The environmentally contaminate tofu liquid waste can be converted into biogas. In Indonesia, 56,000 tonnes of fossil fuels can be replaced by tofu liquid waste biogas.
Tofu liquid waste contains organic material. Through a fermentation process, methanogenic bacteria convert the organic material into biogas. How much biogas is produced from tofu liquid waste? According to Imam Sadzali’s research at the Physics Department of FMIPA University of Indonesia, 100 kg of soybeans can produce 1,500 liters of biogas. A typical tofu industry can produce 750 liters of biogas from 50 kg of soybeans.
Where do the origin of fermentable methanogen bacteria? Methanogen bacteria are obtained from the rumen (also known as the paunch) and cow manure. The amount used is not large. For 100 kg of tofu liquid waste, only 1 kg of cow rumen is needed. With these bacteria, 0.6-0.7 cubic meters of methane gas is produced per 500 liters of liquid tofu waste.
The tofu liquid waste biogas installation is identical to the cow manure biogas installation. It consists of a control basin, inlet basin, digester, settling basin, baffled reflector, and anaerobic filter. The digester has a dome shape with brick walls 6 m in diameter and 10 m high. The digester breaks down the liquid tofu waste into methane gas. At the top of the dome, there is a 1-meter diameter hole for the regulator tap and the gas distribution pipe to the house.
Granite stones are positioned vertically inside the digester. The granite stones are supported by a hollow cast concrete baffle wall which allows water to enter. The granite stones purify the water and absorb the sulfide gas.
To use biogas, simply add a pipe to carry the gas to the cooker. Unlike Liquefied Petroleum Gas (LPG), which has a pressure of around 5 atm, tofu waste liquid biogas has a pressure of only 0.2 atm, making it extremely safe from the risk of explosion.
Nata de Soya
Tofu waste can be utilized as nata de soya to be processed into food. The ratio is the same: 1 kg of tofu waste produces 1 kg of nata de soya. First, filter out the tofu waste. Then boil it until turns yellow. At the time of boiling, add 0.5% sugar, 0.2% urea, and 0,2% phosphate. Boil the tofu waste and leave to cool for two to three hours. Then add 20% nata de soya seeds (azotobacter bacteria) and 0.5% acetic acid.
Mix well and place in a fermentation pan measuring 30 cm x 15 cm x 10 cm. Cover the top of the pan with newspaper and tie it down with rubber or rope to prevent it from coming loose. Leave to ferment for 10 days. To obtain an even layer of nata de soya, make sure the pan doesn’t shake during the process.
Once done, cut the nata de soya into slices of your choice, then boil and chill. Change the water every day for three days to get rid of the acid. The finished cooking water can then be flavored with syrup flavors such as strawberry and vanilla. Once cooled, store in a cool place. Pasteurize the nata de soya for 30 minutes at 80 degrees Celsius for a longer shelf life.
Recycled Car Glass
The diamond-patterned blue women’s bag is not just any bag. It is made from recycled car glass. The bag was made in Taiwan by Ecomax Textile Co. Ltd. As well as bags, the company also makes various shopping bags and clothing from car glass.
Before processing, the Polyvinyl Butyral (PVB) film sheet found between two sheets of car glass is removed. The PVB film on car glass is useful for protecting the driver from broken glass in the event of an accident. The PVB film does not affect the clarity and transparency of the car glass.
Once the PVB film has been removed, the car glass is recycled and refined. The glass waste is then modified by the addition of additional components to create environmentally friendly materials. The raw material is then subsequently transformed into a variety of goods, including bags, pouches, and clothing.
Waste Plastic Bottle
The Jamaica and Brazil football jerseys look like high-quality sports shirts. The shirt feels smooth in the hand. The material of the T-shirts turned out to be PET (Polyethylene Terephthalate) plastic bottle waste.
Far Eastern New Century (FENC) in Taiwan recycles PET plastic bottles. The company develops technologies to maximize the value of various wastes such as plastic bottles, shoes, and textiles into useful materials. The company also specializes in the integration of fibers such as natural fibers, wool, polyester, viscose, and nylon.
The waste PET plastic bottles are first crushed and then subjected to a re-polymerization process to produce recycled chips. The material is then converted into yarn and is ready to be knitted in clothing factories into various T-shirts, shirts, trousers, and jackets.
Waste Coconut Coir
Coconut fiber waste can be used to create exotic-looking plant pots. The coir waste must be soaked in water for two to three days to remove the tannin compound before being used as a pot. The tannins in coir can stop plants from growing.
The advantage of coir pots is that they are porous and can hold water for a long time. This occurs as a result of the slit and cavities in coconut fiber. Watering the plants once every 2-3 days is sufficient.
Fish Waste
The various mango fruit plants look very special. The fruits look abundant and taste very sweet. The secret lies in the routine apply marine fish waste extract solutions. A total of 25 kg of marine fish waste is stored in a closed container and mixed with 2 liters of microbial solution and then fermented for 3-4 weeks.
The dosage is 15-20 cc/liter of water, sprayed every 3-4 days when the plants start to flower. Combine the spraying with sprinkling the extract solution onto the growing medium.
The marine fish extract is rich in amino acids. Although it requires a lot of energy, plants can manufacture amino acids. Therefore, external amino acids can help plants save more energy for other purposes.
The presence of external amino acids can be a nutrient for microbes around plant roots. Amino acids help promote root growth so that nutrient absorption is optimized.
Spraying amino acids on leaves can provide nutrients for bacteria living there. Microbes that grow on the surface of the leaves can boost photosynthetic activity, resulting in an abundance of carbohydrates produced, which can increase the sweetness of the fruit.
The addition of amino acids also helps plants fulfill their potassium requirements to increase the carbohydrate and sugar content of the fruit.
Dregs of Soybean
There is a technique for the high production of sweet oranges in Thailand. Look, 125–130 pamelo oranges fruits per tree per year are possible.
The secret to high production is the use of market fish waste and soybean dregs, which are rich in soluble dietary fiber. Prepare a 200-liter drum. Add fish waste and soya pulp in a 1:1 ratio. Leave to ferment for two weeks. Then spray each tree with 1 liter of the solution diluted with 2 liters of water. One hundred trees can be fertilized for two months with a 200-liter drum.
Wasted Durian Peel
Oil spills that contaminate water are difficult to decompose. Efforts are being made to overcome oil spills by spreading a group of hydrocarbonoclastic bacteria (also known as hydrocarbon-degrading bacteria). The hydrocarbon components are used by the bacteria as a source of carbon and energy for growth.
Another method of cleaning up oil spills was discovered through research by Nurul Izza Husin from the Department of Applied Sciences at Universiti Teknologi MARA (UiTM) in Malaysia. Nurul used durian peel waste mixed with banana stems (pseudostems). All the ingredients were finely chopped, mixed until homogeneous, and then spread on the oil spill. According to the study, the combination was almost as effective as using hydrocarbonoclastic bacteria.
