The materials used as the substrate for fouling organisms in the process of biological wastewater treatment is usually at least one of the following four main points: expensive, weight, occupancy and prone to congestion flow. Coir is a material that can avoid such disadvantages.
According to Master Nguyen Ngoc Bich (Rubber Research Institute VN), one of the measures to improve the efficiency of wastewater treatment in biotechnology is to improve the density of microorganisms in the system. When the wastewater treatment process with suspended growth (no price for fouling organisms), the treated wastewater to go out, have brought a significant amount of microorganisms.
Processing method according to the attached growth pattern (which can cost) to overcome this. Previously, these materials can be used as often as the price of inert material such as sand, ceramic, slag, or plastics. However, such materials are usually expensive (for plastics, investing US $ 75-200 per cubic meter tank volume processing), weight, occupancy and easily obstruct the flow of wastewater through treatment tank.
To search for a type of material as the substrate can overcome the weaknesses mentioned above, coir has begun to be studied since 1996. The government coir pads rubber in the form of a rectangular block size are installed inside an anaerobic treatment tank. With rubber processing wastewater, model performance handling about 90% organic matter.
From the initial application of the technology, research masters Bich successful application of crude coconut fiber in the form of wastewater treatment easier. The coir fiber is the sequence of circular cross section, and no rubber cover, diameter 20cm and 200cm long. Then, the chain is required in parallel on a rectangular frame.
Waste water from a rubber processing plant for anaerobic digesters through with raw coconut fiber as the substrate, hydraulic retention time is two days. As a result, 90% of COD and BOD is removed from the wastewater. This model has been tested regularly operate from May 9/1999 to 2001. Through the quality test on 22 samples of wastewater effluent, treatment efficiency for organic pollutants remained stable, at around 90% COD and BOD for the phenomenon swept out of the microbial treatment tank negligible, favorable for the next process. After over a year of operation, an anaerobic used coir no blockages in the flow of wastewater.
As a major component of coconut fiber is cellulose (80%) and lignin (about 18%), so it is difficult to microbial decomposition. According to estimates by the researchers, the life of coir in the anaerobic tank is about 5 years.
From the above results, masters Cliff has confirmed the ability and efficiency of crude coconut fiber in an anaerobic treatment to wastewater treatment rubber processing industry. In addition, the technology can be applied on in the treatment of wastewater containing organic pollutants. Coir is a cheap material and are available in many parts of our country, so this can be considered as a development of wastewater treatment technologies simple and inexpensive.
Duy Thanh Nguyen ( sales21@vdelta.com.vn)
