Natural organic matter (NOM) affects some qualitative parameters of water such as color. In addition, it can deteriorate the performance of water treatment process including coagulation, adsorption, and membranes. NOM also reacts with chlorine in the chlorination process and may form disinfection by-products. The present study was carried out in laboratory-scale in a batch system using a cylinder shape reactor with effective volume of 2 l. The initial NOM concentrations during the study period were 10, 25, and 50 mg/l. After specific time intervals, samples were taken from the reactor and filtered. Finally, the NOM removal according to total organic carbon (TOC) content of the samples that were analyzed with a TOC analyzer. The results showed that the highest NOM removal efficiency for three initial concentrations 10, 25, and 50 mg/l were 91, 94, and 82%, respectively. These removal efficiencies were obtained at pH 7, contact time of 20 min, and electrical current of 0.1 A. The electrical energy consumption was 0.08, 0.06, and 0.03 kWh/m3, respectively. In this study, the application of electrocoagulation (EC) treatment method using combined Al and Fe electrode was examined to remove NOM from aqueous solution. Based on the obtained results, the EC can be used as an effective method for removing NOM from aqueous solution.

Background & Objectives: Pollution of water resources to organic matters and their associated problems including taste, odor, and formation of disinfectant by-products require evaluating removal methods for these materials from drinking water. This study aimed to evaluate performance of organic matter removal from water using deaerating system.Methods: A PVC pilot deaerator tower (diameter=15, height=140 cm) was designed, constructed, and used for this study. The system was loaded in flow rates of 0.6, 0.8, 1, 1.2, and 1.5 l/min. Absorption of samples were measured at wavelength of 253.7 nm and COD was determined for all samples.Results: COD levels and absorption rates of samples decreased with time for flow rates of.6, 0.8, 1, and 1.2 l/min. However, absorption rates and CODs increased with increasing flow rate (except for flow rate of 1.5 l/min).Conclusion: Deaeration tower system has capability to remove organic matters from water and the highest efficiency was observed at low flow rates. In addition, significant relationships (R2>0.95) was observed between COD and absorption rates (except for flow rate of 1.5 l/min), and that COD may be measured through determination of absorption rate at UV wave length.

Optimization of coagulation process for efficient removal of Natural Organic Matters (NOM) has gained a lot of focus over the last years to meet the requirements of enhanced coagulation. NOM comprises both particulate and soluble components which the latter usually comprises the main portion. Removal of soluble NOM from low turbidity waters by coagulation is not a successful process unless enough attention is paid to stages of formation and development of both micro and macro-floes. This study, which presents experimental results from pilot scale research studies aimed at optimizing coagulation process applied to synthetic raw waters supplemented by adding commercial humic acid with Low turbidity levels, explains how pH and turbidity can be controlled to maximize soluble NOM removal. The removal of NOM at various coagulant doses and coagulation pHs has been assessed through raw and treated (coagulated-settled) water measurements of total organic carbon (TOC). For low turbidity waters, essential floc nucleation sites can be provided by creating synthetic turbidities, for example by adding clay. Adjusting the initial pH at 5.5 or adding clay before coagulant addition allows the formation of micro-floes as well as formation of the insoluble flocs at low coagulant doses.

Background and Objectives: Natural organic matters (NOMs) are abundant in natural water resources and in many ways may affect the unit processes in water treatment. Although NOMs are considered harmless but they have been recognized as disinfection by-products (DBPS) precursors during the chlorination process. Formation of DBPS highly depends on the composition and concentration of NOMs. The objective of this study was to determine natural organic matter and its fractions concentrations in the surface water sources of Tehran.Materials and Methods: Water sampling was conducted monthly between May to July in three rivers of Lar, Jajrood and Karaj, as the main drinking water supplying sources in Tehran. Quantitative parameters of pH, EC, UV254 and DOC were studied based on standard methods. The XAD-7 resin method was used for fractionation of NOMs.Results: Results showed that NOM concentrations in Lar, Jajrood and Karaj rivers were 8.53, 12.9 and 11.3 mg/L, respectively. The HPO (hydrophobic) fraction was predominant compared to the HPI (hydrophilic) fraction in water samples. The mean of total percent of HPO and HPI fractions were about 57% and 43%, respectively.Conclusion: Since the hydrophobic NOM fraction exhibits higher trihalomethane formation potential (THMFP) than hydrophilic part, Tehran water chlorination exhibits higher THMFP than haloacetic acid formation potential (HAAFP). The information obtained from this study may be further employed in the design of the control techniques and management strategies for the water treatment plant, especially for DBPS reduction.