Constructed Wetland for municipal sewage wastewater treatment in Middle East/North Africa [MENA] (Iran)

Contents

1. Introduction
1.1. Case study description
1.2. Area location
1.3. MENA - Iran condition
1.4. Objectives

2. Design
2.1. Basics for CW (Constructed Wetland) design
2.2. Design flowchart
2.3. Investment cost

3. Management plan
3.1. Operation & maintenance
3.2. Benefits and Revenue

4. Conclusion & Recommendation

1. Introduction

1.1 Case study description

The Middle East and North Africa (MENA region) is located between longitudes 13⁰ W and 60⁰ E between latitudes 15⁰ N and 40⁰ N covering a surface area of about 11.1 million square kilometers or about 8% of the area of the world (Fig. 1). MENA is the home for about 300 million people, or about 5% of the world's population, with an average annual population growth rate of 1.7% (World Bank, 2005). The 21 countries in the MENA region have many similarities of arid conditions (85% of the area is desert). Water resources are adversely affected as a result of changes in climate, population, economic development and environmental considerations. The MENA region can be considered as the most water-scarce region of the world (Droogers et al., 2012).

Iran (one of the countries in the Middle East located in southwest Asia) was used as the case study because certain parameters (precipitation, evapotranspiration, temperature and population equivalent) used were derived from this country. Iran has a complete desert climate that is very hot in the summer and relatively cold in the winter with scarce rainfall of 200 mm/year and high evapotranspiration (Droogers et al., 2012). Water crisis has appeared in Iran as a serious problem. There are reasons for that: (1) Lack of proper water management and (2) Occurrence of drought (Motiee et al., 2000)

Consequent to severe water scarcity, there is need for treatment of the generated wastewater for reuse. Constructed Wetland is one of the secondary treatments for treating primary effluent. This was designed to treat municipal sewage wastewater for one thousand persons in Iran.

1.2 Area location

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Figure 1.

Sources: http://forum.nationstates.net/viewtopic.php?f=20&t=211522&start=125 for MENA map and http://www.jacobsenrugs.com/iran.htm for Iran map

1.3 MENA - Iran Condition

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Figure 2.Women fetching water from a shallow depth muddy flowing stream.

Figure 3 A river already dried due to high evaporation

Figure 4 Camel drinking bottle water because of scarcity of natural water body

Figure 5 Woman fetching water from almost dried water pond

1.4 Objectives

Main objective is to design an economically feasible and sustainable constructed wetland for wastewater treatment in Iran (MENA region).

This could be achieved by

a. The reuse of the treated wastewater effluent for irrigation (vegetable production)
b. The reuse of the treated wastewater for fish pond

2. Design

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Figure 6.

Source: http://www.kibbutzlotan.eom/community/ecology/wetlands.html#.UVcftldiLXo

Constructed wetlands are man-made systems, designed and constructed to treat wastewater using the natural processes typical of natural wetlands. These natural processes are an interaction and combination of wetland plants (reeds), substrates (sand, gravels etc) and microbial organisms. Knowledge of these natural processes is used to control the operation and efficiency of the constructed wetlands. Constructed wetlands can be classified according to the water flow regime: surface flow systems and subsurface flow systems. Constructed wetlands with subsurface

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