Subject :	Environmental Studies
Top :	A Critical Evaluation, Analysis and Synthesis of Existing Knowledge Concerning Commercial Waste Storage in UK

Introduction :

Nowadays, it is very clear that the resources of the world are finite and in order to maintain a stable economic growth and standard of living in the future, we must use resources judiciously and sparingly and evolve technologies for cycling wastes and residues thereby save both resources and energy.

Waste is a part of human activity from time immemorial. The earlier times, the population was small, requirements were few and resources were abundant, and the generation "waste was such that it got naturally recycled being mostly biodegradable. However, after the industrial revolution, particularly during the recent decades the resources have been used recklessly and there has been generation of very diverse type of wastes which are often both non biodegradable and hazardous. An ecosystem cannot absorb them in the natural course. The heaping up of such wastes particularly chemicals to, which ecosystem has never been used to poses serious environmental problems.

In fact, nothing has been really wasted and much of the waste is "resource in wrong place". Today's waste is considered as tomorrow's raw material and waste is wealth and trash is cash". World evolved towards a "Throw away society" when population was less, energy was inexpensive, and raw material was plenty. There global realization of the fact that single use of metals, ass and paper would lead to scarcity of such materials as their feed stocks would get exhausted. (Helen Lingard, 1998)

Literature Review :

Man is causing environmental degradation through pollution. He is polluting the mother earth by three methods. Firstly, man is polluting the air by burning millions of tones of hydrocarbon fuels. The poisonous gases coming out of the vehicles, plants and factories, generators etc are making life a misery for our children. London is one among the largest polluted cities in the world. Environmental pollution has brought diseases like TB, lung cancer, eye defects, Asthma, infections, bronchitis etc for adults and children alike. (Githeko AK et al.2000)

Secondly, man is polluting water (underground as well water of oceans) by mixing industrial and household waste materials and chemicals in it. Water drilled from beneath the earth is also polluted beyond repair; this phenomenon is more prominent in the industrial townships and big cities. We can always read about a few incidents of spillage of crude oil in the high seas, which pose a major threat to the environment on the high seas as well as their aquatic lives. Non degradable waste products of technical devises make the situation worst.

Finally, man is polluting the soil by mixing pesticides, fertilizers and toxic chemicals for agricultural production into the same. The soil is becoming toxic because of the lust of man for more money. Industrial wastes are being dumped in the rural areas (where the chemical industries are operating) and the crops produced in the immediate vicinity of the factories and processing units are harmful for human consumption.

Here we are going to discuss some proper ways of waste storage and its recycling in an effective manner.

The reasons for waste utilization are economic, environmental, resource conservation and employment generation; with the constraints of resources cannot afford to call any material as waste. However, it developed countries like USA, Japan and UK that are in forefront of waste utilization, (So as to encourage industry to take to waste utilization, Ire need to be fiscal incentives for using non-conventional raw materials and penalties for not recycling materials. Recycling of wastes is economically advantageous. (Helen Lingard, Guinevere Gilbert, Peter Graham, 2001)

Saves Energy :

Discarding materials after a single use means also wastage of energy. For instance, energy saving in recycling Aluminium in comparison to bauxite, the original ore, 96%, these figures for copper are 90% and for steel from scrap 47%. Glass when recycled saves 8% energy but re-use, of glass containers saves far more. Recycling of waste paper reduces the consumption of energy by 23%. An added advantage of recycling with paper is that it will reduce considerably the per-capita pressure on the annual growth of forests. According to an estimate, a ton of recycled paper saves 4 cubic meters of timber and 900 cubic meters of water, besides reducing the pollution pressure on environment. Thus, low-waste or no-waste technology ensures Mm* conservation of both, natural resources and environmental quality.

While in countries like U.K, resource recovery from garbage has been a high technology area, in many cities developing countries garbage is sorted out by hand for re use as tin, glass, paper, plastics, rags and bones which genera new materials and in the process also generate employment.

Energy from garbage :

Domestic, agricultural and industrial rubbish can be utilized to produce power and heat. In fact in Europe currently the watchword is "Rubbish is the fuel of future” and refuse derived fuel is becoming common. Until now, Relatively cheap fossil fuels and inexpensive land fill sites have kept the concept of using rubbish for fuel at bay. But now, the shortage of rubbish dumps near cities and the spiraling cost of transporting domestic refuse to land fill sites out of town have focused attention on waste-to- energy plants. (Richard C. Hill, Paul A. Bowen, 1997)Waste-to-energy incinerators have been traditionally generating steam for industrial use in different parts of the world. The modern waste-to-energy plants now in operation in the UK generate both power and heat.

In -this waste utilization technology for generation of electricity, the municipal solid wastes or garbage is processed into a refuse derived fuel by removing the ferrous metal and non- combustible materials. The combustible materials are shredded to a size suitable for burning. The Processed fuel is burnt in the boilers to produce steam which drives the turbo-generator to produce, electricity. The electricity is distributed to the consumers from a switchyard. An air quality control equipment removes the fly-ash from the flue-gas before the gas is emptied through he stack. The non-combustible processing residue as well as the ash resulting from burning process are collected and juried in special landfill sites designated for hazardous materials. The ash may contain dangerous materials such toxic metals.

i. Biogas Generation :

Bio wastes or agro wastes can be used as biomass for making biogas.

ii. Pyrolysis :

The garbage can be gasified at temperature 500 to 1000°C in the absence of oxygen. This process, called Pyrolysis, reduces the waste to gases comprising hydrogen, methane, carbon monoxide and carbon dioxide; and liquids containing organic compounds; and carbonaceous char. Some of the gas can be burnt to run the reactor itself. The surplus gas and liquids are available as fuel products. The solid char can be processed to, yield various grades of useful carbon. (Taylor and Francis Journals, vol. 24(3))

iii. Fuel pellets :

This is another method of utilizing garbage as fuel, in the UK, the technology needed is simple. The garbage is passed at various stages over metal meshes to sieve out soil particles. The shredded garbage is passed through a kiln to dry up the moisture with hot air circulation. Iron can be separated using magnets while non-magnetic metals, glass ceramics, etc are removed by sucking the garbage vertically upwards in a strong stream of air. Mixing agricultural wastes like coffee husk or pea-nut shell and sawdust into processed garbage will increase its calorific value. The mixture is then made into pellets or bricks which can be used as a fuel for domestic and industrial use.( Vivian Tam & C. M. Tam & L. Y. Shen & S. X. Zeng & C. M. Ho, 2006)

iv. Ethanol :

Cellulose in garbage can be converted into glucose enzymatically or through chemical hydrolysis. The glucose can be fermented to produce ethanol. Other useful chemicals like acetone, organic acids, glycerol etc., can also be extracted through the hydrolysis of garbage.

v. Compost making :

Compost making is a low-cost but efficient and easy method of utilization of organic wastes. The term compost means a prepared mixture of rotted organic matters which can be used as good manure; Composting is essentially microbial decomposition of rotted organic residue. The collection of rural or urban organic waste and dumping of it in a pit of a reasonable size is the preliminary process for making compost. In the preparation of rural composts any farm wastes, weeds, cattle dung and urine, litters, tree leaves night soil and slaughter-house waste are used. In urban composts the main ingredients are night soil, street and house sweepings.

In UK, Compost making has considerable importance in their rural economy. It helps the farmers to reduce the use chemical fertilizers, a very costly input having undesirable side effects. It also helps to keep the rural surrounds clean.

Sewage Treatment :

It is customary to consider the treatment of sewage in 3 stages: - Primary, Secondary and Tertiary.

i. Primary Treatment :

It is a mechanical process which simply removes solids. Metal screens stop large solids; sands and small stones kettle in a grit chamber from which the water passes into sedimentation tank, where its rate of flow has been sharply reduced and small particles settle as sludge. Scum at the top is removed. The quantities removed at this stage can be huge.

ii. Secondary Treatment :

It is essentially a biological process which reduces most of the organic matter. The secondary treatment is carried out by an engineered biological system in which micro organisms decompose organic matter in the same manner as Occurs naturally in soils and sediments. One hazard that effects the functioning of secondary treatment is that if the sewage contains toxic materials that will kill decomposer Bacteria, and wreck the operation for weeks. The most common design is the activated sludge system which requires electric pumps to aerate and circulate incoming Sew age. Another system is the trickling filter system in which the primary treatment effluent moves by gravity over stones or racks of plastic surfaces that create an aerated surface resembling the rapid flow of water in a natural Stream. Secondary treatment produces a sludge that must be disposed of. The sludge is derived and disinfected and is be used to make fertilizer. It is very rampant in UK.

Oxidation or Waste stabilization ponds

In terms of construction and maintenance costs the cheapest waste treatment systems are oxidation or waste stabilization ponds. These are shallow bodies of water (120 150 cm deep) constructed so as to expose a maximum surface area to the air. Wastes are pumped into the bottom the pond, and algae which grow vigorously at the upper lighted zone, provide the aeration. Use of a semi natural design of this sort requires a large amount of space (about 0.8 ha for the treatment of household wastes of 100 people) and judicious maintenance. Adding devices for mechanical aeration increase the per hectare treatment capacity. They are also effective in the partial treatment or industrial wastes from paper of textile mills, food processing plants, oil refineries, and so on.

It should be emphasized that-the waste stabilization pond is really a conversion system, not a complete treatment system. Here unsanitary organic matter is converted into sanitary algal material and nutrients. The algae can b« harvested for animal food. The pond effluent can be used for aquaculture and irrigation. In some areas the water from -primary or secondary treatment, which contain nitrated and phosphates, is channeled on to land where theft constituents will act as fertilizers and the water will irrigated the crops. Growth of crops, pastures and young plantation has been enhanced by spray irrigation of waste nutrients .However, past experience with all kinds of irrigation that gradual accumulation of nutrients or salts will occur with high input rates leading to deterioration of soil and adjacent water bodies. Therefore, regular monitoring of in environment is essential in areas where such kind fl sewage irrigation is practiced.

Tertiary Treatment

The effluent from even relatively complete second treatment is highly polluting in terms of eutrophication. Still is having most of the original phosphates and nitrates. Also it many contain persistent insecticides, and herbicides, disease causing bacteria and viruses, and a times industrial organic compounds. Thus, this water unfit for direct human use. (Richard C. Hill, Paul A. Bowen, 1997)

A wide variety of methods are used in advanced in the UK (tertiary treatment and they may-be introduced at any stage the total treatment process, not necessarily only after conventional primary and secondary treatment. Their primary and may be more complete removal of phosphates and dissolved organic compounds. The various methods available at present include Chemical coagulation and filtration, carbon adsorption, chemical oxidation, ion exchange, electro dialysis and reverse osmosis.

References :

1. Helen Lingard, Steve Rowlinson, 1998. "Behaviour-based safety management in Hong Kong's construction industry: the results of a field study," Construction Management & Economics, Taylor and Francis Journals, vol. 16(4), pages 481-488, July. [Downloadable!] (restricted)
2. Richard C. Hill, Paul A. Bowen, 1997. "Sustainable construction: principles and a framework for attainment," Construction Management & Economics, Taylor and Francis Journals, vol. 15(3), pages 223-239, May. [Downloadable!] (restricted)
3. Vivian Tam & C. M. Tam & L. Y. Shen & S. X. Zeng & C. M. Ho, 2006. "Environmental performance assessment: perceptions of project managers on the relationship between operational and environmental performance indicators,"
4. Construction Management & Economics, Taylor and Francis Journals, vol. 24(3), pages 287-299, March. (restricted)
5. Helen Lingard, Guinevere Gilbert, Peter Graham, 2001. "Improving solid waste reduction and recycling performance using goal setting and feedback," Construction Management & Economics, Taylor and Francis Journals, vol. 19(8), pages 809-817, December. (restricted) Tanser FC, Sharp B, le Sueur D. Pot¬tential effect of climate change on malaria transmission in Africa. Lancet, 2003, 362:1792–8.
6. Thomas CJ, Davies G, Dunn CE Mixed picture for changes in stable malaria distribution with future climate in Africa Trends in parasitology, 2004, 20:216–20.
7. Githeko AK et al. Climate change and vector-borne diseases: a regional analysis. Bulletin of the World Health Organization, 2000, 78:1136–47.
8. Adam I et al. In the Sudan: chloroquine resistance is worsening and quinine resistance is emerging. Sudan medical journal, 2001, 39:5–11.
9. Hamad AA et al. A marked seasonality of malaria transmission in two rural sites in eastern Sudan Acta tropica, 2002, 83:71–82.
10. Himeidan YE et al. Epidemiology of malaria in an irrigated area in the eastern Sudan. Eastern Mediterranean health journal, 2005, 11:499–504.
11. Bi P et al. Climatic variables and transmission of malaria: a 12-year data analysis in Shuchen County, China. Public health reports, 2003, 118:65–71.