نشریه علوم و مهندسی آب و فاضلاب
سال سوم شماره 4 (زمستان 1397)

Pharmaceutical and personal care products are known as emerging pollutants in water resources. The presence of such products, even in very small amounts (within the range of micro to nano gram), has adverse effects on the environment and health. So far, many methods have been addressed in literatures for the removal of drugs from wastewater, the most important of which are the advanced oxidation processes such as ozonation (removal of over 99% of steroidal and non-steroidal drugs, antibiotics, lipid regulator and anti-inflammatory drug) Fenton and Photo-Fenton (complete destruction of antibiotics such as amoxicillin), photo-Fenton (complete elimination of ofloxacin and trimethoprim), sonolysis (removal of 100% ciprofloxacin), and UV/H2O2 (complete degradation of amoxicillin) and also combinations of these processes to reduce the reaction time and, as a result, costs. Due to the high oxidizing power of the ozone molecule, the ozonation process is a promising technology for the removal of those pollutants which cannot be removed from the water by conventional methods. This paper presents the results of the studies which have been carried out on ozone-based processes for removing contaminants from municipal wastewater and water. In addition, the role of effective parameters on the removal rate of pollutants, such as contact time of ozone with the pollutant, pH, ozone dose, pollutant concentration, and type of drug, were investigated.

In this study, the quality of surface water supplies in the southwestern region of Sistan and Baluchestan Province were evaluated for the purposes of drinking, industry and agriculture based on the results of chemical analysis. Firstly, the results of the analysis of surface waters from four selected stations were studied, then it prepared in GIS environment. In order to determine the quality of water for drinking, Ca, Mg, Na, TDS, TH, Cl, SO4 and HCO3 parameters are used and it was determined that the water of all stations was considered as inappropriate indicating hardness of the water in the area. Wilcox method is also utilized to determine the water quality in agricultural use. In the graph of this index, the horizontal axis index is water salinity in micro masses per centimeter and the vertical axis in relation to sodium absorption (SAR). Studies have also shown that the water of all stations is one of the classes C2-S1, C3-S1, C3-S2. During the statistical years it is considered to be agriculture. Also, in determining the quality of water for industrial use, the Langeous Saturation Index (LSI), which is in fact the difference between the actual pH of water and the saturated water content of calcium carbonate, was used and it was found that in all stations only three years of water for industrial use It is in a state of equilibrium and in the rest of years it is a precipitating and corrosive state. Therefore, the conditions in this area for the construction of water related to industries are also inadequate. To monitor, control and manage the system, the qualitative results of the analysis is entered into the GIS environment and the surface water database of the southwestern region of Sistan and Baluchestan province was formed and in the first step, zoning of important water quality issues to support the correct decision of the face accepted.

Penetration of pollutions to groundwater resources and extending in the aquifer environment can endanger the health in large volumes of groundwater resources as green and sustainable water. Pump and treat methods have not been widely used in Iran in last decades due to the operational complexity, exercising high potential costs and low threat of pollution. In this study, pump and treat methods are investigated for successful implementation and overcoming the failure factors in Iran. The study is library-based and the content is based on the experiences of this method for contaminated sites, scientific and experimental studies of this method, along with guidelines from the US Environmental Protection Agency in a descriptive-analytical manner. It is shown that determination of pollutant type and contamination range through sampling with new tools, hydraulic containment to prevent the spread of contaminated mussels, computer simulation, effective pumping operation, monitoring the contaminated area, employing a suitable purification method and evaluating the total operation performance, reducing the costs and duration of the project and the success of the pump and treat method are effective in achieving the objectives of purification practice in the contaminated area. The principal application of the pump and treat method can prevent the development of pollution in groundwater resources and high purification costs and help to rehabilitate many contaminated aquifers in Iran.

As a result of the climate change and water abstraction in neighbouring countries, domestic water supply to boarder line cities has faced serious challenges due to reduction in available water. Mashhad city is one of the most strategic cities of Iran that would face with water scarcity challenge. Though the Oman Sea water desalinization and transfer to Mashhad is being studied at the moment, this paper defines water demand and conventional and non-conventional regional water supplies and shows that the available regional water resources can meet domestic demand. Despite the low volume of water supply in some individual projects; local water management is superior to sea water transfer scenario in terms of economic and environmental aspects. Agricultural water consumption management based on groundwater entitlement and sewage water recycling are more suitable scenarios for domestic water supply. There are two alternatives for recycling sewage water including 1) substituting agricultural water with sewage in adjacent aquifers and convey clean water for domestic use and 2) secondary treatment of effluent and injecting it into domestic aquifer. Future domestic demand of Mashhad city is 1.5 times of existing demand and regional water supply schemes not only can meet the demand but also provide 122 MCM excess water (31% of demand) as confidence limit.

Now a days, the subject of water and its associated topics have gone beyond technical and service lines and water has become a commodity of strategic nature with the power to influence political, economic, environmental and even military change. This doubled and unprecedented sensitivity is the result of increased demand and scarcity of high quality water resources in adequate quantities. Over time, with less water resources being available, making decisions about water will be more subjected to political decisions. In this context, efficient water management and preservation of water resources for the future will mainly focus on four areas: attracting political support to improve water and wastewater services and management, engaging consumers in look for solutions to water shortage, strengthening regional and inter-sectorial partnerships to achieve water security and motivate consumers and attract their attention to the water crisis. It is clear that gaining success in these four approaches calls for and requires social intervention in the management of water and wastewater services. This article aims to highlight the necessity of a social approach to the management of water and wastewater services, while featuring some requirements and do's and don'ts.

One of the most important problems in drainage systems is the leaching of nitrate and its entry into surface water resources. Increased concentration of nitrate in water resources causes health problems to human and animals. The denitrification process, as one of the suitable solutions for nitrate removal from contaminated water, faces restrictions in agricultural soils due to lack of the carbon materials. Providing carbon in the soil promotes the process and removes more nitrate from the environment. The use of organic materials as cheap and affordable carbon is one of the best options for this purpose. In fact, biofuel reactor are a simple and relatively inexpensive technology in which carbon sources are used to facilitate denitrification. The intensity of denitrification in biological reactors depends on the type of carbon source, temperature, water soluble oxygen, hydraulic residence time and hydraulic parameters. Studies have shown that biological reactors are capable of removing up to 99 percent of nitrates in agricultural drainage. In recent years, numerous studies have been accomplished on the use of biological reactors and their ability and how they are applied to remove nitrates. In this paper, biological bioreactors of denitrification have been investigated as a method for removing nitrate from agricultural drainage.