Treating wastewater from noodle-making craft village with environmentally friendly technology

Wastewater from craft villages producing vermicelli has a high concentration of organic substances, making it difficult to treat. Currently, wastewater from craft villages producing vermicelli is mainly treated through biogas tanks before being discharged into the environment. According to survey results in some "bún" villages, the quality of wastewater after treatment is still 2-8 times higher than the permitted standards, potentially causing high pollution. Assoc. Prof. Dr. Bui Thi Kim Anh and the research team of the Institute of Environmental Technology carried out the task: "Building a model of wastewater treatment in a craft village producing vermicelli with low-cost, environmentally friendly solutions", (code: UQSNMT.01/20-21). The task was graded Excellent by the Acceptance Council at Vietnam Academy of Science and Technology.

Figure 1. Assoc.Prof. Dr. Bui Thi Kim Anh – project manager

The objective of the task is to build a technology model using aquatic plants (surface runoff, groundwater flow, combined technology) combined with simple pretreatment processes to effectively treat pollution. Contamination in wastewater of vermicelli production villages, Da Mai ward, Bac Giang city, opens the possibility of application to other types of craft villages with similar wastewater properties.

The technology selected in the treatment model is based on the applied research experiences of the authors, ensuring that the solution is suitable for the characteristics of the noodle wastewater, while improving the technology and increasing the treatment efficiency. The treatment model uses simple biogas technology in combination with biological filtration and mixed flow plantations. Waste water is separated from starch, solid residue and organically decomposed in biogas tank, then passed through biological filter tank using fixed filter material layer, COD type load can be up to 3kg/m3/day. Studies on artificial tree planting have been applied to treat wastewater with high organic matter and nutrient content. The staff of Institute of Environmental Technology (Tran Van Tua, Dang Dinh Kim, Bui Thi Kim Anh, ...) have conducted many studies since 2004 on the selection of plant species, the development of technology for planting filter fields to treat wastewater contaminated with organic substances such as aquatic product processing wastewater, pig breeding wastewater, etc. Research and applications of artificial tree planting filter technology show that this is a technology that can be applied to treat wastewater from vermicelli villages in Vietnam.


Figure 2. Some wastewater treatment models using artificial tree planting filter sites implemented by the research team

In order to perfect and improve the technology to suit the application conditions in the craft village, the research team has designed, built and piloted a wastewater treatment model of Da Mai vermicelli craft village, on a large scale, to pilot 50 liters/day and night. After 2 months of operation, the system operates stably and the output water quality meets the standards. The parameters of the retention time or processing load of the obtained items can be used as a basis for the actual design. The test operation process also shows that the operating model consumes less energy, limiting costs. This model can be applied on a large scale.

Figure 3. Experimental diagram of the treatment model on a scale of 50 liters/day and night

The application model of wastewater treatment in the vermicelli production village in Da Mai, Bac Giang includes 03 main modules: biogas module, biological filter module and mixed flow tree planting filter module with a treatment capacity of 10 m3/ day.night. The model is designed with a self-flowing, energy-saving mechanism, so operating costs are minimized. In addition, the treatment system also creates a green space, beautifying the landscape for the area. In general, the model is quite suitable for the requirements of low investment costs, especially the almost negligible operating costs.




Figure 4. Some pictures of construction and finished treatment model in Da Mai

Translated by Quoc Khanh
Link to Vietnamese version

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