REFUSE DISPOSAL SYSTEM

Every day, tonnes of waste are being dumped at various landfill sites. All wastes are come from residential, agriculture and so on. If waste is not treated properly, it will produce unpleasant smell which will affect the surrounding and human health.

SOLID AND LIQUID WASTES

      

 Source: Google image. 

SOLID WASTE -  Solid wastes include solid portions of the discarded material such as glass bottles, crockeries, plastic containers, metals and radioactive wastes. The solid wastes may be biodegradable or non-biodegradable. The biodegradable solid wastes are agricultural wastes, food wastes, paper, food processing by products, manure, yard wastes etc. The non-biodegradable wastes include plastic, metals, synthetic materials, radioactive waste etc.

The solid waste management involves disposal of solid waste to land (or ocean) or recovering and reproducing useful substances from the waste through recycling.

The entire methodology of solid waste management is based on:

·       Collection of Waste

·       Disposal

·       Resource recovery

Collection of Waste:

The solid wastes are usually collected by a covered truck.

Disposal of Waste:

After the collection of wastes, the wastes are disposed of by any one of the methods as follows:

·       Dumping

·       Sanitary landfills

·       Incineration

·       pyrolysis

·       Composting

·       Bio gas technology etc

Resource recovery (Recycling):

By the process of recycling, a number of useful products can be obtained from the solid wastes.

Some important products obtainable from solid wastes are described below:

·       Waste papers and cardboards from sugar cane bagasse can be used for the preparation of unbreakable dolls, packing cardboards etc.

·       Metals can be recycled from the industrial scrap.

·       Waste glasses can be used for the preparation of new glass bottle.

·       Electricity can be generated through incineration.

Source: Google image.

LIQUID WASTE - Liquid wastes are the liquid part of the waste material. Liquid waste includes effluents of industries, fertiliser and pesticide solutions from agricultural fields, leachate from landfills, urban runoff of untreated waste water and garbage, mining wastes etc. The liquid waste may contain nontoxic inorganic substances or toxic organic substances.

TYPE OF SOLID WASTE

1) Residential

Residences and homes where people live are some of the major sources of solid waste. Garbage from these places include food wastes, plastics, paper, glass, leather, cardboard, metals, yard wastes, ashes and special wastes like bulky household items like electronics, tires, batteries, old mattresses and used oil. Most homes have garbage bins where they can throw away their solid wastes in and later the bin is emptied by a garbage collecting firm or person for treatment.

Source: Google image.

2) Agriculture 

Crop farms, orchards, dairies, vineyards and feedlots are also sources of solid wastes. Among the wastes they produce include agricultural wastes, spoiled food, pesticide containers and other hazardous materials.

Source: Google image.

3) Commercial 

Commercial facilities and buildings are yet another source of solid waste today. Commercial buildings and facilities in this case refer to hotels, markets, restaurants, go downs, stores and office buildings. Some of the solid wastes generated from these places include plastics, food wastes, metals, paper, glass, wood, cardboard materials, special wastes and other hazardous wastes.

Source: Google image.

4) Construction 

Construction sites and demolition sites also contribute to the solid waste problem. Construction sites include new construction sites for buildings and roads, road repair sites, building renovation sites and building demolition sites. Some of the solid wastes produced in these places include steel materials, concrete, wood, plastics, rubber, copper wires, dirt and glass.

Source: Google image.

SOLID WASTE MANAGEMENT IN MALAYSIA 

Source: Google image.

Solid waste is one of the three major environmental problems in Malaysia. It plays a significant role in the ability of Nature to sustain life within its capacity. Currently, over 23,000 tonnes of waste is produced each day in Malaysia. However, this amount is expected to rise to 30,000 tonnes by the year 2020. The amount of waste generated continues to increase due to the increasing population and development, and only less than 5% of the waste is being recycled. 

Despite the massive amount and complexity of waste produced, the standards of waste management in Malaysia are still poor. These include outdated and poor documentation of waste generation rates and its composition, inefficient storage and collection systems, disposal of municipal wastes with toxic and hazardous waste, indiscriminate disposal or dumping of wastes and inefficient utilization of disposal site space. 

Source: The Maze of Building Team

Waste management is a systematic interaction in various activities involving waste generation, storage, waste collection, waste transportation, waste treatment and waste disposal. 

1. Storage

Solid waste generated is stored temporarily by the waste generators near to its generation point. On a normal basis, the waste is packed using small or medium plastic bags before discharging into a big garbage bag. Solid waste is kept outside of the premises in a bin, until it is then collected by the waste collectors.

2. Collection & Transportation

This stage is the crucial part in solid waste management system. Local authorities may opt to outsource the service. Three concession companies have been appointed which are the Alam Flora Sdn. Bhd (central area), SMW Environment Sdn Bhd (southern area), and E-Idaman Sdn Bhd (northern area).

3. Treatment & Disposal

Solid wastes are collected by collector vehicles before being sent to transfer station for treatment and compaction. Segregation of the recyclables is practiced as an informal activity in Malaysia. Wastes are then compacted to reduce its size before disposal as all the landfill has its maximum capacity for wastes.  

SOLID WASTE DISPOSAL SYSTEM

When considering the system to be employed for the collection of refuse, there are three points to be considered:

• the nature of the waste (either it is perishable or not)
• the nature of the premises that generate the waste (industrial, commercial or domestic)
• the location of the point of generation (height from ground, and position of the floor layout)

1. Simple Storage & direct collection

Bins

The most traditional system to collect the waste disposal.

(souces: https://www.homedepot.com)

Self-standing plastic sacks

This system is considerable as a hygienic way to collect the solid waste disposal.

(sources: TheBinCompany)

Paladin

Large capacity which consists collecting vehicles to ease the workers while collecting the waste from it.

(sources: http://our.haringey.gov.uk/reports)

Refuse Chute

It is constructed of a large diameter pipes and always use in the buildings which is more than 4 storeys.

(sources: Waste Management Chute System)

2. On site treatment of waste before collection

Volume reduction systems: A. Waste compaction

Garbage compactors and waste collection vehicles compress waste so that more of it can be stored in the same space.

(sources: ecowaste)

Volume reduction systems: B. Shredding of waste

Shredding of waste is common practice across almost all areas of the waste industry. Far from focusing simply on paper, shredding is a disposal technique for everything from agricultural to household waste and electrical to industrial waste.

(Sources: https://waste-management-world.com/a/italian-collaboration-leads-to-waste-shredder-sales-for-untha)

Volume of reduction system: C. Baled waste

Baled waste means converting the wastes into a more stable form or into a different physical state by chemical, thermal or biological means.

(Sources: http://recyclingequipment.com/equipment-recycling-machine/balers/auto-tie-baler/american-baler-dc-automatic-tie-horizontal-balers-for-sale)

Incineration

Incinerating is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration which coupled with high temperature waste treatments are categorized as thermal treatment.

(Sources: http://www.newgreenrecycling.com/home/why-incinerating-trash-can-be-a-waste-of-resources)

3. Pipeline collection system

Food waste disposal grinders

The grinder is fitted under the sink, reduces the food waste to fine particles which can carried away by the wastewater system. The grinder works with an amount of tap water to pulverize the materials.

(Sources: http://spmgroup.info/kitchen-sink-grinder)

Pneumatic waste collection system

Pneumatic waste system is also known as Automated Collection System (AWCS), transports refuse by vacuum in underground pipes offering a solution to match the evolutionary process of moving infrastructure below the ground.

(Sources: https://www.youtube.com/watch?v=WpksoxFHg5

METHODS OF DISPOSAL IN MALAYSIA

1. Open dumps landfills

Source: Stuff You Should Know

There are different level of sanitary landfill system, namely level 0 (Open Dumpsite), Level 1 (Controlled tipping), Level 2 ( Sanitary Landfill with Daily Cover), Level 3 (Sanitary Landfill with Leachate Recirculation System), and Level 4 (Sanitary Landfill with Leachate Treatment Facilities and more). However, sadly in Malaysia, in Johor state alone, only 2 out of 14 landfill dumpsites are sanitary landfills. 

2. Composting

Source: Quick Wasters Clearance

Composting of waste is an aerobic method of decomposing solid wastes, involving the decomposition of organic waste into humus known as compost. Industrial composting systems are increasingly being installed as a waste management alternative to landfills, along with other advanced waste processing systems.

3. Incineration

Source: Toronto Environmental Alliance

In countries where the land is scarce and the solid waste generation rate is increasing with an accelerating rate, incineration offers a solution to deal with the solid waste problem. Current locations of our incinerators in Malaysia includes Pulau Pangkor, Pulau Langkawi, Pulau Tioman, Cameran Highlands and Labuan. 

4. Potential waste to energy system

Source: Toronto Sustainability Speaker Series

Currently, Malaysia as a developing country still working towards the direction of achieving potential waste to energy system and making our effort to produce zero waste. 

At present, landfill is the main method of waste disposal (80% usage) in Malaysia. This method expected to fall down to 65% in 2020. In European countries, only those that cannot be recycled will be taken to landfill but for Asian countries (Malaysia , Vietnam , Thailand , Indonesia) all types of waste are disposed in landfill without any pre-treatment. (Ismail Manaf , 2013) 

Source: Agamuthu, 2009

    

Following are some of the issues and problems in solid waste management in Malaysia:

• Lack of adequate and efficient waste disposal facilities in or outside industrial areas;
• The total amount of hazardous and toxic waste generated by industries in Malaysia is estimated at 417,000 metric tonnes per year and it is expected to increase between 8% - 9% per year;
• monitoring and evaluation unit at their facilities for transparency and optimum results.
• Exposures of man and environment to the dangers of radioactive materials;
• Disposal undertaken without proper control and supervision can cause long-term negative impact;
• Illegal and unregulated factories that produce hazardous materials add more pressure to the pollution problem in urban areas;
• Lack of comprehensive guidelines on the disposal of scheduled and hazardous wastes.

These are the actions taken for more efficient solid waste management in Malaysia

• Monitoring and evaluation unit at solid waste management’s contracting companies should avoid conflict interest at their facilities
• Recycling is one the most desired and effective methods for solid waste disposal. A minimum of 10% should be targeted in the near future
• More awareness on solid waste management should be created to individual citizens and organisations so that everyone avoids wastes thereby reducing solid waste
• Systematic safety and health procedures should be applied specially on worker and rag pickers
• Appropriate statistical models should be used to measure the effectiveness of solid waste disposal on soil ground water and air
• Further studies on the collection and disposal of solid waste should be carried out in order to smooth out and integrate the solid waste management activities

So yea! That's all for this week, we'll be assuming sharing or next topics in two weeks' time!

Enjoy your holidays!

SANITARY SYSTEM

SANITARY SEWER SYSTEM

Figure 1: Flushing water closet (Source: What's up Fagans?)

The most contact we have with the sanitary system is simply flushing a water closet or pulling out a plug in a wash hand basin. However, we tend to always forget the existence of sanitary system in our buildings despite its importance to ensure that the environment we live in is safe and clean.

Figure 2: Sanitary Sewer System in a building (Source: DS Plumbing)

A sanitary sewer system refers to a complex network of pipes and pumps that is both provided in a building and buried beneath the street. This system is designed to collect and convey the wastewater or waterborne wastes out of the buildings and transport them from homes, shop houses or industries to the treatment facility. Don’t get confused with the following terminology!

• Sewer – a pipe or conduct for carrying sewage and other liquid waste.
• Sewerage – the works required to collect, treat and dispose sewage including the sewer system, pumping stations, and treatment work.
• Sewage – any liquid-borne waste (include liquids containing chemicals in solution, ground surface or storm water) is admitted into or passes through sewers.
• Sewage disposal system – a system for disposing of sewage, by means of a septic tank, or by mechanical treatment, which is designed to serve a single building or a group of buildings independently of the public sewer.

Figure 3: Sewer, Sewerage, Sewage

The purposes of sanitary and sewer systems are as follow:

• ·       To maintain clean and healthy conditions within a building.
• ·       To collect and dispose waste materials as fast and early as possible in a systematic way.
• ·       To avoid the entry of foul gases from the sewer of the septic tank.

There are two types of drainage system for sanitary and sewerage, namely the drainage system above ground and below ground.

ABOVE GROUND DRAINAGE

*A stack is the main vertical pipe that carries away discharge from water closets and urinals (soil water) or other clear water waste from equipment and non- sanitary fixtures (waste stack). The design of the stack depending on the volume of the sanitary fittings the rate of flow out of the drain into the stack, the diameter of the stack and the type of stack fitting.

Discharge pipes consist of single stack, branching and vent pipe. Single stack pipe is installed vertically to ease the discharge of soil and waste water. Branching pipe is connected to sanitary fitting with single stack pipe. Vent pipe releases compressed air.

There are 3 types of above ground drainage systems employed in the installation of soil and waste water discharge pipes:

1. Single stack system

System where only single pipe (can act as BOTH soil pipe and ventilation pipe) is required. Stack is located inside or outside the external wall of the property and terminates roof eaves level with a cage or perforated cover. Discharge in branching pipes from sanitary fittings are transferred to single stack pipe where it is then drained into the drainage pipe. There is no ventilation pipe needed because stack itself is large enough to prevent pressure fluctuation (it itself can function as a vent pipe). This system is so far the most commonly used in domestic buildings as it is easy to install besides its significance in reducing the cost of soil and waste systems. However, the sanitary fitting should be installed near the single stack pipe separately to reduce the length of the branching pipe and minimize the sound of the flow in the pipe.

Figure 4: Single stack system (Source: Inazarina Ady- Sanitary Pipework)

2. One pipe system @ Single pipe system

One pipe system means 2 stacks in a system. In this system, all soil water (excreta) and waste water (sullage) discharge into one common pipe instead of using two separate pipes, meaning that all sanitary fittings are connected to only one pipe. Ventilation pipes are fitted to each discharge branch (but not each appliance) near to the bend to remove compressed air at this point.  All branch ventilating pipes drain into one main ventilating pipe. This system largely replaces the two pipes system and let itself very well to the use in multi-storey developments. It is far more economical than the two pipes system for a large number of sanitary appliances in ranges. All sanitary fittings should be installed near a main pipe.

Figure 5: Single pipe system (Source: Inazarina Ady- Sanitary Pipework)

3. Two pipes system @ Dual pipe system

This is the oldest system of plumbing. Two sets of vertical pipes, one for soil water as soil pipe (soil discharge pipe) and another for waste water as waste pipes (waste discharge pipe). The soil pipes receive the discharges from soil appliance (soil water from WC and urinals) and deliver it direct to the underground drainage system; The waste pipes collect the wastewater from shower tray, WB and bathtub then convey this to the ground level where it is delivered above the water seal in a trapped gully connected to the drainage system. The soil water and waste did not combine until reach the below ground drainage. The soil pipes as well as the waste pipes are separately ventilated (individual ventilation system), by providing, separate vent pipe or anti-siphon age pipe. It has 4 stacks in a system. This system is suitable when the waste fitting is located far from the waste water fitting.

Figure 6: Dual pipe system (Source: Inazarina Ady- Sanitary Pipework)

BELOW GROUND DRAINAGE

1. Separate drainage system

System in which the waste water and storm water are always kept separated. Two separate sets of sewers are installed, one for collection and conveyance of sanitary sewage and other for storm water. When a separate system is used, the sewerage treatment plant will not get overloaded in periods of wet weather. It is comparatively favoured by the local authorities as the installation and running costs of the sewerage treatment plant can be reduced.

Figure 7: Separate drainage system (Source: Winnipeg)

Advantages of separate drainage system:

• ·       Size of sewers required is smaller
• ·       Since the waste water and the storm water flows in separate pipes, the quantity of sewage to be treated is lesser.
• ·       As the sewers are smaller in sections, they can be easily ventilated.
• ·       During disposal, if the sewage is to be pumped, the separate system is cheaper.
• ·       Rain water can be discharged to the streams without any treatment.

Disadvantages of separate drainage system:

• ·       Since the sewers are of smaller size, it’s more difficult to clean them.
• ·       They are likely to get chocked.
• ·       Initial cost is high, when two separate set are used.
• ·       Maintenance cost of the sewers is also high.
• ·    Generally self-cleaning velocity is not available due to small quantity of sewage therefore, flushing is required at various point.

 2.  Combined drainage system

System in which some or all the storm water joins the waste water drainage system. This means that both surface water and foul water will be discharged into the sewerage treatment plant. In order to avoid the treatment plant being overloaded, it may be possibility to extract some foul water at various points in the drainage network. This can be achieved if the surface water is less dense than the foul water and tends to flow on the top in a drain. A separating device can be used to diver the surface water into a storm water channel or drain.

Figure 8: Combined drainage system (Source: Winnipeg)

Advantages of combined drainage system:

• ·       Both domestic sewage and storm water are carried in a single sewer, so construction cost is minimized.
• ·       The strength of domestic sewage is reduced because of the dilution of storm water.
• ·       The sewers are of larger size, therefore the chances of their chocking are rare, it is easy to clean them.

Disadvantages of combined drainage system

• ·       Initial cost is high due to the larger dimensions of sewers.
• ·       Due to larger dimensions of sewers, handling and transportation is comparatively harder.
• ·       Due to inclusion of storm water, the load on treatment plant increases.
• ·       During heavy rain the sewer may be overflow and may thus create unhygienic conditions.
• ·       It is uneconomical if the whole sewage is to be disposed by pumping.

PIPE GRADIENT

• All above ground and below ground horizontal drainage pipes should be laid to an adequate gradient.
• The fall in a pipe may be defined as the vertical amount by which the pipe drops over a distance.
• Gradient = Fall / Distance
• Gradients from 1 in 40 to 1 in 110 will normally give adequate flow velocities.
• A gradient of 1 in 80 is suitable for commencing calculations for pipe schemes. 
• If the gradient is not less than 1 in 40, then the pipe could block, as the liquidated waste flow out too fast leaving the solids slow down and become stranded.

Figure 9: Fall & Gradient in drainage pipe (Source: Drainage Consultant Ltd)

TRAP

Figure 10: Typical trap (Source: Wikipedia)

All appliances connected to the drainage system must have a trap on them to prevent the entry and penetration of any foul gases into the buildings. Basically, the materials used for trap are plastics and metals. There are different types and shapes of the traps matching their own functions.

Figure 11: Types of trap according to shapes (Source: Pelagan)

SANITARY FITTINGS

Various types of pipe fittings are available in plumbing systems for different purposes and functions. A pipe fitting is used in plumbing system to join multiple pipes of same size or different sizes, to regulate the flow or to measure the flow. They are made up of different materials like copper, iron, brass, PVC etc.

1. Shower   
      

                                                         

Figure 12: Shower (Source: Google) 2. Basins Figure 13: Basin (Source: Google) 3. Bath tub

Figure 14: Bath tub (Source: Google)

4. Urinal Bowl

Figure 15: Urinal Bowl (Google)

5. Water closets (WC) 

Figure 16; Water closets (Source: Saudi Ceramics)

6. Bidet

Figure 17: Bidet (Source: Groupon)

7. Sinks

Figure 18: Sinks (Source: The Home Depot)                                                      

CASE BUILDING INPUTS

Our case building chosen is the Pusat Kesihatan Universiti Teknology Malaysia (PKU, UTM). The following are the examples of the sanitary appliances found in this case building.

Figure 19 : Water basin (Source: PKU, UTM)

Figure 20: Water Closet (Source: PKU, UTM)

Figure 21: Water Hose (Source: PKU, UTM)

ESSENTIAL OF GOOD APPLIANCES

• Cleanliness- strong, smooth, non-absorbent and non-corroding surfaces, largely self-cleansing and permitting easy cleaning.
• Simplicity- for design and construction.
• Accessibility- can function for many work
•  Durability- with standing hard wear
• Economical- in terms of initial and maintenance cost
• Appearance – satisfactory

COMPARISON

Difference Between WATER SUPPLY SYSTEM and SANITARY SEWER SYSTEM

Water Supply System	Sanitary Sewer System
Treated water is transferred using water pipes	To drain the water that has been used
Serves to delivers clean water supply	To collect and remove waste matter systematically
To access all water supply at place who need clean water especially in house, hospital, school and etc.	To avoid the entry of foul gases from the sewer or the septic tank

SO... That's all about sanitary sewer system. Next week we'll be discussing more on SOLID REFUSE DISPOSAL!
SEE YOU NEXT WEEK!

Figure 12: Shower (Source: Google)

2. Basins

Figure 13: Basin (Source: Google)

3. Bath tub

Water Supply System

Sanitary Sewer System

Treated water is transferred using water pipes

To drain the water that has been used

Serves to delivers clean water supply

To collect and remove waste matter systematically

 To access all water supply at place who need clean water especially in house, hospital, school and etc.

To avoid the entry of foul gases from the sewer or the septic tank