Method for removing phosphorus in concentred and dewatered sludge water by virtue of deeply-dewatered sludge water

Abstract

The invention discloses a method for removing phosphorus in concentred and dewatered sludge water by virtue of deeply-dewatered sludge water. The method comprises the following steps of: pre-precipitating the deeply-dewatered sludge water and the concentred and dewatered sludge water respectively, and removing suspended matters in the two types of sludge water; then measuring the pH values of the two types of sludge water and the concentrations of phosphorus respectively; adding the deeply-dewatered sludge water in the concentred and dewatered sludge water in a certain ratio; stirring and standing; then taking the supernatant and measuring the pH value of the effluent and the concentration of phosphorus. According to the method disclosed by the invention, the mutual reactions of sludge water generated in different sludge treatment phases of a sewage treatment plant can be utilized, precipitates are formed by the metal ions of the deeply-dewatered sludge water and the phosphorus of the concentred and dewatered sludge water, solid-liquid separation is performed on the precipitate particulate matters and the supernatant by standing, the effluent is discharged, and the formed phosphorus-containing precipitates are recycled; meanwhile, the pollutant loads of metal ions and phosphorus in the sludge water can be reduced, and the pollutant burden of the backflow of the sludge water to a front-end sewage treatment system or the entrance of the sludge water in a sludge water bio-treatment process is reduced; therefore, the method has the practical significance of treating waste with waste.

Description

technical field

[0001] The invention belongs to the field of sewage sludge treatment, and in particular relates to a method for removing phosphorus in sewage, in particular to a method for removing phosphorus in concentrated dewatered sludge water by using deep dewatered sludge water. Background technique

[0002] At present, the national sewage treatment capacity has increased from 11.4 billion m in 1999 3 increased to 49.6 billion m in 2011 3 , and the sewage treatment rate also increased from 31.9% in 1999 to 80.5% in 2011, and the amount of sludge generated has also increased significantly. However, the excess sludge has a high moisture content and a large volume, which is not suitable for direct transportation and disposal. Thickening and dehydration treatments reduce the volume of sludge. The wastewater generated during the sludge thickening and dewatering process is called concentrated dewatered sludge water. Under the mechanical concentration and high-speed centri...

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