Mondal Md Ibrahim H, Takebira Umme Magreba
Polymer and Textile Research Lab, Department of Applied Chemistry and Chemical Engineering, Rajshahi University, Rajshahi 6205, Bangladesh.
Polymer and Textile Research Lab, Department of Applied Chemistry and Chemical Engineering, Rajshahi University, Rajshahi 6205, Bangladesh.
Sci Total Environ. 2023 Dec 10;903:166854. doi: 10.1016/j.scitotenv.2023.166854. Epub 2023 Sep 9.
The yarn dyeing factories discharge liquid waste laden with a variety of hazardous substances, including microplastic fibre (MPFs), which are found in aquatic ecosystems. During dyeing, MPF shedding factors were determined in this study. Shedding factors were determined at six polyester yarn dyeing factories to assess MPF release for (1) dark and (2) light shading. Three dyeing processes were considered including normal, carrier and high temperature. Sawdust-based activated carbon was utilized to decolourize dye wastewater. Flocculation and clarification were done without a flotation process to obtain low-density MPF. A hot needle test was applied to visual identification under an optical microscope and quantification was done by filtering, weighting and count of the yarn. A maximum of 0.00399 % weight loss (wt.) was found for dark shade in the high-temperature dyeing process and 0.00392 % (light) was found in carrier dyeing to dye a coarser yarn. In contrast, 0.4562 mg L fibre particles (≤ 0.225 mm) shedding in normal dyeing, for a light shade, was observed to a fine yarn where a minimum of 0.00138 % wt. was found. Shorter fibre length, higher denier, and courser yarn were associated with the greatest MPF discharge at high-temperature dyeing for a dark shade. The usual effluent treatment plant (ETP) of the textile industry can remove only 75.52 % MPFs of wastewater. Shedding of MPF during dyeing is remarkably higher than the domestic wash cycle of garments. Wastewater of textiles containing MPFs would appear as a regular and extensive initial source of MP emissions, which can damage the ecological system.
纱线染色厂排放的液体废物中含有各种有害物质，包括在水生生态系统中发现的微塑料纤维（MPF）。在本研究中，测定了染色过程中的MPF脱落系数。在六家聚酯纱线染色厂测定了脱落系数，以评估（1）深色和（2）浅色染色时的MPF释放情况。考虑了三种染色工艺，包括常规、载体和高温染色。利用木屑基活性炭对染料废水进行脱色处理。在不进行浮选工艺的情况下进行絮凝和澄清，以获得低密度的MPF。应用热针试验在光学显微镜下进行目视鉴定，并通过对纱线进行过滤、称重和计数来进行定量分析。在高温染色工艺中，深色染色的粗纱最大失重率为0.00399%，载体染色的浅色染色粗纱最大失重率为0.00392%。相比之下，在常规染色中，浅色细纱的纤维颗粒（≤0.225毫米）脱落量为0.4562毫克/升，其失重率最低为0.00138%。在高温染色的深色中，较短的纤维长度、较高的纤度和较粗的纱线与最大的MPF排放量相关。纺织行业通常的污水处理厂（ETP）只能去除废水中75.52%的MPF。染色过程中MPF的脱落量明显高于服装的家庭洗涤周期。含有MPF的纺织品废水将成为MP排放的常规且广泛的初始来源，这可能会破坏生态系统。
