Determination of Physicochemical Water Quality Parameter of Wastewater from Silk Production Industry in Rajshahi City

Attire is a fundamental necessity for humans, second only to food, and Bangladesh is celebrated for its manufacturing of high-quality garments. Meeting the domestic demand for garments, Bangladesh supplies its textiles globally. In 2022, Bangladesh exported a staggering $57.7 billion in textiles, solidifying its position as the world's second-largest exporter in this sector. A wide variety of fabrics exist, including cotton, silk, and wool. Silk, in particular, has been a symbol of elegance for centuries. Raw silk fibers, produced by silkworms, are composed primarily of two proteins: sericin (approximately 20-30%) and fibroin (approximately 70-80%).In Bangladesh, the total annual demand for silk is 300 Metric Tons and the local production is only around 40 metric tons. Currently, only a few silk firms which are situated in Rajshahi are playing a significant role in the silk production of Bangladesh. Rajshahi is the sixth largest city in Bangladesh which is popularly known as Silk City for its sericulture. The firms involved with this process spend a huge amount of water as it is estimated that the manufacture of one ton of raw silk requires between 850-1000 tons of water. As per some research, approximately 376 liters of water are needed to produce one silk shirt. The drainage system receives a fraction of this enormous volume of water. This waste water may contain various kind of heavy metals and it can be dangerous to any extent if those come in contact with environment. Total nitrogen, chemical oxygen demand(COD), total phosphorus for the dyeing and finishing process, and chemical oxygen demand (COD), NH3eN for the silk reeling process were the main causes of the water pollution effects. This study is about determining the physiochemical water quality parameters of wastewater from silk production industry in Rajshahi city, and also the presence of heavy metal in the drainage water. Results shows that the value of almost all the physiochemical water quality parameter exceeds the permissible limit which shows a high degree of pollution. Necessary steps must be taken to treat this wastewater effectively considering the socio-economical context of Bangladesh.