DETERMINATION OF HEAVY METALS OF WATER, SOIL AND RICE GRAIN IN THE ADJACENT AREAS OF TANNERY AND TEXTILE MILLS AT SAVAR AND NARAYANGANJ

Abstract

In the present study, we investigated the heavy metals contamination in soil, water and crops in the adjacent areas of the Savar tannery and Narayanganj industrial area. The Pb concentration (0.16–0.32 mg/kg Savar, 0.6– 0.21 mg/kg in Narayanganj) in water from all the studied locations was lower than the permissible limit while Cd concentration (0.10– 0.15 mg/kg in Savar and 0.04 – 0.05 mg/kg in Narayanganj), Cr concentration (3.71 – 8.05 mg/kg in Savar and 1.27 – 1.93 mg/kg in Narayanganj) and the Cu concentration (0.17 – 0.49 mg/kg in Narayanganj) in water from all of the studied locations from Savar tannery and Naryanganj industrial area was higher than the permissible limits except the Cu concentration (0.04 – 0.08 mg/kg) in the sites of the Narayanganj area was lower than the maximum permissible limits. The Pb concentration (16.05–22.85 mg/kg in Savar and 21.95–28.4 mg/kg in Narayanganj) and Cu concentration (36.6 – 62.8 mg/kg in Savar and 25.6– 28.1 mg/kg in Narayanganj) in soil from all of the studied locations was lower than the permissible. On the other hand, the Cd concentration (4.13– 5.95 mg/kg) and Cr concentration (9049.95– 10115.9 mg/kg in Savar) in soil from all of the studied locations from Savar tannery study sites were much higher than the maximum permissible limits. The Cd concentration (0.91 mg/kg – 0.97 mg/kg) and Cr concentration (29.8– 32.05 mg/kg) in soil from the study sites in Narayanganj Industrial was lower than the permissible limits. The Pb concentration (8.42–9.2 mg/kg in Savar and 11.33– 12.88 mg/kg in Narayanganj), Cd (0.51–0.52 mg/kg in Savar and 0.41– 0.43 mg/kg in Narayanganj) and Cr concentration (42 –46 mg/kg in Savar and 37 – 41 mg/kg in Narayanganj) in rice grain from all of the studied locations was much higher than the permissible limits However, the Cu concentration of Savar and Narayanganj 18.8– 19.1 mg/kg and 17.8– 18.7 mg/kg respectively in rice grain from all of the studied locations was lower than the permissible limits (40 mg/kg). The trend of Transfer factor (TF) for heavy metals in studied rice grain samples from all of the studied locations was in order: Cr>Cu>Pb>Cd. In case of the sum of soil pollution index (SPI), the lowest SPI (1.38) in soil was found in the SP washing Ltd. samples and the highest SPI (72.31) was found in the Techplan leather samples. The lowest SPI (0.05) in water samples was found in the IsRA Knitting Ltd samples and the highest SPI (0.18) was found in the A.S Leather Export Ltd. samples. The lowest SPI (110.68) in rice grain was found in Yousuf Leather Co. samples and the highest SPI (153.35) was found in the Waseq textile mills Ltd. smaples. In the case of Metal pollution index, the lowest Metal pollution index (MPI) (24.2 mg/kg) in soil was found in the SP washing Ltd of Narayanganj samples and the highest MPI (42.8 mg/kg) was found in the Fthaf Leather of Savar tannery. The lowest MPI (0.06 mg/kg) in water samples was found in the Waseq textile mills Ltd samples and the highest MPI (0.33 mg/kg) was found in the Aboni leather samples. The lowest MPI (11.13 mg/kg) in rice grain was found in the Tanjin Leather Goods Ltd in and the highest MPI (13 mg/kg) was found in the Yousuf Leather Co. samples. Proper management plan should be taken to control the heavy metal concentration in the studied location of Savar and Narayaganj district.