Clean 2009, 37 (4 – 5), 379 – 385 T. Ahmadzadeh Kokya et al. 379 Taher Ahmadzadeh Kokya 1 Bahman Ahmadzadeh Kokya 2 Khalil Farhadi 1 1 Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran. 2 Chemistry Laboratory, Department of Authority of Water Resources, Water Organization, Urmia, Iran. Research Article Evaluation of Remediation Effects of the Auto- Refining Processes of the Lavin River The dependence of the auto-refining process of the Lavin River, Iran, on the types and the quality of chemicals and organic compounds discharged into the river as the wastewater generated by sugar beet industries located nearby, was investigated. For the purposes of this study, sampling was performed utilizing a design-based static stationary sampling pattern. Several study stations were selected around the waste discharge location in order to perform sampling and field investigations during three sampling campaigns within two years. Numerous analytical procedures were per- formed on the samples for water quality assessment. In addition, a recently developed dispersive liquid-liquid microextraction method was employed as a more sensitive sample preparation method for the instrumental chemical analysis, in order to enhance the limits of detection of the trace biocide residues. The evaluation and vali- dation of the data acquired from the field observations, sampling, and river water quality assessment was performed using statistical methods. The obtained results showed that the auto-refining process is an exclusive river remediation factor that indicates a variety of auto-refining capacities for various chemical, physical and bio- logical contaminating parameters affecting the water quality of the Lavin River. Keywords: Auto-refining process; Dispersive liquid-liquid microextraction; Pollution; River; Sugar in- dustries; Water; Received: December 7, 2008; revised: March 23, 2009; accepted: March 23, 2009 DOI: 10.1002/clen.200800222 1 Introduction The improvement in living standards worldwide has resulted in people undertaking many waste producing activities, while there is nowhere to dispose the waste except on our living planet. In addi- tion, mankind is eagerly looking forward to hearing that there is a method to get rid of all waste and junk. However, currently there is no way except providence. In this way, nothing is more regrettable as the degeneration of the environment, which results in a degrada- tion of living standards that cannot be ignored. Currently, water- borne toxic chemicals pose the greatest threat to the safety of water supplies in industrialized nations [1]. The development of an under- standing of the sources, interactions, and effects of water pollutants is essential for controlling pollutants in an environmentally safe and economically acceptable manner [1]. The Lavin River is a wide shallow river located in the north west- ern part of Iran with an average flow rate of 7.43 million cubic meters per year. The river suffers from industrial waste discharge from a sugar beet factory due to inadequate waste treatment. In addition, water pollution in the site has been a major issue for about three decades now, resulting in undesirable effects in the environment (Urmia Water Organization Research Report, UWOR 1999). On the other hand, no extended pollution has been observed anywhere in the river except for one or two km from the waste dis- charge location. This is related to the auto-refining processes of the river that attempts to regain the river's initial condition before con- tamination. Sugar manufacturing facilities process beet into crystalline sugar and other by-products. Sugar beet, Beta Vulgaris, is a biennial plant that is grown in colder climates, that normally reaches maturity in the fall (October and November in Iran). Therefore, the manufacture of beet sugar is very much a seasonal operation [2]. Beet sugar pro- duction processes involve reception, cleaning, extraction, juice clar- ification, evaporation, crystallization, centrifugation, drying, stor- ing, and packing stages [3]. Along with these processes, three-stage purification is performed using considerable amounts of lime, car- bon dioxide and sulfur dioxide. As a result, a number of organic acids and non-sucrose products are precipitated as calcium salts, colloid flocculates, hydroxyl salts and hydroxides. In addition, phos- phate, sulfate and some alkaline metal ions are resolved due to the high pH of the purification process [2]. Sugar industry activities generate large quantities of waste and by-products, e. g., leaves, molasses, press mud, mud and soil arriving at the plant with the raw materials, which may also present a risk from crop pests, pesticide residues, and pathogens [3]. Sugar proc- essing wastewater is very turbid, dark and odorous and has a high content of organic material, and subsequently, a high biochemical oxygen demand, particularly due to the presence of sugars and organic material arriving with the beet. Correspondence: Dr. K. Farhadi, Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran. E-mail: khalil.farhadi@yahoo.com i 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.clean-journal.com