COMPOSTING EXPERIENCE IN EGYPT-EGYPT

A CASE STUDY

 

 

BY

PROFESSOR OLFAT EL-SEBAIE

DIRECTOR OF ENVIRONMENTAL HEALTH,

RESEARCH, AND STUDIES UNIT

HIGH INSTITUTE OF PUBLIC HEALTH

ALEXANDRIA UNIVERSITY

ALEXANDRIA-EGYPT

 

 

 

 

 

 

 

 

 

 

 

 

 

SUBMITTED TO:

INTERNATIONAL WORKSHOP ON

" FINAL DISPOSAL OF MUNICIPAL SOLID WASTE

IN DEVELOPING COUNTRIES it

 

ORGANIZED BY THE WORLD BANK IN

BELLO HORIZONTE - BRAZIL

SEPTEMBER 8 - 11, 1998.

 

 

 

 

COMPOSTING EXPERIENCE IN EGYPT

A CASE STUDY

BY

PROFESSOR OLFATEL-SEBAIE

 

 

1. INTRODUCTION

In Egypt, during the last two decades, the increasing urban population pressure has resulted in the generation of tremendous amounts of solid wastes. Until the late seventies, the local authorities in large cities like Cairo and Alexandria, and in the Secondary cities were not able to tackle the solid waste problems due to the shortage of financial resources, lack of trained and skilled manpower, shortage of adequate and proper equipment, non availability of reliable information and records about the amounts of wastes generated, its nature and methods of treatment and disposal including salvaging of solid wastes. The absence of the national policies, legislation and strategies dealing with environmentally sound solid waste management has aggravated the associated problems.

The great majority of wastes collected by municipalities are disposed of in open dumps. Wastes collected by the Zaballeen system are transferred to their settlements where it is subjected to intensive recycling. Food wastes are used for raising and feeding animals. The produced manure with some food waste are composted to produce organic fertilizers. This conventional Zaballeen system which dates back to the early decades of this century has achieved a maximum recovery system, but the aesthetics and hygiene at these areas are unacceptable.

So this paper will cover the following items:

 

 

2. CURRENT STATUS ON DISPOSAL OF SOLID WASTE IN EGYPT

The predominant waste disposal method in most Egyptian Cities is open dumping. However, over the last decade there has been a trend towards applying proper treatment and disposal methods. Options that have been adopted include sanitary landfilling, windrow composting, landfill composting, simple co-composting for rural areas, and incineration. The application of each of which will depend on the specific

 

location and waste conditions. Table (I) complies information on treatment or disposal establishments in major Egyptian Cities.

Experience with the performance of these systems may be summarized as follows:

2.1. Sanitary Landfilling

The first properly designed sanitary landfill with a daily capacity of 1000 tons has been established in Cairo in 1986. Due to prevailing dry climate conditions hazards front leachate or gas generation are considered to be minimal. Over the past few years other landfill sites leave been established in Cairo.

2.2. Composting

2.2.1 Windrow Composting

The adopted windrow comporting of intermediate level technology and with recycling of recoverable materials has proved to be technically and environmentally sound. Produced compost is finding an increasing acceptance as reflected by the continuous rise in market price. Also recyclable materials have an established market due to the long practice of the private sector (Zaballeen) in the recovery of selected materials. However the capital costs of these imported plants have been relatively high and the rates revenues could hardly compensate the operation expenses.

2.2.2. Landfill Compost

This option is combining the merits of comporting as regards to resource recovery and recycling, as well as the relatively low east of landfilling - while having much less land requirement and site longevity. It was proposed for sometime and has been recently investigated on demonstration scale in Alexandria and Beheira Governorates. It is going to be applied also in other Governorates especially in the Delta region, where no land is available for other technologies, the non availability of skilled personnel - as well as its low cost.

2.2.3. Co-Composting

This technology has been practiced in Egypt for centuries up till now in rural areas where animal wastes (manure) is co-composted with household wastes and agricultural residues. Now this simple technology for rural areas is being demonstrated currently in Abu Qir in Alexandria./ In Port Said, this technology is applied on the municipal sludge produced at the Sewage Treatment Plant which is to be co-composted with part of the city refuse. The produced compost has not been evaluated yet as the plant still under experimental trials.

 

 

2.3. Incineration

It has been introduced in several Egyptian cities since the mid eighties. Batch module incinerators with no energy recovery of capacities ranging between 0.4 1 ton/hour. The small capacities are manually fed while the larger capacities are fed by overhead cranes. The performance of these units is very poor due to the following constraints: high fuel consumption, the maintenance and spare parts problems, small capacities which not exceed 30% of the generated waste. Studies on the viability of the incineration option in Egypt, tend to indicate - on account of economic, technological and environmental considerations - that its prospects will be largely confined to hazardous and hospital wastes.

In Egypt today solid waste generation can be roughly estimated at about 30,000 tons/day, out of which about 20,000 tons/day produced in cities, i.e., in urban areas. The rest of the amount generated would come from semi-urban and rural areas. From table (I) and the aforementioned methods of disposal composting is representing now only 9.5% of the urban methods of disposal, awhile sanitary landfill represent 5% of these methods, 85% of the urban waste is open dumped. After the next five war noun the composting method will represent 33.5%.

2.4. Sources of Organic Soi] Conditioner

Traditionally organic soil conditioner used in Egypt was the silt of the Nile which brought by the flood to all agricultural lands. This was before the building of the high dam up to 1961. In addition the Farmers were using the animal manure either raw or composted anaerobically in heaps sealed with mud at the edges of their fields. After the building of the high dam, the silt has been stored in Lake Nasser and little is allowed to go across the River Nile which is not enough to fertilize the land. This led to the use of chemical fertilizers. Nowadays, the rising price of chemical fertilizers plus Increased awareness of the organic farming methods, is stimulating interest in composhng. The ensuing compost fertilizer has the advantage that it release major nutrients into the soil for longer period than chemical fertilizer. It also build up organic soil matter. The compost fertilizer has the further advantage that it helps to hold loose soils together, and aerates hard clay and compacted soils or retain matter for longer periods. These advantages also are useful for land reclamation of the desert which represent 96% oft he Egyptian area.

 

3. HISTORY OF EVOLUTION OF COMPOSTING

The Zaballeen system has been in operation for more than 50 years in larger Egyptian cities. The collected wastes are transported to Zaballeen settlements where recycling of hand sorted recoverable materials (paper, glass, plastics, metals) are taking place. The remaining organic waste are fed to pigs. In fact, breeding of pigs takes place in Egypt only at Zaballeen settlements. In addition to pigs the Zaballeen usually have some Goats and Lambs at their settlements. These animals are fed with selected food wastes. Once or twice a year the wastes are collected from the pigs barn and after being allowed to mature for several months is sold as organic fertilizer. Ten years ago, at one of the Zaballeen settlements in Cairo (Manshiet Nasser) a 50 tons/day composting plant has been established to treat the wastes collected from pig barns. The plant comprises a windrow area and a screen for producing fine compost. The aesthetics and hygiene at these areas are unacceptable. This plant is a part of W.B project to Improve the solid waste management in the Zaballeen settlement.

 

In 1978, a high level committee committee of experts was convened at the Ministry of Local Affairs, with participants from the Ministries of Agriculture, Industry Public Health, Planning, Economy, and Electricity, from Research Industries and from Governorates of Cairo, Alexandria, and Giza.

This committee investigated and studied 35 international projects from different countries using different techniques for converting municipal solid waste into organic fertilizers, among other useful products. The committee made several recommendations including:

Later in the beginning of the nineties and according to the strategies of the environmental action plan of Egypt on 1992. Local compost plants 80% of it is manufactured in Egypt. The first local plant has been erected in Zagazig and the second is following in Alexandria. Ten other plants have been contracted to be established in the capital cities of the Governorates.

Egypt policy towards composting agree with what were proposed within Agenda 21, which was adopted at the united Nations, Environmental Conference at Rio de Janeiro in 1992, as measures to advance sustainable agricultural and agricultural community development through :

 

Egypt has accounted for 50 other compost plants in its fourth five years plan (1997-2002), to be constructed and erected locally.

 

 

 

 

4. APPLIED COMPOSTING TECHNIQUES

Whatever the level of mechanization and \sophistication almost all current composing systems rely on windrowing for all or part of the decomposition process.

4.1 Windrowing of Size-Reduced Wastes:

This is the most common type of plant in use today and has the following main features:

1 - Reception and storage : this can take the form of a deep bunker with a grab crane, or a hopper with belt conveyor.

2 - Elevation to attain sufficient height to enable subsequent processes to be fed by gravity; this usually takes the form of an inclined elevator belt, but sometimes the hopper slat conveyor is inclined and extended outside the hopper.

3 - Picking belt for the removal of salvage and contraries.

4 - Overhead magnet, for the extraction of ferrous metal.

5 - Size reduction normally a hammermill.

6 - Transport of the shredded wastes to the windrows in the fermentation yard; this can be by overhead conveyor belts or tractors and trailers.

7 - Windrow turning system, usually front-end loaders are used, but other machines are available.

8 - Maturation area.

9 - Screening and bagging.

10 - Storage area.

The heart of this type of plant and the main justification for its added cost, is the hammermill, which reduces the size of the wastes to about 80% below 50mm. This increases the surface area exposed to bacterial attack and may assist in speeding up the process of decomposition. It also mixes the wastes, destroys most of the fly larvae, reduces the attraction of the wastes to insects, and grinds glass to the equivalent of sand.

Shredding is certainly an essential treatment for the wastes of temperate, industrialized countries, for such wastes certain many objects which would be highly resistant to decomposition, but it may be a questionable requirement in countries where the proportion of vegetable putrescible matter is very high, and where lower living standards and intensive private salvaging tend to minimize the proportions of salvageable materials and contraries in the wastes.

4.2 Windrowing of Partily Fermented Wastes

This type of system has all the features of the preceding type, except that instead of a hammermill a very large drum is employed; this has a capacity of several hundred tones and the wastes are retained within it for up to 1-2 hours during which the following functions are performed :

Size reduction in the drum is less efficient than in a hammermill and most plants of this type now incorporate screening and pulverization after the wastes leave the drum, but screening efficiency is low owing to the high moisture content, resulting in some loss of compostable material in the screen rejects.

It is the custom to windrow drum-treated wastes in the fermentation yard for four weeks during which it is turned at 4-5 intervals. Then the fermented waste is transferred to maturation yard to be matured for another four weeks without turning.

4.3 Compost Quality

As shown in table (I) the only source of input of these plants is the domestic solid waste except for Port Said composting plant which includes sludge. The ratio of sludge to domestic solid waste has not determined yet as the operation of the plant in

The heart of this type of plant and the main justification for its added cost, is the hammermill, which reduces the size of the wastes to about 80% below 50mm. This increases the surface area exposed to bacterial attack and may assist in speeding up the process of decomposition. It also mixes the wastes, destroys most of the fly larvae, reduces the attraction of the wastes to insects, and grinds glass to the equivalent of sand.

Shredding is certainly an essential treatment for the wastes of temperate, industrialized countries, for such wastes certain many objects which would be highly resistant to decomposition, but it may be a questionable requirement in countries where the proportion of vegetable putrescible matter is very high, and where lower living standards and intensive private salvaging tend to minimize the proportions of salvageable materials and contraries in the wastes.

4.2 Windrowing of Partily Fermented Wastes

This type of system has all the features of the preceding type, except that instead of a hammermill a very large drum is employed; this has a capacity of several hundred tones and the wastes are retained within it for up to 1-2 hours during which the following functions are performed :

Size reduction in the drum is less efficient than in a hammermill and most plants of this type now incorporate screening and pulverization after the wastes leave the drum, but screening efficiency is low owing to the high moisture content, resulting in some loss of compostable material in the screen rejects.

It is the custom to windrow drum-treated wastes in the fermentation yard for four weeks during which it is turned at 4-5 intervals. Then the fermented waste is transferred to maturation yard to be matured for another four weeks without turning.

4.3 Compost Quality

As shown in table (I) the only source of input of these plants is the domestic solid waste except for Port Said composting plant which includes sludge. The ratio of sludge to domestic solid waste has not determined yet as the operation of the plant in the experimental period. At present, the total amount of domestic solid waste composted daily all over Egypt reaches 1900 tons/day. The quality of the compost produced agrees with the limits of Ministry of Agriculture Law 100/1967 for organic fertilizers standards. Table (II) represent the quality of the compost produced from Abis Compost Plant in Alexandria.

5. OPERATION EXPERIENCE OF THE COMPOSTING SYSTEM

5.1 Technical Aspects:

Before considering a composting project it is necessary to carry out a physical analysis of the wastes using reliable sampling methods. Although dissimilar constituents occur in solid wastes through out the cities, there are wide variations in relative proportions. Bacteria use carbon as energy source and nitrogen for cell building, thus the process of decomposition involves the reduction of the relative proportions of these elements, known as the C/N ratio, from an original level which may range from 20: 1 to 70: 1 to a point where the available carbon has been consumed and activity ceases. The final C/N ratio usually lies between 15:1 and 25:1, moisture content in the waste is considered as determining factor in the composting process and it would not to exceed a 50% content in the fermentation process, and 15% in the matured compost.

Temperature also should be maintained at 60-70 c for at least 3 days during the fermentation process, to be sure that pathogenic organisms And nematodes are killed.

5.2 Mechanical Aspects :

5.2.1 Receiving Facilities :

The feeding of the apron conveyor to hand sorting conveyor by the wheel loader should be even and continuous. Large items like car tires and vegetable carrying baskets and bricks should be removed in the receiving hall before feeding to avoid the breaking of the apron conveyor.

5.2.2 Hand Sorting Line :

The hand sorting conveyor should be set at a reasonable speed to allow a high rate of sorting. Where salvage has been carried out under controlled conditions in plants designed for that purpose there has been no evidence of adverse effects on the health of the hand sort workers. There could, however, be risks to the public health if the subsequent use of the salvaged materials if it is not carefully controlled. The main areas of risk concern workers who refuse to wear safety gloves, boots and masks.

5.2.3 Homogenizer

The Dano Drum is used for the shredding of the ' waste and the addition of water to start the fermentation process. The size of sieve screen openings in the fractionator drum should be reduced to a 45mm diameter, so the waste to be composted will not be lost with the reject of the drum.

5.2.4 Maturation Yard :

One of the difficulties in marketing of compost is the seasonality. Consequently, the area required for maturation must be made for storing the daily production of the matured compost of the plant for a long period of time.

As an encouraging example of even apparently insoluble problems being solved, there is that of broken glass in refuse, which is very objectionable in the finished compost and practically impossible to eliminate. Recent tests have shown glass, non-crystalline and a much softer silica compound than quartz, is utilized by soil microorganisms to satisfy their requirements of silica. What is needed of handling broken glass in municipal waste is simply an efficient composting process with high carbon dioxide concentration. The glass particles end up with no sharper edges and no larger than beach sand. It has been thoroughly tested and it works.

5.2.5 Generator:

Plants should have another source of electricity to overcome the problem of power failures .

5.3 Final Disposal Site:

Therefore, each city having a compost plant must take necessary steps to secure land for use as a final disposal site.

5.4. Environmental Impacts:

Before the issuing of the environmental law number 4 for 1994 and its executive regulations on 1995, EIA was not required. So most of the plants operating now have no EIA study. Those plants under construction, they have some sort of ElA according to the guidelines of the Ministry of Environment.

6. MARKET ASPECTS OF COMPOSTING

6.1 Compost Demand

The development of new farm land has been continually advanced as a national policy since the first 5 year plan (1982-1987). The plan to develop new farm land at the same rate into the future is currently in progress. The value of yields per cultivated land in the newly developed farm land areas is 30% less than the yields in the traditional cultivated land for the Nile Delta. For this reason, the improvement of the fertility level of newly developed farm land has come to be regarded as an important issue. The above mentioned conditions in the Egyptian agricultural sector indicate that the potential demand for organic fertilizer and soil improvement material; in recent years has been increasing throughout Egypt.

A Farmer survey has been carried out in Alexandria region proved the above statement and also indicated the willingness of the farmers to pay for the compost. Table (III) presents the trends in compost prices where the price is tripled for fine compost and doubled for coarse compost over ten years period. Also table (IV and V) report the accounts of Abis compost plant, which \shows that there is a market for the compost and salvaged materials and their selling prices share in the income of the plant. It is only personnel costs which are directly furnished by the Governorate. If personnel cost are excluded the financial balance shows a slight profit although there are no problems in terms of continued operation.

6.2 Investment Program:

The environmental action plan of year 1992 has proposed an investment program as foreseen to improve management of solid waste to reduce impact on health, air, and water quality. Also this program includes the utilization of household and agricultural waste as natural resources. The investments have divided into two phases of five years each as shown in table A).

7. LESSONS LEARNED

The unfavorable status of composting will change as people become sufficiently environmentally conscious to demand that waste management includes social and environmental benefits. Thus, composting is becoming a wall of savaging the remaining organic resources to maintain the productivity of land. Other uses would be land reclamation, sludge stabilization or conditioning and recreation. So it offers the logical solution for sewage sludge and solid waste disposal without damaging the environment and in full harmony with the ecology.

In all of the potential application no monetary return is involved. In fact not only would there be no cash return, but there would be actual expenditures because of transportation and application costs. However, the long term benefits more than make up for the costs involved. The fallacy of judging the success of a compost operation in terms of its money making record is a misconception that has always plagued composing, and one that must be corrected. Thus, if the product cannot be sold, and a deficit results in terms of operational and capital costs, the entire enterprise is regarded as a failure regardless of how well the plant may be operated. Yet no one expects an incineration operation to earn money. Since composting also is a method for treating wastes, its success should be judged on the basis of performance and not on account of profit.

The consensus at present is that composting will find its niche as regional management becomes the order of the day when this time comes agricultural waste disposal will become a public responsibility to a much greater extent that at present. Most of these wastes are readily composted with municipal refuse. Furthermore because available sites for waste burial are rapidly diminishing and therefore must be used at maximum efficiency and as air quality standards become stricter to a point at which air pollution control becomes so expensive as to rule out incineration, the only technology available for solid waste processing will be comporting.

 

 

Although it is reported that soil improvement is indispensable in desert development, an evaluation of the investment effect in using compost will be necessary to further prove its indispensability. This evaluation will also serve the purpose of determining a reasonable price for compost. It will also be necessary to examine whether farmers using compost have to improve the soil with their own capital or if they receive government subsidiary. Furthermore, the question of how to transport the compost and rejected waste from the plant to farm land and disposal sites, and who will bear the cost of haulage should also be examined.

Moreover, a search for compost markets is essential before the proceeding to implement new compost plants.

8. REFERENCES

1- Ministry of Environment, 1 992. " Environmental Action Plan ".

2- JICA 1995. Basic Design Report on The Project for Improvement of Solid Waste Management in Alexandria, Egypt.

3- EL-Sebaie O., 1995. " Solid Waste Management in Alexandria, Egypt ". Proceedings of Second Annual World Bank Conference on Environmentally Sustainable Development, Held on September l994.

4- EL-Sebaie O., 1985. " Composting Process of Domestic Solid Waste and its Technical Aspects ". Proceedings of Workshop on Solid Waste in Egypt, Organized by WHO and Ministry of Health.

5- EL-Sebaie O., 1994. "Solid Waste Management in Egypt", WHO Special Studies Report.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table (I): Major Modern Treatment or Disposal Facilities. (Ref. 1)

 

Technology

 

City

Capacity

Status

1. Sanitary Landfilling

Cairo

Up to 1000 tons/day

In operation 1986.

2.a. Windrow Composting

Cairo-Shoubra

10 tons/hour

In operation since 1985

 

Cairo-EL-Salam

6 tons/hour

In operation since 1985

 

Cairo Manshit Nasser

5 tons/hour

In operation since 1994

 

Alexandria

10 tons/hour

In operation since 1985 W.B.

 

Damietta

10 tons/hour

In operation since 1986

 

Giza

6 tons/hour

In operation since 1986

 

EL-Zagazig

6 tons/hour

In operation since 1997 (national)

 

Ismailia

6 tons/hour

In operation since 1998 (national)

 

Alexandria

10 tons/hour

In operation since 1998 (Japan)

 

Alexandria

6 tons/hour

Under Construction (national)

 

Beni Souif

6 tons/hour

 

2.a. Windrow Co-Composting

Port Said

30 tons/hour

In experimental operation since 1998 (USAID)

 

EL-Mansoura

6 tons/hour

Under Construction (national)

 

EL-Faioum

6 tons/hour

Under Construction (national)

 

50 Other cities

6 tons/hour each

Planned for the next 5 year plan

3. Incineration

Banha, Tanta, EL-Mahala, EL-Zagazig,

   
 

Giza, Beni Souif, Shebin EL-Kom,

0,4-0,1 tons/hour

Operating discontinuosly since 1983

 

EL-Mansoura

 

 

 

 

 

 

 

Table (II): Results of Analysis of Produced Organic Fertilizer (Compost) Samples from Abis Compost Plant in Alexandria. (Ref. 3)

 

Type of Analysis

Fine Compost

Coarse Compost

Specification of Law 100/1967

Nitrogen %

0.99

0.90

0.5 + 0.04% min.

Organic Matter %

22.60

18.60

18 + 1% min.

Humidity %

11.50

38.00

30 + 2% min.

Density (Sp; gr) (t/m)

0.65

0.78

750 + 40 max.

Carbon : Nitrogen

22.80

20.70

1:18 - 1:25

NaCI %

1.06

1.10

5.00

Volume of Particles

Suitable volume in order to apply on soil

Bacteria (Coliform)/1 gm

No Present

Not Present

 

Bacteria (Plate Count)/1 gm

550.0

21 x 10

 

Fungi

Same number and types as found in atmosphere

Nematodes

No Present

No Present

No Present

       

Heavy Metals

     

T-Hg (g/kg)

0.01

0.01

 

Cd (g/kg)

0.00

0.00

 

Zn (g/kg)

0.26

0.32

 

Cu (g/kg)

0.02

0.03

 

Pb (g/kg)

0.07

0.06

 
       

 

 

 

Table (III): Trends in Compost Prices (1985 1994) (Ref. 2)

 

Apr. 1985 Apr. 1986 Jul. 1989 Jul. 1990 Jul. 1991 Jul. 1992

Mar. 1986 Jun. 1989 Jun. 1990 Jun 1991 Jun. 1992 Aug. 1994

   

Fine Compost

7.5 11 11 15 20 25

   

Coarse Compost

5.5 11 7.5 9 10 11

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table (IV): Abis Compost Plant Operating Results (1993 1994) (Ref. 2)

   

1) Solid Waste Treatment Capacity

160 tons / day

   

2) Operation Time

13-14 hours/day (299 days/year)

   

  1. Compost Production Quantities:
 

Fine Compost

3.3 tons/day (998 tons/year)

Coarse Compost

80.1 tons/day (24,043 tons/year)

   

4) Sales Results:

 

Compost

281,964 LE

Reusable Items

58, 714 LE

Total

340,678 LE

   

5) Operating Cost

 

*Equipment Maintenance

90,612 LE

*Utilities (electricity, water, fuel)

85,083 LE

*Incentive Costs

136,689 LE

Total

312,384 LE

   

6) Personnel Costs

109,200 LE

   
   
   
   

Of the above costs, personnel costs are directly furnished by the Governorate.

If personnel costs are excluded, the financial balance shows a slight profit and so there are no problems in terms of continued operations.

 

 

Table (V): Abis Compost Plant Accounts (1989 1993) Ref. 2)

 

 

1991/92

 

1992/93

1993/94

INCOME

340,678

330,446

309,179

       

EXPENDITURE

330,446

275,460

279,181

       

BALANCE

10,232

47,344

30,105

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table (VI): Solid Waste Investment Program*

 

 

Project

Estimated Cost (LE Millions)

 

Phase I

Phase II

     

Municipal Waste

   

  • Strategies and Pilot Studies

19

 

  • Generation of Biogas

16

 

  • Improved Collection System-Urban Areas

160

300

  • Improved Collection System-Rural Areas

33

80

  • Sanitary Landfill

16

150

  • Manufacturing of Equipment for Composting Plants

10

 
     

Hospital Waste

   

  • Pilot Study

5

30

  • Upgrading Existing Small Incinerators

2

30

     

Agricultural Waste

   
  • Decomposition and Generation Biogas, and Production of Compost

7

120

     

Industrial Hazardous Waste

   

  • Strategy

3

 

  • Pilot Projects

19

 

  • Incineration (Cement Kiln or Other Kiln)
 

130

  • Secure Landfill
 

65

     

Total Solid Waste

290

905