Cambodia's needs for sewage treatment technology

Tongji University recently issued a survey report on Cambodian wastewater treatment technology demands, listed the needs for sewage treatment technology in Cambodia and discussed possible cooperation on wastewater treatment technology between Cambodia and China.

Municipal pipe network constructions

For the cost and practical considerations, combined piping network is the main way expected to be achieved in recent planning, and in the long-term planning, it could be gradually transferred into intercepted combined sewage drainage system and separated sewage drainage system in the urban areas discharging to sensitive receiving environment. During the rainy season, stabilisation pond systems treating stormwater and sewage water can have overflow bypass if flow is greater than its design max flow.

Centralized sewage treatment technology

Cambodia has an emerging demand for wastewater treatment technology, especially for the municipal centralized sewage treatment technology. Considering its domestic development status, e.g., underdeveloped economic level, lack of funds, not stable energy supply, and limited technical and management experience, it is not suitable to introduce complex treatment process (membrane technology etc.) simultaneously. Combined with the operation experience of sewage treatment plants in Siem Reap and other provinces, the main processing technology will focus on simple biochemical treatment process, for example stabilization ponds.

Decentralized industrial wastewater treatment technology and equipment

Garment Manufacturers Association in Cambodia estimated that each washing machine produced 80 tons of wastewater per day and daily washing wastewater emissions are about 3000 tons. The wastewater mainly includes the following characteristics:

1) Containing large numbers of dye leading a high chroma.

2) Poor biodegradability, the ratio between BOD and COD ratio is below 0.2. The dye molecules are not easy to degrade.

3) Seasonal changes, clothing varieties and markets cause the fluctuation both in wastewater quality and quantity. Fluctuation will bring difficulties in the stable operation for processing units.

Because there is no centralized industrial wastewater treatment facilities and supporting pipe network, the water washing enterprises discharge wastewater to nearby natural water bodies. Due to increasingly strict emission standards, these enterprises are in urgent need of decentralized treatment facilities, especially of the integrated equipment type instead of the original simple filtration facility.

In addition, if the environmental treatment device could also be used to treat the wastewater from printing, dyeing and fur tanning, it would be attractive to introduce them to the garment manufacturing industry for their wastewater treatment. Once an enterprise cluster effect is formed, infrastructure investment costs could be reduced.