‘Hoa ruoi’ (Hoa fly) and ‘Hoa linh den’ (Hoa Black Soldier Fly) are the nicknames given to Nguyen Trong Hoa by his friends. The student raises flies to treat waste.
Hoa is the leader of a team of four members who are using black soldier flies (Hermetia illucens) to treat organic garbage which helps minimize the amount of waste at landfills.
Black soldier fly larvae are also used as food for cattle and poultry, and as organic fertilizer
Thanks to high nutritional value, black soldier fly larvae are also used as food for cattle and poultry, and as organic fertilizer to improve soil fertility and increase soil porosity with no harm to the environment.
The four members of the team are all from the Faculty of Food and Environment Engineering at Nguyen Tat Thanh University. The research has been done under the guidance of Le Nguyen, a lecturer and researcher at the school.
According to Hoa, black soldier flies are sourced from North America which can consume decomposed organic materials, including carrion (corpses, dirty materials). Black soldier fly larvae decompose organic matter very quickly and their growth depends on the quality and quantity of input feed.
|Black soldier flies are sourced from North America which can consume decomposed organic materials, including carrion (corpses, dirty materials). Black soldier fly larvae decompose organic matter very quickly and their growth depends on the quality and quantity of input feed.|
The team conducted a pilot fly farm in My Tho area of Tien Giang province. The material used was soybean residue collected from tofu workshops, and pineapple peels collected from a candy production workshop. All these materials were ground and fed fly larvae.
In order to create strong larvae to increase the waste treatment efficiency, according to Hoa, it is necessary to raise them in suitable temperatures from 25 to 35oC, at a humidity level of 60-80 percent, food humidity of 70-90 percent and density of 2-3g eggs per square meter. These are the best conditions for larvae growth and development.
The students also created a bio-bin to help separate and disintegrate organic waste at home by punching holes below to collect leachate. There is also a spout to collect fly larvae placed above.
The use of household bio-bins not only creates a source of food, but also helps to sort waste at source and minimize the amount of waste collected.
The researchers found that black soldier fly larvae grow most quickly in tofu and pineapple residues.
Hoa stressed that it would be better to provide materials in different periods. This allows fly larvae to thoroughly treat waste before their produce bad odor.
If providing substrate at once in large quantity for the whole rearing time, the decomposition won’t be enough, bacteria will develop, and a bad odor will be created.
Black soldier fly larvae are voracious, having a wide mouth structure that eats all organic compounds quickly when compounds have time to decompose and produce odors.
Experiments showed that fly larvae can reduce 80 – 90 percent of waste and pathogens.
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