process control and operation, the paperproduct produced and the degree of chemical recover)' and WASTE-WATER treatment prior measures have been taken by the Industry in recent years to reduce the WATER intakeand pollution potential of pulp and paper mills. These measures include the tightening up ofwater using systems, more effective WASTE-WATER treatment systems and reuse of treated watersources, new production processes, technically improved machinery and equipment, as well asimproved MANAGEMENT and operation of production.

6 (vi)TABLE OF CONTENTSC hapter Page1 THE pulp AND paper INDUSTRY IN SOUTH AFRICA Introduction paper and pulp Production in South Africa WATER and WASTE-WATER in the pulp and paper Industry 22 THE pulp MANUFACTURING PROCESS Raw Materials Debarking Chipping Pulping 43 BLEACHING Conventional Bleaching Bleaching Bleach Effluent Quality

7 Colour 74 paper MANUFACTURE FROM pulp AND waste paper Stock Production paper Machine Feed Coating Tissue paper paper Production from waste paper 105 SURVEY RESULTS Introduction WATER and WASTE-WATER MANAGEMENT 11(vii)

8 TABLE OF CONTENTSC hapter Page6 WATER REUSE Reducing WATER Consumption Reuse of WATER 147 WASTE-WATER CHARACTERISTICS OF pulp AND paper MILLS Suspended Solids Dissolved Solids 168 WASTE-WATER TREATMENT PRACTICES WASTE-WATER Treatment Technologies Biological WASTE-WATER Treatment of pulp and paper waste Waters 179 POLLUTION CONTROL - RESEARCH AND DEVELOPMENT 18 BIBLIOGRAPHY 20(viii)LIST OF TABLESTABLE Page1 paper production in South Africa (1988)

9 22 Basic raw material requirement 43 Bleach plant WASTE-WATER analysis (example for a Kraft pulp process) 84 Specific WATER intake (SWI) for various mills 115 WASTE-WATER quality discharged (mg/ ) 126 Specific pollution load (SPL) 12 FIGURE1 A general flowsheet for the pulp and papermakine process 3 ABBREVIATIONSCOD Chemical oxygen demandSPL Specific pollution loadSVVI Specific WATER intakeTDS Total dissolved solids00 BAGASSEGLOSSARYW aste fibrous residue after the extraction of sugarfrom caneBLACK LIQUORThe black liquid remaining after digestion of timber ina chemical pulping process.

10 Black liquor contains thespent cookery chemicals, lignin, resins and other non-cellulose constituents in solutionBLEACHINGT reatment of cellulosic fibre with chemicals toincrease brightness and stabilityBROKEP aper rejects which may be collected and repulpedBROWN STOCKThe mixture of black liquor and pulp produced afterdigestion of timberCELLULOSEA carbohydrate polymer of glucose unitsCHEMICAL PULPINGThe defibrisation of timber by the use of chemicalssuch as sulphite, soda and sulphate processes. Theyield of pulp is about 5(Kr but the pulp produced is ofhigher quality than that from mechanical pulpingCLOUDY WATERR ecycle of paper machine WATER which contains manyfine fibresCROSSKLOW MICROFILTRATION A pressure-driven filtration process for the removal ofsuspended and colloidal particles from waste waterL1 SSOLYEI) AIR FLOTATIONThe use of air, dissolved under pressure, to assist inthe flotation of solid material present in waste solids can then be skimmed from the liquidsurface for recovery or disposal(xi)