Source Analysis And Detection Of Heavy Metals Antimony In The Life Cycle Of Polyester

The development of industrial processes such as dyeing, metal plating, mining operations, etc., has brought about water pollution due to the release of soluble toxic heavy metal ions. Heavy metals are not biodegradable and their propensity to accumulate in living organisms represents a health risk for human, animal and plant life. Moreover, these chemical species are often difficult to remove from aqueous effluents. As a synthetic fiber, polyester is the largest kind of fiber in the world. And then it is also faced with the risk of heavy metal pollution, especially antimony in its production process during its life cycle. Through the analysis of the existing literature data, we can analyze the presence of toxic heavy metal antimony in polyester fiber. The antimony mainly comes from the synthesis of the monomers PET during which the catalyst containing antimony is added in the synthesis of PET, such as antimony trioxide, antimony acetate, and ethylene glycol antimony. Therefore, this will increase the risk of heavy metal antimony contamination for downstream industries. In this paper, the important process of lifecycle of polyester was analyzed and the source apportionment of antimony during the process was determined. Then ICP-AES method was used to detect the total amount of heavy metal antimony in polyester fabrics and the content of antimony in polyester dyeing effluent. Following results were obtained:1. The condition of digesting process for polyester was studied. The inductive coupling plasma atomic emission spectrometry was carried out to detect the total amount of heavy metal antimony in polyester fabrics and the antimony concentration was 95μg/g with the 82.9%- 114.3 % recovery rate.2. The release of antimony ions during the dyeing process of PET was determined by ICP-AES method. The results showed that the concentration of heavy metal antimony in the effluent after dyeing is up to 0.41mg/L with 94.3%-114.3% recovery rate. The rate of heavy metal antimony diffusion equation was obtained on the basis of analysis of the principle of molecular diffusion: P=7.612×10-4×e0.0312 T, where P is diffusion rate(μg·g-1·min-1), T is temperature. Using this equation to calculate the concentration of antimony release on the holding stage of dyeing at 130℃ and the cooling stage of dyeing, the results showed that the calculated and the actual value has satisfaction consistency.3. In this paper, the results and related analysis showed that antimony-containing catalyst which was added in the syntheses of PET is an important source in the life cycle of polyester fabric. Meanwhile, the trials of polyester fabric heavy metal antimony test results showed that the concentration of heavy metal antimony can reaches 95μg/g. The amount of heavy metal antimony release from polyester fabric was 4.1μg/g during high temperature high pressure dyeing process, which indicated that only 4.3% of the total heavy metal antimony will be released during the dyeing process.