KOCKS INGENIEURE Case Studies for Options of Sustainable Sewage Sludge Disposal in China - Abstract and Conclusive Information - Dr. Weimin Shen, Kocks Consult, Koblenz, Germany

KOCKS INGENIEURE Introduction of the Project “Case Studies”  Financed by KfW  Conducted by a consulting consortium with following members Ingenieure Meschke und Schuster Dahlem Beratende Ingenieure Hamburger Stadtentwässerung Kocks Consult NCMEDRI  Supported by seven major cities in China

KOCKS INGENIEURE Location of Site Investigations

KOCKS INGENIEURE Proposed Measures for Seven Cities

KOCKS INGENIEURE Present Situation of Landfills  Disposed within WWTP sites or dumped on public areas  Shortcomings of disposal of sewage sludge on sanitary landfills: such as high water content, low shear strength and insufficient stabilization Present problems with operation and safety  Limited sanitary landfill capacity for medium or long term needs

KOCKS INGENIEURE Future Development of Landfills  Advanced preconditions for sludge characteristic for disposal on sanitary landfill water content of sewage sludge less than 65% shear strength of sewage sludge more than 25kN/m 2 Additional costs for sludge post-treatment on WWTP  Requirements for location and operation of sanitary landfill distance to cities with regard to the environmental protection advanced treatment of landfill gas and seepage water Additional costs for transportation and operation

KOCKS INGENIEURE Future Development of Landfills  In general, the total costs for sludge disposal on sanitary landfill will increase significantly in the future.  In the long term, such solutions are not sustainable for major cities due to shortage of landfill capacity.

KOCKS INGENIEURE Present Situation of Agricultural Use  Reasons for the lack of positive examples does not comply with regulations and standards, such as concentration limits for relevant pollutants in sewage sludge no stable and sustainable market needs, such as available farmland no sufficient control and management, such as limits for quantity, time and location minor acceptance of public, especially against the epidemic risks such as SARS in China

KOCKS INGENIEURE Future Development of Agricultural Use  Advanced preconditions for agricultural use limits for pollutant concentrations in sewage sludge limits for sludge application quantities limits for use objects and sites, such as forestry or non-food products limits for contaminants concentrations in the soil  Agricultural use should be considered as the most economic solution if the above mentioned pre-conditions can be fulfilled.  In the future, the agricultural use will play only a minor role for major cities in China.

KOCKS INGENIEURE Present Situation of Incineration  A high potential for sludge incineration has been identified since last years.  Realized mono-incineration, for example: Shanghai  Realized co-incineration, for example: Changzhou in coal power plant Suzhou in coal power plant Nanjing in coal power plant Beijing in cement industry

KOCKS INGENIEURE Future Development of Incineration  In the future, co-incineration will play a important role for the sludge disposal in major cities in China.  Simple pre-conditions on co-incineration in coal power plants water content of sewage sludge less than 80% available Possibly: maybe limited capacity of one coal power plant  High acceptance of coal power plants generation of extra income reuse of ashes no additional measures for waste gas cleaning But: investment for installation of a station for reception, storage and dosage

KOCKS INGENIEURE Conclusion  Agricultural use plays a minor role for major cities and will not be applicable on a large scaled.  Landfill is generally limited by scare capacities of the existing landfill sites and an intermediate solution for the following years.  Clear preference is given to the sludge incineration in coal power plants if available.

KOCKS INGENIEURE Outlook  Small Cities Landfills are present and pragmatic solutions for most small cities. If possible, it should be tried to realize agricultural use as the most economic option.  Major Cities Landfills are only intermediate solutions before other options will be realised. Co-incineration will be the preferred option for major cities in the future, if facilities are available.

KOCKS INGENIEURE Thank you for your Attention ! Address:Dr.-Ing. Weimin Shen Kocks Consult GmbH Stegemannstr , D Koblenz, Germany Tel.:+49 (0)261 / Fax. :+49 (0)261 /