Water Quality Indices as Important Tools for Water Quality Assessment in WWTP: The case of the waste water treatment plan of Ain El Hout Tlemcen

Abstract

The scarcity of conventional water resources represents for Algeria, because of its Mediterranean climate arid to semi-arid, a major concern. The global water potential of Algeria does not exceed 13.2 billion m3 of water, which offers an annual volume of 412 m3 to each citizen. Considering the vulnerability of available water resources to the impact of climate change, population growth as well as socio-economic factors, a situation of severe water scarcity occurs, which hinders the development of the country. This project seeks to study the feasibility of reusing the treated domestic wastewater for agricultural purposes as an adaptation measure to climate change. The area under investigation is Tlemcen Town, an arid region located in North Western Algeria. Climate studies have shown that climate change through the drought that has occurred in the past decades has affected the whole of the country and more particularly the North Western region. This has been characterized by a negative impact on available water resources as well as on the agricultural productivity. In Algeria, agricultural irrigation is the primary water-consuming sector followed by domestic and industrial sectors. It is therefore imperative to rationalize the use of conventional water resources. The reuse of treated wastewater represents the alternative for the preservation of the available water resources and the promotion of the agricultural sector. The present study is intented to calculate water quality index (WQI) of an urban wastwater treatment plan, in Ain El Hout in Tlemcen town , in order to ascertain the quality of water used in agriculture, to detect the major problems in WWTP, to analyze the water quality parameters in discharged effluents and to assess the water quality indices for the effluents discharged from WWTP. There are several ways to assess the quality of water as deemed fit for irrigation. Water quality index, indicating the water quality in terms of index number, offers a useful representation of overall quality of water use, as well as in pollution abatement programmes and in water quality management. A number of parameters affect the usability of water for a particular purpose. In this study the water quality index will be electrical conductivity, total suspended solids, dissolved oxygen, biological oxygen determined on the basis of various physic-chemical parameters likexiv Temperature, pH, demand, Chemical Oxygen Demand, Phosphates, nitrate, Ammonium Nitrogen and Nitrite