REPORT ON THE REGIONAL TRAINING COURSE ON LOW-COST ...

WHO-EM/CEHA/46-E

REPORT ON

THE REGIONAL TRAINING COURSE ON LOW-COST WASTEWATER TREATMENT TECHNOLOGY

Amman, Jordan, 7-12 December 1991

WORLD hZrlLTH ORGANIZATION Regional Office for the Eastern Mediterranean

Centre for Environmental Health Activities (CEHA) Amman, Jordan

April 1992

CONTENTS

Page No.

ABBREVIATIONS • . • • • . • . • . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • i

EXECUTIVE S011l1A.R.Y • • • . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ii

1. INTRODUCTION. • • • • • • • • • • • • • • • • • • • • • • • • • . • • • • • • • • • • • • • • • • 1

2. OBJECTIVES AND SCOPE. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1

3. PROCEEDINGS

3.1 Wastewater Treatment Technologies and Criteria for Selection and Decision Sequence •••••• 2

3.2 Microbiology and Kinetics of Wastewater Treatment................ . . . . . . . . . . . . . . . . . . . . . . . . . 3

3.3 Low-Cost and Energy Saving Treatment Alternatives •• 3

3.4 Waste Stabilization Ponds ••••••••••••••••.••••••••• 4

3.5 WHO Health Guidelines for Use of Wastewater In Agriculture and Aquaculture •••••••••••••.•••••• 5

3.6 Land Treatment of Wastewater .•••.•.•••••••••••••••• 6

3.7 On-site Treatment of Wastewater •••••••••••••••••••• 7

3.8 Sludge Handling and Disposal ••••••••••••••••••••••• 8

3.9 Training/Education Approach in Sanitation for Developing Countries •••••••••••.•••••••••••••• 9

3.10 Visit to Al-Samra Wastewater Treatment Plant ••••• 10

4. COUNTRY REPORTS

4. 1 Afghanistan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O

4 . 2 Egypt • • • • • . • • . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.3 Islamic Republic of Iran .••••••••••••••••••••••••• 11

4.4 Jordan ............................................ 11

4.5

4.6

4.7

4.8

4.9

Page No.

Morocco • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pakistan.

Sudan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Syrian Arab Republic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tunisia • • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12

12

13

14

15

4.10 Republic of Yemen •••• • • • • . • • • • •••• • • • • • • • • • • • • • •• 15

5. EVALUATION. • • • . • • • • • • • • • • • • . • • • • • • • • • • • • • • • • • • • • • • • • • • 16

ANNEXES

Annex 1 . AGENDA.... . . • • • • . • • • • • • • • • . • • • • • • • • • • • • • • • • • • • • • • • 17

Annex 2. PROGRAJwll1E. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 18

Annex 3. LIST OF PARTICIPANTS • • • • • •• • • •• • • .. • • • • •• • •••• •••• 20

Annex 4. LIST OF REFERENCES •••• • • • •. • . • • • • • • • • • • • • • • • • • • • • • 23

Annex 5 EVALUATION QUESTIONNAIRE • ••••• • • •• • • • • • • • • • • ••••• • 25

BOD

CEHA

CEHANET

EMR

Mgd

UASB

UNEP

UNRWA

VIP

WAJ

WHO

WSP

WTP

.

.

.

.

.

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WHO-EM/CEHA/46-E Page i

ABBREVIATIONS

Biochemical oxygen demand

Regional Centre for Environmental Health Activities, Amman, Jordan

CEHA's Environmental Health Regional Information Network

Eastern Mediterranean Region of WHO

Million gallons per day

Upflow anaerobic sludge blanket

United Nations Environmental Programme

United Nations Relief and Works Agency for Palestinian Refugees in the Near East

Ventilated/improved pit latrine

water Authority of Jordan

World Health Organization

Waste stabilization ponds

Wastewater treatment plant

WHO-EM/CEHA/46-E Page ii

EXECUTIVE SUMMARY

The "Regional Training course on Low-cost Wastewater Treatment Technology" was organized by the Regional Centre for Environmental Health Activities· (CEHA), Amman, Jordan from 7 to 12 December 1991. Representatives from Afghanistan, Egypt, Islamic Republic of Iran, Jordan, Morocco, Pakistan, Sudan, Syrian Arab Republic, Tunisia, and the Republic of Yemen, and three WHO consultants from India, the United Kingdom and Jordan, and staff members from CERA participated in the course.

The participants made brief presentations on the·methods of wastewater treatment in their countries, emphasizing utilization and performance of waste stabilization ponds.

The three consultants presented papers on: (i) wastewater treatment technology and criteria for selection ·and decision sequence for treatment; (ii) microbiology and kinetics of wastewater treatment; (iii) low-cost and energy-saving treatment alternatives, (iv) waste stabilization ponds; (v) WHO Health Guidelines for Use of Wastewater in Agriculture and Aquaculture; (vi) land treatment of wastewater; (vii) on-site treatment of wastewater; (viil) sludgehandling and disposal; and (ix) training/education approach in sanitation for developing countries. After each presentation, ample time was provided for in-depth discussions.

A field trip was arranged, in collaboration with the Water Authority of Jordan, to Al-Samra Wastewater Treatment Plant� which is composed of 32 ponds of an anaerobic, facultative and maturation (aerobic) nature, the largest in the Region, treating a wastewater flow of about 100, 000 m3/day.

1. INTRODUCTION

WHO-EM/CEHA/46-E Page 1

The Regional Training Course on Low-Cost Wastewater Treatment Technology was organized by the Regional Centre for Environmental Health Activities in Amman, Jordan, from 7 to 12 December 1991. It was attended by thirteen participants from ten EMR Member states and three observers (one each from the Ministry of Health, Jordan; UNRWA, Gaza Refugee Camp; and UNRWA, Syria Refugee camp) .

Dr Hussein Gezairy, Regional Director for the WHO Eastern Mediterranean Region, in his message for the opening of the training course, (which was read by Dr H. El-Baroudi, CEHA Coordinator) , welcomed the participants and expressed his gratitude to the Government of Jordan and its Ministry of Health for hosting the course.

In assessing the environmental quality in the Region, Dr Gezairy stated that because of municipal and industrial wastes and agricultural run-offs, many water resources were already polluted. Therefore, water pollution control regulations need to be strictly followed and enforced by responsible national authorities. As part of such regulations, wastewater treatment must be made mandatory to prevent further pollution of these limited resources.

Dr Gezairy stressed the judicious use of the limited water resources within a well-prepared water conservation strategy, and he cited the example of the reuse of treated wastewater for industrial or agricultural uses as being an efficient water conservation method. Water scarcity in the Region poses formidable technical, social and managerial challenges to all those involved in ensuring sustainable socioeconomic development. Water in an arid area is too valuable to be used just once and then discarded. The well-being of future generations depends on wise water management and conservation policies and habits.

In conclusion, Dr Gezairy emphasized that transfer of technology, and training and orientation of national professionals are continuing processes, which require strong support from universities, research institutions and field practitioners in the Member states.

-

The agenda 2 respectively.

and the programme of the course are in Annexes 1 and A list of participants is in Annex 3 .

2 • OBJECTIVES AND SCOPE

The objective of the course was to offer recent information on c.-::::::-o"'J=:!.2."::? :-:·,1-c'.:l-:t •,•2.s--:e�•:a�a:- t-::-�a+::.r::e:-:-: +:ec�r.o�·:;gy f�r the professional staff in charge of planning and designing of wastewater treatment plants, with particular emphasis on the performance of stabilization ponds in order to raise the level of knowledge of the


course participants in this field. The course also provided a forum for the participants to exchange and discuss their respective experiences and information on the subject.

The training course covered the following areas:

wastewater treatment technologies and criteria for selection/design sequence; microbiology and kinetics of wastewater treatment; low-cost/energy-saving treatment alternatives; waste stabilization ponds; WHO Health Guidelines for Use of Wastewater in Agriculture and Aquaculture; land treatment of wastewater; on-site treatment of wastewater; sludge handling and disposal; training/education approach in sanitation for developing countries.

Each participant made a brief presentation on the methods of wastewater treatment in their respective country, emphasizing the utilization and performance of waste stabilization ponds.

3. PROCEEDINGS

A list of references related to the items of agenda is given in Annex 4.

3.1 Wastewater Treatment Technology and Criteria for Selection and Decision Sequence

The purpose of wastewater treatment is:

to remove material that may form sludge/scum and the organic matter/nutrients that may cause depletion of oxygen and entrophication in the receiving water bodies; to prevent the • spread of . diseases that are transmitted through water/wastewater: and to maintain clarity and purity in the receiving waters.

The type and sequence of treatment processes in four stages are given as:

pretreatment (screening, grit removal, pre-aeration, flow measurement); primary treatment (removal of settleable and floatable solids) : secondary treat�ent (biological/chemical removal of organics) ; disinfection (removal of pathogens) .


There is no single treatment that can meet all the criteria required for the selection of a wastewater treatment system, but the aim is to minimize the disadvantages. The criteria for selecting the type of treatment are given as: health, ecological/environmental reuse, nuisance, cultural, operational, and cost.

Comprehensive comparison was made of different types of treatment processes with ranking process characteristics, and an example for selecting the best alternative was given. Staging of treatment plant's physical development and level (degree) of treatment and the advantages of each level of treatment with their inherent capital and operational cost characteristics were discussed.

3. 2 Microbiology and Kinetics of Wastewater Treatment

The basic process of waste (organic matter) stabilization through aerobic and anaerobic steps, depending on the availability of oxygen in the environment, takes place within a general ecosystem. Nutrients in the ecosystem are recycled through conversion of organic nitrogen and phosphorus ultimately into nitrates and phosphates, later to be taken up by producers. The role played by producers, consumers and decomposers in the recycling of carbon, nitrogen, phosphorus and sulphur in such an ecosystem were stressed.

Applications of these basic principles into the treatment systems were discussed to show the essential unity of all types of biological treatment processes, the effect of nutrients, temperature, etc., in ponds and other systems treating different types of wastewater. Some principles of reactor design based on treatment kinetics were also considered in so far as they are generally large bodies of water and therefore much affected by ambient temperatures, environmental conditions and mixing characteristics. Mixing conditions in treatment units, particularly in waste stabilization ponds are important as far as substrate biochemical oxygen demand {BOD) removal is concerned. Actual dispersed flow status is something in between ideal plug flow and completely mixed flow conditions, and is specified depending upon the proportions of the pond's dimensions. A practical approach to determine dispersed flow conditions, in order to estimate the removal of BOD and pathogens in ponds, is expressed by a factor called dispersion number.

3. 3 .Low-Cost and Energy saving Treatment Alternatives

In the Eastern Mediterranean Region (EMR) , only 59% of the total population and about 20% of the rural population have adequate sanitation facilities. The factors contributing to this include lack of funds, high unit construction costs, lack of expert professional staff and utilization of inappropriate technologies. Also, the ��1��3� ��!:d a�� i�!3nt ��r��lity =�t13 �==�r �n �=�n�=i�s w�e�e coverage for adequate sanitation and safe supply of water is the lowest. Therefore, there is a need to look for simple, low-cost technologies to increase adequate sanitation coverage in the Region.


The following are important considerations in deciding on the type· of treatment system to adopt:

inexpensive without sacrificing effectiveness and efficiency; simple to operate and maintain; minimum need for skilled operators; dependency on locally-produced material; promotion of community participation; compatibility with local values and preferences; promotion of resource recovery; conservation of resources and environment; efficiency in removal of pollutants (to satisfy effluent quality criteria).

The treatment alternatives considerations are given below:

waste stabilization ponds; land application; eco-pond system; macrophyte ponds

that can achieve the above

paddy fields, with or without fish cultivation; rice duckweed fish; wetland treatment.

3.4 Waste Stabilization Ponds

The subject of waste stabilization ponds (WSP) includes the following:

algae production and simultaneous oxygen production; oxygen consumption in BOD removal;

- nutrients (nitrogen and phosphorus) removal; removal of coliforms, helminths, etc. ; absence of "nuisance" conditions, such as those caused by sulfide formation and by mosquitoes; avoidance of groundwater pollution; presence of dissolved oxygen in effluent.

Pond design should take into consideration not only BOD removal, but also coliform and nutrient removal, as well as the potential of. sulfide formation, as the latter is toxic to algae when pr·esent in concentrations above 4 mg/1.

Mixing conditions in the pond also affect pond performance and need to be looked at in a proper design. "Thumb rule" designs on the basis of area loading (kg BOO/ha/day) , and with a depth assumed between 1 and 2 metres, are not always adequate. Various possible ccr.iigurations involving �naercbic, facultativg a�d �aturation ponds were discussed, as were combinations of aerated lagoons and waste stabilization ponds that optimize land and power costs. Since

WHO-EM/CEH.A/46-E Page 5

irrigation with waste stabilization pond effluent have high potential for utilization in the Region, their health aspects are covered with special reference to faecal coliforms and intestinal nematodes.

At the request of the participants, a discussion was held on relatively recent developments in anaerobic technologies, including upflow anaerobic sludge blanket (UASB), as it appeared to have an application in replacing open anaerobic ponds with their concomitant odour problems.

Illustrative examples were solved, using the design criteria based on the concepts given above, using the following steps·:

algal production oxygen production BOD removal dispersion number sulfide production coliform removal

3.5 WHO Health Guidelines for Use of Wastewater in Agriculture and Aquaculture

Water is generally uncultivated because of becoming a limiting development.

scarce in the EMR, and large land areas are the lack of irrigation water. Hence, it is

factor for agricultural and industrial

As a substitute for freshwater in irrigation, wastewater effluent has an important role to play in water resource management. Each drop of water available must be used and managed in a safe and feasible manner. No "high-quality" water (unless there is a surplus) should be used for a purpose that can tolerate a lower grade.

About 90% of phosphate and 8 5% of organic matter will be removed from the effluent before it joins groundwater, while it percolates through layers of the ground during irrigation. This will improve yields of agricultural products and will function as a further step to the treatment provided •

. . . Nearly . all excreted pathogens can survive in water, soil, and on crops for a sufficient length of time to pose health risks to farm workers, handlers and consumers. Crop irrigation with untreated wastewater causes excess infections of intestinal nematodes in farm workers and consumers. Therefore, irrigation with raw sewage is not encouraged at all.

:-:� :!. :: �c�:rT"Je!"c.ec. .:iic::-::b ic l ::g ic�l �:.:.J.1:. t�· gu:.c.el2.:1ss f ::r wastewater reuse in agriculture, adapted by WHO in 1989, indicate that helminths present the highest risk of effluent-related disease transmission due to the long latency period in the soil, long


persistence in the environment, and low infective dose, practically no host immunity. On the other hand, enteric viruses seem to be the least probable in terms of risk to health, and risk of infection due to protozoa and bacteria are between that of helminths and viruses. The WHO Guidelines recommend about 99% removal of helminth eggs and a major reduction in the concentration of excreted bacteria to a geometric mean of 1000 faecal coliforms per 100 ml.

The design of conventional secondary (biological) treatment processes have been based on the criteria of BOD and suspended solid removal; therefore, they do not comply with the effluent quality requirements of the WHO Guidelines. Domestic wastewaters of most of the Member Countries in our Region contain nematode eggs to an average concentration of about 200 eggs/1. In areas where raw wastewater irrigation is practised, this concentration goes up as high as 3350 eggs/1. Thus, the new treatment plants that will be designed in the Region must comply with the Guidelines criteria for removal of nematode eggs.

3. 6 Land Treatment of Wastewater

Land treatment is essentially the controlled and deliberate application of wastewater, either untreated or partially treated, as a means of disposal and as a form of treatment of waste.�rganics.

Land treatment relies on purely natural processes for the stabilization of organic matter and the separation of inorganics, whether in solution or as suspended material. The majority of elements found in municipal wastewater can be handled by natural processes in the environment: biological, biochemical, chemical and physical. However, since man's intervention to enhance the rate of these is very limited in land treatment technologies·, the overall treatment rate is slow. It also follows that the land.:..:area required is large compared with other methods of wastewater-Ztreatment and disposal.

The benefits of land treatment are: its simplicity, very little energy is needed, and the degree of control needed is limited and does not require highly trained staff for successful implementation. Although the term "land treatment" implies the use of land in treatment, this method of disposal of waste organics can recover valuable nutrients from waste and can produce an effective soilconditioning mulch. This is a direct form of resource recovery and can play an important part in the local agroeconomy. The simple technology offered by land treatment has to be carefully assessed in relation to the level of health awareness, hygiene education and control that can be expected in the project area. As in the case of "appropriate technologies" in sanitation and wastewater management, the success of lar.d treatmer.t depe:1ds centrally or. the inV·:Jl ve::!lent of the local community and its willingness to adapt to changes in its agricultural, social and cultural practices.


Public health risk has to be assessed with great care if land treatment is proposed. The survival of pathogens is known to be highly variable, depending on the types of organisms and where these are found in the environment, and the periods of survival may vary from 10 days or so in the case of certain bacteria, to many months or years in the case of the helminth Ascaris. While disinfection can be used with wastewater treatment to reduce the load of pathogens (bacteria and viruses) discharged into the environment, it is not effective in inactivating helminth eggs. Since intestinal parasites are the diseases that are endemic in many communities, the use of disinfection as a precursor to land treatment may give a false sense of security and lead to poor land use.

If land treatment is properly managed through natural processes of purification (e.g., sunlight, predation of bacteria in the soil and physical entrapment of pathogens within the soil), then the need for disinfection has to be questioned.

Three types of processes are included in land treatment: irrigation, groundwater recharge and surface run-off methods. Design parameters and practical issues were discussed. However, all these types operate at much lower rates than waste stabilization ponds, and all require a degree of pre-treatment of the wastewater before it is applied to the land. Nevertheless, there are surely circumstances where these methods are appropriate or where, in combination with other technologies, they can yield a net benefit to the community.

3.7 On-site Treatment of Wastewater

The range of sanitation systems that can be employed in rural and peri-urban areas were described. These are typically low-cost systems when compared with conventional sewerage and municipal wastewater treatment plants. However, it would be wrong to assume that health and standards of hygiene need necessarily be compromised when such low-cost technologies are used.

It is worth considering whether a water-borne sewerage system, and thus the production of wastewater, is in fact always the most appropriate choice to make. Wastewater collection and treatment systems are the most costly infrastructural investments. For example, a conventional sewerage system may cost per capita 20-40 times more than a simple dry.system, such as a pit-latrine. It is, therefore, certainly worth questioning the use of sewerage systems in communities where water is in short supply, that is, arid or semi-arid regions where the technical support to design, construct, operate and maintain sewerage systems and treatment plants is lacking and where financial resources are rather limited.

:s ·.. -::e�::!.ly n�c:'!r:sary t'J nb: -:ae-::�l ':".atter •;�.":.� ·..;�:er :C._;1 tr.e first place? Much of the cost of sewage treatment is in fact dedicated to the separation of the two.

WHO-EM/CEHA/46-E Page_ 8

In some of the densely populated areas of old established cities that already possess sewers, there is probably little choice but to continue with this approach. However, in other situations a much wider choice does exist and should be thoroughly evaluated. It is also clear from the data concerning sanitation coverage of rural populations in the Region at the end of the International Drinking Water and Sanitation Decade, that the problem still remains and is of substantial dimension.

The provision of sanitation is to break the faecal-oral route in disease transmission. It is also possible by using certain technologies for excreta disposal to recover valuable resources from the waste. Thus, by the appropriate selection of a sanitation system that meets the particular needs of a community and location, savings can be made in water demand, fertilizer needs and wastewater disposal costs, while the environmentally polluting nature of waste can be greatly reduced. Better food protection (i.e. , safety) is also possible, and a marked improvement in health is certain.

There are many alternative systems available that can be used in a variety of combinations, such as:

1) The ventilated pit latrine (VIP) , which is the simplest and cheapest of the sanitation systems, provideti care is taken in the design, construction and its use.

2) The pour flush toilet uses a small amount of water to provide a seal and is an effective low cost alternative to the pit latrine.

J) The septic tank requires a piped supply of water, and uses sewers to transfer excreta and sullage into the tank.

4) The aqua privy uses a water seal to eliminate-odours. 5) The composting toilet converts waste organics into humus

which is used as a soil fertilizer.

3.8 Sludge Handling and Disposal

In all biological systems, some sludge has to be removed from the system and disposed of separately. Approximately 0.3-0.4 kg sludge/kg BOD is removed in aerobic treatment processes. For anaerobic treatment processes, sludge production may be less in the order of 0.2-0.25 kg/kg BOD removed. There are different methods of sludge handling, dewatering and disposal. -Sludge dewatering methods include:

Natural:

(i) open sandbeds; (ii) covered sandbeds; (iii) $ludge lagocns.

Mechanical:

(i) sludge thickeners: (ii) vacuum filters:


(iii)build up of top soil: wet sludge can be spread in thin layers of 3-5 cm at-a time on eroded or waste land and allowed to dry, contouring the fields as necessary so as to gradually build up a top soil of agricultural value; and

(iv) co-disposal with pre-sorted solid wastes. This may be either in the form of composting by providing carbon per nitrogen ratio of 17:1, or direct disposal in a sanitary landfill.

A rational method of determining the sludge dewatering time on open sandbeds was presented, and essential differences were brought out between the characteristics of aerobic and anaerobic sludges, open sandbeds and covered sandbeds, etc. A sandbed design example, with all its details, was also presented.

3.9 Training/Education Approach in Sanitation for Developing Countries

Programmes and curricula in the field of sanitation in teaching institutions, particularly those in developing countries, should be updated over time, according to the needs of each country and the new developments that are taking place.

Wastewater treatment is a favourite subject in environmental engineering, but the study of its environmental impact on the ecosystem is usually avoided. In fact, the whole concept of ecosystem, environmental impact and protection, in which wastewater treatment occupies a certain part, should be included in the curricula of teaching institutions offering courses on the environment. Another aspect is the inter-disciplinary character of environmental subjects in general; it is, therefore, recommended that "cross-teaching" (scientists teaching engineering students and engineers teaching science students) would be beneficial for better understanding, interpretation and dissemination of knowledge on the environment.

Continuing education is a necessity to update existing knowledge and information. In this age of fast developments in every sphere of science and technology, education .is an ongoing life time process, and not relegated to the period of time spent at university. In order to become more conscientious about our environment, the abovementioned concept of ecosystem, environmental impact and protection should be offered to all engineering students in particular.

. T7aching institutions and universities should not work in �l�l�t==� ��o� �t�cr =3:�v�� =e��i�3 e�� st�t��on� �f ��e country. This is of vital importance particularly in developing countries, because technical cooperation among countries is extremely beneficial. In order to bridge the gap and encourage collaboration


between teaching institutions and other agencies and institutions working in the same field in the country, it is suggested that staff members of universities, as a rule, be asked to serve for a period in the relevant agency/institution of the government so that university staff will be exposed to the actual problems of the community, and thus have an opportunity of suggesting practical solutions.

To be able to produce successful projects, governmental agencies and institutions engaged in the field of water supply, sanitation and wastewater treatment and disposal in developing countries should use the "community participation approach" in the planning, design, construction and operation stages of their projects. Courses on the subject of community participation should be added to the teaching curricula of environmental and civil engineering students. The introduction of the same concept into continuing education studies, aimed at practising engineers and other professionals, is also encouraged.

3.10 Visit to Al-Samra Wastewater Treatment Plant

A half-day field trip was arranged, in collaboration with the Water Authority of Jordan, to Al-Samra Wastewater Treatment Plant to give an opportunity to participants to observe the·actual waste stabilization ponds in action. A guided tour of the'•freatment plant was provided by the engineer incharge of the plant. rt·was explained that there continued to be complaints about .obnoxious odours, particularly in the early morning hours, by the villagers 7-8 km away from the plant. Effluent from the treatment plant is the main tributary that feeds the King Talal Dam Reservoir used for irrigation.

4 . COUNTRY REPORTS

4.1 Afghanistan

Mr Abdul Wakil Akram, Ministry of Public Health, Kabul made a short presentation describing the wastewater collection and disposal situation in his country. There are no· wastewater collection networks in Afghan cities. on-site wastewater treatment and disposal methods are mainly used. Large buildings and government offices in Kabul ·have large cesspools dug into the ground: these pools have sides lined with stone masonry without mortar, with the result that sewage seeps into the soil. Individual houses usually have pit privies in one corner of the plot. When a pit is filled, it is abandoned and another one is dug.

4. 2 Egypt

A short presentation was made by Mrs Fatma Mustafa, Training Engineer of the National Organization for Potable Water and Sanitary Drainage, Cairo, and Mr Yahia M. Zaky of the Hydraulic Department of


the same Organization, on the method of wastewater treatment in general in Egypt. In Cairo, there are six wastewater treatment plants, which, with the exception of one, are of a conventional biological-process type (mostly activated sludge). A waste stabilization pond system has been designed for the 10th of Ramadan City, and it is .now functioning, though there are some problems. Because of underpopulation, the city is not producing enough wastewater as had been projected in its original design. Proposals were made to build waste stabilization ponds as wastewater treatment plants for cities of Alexandria, Suez and Tanta.

4.J Islamic Republic of Iran

A joint paper was presented by Hasan Ali Jafari, Senior Expert on Environmental Health, Ministry of Health and Medical Education, Isfahan Province, and Mr Nazem Jorfi, for Khoozestan Province.

It is the responsibility of the Ministry of Energy to implement the master plan and feasibility studies, and design and construct wastewater collection and treatment plants. The Ministry of Health and Medical Education is the responsible authority for pollution control and wastewater quality monitoring.

Isfahan, Shahin-Shahr, Kh.omeini-Shahr and Behbahan cities have wastewater treatment plants of a conventional type (activated sludge and trickling filters). Waste stabilization ponds are used for treating domestic wastewater of Hoveizah and Poolad-Shahr. Wastewater treatment plants are under construction for the following cities: Bandar Abbas, Tebriz, Meshed, Kashan, Shahreza, Shahr-e Kord and Sousangerd. Proposals for implementing wastewater treatment plants in many other cities and towns are under study.

4. 4 · Jordan

Muwaffaq Al Saqqar, Ministry of Water and Irrigation, Amman, his country's report on Low-cost Wastewater Treatment in About 52% of the rural population and 75% of its urban

are served by wastewater disposal facilities. All major Jordan have wastewater collection systems and !reatment

Fourteen WTPs are produci�g about 38 million m in 1990

Dr presented Jordan. population cities in plants. and it is expected that 60 million m of effluents will be produced

.in 1995.

Waste stabilization ponds (WSP) are considered to be the most appropriate treatment technology in Jordan, when land is available. There are six WSPs in Jordan, effluents of which account for about 85% of the total wastewater generated in 1990. Al Samra WSP complex, which is the largest wastewater treatment installation in Jordan, ��:-�"'::: :_bu4:•�f; ab:,ut a 1% ,,..

.1: �� t:::it-:11 --.... � s":-.. e"'4at:�r g�n'1�3.'ted ir, t!ie

country.


The project consists of 39 km of steel pipeline connecting·Anunan to the plant site. This pipeline is the longest siphon in the world, with lOOm head difference between the inlet and outlet. It serves most of the population of Amman (present population: one million); in addition, the wastewater generated in Zarqa (present population: 400,000) is also· pumped into this siphon. There are three identical trains of ponds in the plant, each composed of two aerobic ponds (Sm), four facultative ponds (2m), and four matur�tion ponds (1.2m). The total pond volume is about 3.6 mill!on m . At present, raw wastewater effluent is about 100,000 m /day and the WTP is functioning at about 50% overload. Recently, a comprehensive study has been initiated by the Water Authority of Jordan for an extension and upgrading of the ponds in Al-Samra WTP and to determine their impact on the environment.

4.5 Morocco

Mr Mustafa Al Muqaddam, Ministry of Health, Rabat, presented an interesting country report about the studies carried out in Morocco. It is considered that wastewater is a valuable water resource that should be properly reclaimed and reused. Morocco is paying serious attention to the reclamation and reuse of wastewater for agriculture. A series of studies and investigations on. low-cost wastewater treatment (waste stabilization ponds) are programmed� One of these experimental studies is currently in progress at Quarzazate City. In terms of compliance with the WHO Guidelines, the stabilization ponds with a detention time of 19 days produce highly satisfactory effluent (faecal coliforms 1000/lOOml and free of helminth eggs). A peculiar characteristic of this pond effluent is that it has an unusually high ratio of faecal streptococci to faecal coliforms, and this situation has been considered a complicating aspect of the final· assessment of the effluent quality as far as its reuse in agriculture is concerned.

4.6 Pakistan

Dr Javed Anwar Aziz, Institute of Public Health Engineering and Research, University of Engineering and Technology, Lahore, presented a report on the Application of Low-Cost Wastewater Treatment Technologies in Pakistan.

Approximately 70% of the population live in rural areas. Around 80% of the urban and 40% of the rural population have access·to potable water. Only 52% of the urban and 10% of the rural population are covered by sanitation facilities. In urban areas, sewage and industrial wastes are rarely treated and are mostly disposed of without treatment into water courses used for crop irrigation. To regulate the effluent discharges, the Pakistan Environmental Protection Agency has now proposed environmental quality control e�i�si�� s�ar.darjs.

WHO-EM/CEHA/4 6-E Page 13

In Pakistan, the cities of Karachi and Islamabad only have been provided with wastewater treatment plants consisting of trickling filters and activated sludge process, respectively. None of these plants has ever worked up to the desired efficiency, primarily due to lack of skilled operators. In view of the poor operation of these facilities, the recent trends in the country are to opt for waste stabilization ponds or aerated lagoons in wastewater treatment . In this respect, the Institute of PUblic Health Engineering and Research has conducted pilot-scale studies on the ponds system, and has suggested guidelines for the design of such facilities in and around Lahore. Encouraged by the research results, several cities, including Karachi, Hyderabad, Faisalabad, Lahore, Mardan, Quetta and Okara, have now planned to build pond systems to treat their domestic wastewaters. Ponds have also been built in many rural areas of Sind Province; however, their performance has been poor as they were left unattended and the communities used them to dispose of their solid wastes as well. An aerated lagoon facility has been provided in Karachi , which , due to lack of proper operation, has been operating poorly . Another aerated lagoon has recently been installed at Peshawar ; the results of its performance are still awaited.

It is envisaged that in the future more waste stabilization ponds and aerated lagoons will be constructed in Pakistan. It is realized that for the proper operation of these facilities the availability of skilled operators is necessary. In addition, the users must be educated to appreciate the benefits of the facility so that they can maintain it properly and do not misuse it.

4 . 7 Sudan

A joint country paper was presented by Mr Abdel Gadir El Tahir El Tilib, Director of Public Health Engineering Administration, Ministry of Housing and Utilities, Khartoum and Mr Mamoun Abdel Bagi Abdalla, Assistant Director in the same Ministry.

In Sudan, wastewater collection system exists only in Khartoum and in Khartoum North. The Khartoum drainage scheme started operating in 1959 with a network of sewers of about 146 km long with 13 pumping/lift stations, carTTing wastewater to a treatment plant with a capacity of 14, 600 m /day. The scheme is now getting old and is already overloaded. It is , therefore, now being rehabilitated to improve its performance and efficiency. The old . treatment plant will be abandoned completely and a new stabilization ponds system is being built to replace it . It is a three-stage pond system, consisting of anaerobic, fa�ultative and maturation units with a total capacity of 31, 400 m /day. The final effluent will be used for the irrigation of a green belt proposed around Khartoum City. This scheme covers about less than 20% of the population of Khartoum, -�d t� a rest c � ��e p=;u! at!cn is se�•ed ty cess?c�ls , pit privies , septic tanks and others.


The Khartoum North sewerage scheme started operating in 1971, with the industrial area as the first phase, and the second phase being the residential area, which has not yet been implemented. The scheme consists of 30 Jan of network of sewers , plus three lift/pump stations with 7 km long twin forced mains . The treatment plant consists of a three-stage stabilization pond system designed for a capacity of 6 million gallons per day. Due to the strong quality of industrial waste and the lack of nutrients and bacteria in the domestic wastewater, plant performance has been very poor and the effluent is left for evaporation and seepage. Serious consideration is now being given to the rehabilitation of this scheme, and also to the implementation of the second phase to improve the standard of l iving and sanitation in the city and to help in the treatment of industrial wastes, together with domestic wastewater so that better effluent is produced which may be used in irrigation.

4 . 8 Syrian Arab Republic

Mr Hinen Haddad, Ministry Engineering Department, Damascus, of Sewage Treatment in Syria.

of Housing and Utilities, Sanitary presented a report on the Methods

There has been no treatment of wastewater in the Syrian Arab Republic. Consequently, pollution of water bodies into which this wastewater is being discharged, has been increasing rapidly. However, some wastewater treatment plant feasibility studies were completed by the Ministry of Housing and Utilities, in collaboration with foreign and national consulting companies. These studies were based on conventional treatment methods, such as the activated sludge process, which requires highly skilled staff to operate and maintain the plants, in addition to the high cost of operation and maintenance. In other words, these treatment methods are not appropriate to the country' s local conditions.

In order to bridge this gap, the Ministry of Housing and Utilities recently issued the following recommendations regarding the type of wastewater treatment to be adopted:

1 ) Employment of WSPs should be sought in all regions where conditions are appropriate.

2 ) Possibility of modification should be sought in the design of treatment · plants, based on conventional systemz to . reduce the need for expensive, sophisticated mechanical/electrical equipment, and to meet the effluent quality requirements of WHO Health Guidelines for reuse in agriculture.

The following are the Utilities felt the need to �eth�d of wastewat9r treatment:

reasons why the Ministry of Housing and issue recommendations concerning the


a) There is enough existing land, at low cost or no cost at all (the land belongs to the State), around the proposed sites of treatment plants.

b) The Government is facing serious difficulties in financing the treatment plants.

c) There are · serious limitations in the technical expertise available in the country for operating and maintaining the sophisticated type of treatment plants.

d) There is a need for the reuse of treatment plant effluents for irrigation, and, therefore, compliance with the WHO Guidelines is important.

4.9 Tunisia

About 70% of the population is served by the water supply distribution system and about 35% have sanitary facilities for disposal of wastewater in Tunisia. At present, there are 23 wastewater treatment plants functioning, and 20 more are to be constructed in the near future. The types of existing treatment plants are given below:

13 activated sludge 2 trickling filter 3 WSP 2 primary lagoon 3 oxidation ditch

The "Water Code", which was adopted in 1975, defines the quality of effluent that may be used in irrigation. The Water Code prohibits the irrigation of vegetables consumed raw with wastewater even if it is treated.

a) Any kind of water that is to be used in agriculture should not present a risk to health, nor be a nuisance to the neighbourhood.

b ) Water to be used in agriculture should authorization should be · sought for the Ministries of Agriculture and Public Health.

be treated, purpose from

and the

In 1990, about 8 3 million m3 of treated effluent was produced, of which 13 million m3 were reused in agriculture.

4.10 Republic of Yemen

Sana ' a, which is considered the historical capital of Yemen , has a sewerage scheme covering 50% of the population. The Government is seeking financial support to build a sewe·rage scheme that will serve ��g =�rna�n��g pc?�lat i �n o f �he c�,ital . At ,rese�t , therg is no plan� to treat the wastewater collected from the city, so it is applied on land which is not appropriate for this purpose, causing


some · problems in the area, such as odour, mosquito breeding and contamination of groundwater in surrounding wells. To solve these problems, the Government has decided to build an activated sludge plant to minimize land requirements, as the land needed for the treatment plant belongs to a tribe.

A water supply and sewerage project was executed with 90% grant from the Federal Republic of Germany for the city of Ibb, which has a population of 60, 0 00. The treatment plant of this project is an activated sludge system, as there was · not enough land to build a WSP. There is also a problem in sludge disposal from the treatment plant, because of the high humidity and an insufficient number of drying beds. The plant effluent is discharged into a wadi , on the banks of which there are some villages that depend on the same wadi for their water supply. These villages claim that their water supply is contaminated by the disposal of the effluent, and are, therefore, demanding the construction of a new water supply project.

For 11 out for the employ WSPs who are not dimensions of houses.

other cities in the country, studies are being carried construction of water supply and sewerage projects which as the system of treatment. The rest of the population

served by sewerage systems, usually use cesspools of about 20m x 2m x 2m (20m deep) in- front of their

5. EVALUATION

An assessment made through the "Evaluation Questionnaire" (see Annex 5) filled in by the participants indicated that the course was well received and was quite useful to them, with good coverage of the subjects. The course material was quite relevant to their present work. suggestions • relating to some adj ustments about- the length of time assigned to some of the subjects, will =be given due consideration for future courses.


Annex 1

AGENDA

1. Wastewater treatment technologies

2. Microbiology and kinetics of wastewater treatment

3. Low-cost and energy saving treatment alternatives

4. Waste stabilization ponds

5. WHO Health Guidelines for Use of Wastewater in Agriculture and Aquaculture

6. Land treatment of wastewater

7. On-site treatment of wastewater

8. Sludge handling and disposal

9 . Training/education countries

approach in sanitation for developing


Annex 2

PROGRAMME

Saturday. 7 December 1991

08. 30

09. 30

09. 30

10 . 00

10 . 3 0 - 1 1 . 0 0

11 . 0 0 - 12 . 0 0

12 . 3 0 - 13 . 3 0

13 . 3 0 - 14 . 3 0

Registration and tour of CEHA

Opening session

Announcements Adoption of agenda

Introduction to wastewater treatment technology, by Dr S. Al-Salem

criteria for selection and decision sequence for wastewater treatment, by Dr Al Salem

Microbiology and kinetics of treatment, by Professor s . Arceivala

wastewater

Sunday, 8 December 1991

08. 30 - 09. 30

09. 30 - 12. 00

12. 00 - 14. 00

14. 30 - 15.00

Low-cost and energy saving wastewater treatment, by Dr Al-Salem

Waste stabilization Arceivala

ponds, by Professor

Introduction to WHO Health Guidelines for Use of Wastewater in Agriculture and Aquaculture, by Dr Al-Salem

Film on waste stabilization ponds

Monday, 9 December 1 9 9 1

08. 30 - 10. 30

11..00 - 13. 00

13. 30 - 14. 30

Land application/treatment of wastewater, by Professor P. Hillman

Design on WSP, by Professor Arceivala

On-site treatment of wastewater, by Professor Hillnan


Tuesday. 1 0 December 19 9 1

08 . 3 0 - 10 . 3 0

11 . 0 0 - 13 . 0 0

13 . 3 0 - 14 . 3 0

On-site treatment of wastewater, by Professor Hillman

Sludge handling and disposal, by Professor Arceivala

Presentations by participants

Wednesday. 11 December 1 9 9 1

08 . 3 0 - 10 . 3 0

11 . 00 - 1 2 . 0 0

12 . 0 0

Presentations by participants

Briefing on As-Samra WSP

Trip to As-Samra waste Stabilization Pond

Thursday, 1 2 December 1 9 9 1

08 . 3 0 - 09 . 3 0

09 . 3 0 - 1 0 . 3 0

11 . 0 0 - 12 . 0 0

12 . 0 0 - 13 . 00

Training/education approach in wastewater treatment for developing countries, by Professor Arceivala

Open discussions

Evaluation of the course (Questionnaire)

Closing session and speeches


Annex 3

LIST OF PARTICIPANTS

AFGHANISTAN

Mr Abdul Wakil Akram Ministry of Public Health Kabul

EGYPT

Mr Yahia Mohamed Zaky Sanitary Engineer Hydraulic Department National Organization for Potable Water

and Sanitary Drainage Cairo

Mrs Fatma El Zahraa Moustafa Training Engineer National organization for Potable Water

and sanitary Drainage Cairo

ISLAMIC REPUBLIC OF IRAN

Mr Jorfi Nazem Senior Expert on Environmental Health Ministry of Health and Medical Education Khoozestan Province

Mr Hassan Ali Jafari Senior Expert on Environmental Health Ministry of Health and Medical Education Isfahan Province

JORDAN

Dr Muwaffaq Al Saqqar Ministry of Water and Irrigation Amman

MOROCCO

WHO-EM/CEHA/46-E Page 2 1

Mr El Moustafa El Muqaddam Ministry of Health Rabat

PAKISTAN

Professor Dr Javed Anwar Aziz Institute of Public Health Engineering and

Research University of Engineering and Technology Lahore

SUDAN

Mr Abdel Gadir El Tahir El Tilib Director Public Health Engineering Administration Ministry of Housing and Public Utilities Khartoum

Mr Mamoun Abdel Bagi Abdalla Assistant Director Public Health Engineering Administration Ministry of Housing and Public Utilities Khartoum

SYRIAN ARAB REPUBLIC

Mr Hinen Haddad Ministry of Housing and Utilities Damascus

TUNISIA

Mr Lotfi Helaoui . , Ingenieur

Direction et de la

M inistere Tunis

• ' I I de l 'Hygiene du milieu Protection de l ' Environnement de la Sante'

REPUBLIC OF YEMEN


Eng. Abdul Wali Mohammed Seif Manager Ibb Treatment Plant General Organization for Water and Wastewater Ministry of Electricity and Water Sana'a

Dr H . El-Baroudi WHO Coordinator

WHO Secretariat

Regional Centre for Environmental Health Activities Amman

Dr A . Gur Information and Technology Transfer Adviser Regional Centre for Environmental Health Activities Amman

Professor P . Hillman WHO Consultant 82 Oak Tree Road Bitterne Park Southampton 502 4PH UK

Professor s . Arceivala WHO Consultant Associated Industrial Consultants (India) Private Ltd. Raheja Centre Nariman Point Bombay 400 021 India

Dr S . Al-Salem WHO Consultant Water Authority of Jordan Ministry of Water and Irrigation Amman Jordan


Annex 4

LIST OF REFERENCES

1. California State University. Operation of Wastewater Treatment Plants, Vol. 1, EPA 1988, Sacremento, U.S.A.

2. EPA. Process Designing Manual - Wastewater Treatment Facilities for Sewered Small Communities , EPA-625-11-77-009, October 1977.

3 .

4.

Seidel, F. H. the Hashemite 1981.

Recommended Wastewater Treatment Guidelines for Kingdom of Jordan. WASH Field Report No. 17, July

Wang, B. Ecological Waste Treatment and Low-Cost, Energy Saving/Generating and Technology for Water Pollution Control in ISLEWTT, Harbin, 1990 . Pergamon Press, 199 1 .

Utilization Systems on Resources Recoverable China . Proceedings of IAWPRC Vol . 24 , No. 5 ,

s . Bhamidimarri, R . , Shilton, A . , Armstrong, I., Jacobson, P. and Scalet, D. Constructed Wetlands for Wastewater Treatment Technologies . IAWPRC Vol . 24, No. 5, 19 9 1 .

6 . Batchelar, A., Boracco, R. and Pybas P. J. Low-Cost and Low-Energy Wastewater · Treatment Systems : A South African Perspective. Pergamon Press. IAWPRC Vol. 24, No. 5, 1991.

7. Gloyna E. F. Low-Cost Wastewater Treatment Ponds, Supplemental Aeration, Effluent Polishing, Wetlands and Land Disposal. University of Texas (Austin) , U.S . A., 1991.

8. Water Quality International Magazine of IAWPRC, No. 4, 1990.

9. Eckenfelder, W. w . Water Quality Engineering for Practicing Engineers. Barnes and Nobles, 1970 .

10. Adams, c . and Eckenfelder, w . w . Process Design Techniques for Industrial Waste Treatment. Enviro Press, 1974.

11. Shuval, H . I. and Adin, A . et al. Wastewater Irrigation in Developing Countries, Health Effects and Technical Solutions . World Bank Technical Paper Series No . 51, 1986.

12 . Mara, D. and Cairncross s . Guidelines for the Safe Use of Wastewater and Excreta in Agriculture and Aquaculture : Measures ::-:r P·1blic Health P!:"·Jtecticn . W:IO/TJNE? . 1�39 .

.


13 . WHO. Health Guidelines for the Use of Wastewater in Agriculture and Aquaculture . WHO Technical Report Series No. 778, Geneva, 1989 .

14 . Pacey , A. Sanitation in Developing Countries. J. Wiley, 1978.

15 . Feachem , R. G. and Cairncross s . Small Excreta Disposal Systems • . Ross Institute , 1978.

16 . Feachem R. G. and Cairncross s. Environmental Health Engineering in the Tropics. J. Wiley , 1983.


Annex 5

EVALUATION QUESTIONNAIRE

(Total number of course participants: thirteen)

Question 1

Question 2

Question 3

Question 4

Question 5

Quest ion 6

How useful did you find the course?

Not very useful Fairly useful Quite useful

0

3

10

How was the technical content of the lectures?

Poor Average Good

0

1

12

How relevant to your present work was the course?

Not very relevant Fairly relevant Quite relevant

How was the quality of audibility and visual

Poor Average Good

0 3

10

the lectures presentation?

0

4

9

in terms of

Were participants' presentations useful?

Not useful Useful It may be made more useful if following changes are made

How useful was the

Not very useful Fairly useful Quite useful

site

0

13

0

visit?

0 2

11

More opportunity should be given for discussions 1 Enough discussions took place 12 More discussions than necessary O

Question 8

Question 9

WHO-EM/CEHA/4 6-E Page 2 6

How did you benefit from the course?

Increased my knowledge of the subject Refreshed my knowledge of the subject No significant benefit

How was the amount of handout material

Not enough Fairly enough Too much

0 12

1

1 0 3 0

Question 10 How was the theoretical/practical nature of the course in general?

Too much theoretical (add more practical aspects) 2 A bit theoretical (add a little more practical aspects)2 Theoretical/practical in good combination 9 A bit practical (add a little more theoretical aspects)O Too much practical (add more theoretical aspects) O

Question 11 Was the course of right length?

Subjects Too short Right length

Introduction to WT 0 12 Criteria for selecting

the type of WT 4 9

Microbiology of WT 7 4 Low-cost and energy

saving WT 2 11 WSPs 1 12 WHO Health Guidelines 4 8 Design of WSPs 1 12 On-site WT 3 10 Land application WT 1 1 1 Sludge treatment and

disposal 6 6

��A bit long

1

0

2

0

0

1 0

0 1

1


Question 1 2 Please write down in the order of importance to you the topics discussed in the course given in Question.

Question 13 Suggestions for improving future offerings of the course

REPORT ON THE REGIONAL TRAINING COURSE ON LOW-COST ...

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