Team:Hong Kong UCCKE/Description
Part 1: The Problem
1.1 How serious is Hong Kong Food Waste Problem?
Every day, 3662 TONNES of food waste is disposed of in Hong Kong, which is equivalent to (by weight):
Meanwhile, food waste has been the largest contributor to MSW landfills disposal in HK, taking up 34.1% of it in 2017.
Plate 1: Composition of MSW disposed of at landfills in percentages in 2016 and 2017 - By major waste type [1]
To add fuel to the fire, the three current landfills of Hong Kong are facing imminent saturation crisis. They have already reached their capacity in 2015,2017 and 2019 respectively. Although they have all undergone expansion, they are expected to be filled up again in 2020. Known for being densely populated, the area in Hong Kong that can be exploited as new landfill is limited and scarce. Therefore, the need of reducing waste, in which food waste takes up most, is critical.
Figure 1: Geographical distribution and utilization of landfills in Hong Kong [2]
Landfills in Hong Kong
1.2 Is the Government helping to relieve the problem?
The food waste problem is so severe and non-neglectable, so the government has always said to show great concern on it. Yet, the small amount of resources which is attributed in the area and the non -decreasing food waste deposit shows the government is talking more than doing. Firstly, the 4-years-delay of schedule of building Organic Waste Treatment Facilities shows their unconcerned and cold-shouldered atti tude to the critical problem. Secondly, their failure to meet goals and shows their scarce effort and sincer ity. For instance, they promised to reduce food waste to landfills by 40% by 2022 in 2014, yet now after 5 years, in 2019, the food waste number still keeps an increasing trend. Another example is the waste charging system suspended from 2016 to barely starting in 2019.
Figure 2: Failure of the government to meet their food waste targets[3]
Therefore, we, as a Hong Kong citizen, has to stand out to help resolve the problem before it is too late.
1.3 How Hong Kong Lifestyle and tradition contributes to the problem:
Following the astronomical figures mentioned above, huge discussion over food waste was raised in the community. Yet, despite public awareness, little is willing to take action. Why?
Firstly, Hong Kong people,especially the elderly, are influenced by the Chinese Traditional thinking that ‘More is Better’. So, during mealtimes, the table is filled up with various dishes that is impossible to finish, leaving fresh food to be wasted. The problem is even more severe and conspicuous during special festivals and occasions, when prosperity was upheld.
Dinner at a typical Chinese household
Secondly, as an international city, Hong Kong has a fast living pace. Citizens are so overfilled with work everyday that they barely have time for a relaxing meal. When everything is about speed and efficiency , who has time to think about the future of the environment?
Crowded and fast-paced lifestyle in Hong Kong
Last but not least, eating out is very often in Hong Kong, which makes controlling the food quantity even harder, resulting in leftovers.
Eating out at a restuarant in Hong Kong
All in all, with the traditional and cultural norms, it is very hard to touch the hearts of Hong Kong citizens and cause them to make a change, especially with so many external factors limiting. That’s why the root of the problem is so hard to be eliminated.
Considering this, we target our project on the aftercare - dealing with food waste.
1.4 How is the current food waste recycling industry of Hong Kong?
Hong Kong has a low food waste recycling rate of 1.13%(2017). This is caused by the delay of Government’s schedule. According to the food waste and yard waste plan for Hong Kong in 2014,the government plans to build a network of around 5-6 Organic Waste Treatment Facilities(OWTFs) between 2014 and 2024 with a total recycling capacity of about 1,300-1,500 tonnes per day to turn waste into energy by using anaerobic digestion technology.
Government plans on building facilities that handle food waste[4]
However, until now in 2019, only the First Facility is built in Siu Ho Wan (North Lantau), treating only 200 tonnes (0.05%) of food waste.
OWTF2, which is planned to be built in 2018, has just undergone funding and contract signing process, and is expected to be operational only in 2022.
While OWTF3, which is planned to be built in 2021, is still under feasibility study and subsequent environmental impact assessment, and is expected to be operational only in 2026. Therefore, with the 4 to 5 years delay of schedule of the Government, only a small amount of food waste can be treated by the facilities.
On the other hand, there are certain obstructions that inhibit the food waste recycling industry to thrive.
The current situation of the government plans[5]
Restaurants and Industrial suppliers lack in human resources and staff training to separate food waste. If employees are assigned to separate food waste, it will cause great loss on frontline employees, and increase their working pressure. They also lack space to put food recycling facilities. Moreover, some reflected that they failed to compromise the food waste collection time with the collector, and soon quitting the food recycling procedure.
For Commercial and Business community, they refuse to send food waste to recycling centres proactively because the recycling centres don’t provide collection trucks, leaving them to carry them delivery cost. While the delivery cost is high as recycling centres are located far from the urban area.
For recyclers, they often lack space for putting treatment facilities as the land rental price is high in Hong Kong due to the land shortage problem mentioned above. Moreover, the recycled products from food waste are usually animal feed(fish feed most likely) and compost and fertilizers, which has a small local market and thus results in low income. This is also the major reason why investors don’t invest in food waste recycling, leaving the industry to stay downturn.
With the above obstructions, we decided to design a domestic food waste treatment facility which can be convenient to users, free of transportation, and avoiding all of the problems mentioned above. So that Hong Kong people could truly agree with and adopt to the habit of recycling food waste and take a part to stop the food waste crisis before it’s too late.
Part 2: Searching the Target
2.1 [Method] Why not build a public treatment facility?
The above obstructions and failing experience proves that building a public treatment facility is ineffective and unpopular in Hong Kong. Moreover, like we have mentioned, Hong Kong is a crowded city with a population close to 8 million, and we are deeply disturbed by the land shortage problem. Therefore, the government prioritises building public housing estates over everything. It would be hard to find a large piece of unoccupied land to build a public treatment facility. So we believe building a small domestic machine that fits at home will be more effective in reducing food waste.
2.2 [Type] Why domestic, but not industrial food waste?
According to the government’s data in 2017, Out of the 3662 tonnes food waste disposed per day, Domestic waste takes up a major part of 65%, while only 35% is from the commercial and industrial region.
Plate 2 Composition of municipal food waste disposed of at landfills in percentages in 2016 and 2017- By waste category[6]
Besides,the government has already built certain facilities to deal with industrial wastes. Including 200 tones daily handled by OWTF 1 to generate electricity, biogas and fertilizer, while there is no facilities specifically targeting the household food waste. Also, we have more touch to the audience of household food waste, as we can easily receive opinions from our housing estates, and use the school canteen as a prototype to practice our project in the embryo state. So we made domestic food waste our target.
2.3 [Product] Why detergent, not fertilizer or compost?
According to the interview with Hong Kong recycling company, farmers usually will not accept fertilizer and compost made up of food waste, due to the possibility of containing GM crops which will affect their brand image and unknown materials which may affect their growth of crops. This is also because of the relatively low credibility of food waste content as there is no standardisation in the ingredients of the product and the rare usage.
Therefore, making homemade detergent will be more persuasive to users who made it themselves and thus have a better market.
Part 3: What are we doing?
We took reference of Dr.Rokuson’s eco-enzyme and brainstormed our project design. We create a machine that can store three types of food waste, meat, vegetables and rice,separately in an anaerobic condition and let the microorganisms do the work.
- The food waste polymers will first be hydrolysed into smaller molecules by hydrolytic enzymes, which are then consumed by microbes.
- The sugars, amino acids, and fatty acids are then primarily fermented by endo-products and groups of bacteria to acetate, propionate, butyrate, lactate, ethanol, carbon dioxide, and hydrogen.
- Next, by acetogenesis, more acetate and hydrogen are formed. Lastly, methanogens degrade the substrates to Methane gas. The acetic acid and other substance produced in the process of anaerobic respiration will have a cleansing effect, and the useless food waste are transformed to something new.[7]
Of course, the full anaerobic digestion process takes up a long time up to 3 months, which is inapplicable in the HK fast paced lifestyle. So we used synthetic biology to insert certain food enzymes into the bacteria, and use the bacteria as a working agent in the digestion process.
Together with the optimal conditions designed for anaerobic digestion, we can hopefully speed up the process up to 3 times, 5 times, producing domestic detergent out of meal leftovers that can be later used to wash the dishes, clean the house. With the help of this simple machine in housing estates and school, Hk food waste can be greatly reduced, and we may be one big step away from the problem.
References
[1] Waste Statistics for 2017 from Environmental Protection Department
[2] Hong Kong BLUEPRINT FOR SUSTAINABLE USE OF RESOURCES 2013 – 2022 from Environment Bureau
[3] A FOOD WASTE & YARD WASTE PLAN FOR HONG KONG 2014-2022 from Environment Bureau
[4] A FOOD WASTE & YARD WASTE PLAN FOR HONG KONG 2014-2022 from Environment Bureau
[5] A FOOD WASTE & YARD WASTE PLAN FOR HONG KONG 2014-2022 from Environment Bureau
[6] Waste Statistics for 2017 from Environmental Protection Department
[7] Renewable biological systems for alternative sustainable energy production (FAO Agricultural Services Bulletin - 128) by Osaka University