Introduction

In 2016 domestic food waste accounted for more than 22% of municipal solid waste in Hong Kong. As landfill capacity becomes inadequate, domestic food waste management plays an important role in reducing municipal solid waste. In view of this, the Environment and Conservation Fund (ECF) has launched a funding scheme known as “Food Waste Recycling Projects in Housing Estates” in July 2011, to encourage food waste reduction, source separation, collection and recycling of food waste produced from domestic households.

This Best Practice Guide (the Guide) aims to provide important notes of food waste recycling for housing estates which participated in the Food Waste Recycling Projects in Housing Estates (“the Project” hereinafter). This guide is divided into three sections which list out the key points for the attention of the following stakeholders:

Household: source separation of food waste, delivery of the separated food waste to Property

Management Company (PMC) and the application of the compost product.Staff of PMC: collect source separated food waste from participants; manage the composter site

and the operational details.Operator of the composter: collect and process the source separated food waste from collection

point (s) and engage in the daily operation of food waste composter.

A. Notes to household on daily operation

Residents who participated in the Project should separate their own food waste for recycling. Among the domestic food waste, examples of the recyclable and non-recyclable components are listed as below:

Recyclable × Non-recyclable Fruits: Fruits, fruit peels Liquid: such as soup and juice Vegetables: Vegetable leaves, roots and seeds, and peels Wood/ bamboo: chopsticks, toothpicks

Grains: Rice and other grain products Cardboards: Paper packaging Noodles: Noodles, bread and other wheat products Metal Products Beans: All kinds of beans Glass products Meats: Raw and or cooked chicken, duck, fish and meats etc.

Plastic products: such as plastic bags, plastic table cloth and nylon string

Gardening: Floral, leaves and herbs Household chemicals: such as detergents and insecticides

Residues: Residues of sugar cane, tea leaves, Chinese herbal medicines and coffee ground Bones1

Snack: Biscuits Stone fruits: Stone of mango and durians, etc. Shells: Egg shells, shrimp shells, etc. Hard shell: Shellfish , shell of crabs, etc.

Dense fibre: Peels and cob of corns, dried leaves for rice dumplings Others: Absorbent pads

Large bones of hog, beef, chicken and duck could not be recycled

Table 1 – Food waste separation classification

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Recyclable Non-Recyclable

Fruits:

Fruit core, fruit peel

Vegetables:

Vegetable leaves, roots & seeds

Liquid:

Such as soup & juice

Large bones

Grains:

Rice & other grain products

Noodles:

Noodles & other noodle

products

Plastic Cutlery:

Wood chopsticks & toothpicks

Plastic Products:

Such as plastic bags & plastic

table cloth

Beans:

All kind of beans

Meats:

Raw or cooked chicken, duck,

fish & meats etc.

Cardboards Metal Products

Gardening:

Leaves & herbs

Residues:

Residues of cane, tea leaves &

Chinese herbal medicines

Glass Products Household Chemicals:

Such as detergents &

insecticides

Figure 1 –Food Waste Source Separation

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A1. Notes for Food Waste Separation

Minimize the generation of food waste, most of the surplus food (such as leftover ingredient from soup) can be avoided Do not put “Non-recyclable food waste” into the food waste container (please refer to Figure1) Drain out liquid as much as possible until no liquid can be seen at the bottom of the container For packaged food, remove packaging material before putting the food waste into the container Use the food waste container to contain food waste, not plastic bag Cover the food waste container properly to avoid leakage and keep the surface of container clean

Figure 2 – Improper separation of food waste: excessive liquid

A2. Notes for Food Waste Delivery

Deliver the containerized food waste to the collection point(s) within the designated schedule Take one clean food waste container for the next time If the food waste cannot be timely handed in, keep it in the refrigerator temporarily to avoid odour generation

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A3. Application of the Compost

Appearance of food waste originated compost should be: black to dark brown in colour loose and soft in texture light odour of humus soil

The Application of Compost in Pot Planting and Ornamental Plants

To improve soil structure Mix compost and soil (volumetric ratio of compost : soil, 1 : 10) before use To improve fertility of soil (boosting) Add compost around the root of the plant and cover with a layer of top soil Compost Tea (boosting ) Dilute the compost with water and spray the supernatant onto the plant (if applicable) or

into the soil

User of compost product is advised to consult the soil and nutrient requirements of different plant species. Trial tests using small amount of compost is advised before massive application.

Figure - 3 Compost use as soil conditioner

Figure - 4 Compost use as plant fertilizer

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Notes for Daily Operation of Property Management Company (PMC)

Food Waste Collection Point

Composting Operation Site

Logistics of Food Waste Collection

Submission of Operation Record

B. Notes to

PMC Staff

B.1 B.2 B.3 B.4

Collection and Transfer of Food Waste

General Notes for the operation of the composting system

C. Notes to

Operator Handling of Food

Waste

C.1 C.2 C.3

Figure 5 – Flow Chart of food waste recycling and composting

B. Notes to Property Management Company (PMC) Staff

PMC staff plays an important role in the Project who is responsible for overseeing the whole operation. PMC personnel needs to communicate with the residents to gauge their feedback; manage the food waste composter and instruct the front line staff about daily operation. PMC staff should go through this Guide during implementation of the Project, so as to be conversant with the operation of composter and its operation manual.

B.1 Logistics of Food Waste Collection

Before food waste collection, PMC should prepare 2 food waste containers for the participating household. The container should be

A proper sealable container (about 3-5 litres) which can prevent spillage of odour Robust and leak-proofed Marked as "Food Waste Container" on a proper label Marked with the types of recyclables and non-recyclables food waste and identity of the participating household on a proper label

Figure 6 –The container should be clearly marked as “Food Waste Container”

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B.2 Food Waste Collection Point

The collection point should be at the reception area / the lobby of the residential building or a designated point in the housing estate. PMC should inform the participating household the following:

Hand in the food waste to the designated collection point according to schedule The collection method ： Hand in the

containerized food waste and collect one clean

container for the next time

Record the participation of household

Figure 7 – Collect a clean container for the next time when hand in food waste

Management of Temporary Storage

As food waste is putrescible, the operator should transfer the collected food waste to the composting site immediately after the collection period

The temporary storage area should not take up public areas and should be provided with proper ventilation Avoid spillage of leachate and odour, keep the transfer route clean Keep the passageway free from obstruction Regular cleaning, for example, daily cleaning after the collection operation

Figure 8 –Food waste containers should be properly kept in temporary store

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Occupational Safety and Health Management

The food waste container and the transfer equipment should be stored safely

Record Management

Ensure the records are complete and return to the responsible staff (PMC) for processing and storage. At the collection point, the following items should be recorded: Residential unit of participating household Measure and record the net weight of the food waste (alternatively this may be done at thecomposting site).

B.3 Composting Operation Site

The location for setting up the food waste composting system (composter) should be indoor area (such as refuse room), it should be as far as possible and away from residents to avoid nuisance.

Environmental Management

Apart from the composter, the composting site should be spacious enough to accommodate: Equipment for food waste pre-treatment (e.g. colander, buckets, weighing scale, table, chair and personal protective gear etc.) Food waste holding pals Temporary area for the collected food waste Stainless steel working platform (if necessary) Bulking agents such as dry leaves, tea and coffee ground, coconut coir and wood chips (if necessary) compost maturing area (sufficient for 21-day maturing after discharge from composter)* Storage area for matured compost * Adequate safety access and guardrail around the composter Man access and space for the operating the composter system, such as: a) weighing and recording of the collected food waste, b) washing food waste containers and other equipment, and c) sorting out non-recyclables

[*Mature compost can be stored separately]

Other points to note Water supply should be in place for cleansing purpose Wastewater discharge should be connected to the Government foul sewer, or sewage treatment plant in the housing estate

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Occupational Safety and Health Management

For indoor composting system: Exhaust ventilation should be installed to ensure sufficient air change in the room Turn on the exhaust ventilation during the operation of composter The exhaust outlet should be away from resident to avoid nuisance Ensure the operation area have sufficient lighting and air flow Do not place any miscellaneous objects, chemicals, flammable substances or naked flame near the composter Keep the working environment clean, apply pest control Separate the composter and operator by rail, fence or platform from the other operation

Figure 9 – Protective fence or platform to protect the operator/ composter

B.4 Submission of Record

Records are referring to daily operation record and questionnaire. Please complete and return the records to the Help-desk on time.

Daily Operation Record

• The participating housing estate should complete the “Composting Machine Operation Record”,“Report Form for Food Waste Recycling Projects in Housing Estate“ and “Financial Report”.The schedule for report submission is stated as below:

Composting

Machine

Operation Record

Report Form for Food

Waste Recycling

Projects in Housing

Estate

Financial Report

First six

months Report once a month

Report every 6 months !f ter six months

Report once a month

Report every three months

Environmental and Conservation Fund – Waste Recovery Projects

Vetting Sub-committee Secretariat

Submit to Help-desk for Food Waste Recycling Projects

in Housing Estates

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Questionnaire

•

•

Questionnaire surveys will be conducted 3 times during the project period. They aim to evaluate residents’ awareness of food waste reduction and behavioral change through participation in the Project: 1) before commencement of Project ; 2) six months after the commencement of the Project; and 3) 24 months after the commencement of the Project (upon completion) In addition, the PMC has to submit questionnaire on education activities, promotion event photos, copy of publicity materials and leaflets

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C. Notes to Daily Operation of the Composting System

The operator should follow the food waste collection route to collect and transfer the food waste from the households to the composting facility. He/she should separate the recyclable food waste according to this Guide; put it into the composting machine to convert it into compost. During the operation, he/she should pay attention to environment hygiene and occupational safety. The produced compost should be properly stored for the second maturing (about 21 days) before use for planting.

C.1 Food Waste Collection and Delivery

The PMC personnel should designate the collection and transfer logistics properly so as to avoid possible nuisance to the residents.

Environmental Management

Any spillage of food waste should be cleaned up immediately Cleaning agent and apparatus should be kept in a trolley for handy use.

Transportation Management

All food waste containers should be put into a large box or trolley for transferring to the composting site Avoid spillage of food waste during transfer Food waste containers should be packed neatly and orderly inside the large box or trolley.

Occupational Safety and Health Management

Maintain proper posture during manual moving of containers. For example, keep the back straight, use the feet to maintain stability, move object smoothly Wear an appropriate gloves to avoid sharp objects such as, fish bones ... Wear safety shoes to prevent slipping Wear face mask, so as not to inhale dust or suspended particles during operation Wear fluorescent vest when work in dim environment Provide adequate lighting to the work place

Record Management

The number of participants, amount of food waste collected, output of compost and the indicated temperature of the digestion chamber should be recorded correctly and returned to the responsible staff (PMC). The PMC in-charge should submit the "Composting Machine Operation Record" to the “Help-desk Service for Food Waste Recycling Projects in housing Estates” monthly.

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C.2 Treatment of the Collected Food Waste

There are some non-recyclable materials inside the collected food waste. Operator should separate the non-recyclable food waste/material according to the Table 2 and the Figure 10.

Recyclable × Non-recyclable Fruits: Fruits, fruit peels Liquid: such as soup and juice Vegetables: Vegetable leaves, roots and seeds, and peels Wood/ bamboo: chopsticks, toothpicks

Grains: Rice and other grain products Cardboards: Paper packaging Noodles: Noodles, bread and other wheat products Metal Products

Beans: All kinds of beans Glass products Meats: Raw and or cooked chicken, duck, fish and meats etc.

Plastic products: such as plastic bags, plastic table cloth and nylon string

Gardening: Floral, leaves and herbs Household chemicals: such as detergents and insecticides

Residues: Residues of sugar cane, tea leaves, Chinese herbal medicines and coffee ground Bones1

Snack: Biscuits Stone fruits: Stone of mango and durians, etc. Shells: Egg shells, shrimp shells, etc. Hard shell: Shellfish , shell of crabs, etc.

Dense fibre: Peels and cob of corns, dried leaves for rice dumplings Others: Absorbent pads

1 Large bones of hog, beef, chicken and duck could not be recycled

Table 2 – Food waste separation classification

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Recyclable Non-Recyclable

Fruits:

Fruit core, fruit peel

Vegetables:

Vegetable leaves, roots & seeds

Liquid:

Such as soup & juice

Large bones

Grains:

Rice & other grain products

Noodles:

Noodles & other noodle

products

Plastic Cutlery:

Wood chopsticks & toothpicks

Plastic Products:

Such as plastic bags & plastic

table cloth

Beans:

All kind of beans

Meats:

Raw or cooked chicken, duck,

fish & meats etc.

Cardboards Metal Products

Gardening:

Leaves & herbs

Residues:

Residues of cane, tea leaves &

Chinese herbal medicines

Glass Products Household Chemicals:

Such as detergents &

insecticides

Figure 10 –Food Waste Source Separation

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•

•

•

•

•

•

Collection Transfer

Weighing

Recording Drain out liquid / Screening Using bin lifter

Manual operation Cleaning the container (Discharge the wastewater to

foul sewer)

Return the

container to the

collection point

Put the separated food waste into the composter

Figure 11 - Daily Work Flow for the Operator

Notes to the operator during operation: Drain out the liquid from the food waste

Large pieces (e.g. fruit peel, pudding, moon cakes, etc.) should be cut into small pieces

Big bones, durian, dry leaves of rice dumpling and corn cob should be discarded as waste

Remove packaging material, plastic bag, absorbent pad and nylon strings

Treat the collected food waste daily and avoid overnight storage

Keep the composting site clean

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•

•

•

•

C.3 Operation of the Composting Machine

The composting machine (composter) should be operated by trained operator. The operator should read the operation manual and follow the supplier’s instructions.

The composter has three main parts 1) bin lifter (if provided); 2) digestion chamber and 3) odourtreatment unit (OTU).1) Bin lifter (if provided)

Check if the food waste collection bin is overloaded or not Before ascending, ensure the food waste collection bin is properly secured to the bin lifter Be aware of any noise or excessive vibration during ascending Clean the bin lifter properly after use

2) Digestion chamberBefore putting the food waste into the chamber, check the display temperature of the chamber. Temperature inside the digestion chamber should be maintained at 55℃ to 65 ℃. (If the indicated temperature is low, the compost may be too wet. If the indicated temperature is high, burnt odour may be detectable) Open the feeding door and observe if the material inside the digestion chamber has reached the high level mark. If the volume reaches the mark, the compost should be discharged before putting more food waste into the chamber Observe whether the compost inside the digestion chamber is normal or not (the compostshould have loose texture. If the material looks sticky, water content in the compost may be too high) Observe whether there is a water droplet inside the digestion chamber (water droplet means the exhaust gas device such the air supply screen, exhaust gas screen or the OTU has been blocked) Clean the air supply / exhaust gas screen regularly. It is recommended to clean the screens every day or every two days Check if the paddle (s) of the agitation system is damaged or not Put the separated food waste into the digestion chamber. The height of digesting material inside the chamber MUST NOT COVER the bottom of the air supply / exhaust gas screen Close the feeding door and switch on the composter. Observe if there is any abnormal vibrations or noise After about 5 minutes, open the feeding door and observe whether the conditions inside the digestion chamber is normal or not Manually check the operation of the agitation system inside the digestion chamber periodically (do not put your hands into the digestion chamber when the composter is switched on). It is recommended to check the agitation system once a week

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only)

Exhaust gas screen

Highest level mark Agitation system

Air supply screen

Fig. 12 Digestion chamber (for reference

3) Odour treatment unit (OTU)

Observe and check the exhaust flow of the OTU (if the discharge flow is low, the air supply screen, exhaust gas screen or an OTU may have been blocked) Regularly drain off the liquid inside the OTU (if applicable) at least once a week. Under normal operation, the drain valve must be kept closed to avoid the gas from the digestion chamber bypass the odour treatment Regularly clean or replace the activated carbon filter inside the OTU (if applicable), at least once every two weeks. After the replacement, the soiled filter should be cleaned. If there has any damage to the filter, inform the composter supplier for replacement Regularly remove compost dust deposited in the OTU (if applicable), at least once every month

過濾棉

Odour Treatment Unit (for reference only)

Odour Treatment Unit – discharge valve (for reference only)

Contact the composter supplier for regular inspection according to the

maintenance schedule

《Contact the composter supplier if the abnormal

situation persists》

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