ISO/TR TECHNICAL REPORT 20736 First edition 2021-07 Sludge recovery, recycling, treatment and disposal Guidance on thermal treatment of sludge Valorisation, recyclage, traitement et élimination des boues - Lignes directrices pour le traitement thermique des boues Reference number IS0/TR20736:2021(E) ISO @IS02021 IS0/TR 20736:2021(E) COPYRIGHT PROTECTED DOCUMENT @ iS0 2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2021 - All rights reserved IS0/TR 20736:2021(E) Contents Page Foreword .vi Introduction. ..vii 1 Scope. ..1 2 Normative references. ..1 3 Terms and definitions .1 4 Abbreviated terms .3 5 Sludge properties. .4 5.1 General. 4 5.2 Physico-chemical characteristics .4 5.2.1 General. .4 5.2.2 Dry matter. .4 5.2.3 Loss on ignition. 4 5.2.4 Calorific value. 5 5.2.5 Grease, scum and screening .5 5.2.6 Physical consistency and others .6 5.3 Chemical and microbiological characteristics 6 5.3.1 General 6 5.3.2 Sulfur. 6 5.3.3 Phosphorus. 7 5.3.4 Nitrogen.... 7 5.3.5 Chlorine and other halogens 7 5.3.6 Organic micro pollutants. 7 5.3.7 Trace elements. 8 5.3.8 Pathogens. 8 6 Thermal processes fundamentals .8 6.1 General 8 6.2 Drying. .9 6.3 Hydrolysis. 10 6.4 Incineration .11 6.5 Pyrolysis.. 12 6.6 Gasification. 13 6.7 Thermolysis 14 6.8 Carbonization 14 6.9 Wet oxidation .14 6.10 Melting 15 6.11 Pasteurization .15 7 Technologies ..16 7.1 General 16 7.2 Drying 16 7.2.1 Direct dryers 16 7.2.2 Indirect dryers 20 7.2.3 Solar dryers 22 7.3 Hydrolysis. 23 7.4 Incineration 24 7.4.1 Fluidized bed furnace 24 7.4.2 Multiple hearth furnace (MHF) 28 7.4.3 Hybrid furnace. 31 7.4.4 Others 32 7.5 Pyrolysis 33 7.6 Gasification. 33 7.7 Thermolysis 35 7.8 Carbonization. 36 @ IS0 2021 - All rights reserved ii IS0/TR 20736:2021(E) 7.9 Wet oxidation .36 7.10 Melting .37 7.11 Pasteurization. .39 7.12 Emerging technologies. .40 7.12.1 General. .40 7.12.2 Oxidation technologies .40 7.12.3 Enzymatic sludge hydrolysis ..41 7.12.4 Plasma gasification .41 7.12.5 Ultrasound pretreatment .41 7.12.6 Microwave irradiation. .41 7.12.7 .42 Infrared radiation 7.13 Design aspects .42 7.14 Auxiliary equipment. ..42 7.14.1 General. ..42 7.14.2 Transport, receiving area, storage and feeding systems .43 7.14.3 Heat supply and recovery ..43 7.14.4 Gas cleaning .44 7.14.5 Ash and other residues handling ..44 7.14.6 Wastewater treatment. ..44 7.14.7 Process monitoring. ..44 7.14.8 Safety systems. .45 8 Operational aspects. .45 8.1 General .45 8.2 Drying. .46 8.3 Hydrolysis. .46 8.4 Incineration .46 8.4.1 General ..46 8.4.2 Fluidized bed furnace. ..47 8.4.3 Multiple hearth furnace .48 8.5 Pyrolysis.. .49 8.6 Gasification. .49 8.7 Thermolysis. .49 8.8 Carbonization. .49 8.9 Wet oxidation 49 8.10 Melting .50 8.11 Pasteurization. .50 8.12 Hazards. 50 9 Management of energy and secondary resources .50 9.1 General .50 9.2 Drying 51 9.3 Hydrolysis. 51 9.4 Incineration 51 9.5 Pyrolysis.. 52 9.6 Gasification .53 9.7 Thermolysis. .54 9.8 Carbonization .54 9.9 Wet oxidation. .54 9.10 Melting. .54 9.11 Pasteurization. 54 9.12 Thermal treatments and circular economy .55 10 Management of residues .55 10.1 General 55 10.2 Flue gas. 55 10.2.1 Characteristics and parameters .55 10.2.2 Equipment .57 10.3 Ashes. ..59 10.3.1 Composition/parameters. .59 iv @ IS0 2021 - All rights reserved IS0/TR 20736:2021(E) 10.3.2Processes and equipment 60 10.4 Wastewater 61 11 Decommissioning of installations 61 11.1 General 61 11.2 Specifi