D Rabbani - Environmental Health Department, Health Faculty, Kashan University of Medical Sciences, Kashan, Iran
N Mahmoudkashi - Environmental Health Department, Health Faculty, Kashan University of Medical Sciences, Kashan, Iran
F Mehdizad - Environmental Health Department, Health Faculty, Kashan University of Medical Sciences, Kashan, Iran

Aims Several methods have been used for textile wastewater treatment. The aim of thisstudy was to evaluate the efficiency of Rosa damascena watering waste ash for COD andcolor removal from textile wastewater.Materials & Methods Rose watering waste was gathered from one of the Kashan processingplants. The raw wastewater sample was taken from one of the textile industries in Kashancountryside. All experiments were run in the fixed volume (1L) of textile wastewater,contact times (15, 30, 45, 60, 75, and 90min), pHs (3, 5, 7, and 9) and different doses of rosewatering waste (500, 1000, 2000, and 4000mg) at the room temperature (25°C). Moreover,biosorption kinetic studies for COD were done using the pseudo first and pseudo secondorder models.Findings The amount of COD and color removal were increased by contact time increasingfrom 15 to 60min and the maximum removal of COD (50.3%) and color (31.4%) were seenat minute 60. Therefore, the contact time of 60min was chosen as the optimum contacttime for the first step. The maximum amount of COD (51.9%) and color (32.9%) removalwere seen at pH=5 and biosorbent dose of 2000mg. Changes at pH and biosorbent dosehad significant effects (p<0.05) on amount of COD and color removal.Conclusion The optimum condition for removing COD and color from textile wastewateris at contact time 60min, pH=5 and biosorbent dose of 2000mg. Rosa damascena wateringwaste ash was more effective on the COD removal than the color.

Color, Biological Oxygen Demand Analysis, Waste Water, Textile Industry