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The deterioration of environmental quality due to wastes generated from tannery industries is an alarming global issue in Bangladesh. To assess this problem in an area adjacent to the recently shifted tannery industries at Hemayetpur, soil, water and plant samples are collected from upstream as control, secondary treatment ponds, main discharge station and downstream at 500, 1000, 2000 and 3000 m across the areas and are analyzed for environmental quality. The water samples of Dhaleswari river are slightly acidic to moderately alkaline pH from 6.55 to 10.60, high TDS from 176 to 10,433 mg/l, EC from 305 to 18,206 μS/cm, nitrate from 0.14 to 194 mg/l, sulfate from 10.72 to 8922 mg/l, moderate phosphate from 0.58 to 7.2 mg/l and low DO from 1.61 to 5.50 mg/l. It is clearly noticed that most of the water parameters exceeded WHO guideline values except pH and phosphate that indicates Dhaleswari river water quality is declining slowly. The available concentrations of nitrogen, phosphorus, potassium and sulfur in soil varies from 12 to 263, 1.19 to 38, 17 to 170, 251 to 680 mg/kg, respectively, whereas, the total concentration ranges from 0.03 to 0.14%, 0.090 to 0.14%, 0.12 to 0.48%, and 0.11 to 0.42%, respectively. In soil samples, total phosphorus and potassium concentrations are increased but sulfur decreased. The soils are found acidic in nature that have high EC 8.17 dS/m. A significant positive correlation is found with each other of nitrogen, phosphorus, potassium and sulfur concentrations in soil samples. The nutrients in plant samples have no deficiency those are within the optimum range. Dhaka Univ. J. Biol. Sci. 31(1): 29-43, 2022 (January)

An investigation was conducted to determine the distribution and concentrations of different forms of Zn in the soils of Gazipur. Gerua, Kalma and Khilgaon soil series were identified in three land types, named as highland, medium high land and medium low land, respectively. Soil samples were collected from each soil series at three different depth such as surface (0 -15 cm), subsurface (15 -40 cm) and substratum (40 cm+) to determine soil characteristics and the distribution pattern of Zn fractions. Results indicated that amount of total Zn varied significantly, ranges from 14.99 to 36.11 ?g/g at different depth of different land types. Moreover, the purpose of the sequential extraction or fractionation was to find out the Zn in the exchangeable (Exch.), organic matter (Org.) bound, Mn oxide (Mn-O), amorphous Fe oxide (Am. Fe-O), crystalline Fe oxide (Crys. Fe-O) and residual (Res.) fractions. In Gerua, Kalma and Khilgaon soils, Zn concentrations predominated in Res. followed by Crys. Fe-O and Am. Fe-O fractions. Results reflected that soil properties influence the distribution of different Zn fractions in soils.Dhaka Univ. J. Biol. Sci. 25(1): 19-25, 2016

Experiment was carried out to assess the concentration of Zn, Cu, Pb, Fe and Mn in agricultural soil and plant near selected brick kilns. Soils and plants samples were collected from four points such as 250, 500, 1000 and 1500 m away from brick kilns. Three metals were found at elevated levels in the soils near brick kilns such as, Pb (92.5 to 214 mg/kg), Zn (86 to 156 mg/kg) and Cu (24.7 to 46.9 mg/kg). It may be caused due to burning of poor quality coal and fire woods. The uptake of heavy metals in the nearest areas (250 m) of the brick kilns was significantly higher than the areas far from the brick production and their concentrations range from 7 to 543 mg/kg for Pb, 23 to 101 mg/kg for Zn, 10 to 41 mg/kg for Cu, 35 to 1309 mg/kg for Fe and 26 to 126 mg/kg for Mn. Results indicated that soils and plants accumulated maximum amount of micronutrients within 500 to 1000 m distance from brick kilns significantly decreased with distance. Iron and manganese were not polluting the soils near brick kilns but affecting the plants. Therefore, it can be suggested that no agricultural crops should be grown within 1000 m distance from a brick kiln.Dhaka Univ. J. Biol. Sci. 25(1): 75-81, 2016

A pot experiment was carried out to observe the effect of waste water irrigation on the growth and nutrient status of Kalmi (Ipomoea aquatica) in the nethouse of the Department of Soil, Water and Environment, University of Dhaka. The soil samples were collected from Tejgaon, Rampura, Sitalakhya and from the north?side of Rampura area, the latter is located at a distance from the polluted area and has been used as the control soil. The pots containing the first three soil samples were irrigated with wastewater collected from the adjacent industrial area and control pots were irrigated with tap water. The plants on Tejgaon soil produced the maximum biomass while the plants on Sitalakhya produced the least amount of biomass. The accumulation of toxic metal concentration was found to be the highest in Kalmi grown on Tejgaon followed by Rampura and Sitalakhya. The metal concentration in Kalmi (dry weight basis) ranged between 31 and 408 mg/kg for Zn, 27 to 45 mg/kg for Cu, 0.2 to 5.0 mg/kg for Pb and 0 to 2 mg/kg for Cd, respectively. The concentrations of heavy metals in the Kalmi were higher than the recommended standards in all the treatments except control.DOI: http://dx.doi.org/10.3329/dujbs.v23i1.19820Dhaka Univ. J. Biol. Sci. 23(1): 1?8, 2014

A macrocosm study was carried out to assess the transfer of arsenic (As) from irrigation water and sludge of arsenic removal water filter to two varieties of Amaranthus and their effects on phosphorus (P), potassium (K), sulfur (S), calcium (Ca) and magnesium (Mg) uptake. P and K uptake in shoot and root were negatively affected by As that were not significant. However, a significant negative relationship was observed between As and S in shoot. A positive and significant relationship existed between As and Ca of green Amaranthus shoot but it was negative and insignificant in case of red Amaranthus . Mg content of shoot and root was positively affected by As in green Amaranthus . On the other hand, in the red Amaranthus the relation between As and Mg was positive in the shoot but negative in the root. DOI: http://dx.doi.org/10.3329/dujbs.v21i1.9748 DUJBS 2012 21(1): 87-96