General Sewage Technology

Treatment of pit wastewater from coal mining

Pit groundwater from coal mining in Vietnam is heavily polluted by high solids loads as well as high concentrations of iron and manganese. As the wastewater is not treated in any way, the outfalls are polluted. The project partners therefore develop a new, innovative pit water purification system allowing the national limit values for wastewater to be met.



The water pumped off as part of mining operations is currently delivered without treatment to the outfalls. The heavy pollution of the wastewater with solids as well as iron and manganese poses a threat to drinking water obtainment in many locations. Also, the polluted water can be used only to a limited degree for irrigation, particularly for rice cultivation. Purification of the pit wastewater can aid in substantially reducing the environmental strains of coal mining in the Vietnamese province of Quang Ninh.

During the project, the project partners develop a first pilot plant based on water quality research in the laboratory and in the field. The pit water purification plant is one of the first modern plants in Vietnam for treatment of wastewater with high manganese content.

Besides planning and construction of the wastewater treatment plant, the research project comprises educational programmes for the management and workforce. The training documentation are similar in function to an operating manual and assist in keeping the plant running without problems.


  • The process developed entails manganese removal in two stages. The second stage, downstream of the iron-hydroxide-coal-sludge separation, requires particularly low solids content.
  • Treatment of the pit water in the field plant largely facilitates meeting and even undercutting the Vietnamese limit values for wastewater-borne substances.
  • The flexible process control allows adaptation of the treatment to the fluctuating properties of the feed flow. This allows, among other things, reduction of the chemicals required.
  • The system developed can also be employed elsewhere and can be modified for removing other substances from water.

More Project Informations

Project title:  Verbundprojekt Bergbau und Umwelt Vietnam (RAME) - Unterverbund 3 Wassermanagement und Wasserbehandlung

Project number:  02WB0915-17

Project period:  2007 - 2011

Project region:  Germany (Brandenburg, Saxony), Vietnam

Project contact:

Herr Dr. rer. nat. habil. Bilek

This email address is being protected from spambots. You need JavaScript enabled to view it.

+49 (0) 351 4050 - 674

Herr Prof. Dr.-Ing. habil. Beims

UBeims @

+49 (0) 351 4050 - 6354

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Source: German National Library of Science and Technology Hannover (TIB)