Environmental Pollution and Protection

7

Authors: Swabha Takshak, Shashi Bhushan Agrawal

Supplemental ultraviolet-B (s-UV-B) radiation (ambient+3.6kJ m-2 day-1) was given to two medicinal plants Withania somnifera and Coleus forskohlii for 3 h day-1 during the solar noon period. Changes at the anatomical level were studied in leaves and roots of the plants. Variations were observed in all s-UV-B treated plant-parts (except roots of W. somnifera). The changes included increased leaf thickness (W. somnifera), enhanced accumulation of UV-B absorbing compounds in leaves of both plants and roots of C. forskohlii, and reduced thickness of cork- and cambial cell layers in C. forskohlii. Due to reduction in the number of oil bodies in cork cells, essential oil content of C. forskohlii also reduced. The results suggest that the test plants are capable of defending themselves (at least partially) against s-UV-B; further in-depth studies are required to derive more substantial results linking the cellular level changes to the overall plant performance.

10

Authors: M. H. Kabir, M.M.H. Miah, M.M. Rahman, M. Kamal, M.T. Chowdhury

The activity concentrations of 238U, 232Th and 40K radionuclides have been determined for Sediment, Fish and Coral Samples collected from the St. Martin’s Island, Chittagong, Bangladesh. A total of 7 Samples (4 sediments, 2 fishes and 1 coral) from 3 different kinds were analyzed by using a High Purity Germanium (HPGe) detector of relative efficiency of 38%. For sediment samples, the mean activity concentrations of 238 U, 232Th and 40 K have been found 17.243±2.14, 25.207±2.302 and 460.802±50.957 Bq/Kg, respectively. The mean activity concentrations of fish samples for the corresponding radionuclide were 10.86±16.615, 10.555±13.51 and 364.92±361.345 Bq/Kg respectively. Also for coral sample, the mean activity concentrations for the corresponding radionuclide were13.06±2.1, 16.57±2.65 and 84.96±43.29 Bq/kg, respectively. The radionuclide 137Cs has not been detected in any of the samples. For sediment samples, the mean radiological hazard parameter values of outdoor absorbed dose rate, indoor absorbed dose rate, external radiation hazard, internal radiation hazard, annual effective dose equivalent, radium equivalent activity and representative level index were 43.863±2.877, 52.636±3.452 nGy.h-1, 0.239±0.015, 0.286±0.018, 53.793±3.525 µSvy-1, 88.695±5.672 Bq/kg, and 0.673±.04375 respectively. For fish samples, the mean values of the corresponding radiological indices were 27.368±19.606, 32.841±23.52 nGy.h-1, 0.146±0.103, 0.175±0.129, 33.563±24.227µSvy-1, 54.052±38.446 Bq/kg, and 0.421±0.302, respectively. For the case of coral sample, the values of the corresponding radiological indices were 20.183±7.36, 24.219±8.832 nGy.h-1,0.117±0.014, 0.152±0.017, 24.752±9.02 µSvy-1, 43.29±5.466 Bq/kg, and 0.309±0.041 respectively. The obtained results of this study show that most of the sample’s values are lower and the remaining are higher than the World average values. The mean representative index value is less than unity which confirms that the St. Martin area is safe for the inhabitants and the tourists. The results will be used as a baseline data for further researchers.

10

Authors: Arezoo Dadrasnia, Mohammed Maikudi Usman, Kang Tzin Lim, Rita Devi Velappan, Nasser Shahsavari, Pravin Vejan, Ahmad Fahim Mahmud, Salmah Ismail

Generation of wastewater is just unavoidable but its discharge into the environment is of great concern. Wastewater mainly comprised of any unwanted waste that could pollute our water system including sewage sludge, wastewater from domestic, industrial, dairy, fish canning and oil and gas industry. Since the early 1990s, microbial treatment processes have gained increasing attention due to its facility and high efficiency compared to conventional techniques. This paper focuses on the essential mechanisms involved in different microbial treatment techniques and special attention on the most recent challenges and developments will be highlighted in this review.