Evaluation study on efficiency of using sandy filters as primary processing of sewage water in Ramadi city

Sewage water characterization is of high importance to reduce its harmful effects. Hence this study was carried out to evaluate primary processing of sewage water of Ramadi city using sandy filters. The experiments were conducted in the College of Agriculture, University of Anbar during the spring season of 2019. Three separation funnels of 250 ml volume, with the diameter and length of 4 cm and 20 cm, respectively, were designed. Each funnel had a conical end and was provided with a valve to control the water movement. To perform the experiments, the funnels were filled with different sizes of sand particles, namely fine sand (FS) (with 0.85-1.70 mm diameter), coarse sand (CS) (with 2.36-3.36 mm diameter), and sand mixture (SM) (50:50 ratio). Then the sewage water was passed through the three funnels and all extracted water was collected from each funnel separately. The chemical properties of water samples were also measured both before and after processing to evaluate the efficiency of processing. The chemical analyses consisted of pH, EC, Ca, Mg, Na, K, Cl, and SO4 as well as heavy and micronutrients (Cu, Cd, and Pb). The biological oxygen demand (BOD) and chemical oxygen demand (COD) were also measured. The efficiency of processing by sand showed contrasting results, where the FS was more efficient in decreasing Pb and Cd as well as COD and BOD, while there was an increase in Na, Cl, and SO4, in addition to pH and EC. The CS was the most efficient filter in decreasing Mg, Ca, and Cl contents, whereas MS was more efficient in reducing Ca and K concentrations.