Standards Development

Scope

This document provides guidance for the operation and maintenance of MSW leachate treatment and reuse system, aiming to promote the system operating efficiently and stably, save economy and energy costs, and reduce safety risks during operation.

This international standard supplements and is intended to be used in conjunction with ISO 24297. It includes the terms and definitions, the purpose, principles and issues need to be considered in the operation and maintenance, components of operation and maintenance system, process operation control, equipment maintenance, guidance on health and safety issues and other aspects of operation and maintenance.

This standard provides fundamental principles and useful guidelines for the operation and maintenance of MSW leachate treatment and reuse system. It applies to all stakeholders. It can help relevant authorities, training organizations, certification bodies and other responsible entities to develop regulations, plans and manuals, as well as to provide technical guidance to designers, operators and managers of leachate treatment and reuse systems.

Purpose

MSW leachate is a kind of wastewater containing highly concentrated organic matters, nitrogen and salts. In MSW leachate treatment and reuse system, combinations of different treatment technologies (including preliminary treatment, biological treatment and membrane treatment) are required to ensure water quality meets requirements of discharge or reuse.

ISO 24297 “Guidelines for treatment and reuse of leachate from municipal solid waste (MSW) incineration plants” addresses topics such as process design, parameters that should be monitored, etc., but it does not provide detailed principles and instructions of operational and maintenance for MSW leachate treatment and reuse system.

Reasonable operation and maintenance is important for the sustainable, stable and safe running of the treatment and reuse system. This proposal will address in practical terms, the essential operation and maintenance activities that the owner/users of MSW leachate treatment and reuse systems should be undertaking. Generally, an operation and maintenance program is made up of an interconnected system including process control, equipment maintenance, staff training, budgeting of economy and human resource cost, etc.

The purpose of the proposal is to provide the technical specifications and operation guidelines for the issues that need to be considered and the problems that may be encountered in the operation and maintenance of the leachate treatment and reuse system, aiming to promote efficient and stable operation, avoid economy and energy waste, and reduce safety risk. 

The complex water quality and process combinations make it complicated and challengeable to operate and maintain the MSW leachate treatment and reuse system.Meanwhile, guidelines for other wastewater operation and maintenance are not suitable for MSW leachate, because the issues, safety risks and relevant coping methods in operation and maintenance of MSW leachate treatment and reuse system are significantly different from those of conventional wastewater. The differences can be summarized into the following aspects:

1) The complex water quality of leachate leads to problems that are different from other sewage in treatment process, and these problems should be considered in operation and maintenance. For example, high concentrations of calcium ions and magnesium ions in leachate could cause pipeline scaling, or even blocked, which is detrimental to the stable operation of the treatment system, so it is necessary to regularly clean and dredge the pipeline;

2) The complex water quality of leachate leads to different types and yields of products from other sewage, and these products need to be controlled and managed by reasonable operation and maintenance. For example, the organic matters can be converted to biogas after anaerobic digestion process. The biogas yield is generally low in the anaerobic treatment of most kinds of sewage, but very high in MSW leachate treatment because of high concentrated organic matters. The biogas produced in MSW leachate treatment could generate safety hazards. But it also could be recovered as energy under proper operation and maintenance;

3) The complex water quality of leachate leads to different process parameters from other sewage, so the precautions and control measures in operation and maintenance are different. For example, in MSW leachate treatment, the concentration of activated sludge in the aerobic and aerobic processes is relatively higher than most other sewage to ensure the treatment efficiency and stability because of high concentrations of ammonia nitrogen;

4) The leachate treatment and reuse systems are combinations of different technologies, so the factors that need to be considered in operation and maintenance are more complex and changeable than other sewage. These treatment technologies involve microbial metabolic processes and phy-chemical processes, and it is important and necessary to ensure that each process runs smoothly to facilitate system stability, personnel safety, and economic and energy saving.

The absence of standards could lead to ineffective operation, environmental pollution and potential safety risks, so it is necessary to develop a standard for the operation and maintenance of MSW leachate treatment and reuse system.

This standard provides the technical specifications and operation guidelines for the issues that need to be considered and the problems that may be encountered in the operation and maintenance of the leachate treatment and reuse system, aiming to promote efficient and stable operation, avoid economy and energy waste, and reduce safety risks.