WASTE MANAGEMENT

What is waste? How hotels are damaging the environment?

From plastic straws to disposable coffee cups, the environmental concerns of the hospitality industry have made headlines in recent months, and for all the wrong reasons. Hotels continue to damage the environment courtesy of the usual culprits such as unnecessary packaging and energy usage as well as the waste that comes from the endless paper receipts, registration cards and invoices that reception desks keep churning out.

Waste management is the organization of efforts seeking to reduce environmental impact and waste.

Why occurs waste?

hotels have to pay for the removal of their waste. Because hotel guests can create up to 2 pounds of waste a night, paying for waste removal can get expensive.

Once the hotels collect all of their waste, they need a place to put it. This results in filling up landfills, which is not only detrimental to the environment, but expensive. As the amount of space available becomes smaller, landfills begin to charge more for the removal of waste, which, again, contributes to the high costs of waste removal.

Pollution is another consideration. The landfills give off carbon dioxide and methane gases that pollute the air. And, the fuel needed to transfer the waste to the landfills also increases greenhouse gas emissions. Lastly, waste can soak into the soil and lead to contamination of water.

TYPES OF WASTE:

  • Solid waste
  • Liquid waste

 

SOLID WASTE:

Solid waste refers to the range of garbage materials—arising from animal and human activities—that are discarded as unwanted and useless. … As such, landfills are typically classified as sanitary, municipal, construction and demolition, or industrial waste sites.

Solid-waste management, the collecting, treating, and disposing of solid material that is discarded because it has served its purpose or is no longer useful. Improper disposal of municipal solid waste can create unsanitary conditions, and these conditions in turn can lead to pollution of the environment and to outbreaks of vector-borne disease—that is, diseases spread by rodents and insects. The tasks of solid-waste management present complex technical challenges. They also pose a wide variety of administrative, economic, and social problems that must be managed and solved.

 

Types of Solid Wastes:

  • Household Hazardous Waste (HHW) – Proper Management of Household Hazardous Waste.
  • Construction and Demolition Debris – Information on Construction and Demolition Debris.
  • Industrial/Commercial Waste – Information of Industrial/Commercial Waste.

Another type of solid waste, perhaps the fastest-growing component in many developed countries, is electronic waste, or e-waste, which includes discarded computer equipment, televisions, telephones, and a variety of other electronic devices. Concern over this type of waste is escalating. Lead, mercury, and cadmium are among the materials of concern in electronic devices, and governmental policies may be required to regulate their recycling and disposal.

 

SOLID-WASTE TREATMENT AND DISPOSAL

1). Incineration

Furnace operation

Burning is a very effective method of reducing the volume and weight of solid waste, though it is a source of greenhouse gas emissions. In modern incinerators the waste is burned inside a properly designed furnace under very carefully controlled conditions. The combustible portion of the waste combines with oxygen, releasing mostly carbon dioxide, water vapour, and heat. Incineration can reduce the volume of uncompacted waste by more than 90 percent, leaving an inert residue of ash, glass, metal, and other solid materials called bottom ash. The gaseous by-products of incomplete combustion, along with finely divided particulate material called fly ash, are carried along in the incinerator airstream. Fly ash includes cinders, dust, and soot. In order to remove fly ash and gaseous by-products before they are exhausted into the atmosphere, modern incinerators must be equipped with extensive emission control devices. Such devices include fabric baghouse filters, acid gas scrubbers, and electrostatic precipitators. (See also air pollution control.) Bottom ash and fly ash are usually combined and disposed of in a landfill. If the ash is found to contain toxic metals, it must be managed as a hazardous waste.

Municipal solid-waste incinerators are designed to receive and burn a continuous supply of refuse. A deep refuse storage pit, or tipping area, provides enough space for about one day of waste storage. The refuse is lifted from the pit by a crane equipped with a bucket or grapple device. It is then deposited into a hopper and chute above the furnace and released onto a charging grate or stoker.

2). Energy recovery

The energy value of refuse can be as much as one-third that of coal, depending on the paper content, and the heat given off during incineration can be recovered by the use of a refractory-lined furnace coupled to a boiler. Boilers convert the heat of combustion into steam or hot water, thus allowing the energy content of the refuse to be recycled. Incinerators that recycle heat energy in this way are called waste-to-energy plants. Instead of a separate furnace and boiler, a water-tube wall furnace may also be used for energy recovery. Such a furnace is lined with vertical steel tubes spaced closely enough to form continuous sections of wall. The walls are insulated on the outside in order to reduce heat loss. Water circulating through the tubes absorbs heat to produce steam, and it also helps to control combustion temperatures without the need for excessive air, thus lowering air pollution control costs.

Waste-to-energy plants operate as either mass burn or refuse-derived fuel systems. A mass burn system uses all the refuse, without prior treatment or preparation. A refuse-derived fuel system separates combustible wastes from noncombustibles such as glass and metal before burning. If a turbine is installed at the plant, both steam and electricity can be produced in a process called cogeneration.

Waste-to-energy systems are more expensive to build and operate than plain incinerators because of the need for special equipment and controls, highly skilled technical personnel, and auxiliary fuel systems. On the other hand, the sale of generated steam or electricity offsets much of the extra cost, and recovery of heat energy from refuse is a viable solid-waste management option from both an engineering and an economic point of view. About 80 percent of municipal refuse incinerators in the United States are waste-to-energy facilities.

3). Composting

Another method of treating municipal solid waste is composting, a biological process in which the organic portion of refuse is allowed to decompose under carefully controlled conditions. Microbes metabolize the organic waste material and reduce its volume by as much as 50 percent. The stabilized product is called compost or humus. It resembles potting soil in texture and odour and may be used as a soil conditioner or mulch.

Composting offers a method of processing and recycling both garbage and sewage sludge in one operation. As more stringent environmental rules and siting constraints limit the use of solid-waste incineration and landfill options, the application of composting is likely to increase. The steps involved in the process include sorting and separating, size reduction, and digestion of the refuse.

 

·       Sorting and shredding

The decomposable materials in refuse are isolated from glass, metal, and other inorganic items through sorting and separating operations. These are carried out mechanically, using differences in such physical characteristics of the refuse as size, density, and magnetic properties. Shredding or pulverizing reduces the size of the waste articles, resulting in a uniform mass of material. It is accomplished with hammer mills and rotary shredders.

·       Digesting and processing

Pulverized waste is ready for composting either by the open windrow method or in an enclosed mechanical facility. Windrows are long, low mounds of refuse. They are turned or mixed every few days to provide air for the microbes digesting the organics. Depending on moisture conditions, it may take five to eight weeks for complete digestion of the waste. Because of the metabolic action of aerobic bacteria, temperatures in an active compost pile reach about 65 °C (150 °F), killing pathogenic organisms that may be in the waste material.

4). Sanitary landfill

Land disposal is the most common management strategy for municipal solid waste. Refuse can be safely deposited in a sanitary landfill, a disposal site that is carefully selected, designed, constructed, and operated to protect the environment and public health. One of the most important factors relating to landfilling is that the buried waste never comes in contact with surface water or groundwater. Engineering design requirements include a minimum distance between the bottom of the landfill and the seasonally high groundwater table. Most new landfills are required to have an impermeable liner or barrier at the bottom, as well as a system of groundwater-monitoring wells. Completed landfill sections must be capped with an impermeable cover to keep precipitation or surface runoff away from the buried waste. Bottom and cap liners may be made of flexible plastic membranes, layers of clay soil, or a combination of both.

LIQUID WASTE:

Waste water or sewage that are generated from a home or community including toilet, bath, laundry, lavatory, and kitchen- sink wastes, and surface run off may be classified into four.

  • Sanitary sewage
  • Industrial sewage
  • Storm sewage or
  • Mixed sewage (a mixture of all)

Sanitary sewage also called domestic sewage contains human wastes and wash water from homes, public buildings or commercial and industrial establishments.

Domestic sewage/liquid waste here is meant waste from kitchen, barn, bathroom, laundry, etc., which do not contain human excreta or sewage Industrial sewage is the used water from manufacturing processes, usually carrying a variety of chemical compounds. Storm sewage, or storm water, is the surface run off caused by rainfall, it carries organics, suspended and dissolved solids, and other substances picked up as it travels over the ground.

Points to be consider before selecting one particular sewage disposal technique

There is no single individual sewage disposal technique that can be universally applied under all conditions. However, the selection of a particular method will depend upon the following major factors:

  • The nature of soil formation and stability of the locality
  • The availability of adequate land for sewage disposal
  • The quantity of sewage to be disposed of
  • The degree of sewage treatment to be achieved
  • The presence of well water, and whether it is used as the source of the water supply
  • The level of the water table of the ground water
  • The proximity of the disposal site to surface water sources
  • The relative cost of the disposal technology

 

 

SEWAGE/WASTE WATER TREATMENT

WHY TREATMENT?

Before discharging wastewater back into the environment and the natural hydrologic cycle, it is necessary to provide some degree of treatment in order to protect public health and environmental quality. The basic purposes of sewage treatment are:

  • To destroy pathogenic microorganisms
  • To remove most suspended and
  • To remove dissolved biodegradable organic materials.

Treatment methods

Treatment methods are grouped into three general categories:

  • Primary treatment: Screening, grit removal, and sedimentation (settling)
  • Secondary or biological treatment: biological processes and additional settling.
  • Tertiary or advanced treatment: not all sewage treatment plant requires tertiary (advanced) treatment.

Importance of Waste Management in Hotels

Waste management in hotels is important as it is getting increasingly difficult to dispose of waste. Moreover, it makes good sense to the business. When supplies are judiciously used it saves a lot of money on raw materials. You can generate additional income by selling old resources and by reusing and recycling useful materials. Therefore, you end up decreasing the cost of waste disposal as the amount of waste produced is decreased.

It can start with:

  • Using refillable dispensers for soaps, shampoos, and conditioners
  • Using washable cloth products and dishware instead of disposable ones
  • Using water filters instead of plastic bottles
  • Reducing and reusing supplies packaging materials
  • Reducing the number of paper products
  • Switching to LED lights

RECYCLING:

Separating, recovering, and reusing components of solid waste that may still have economic value is called recycling. One type of recycling is the recovery and reuse of heat energy, a practice discussed separately in 

incineration. Composting can also be considered a recycling process, since it reclaims the organic parts of solid waste for reuse as mulch or soil conditioner. Still other waste materials have potential for reuse.

·       Separation

Before any material can be recycled, it must be separated from the raw waste and sorted. Separation can be accomplished at the source of the waste or at a central processing facility. Source separation, also called curbside separation, is done by individual citizens who collect newspapers, bottles, cans, and garbage separately and place them at the curb for collection.

·       Reuse

Recovered broken glass can be crushed and used in asphalt pavement. Colour-sorted glass is crushed and sold to glass manufacturers as cullet, an essential ingredient in glassmaking. Steel cans are baled and shipped to steel mills as scrap, and aluminum is baled or compacted for reuse by smelters. Aluminum is one of the smallest components of municipal solid waste, but it has the highest value as a recyclable material. Recycling of plastic is a challenge, mostly because of the many different polymeric materials used in its production. Mixed thermoplastics can be used only to make lower-quality products, such as “plastic lumber.”