Monitoring of Phenol in Wastewater Bioremediation by HPLC

Bioremediation emphasizes the detoxification and destruction of toxic substances by microorganisms. Wastewater obtained from an industrial concern was solvent extracted with methyl alcohol and dichloromethane and analysed by GC/MS. Besides phenol, a large variety of organic compounds were detected. Under controlled laboratory conditions, the wastewater was innoculated with a mixed culture of microorganisms specially selected for their abilities to degrade phenol. Samples were collected at regular intervals from the stirred tank bioreactor and analysed for phenol by reverse phase HPLC with a C18 column. Results shows that from an initial phenol concentration of 987 ppm, slightly more than 50% was destroyed within 163 hours. The dry weight of the microorganisms and the plate count (CFU/ml) shows a steady increase from 0.5238 gms to 0.5355 gms and from 1.1E+9 to 1.94E+13 respectively over the same period. This suggested that the phenol was consumed by the microorganisms as the sole carbon source.     

Use of X-ray absorption imaging to examine heterogeneous diffusion in fractured crystalline rocks

Heterogeneous diffusion in different regions of a fractured granodiorite from Japan has been observed and measured through the use of X-ray absorption imaging. These regions include gouge-filled fractures, recrystallized fracture-filling material and hydrothermally altered matrix. With the X-ray absorption imaging technique, porosity, relative concentration, and relative mass of an iodine tracer were imaged in two dimensions with a sub-millimeter pixel size. Because portions of the samples analyzed have relatively low porosity values, imaging errors can potentially impact the results. For this reason, efforts were made to better understand and quantify this error. Based on the X-ray data, pore diffusion coefficients (Dp) for the different regions were estimated assuming a single diffusion rate and a lognormal multirate distribution of Dp. Results show Dp for the gouge-filled fractures are over an order of magnitude greater than those of the recrystallized fracture-filling material, which in turn is approximately two times greater than those for the altered matrix. The recrystallized fracture-filling material was found to exhibit the greatest degree of variability. The results of these experiments also provide evidence that diffusion from advective zones in fractures through the gouge-filled fractures and recrystallized fracture-filling material could increase the pore space available for matrix diffusion. This evidence is important for understanding the performance of potential nuclear waste repositories in crystalline rocks as diffusion is thought to be an important retardation mechanism for radionuclides.     

Ferric Oxide Incrustations on Cell Walls of the Green Alga Cladophora rupestris Growing near an Iron Ore Unloading Terminal

Cladophora rupestris plants growing near an iron ore unloading terminal bore red-brown cell wall incrustations. These were shown to be of ferric oxide by histochemical tests. Iron-free Cladophora plants transplanted to this same location developed Fe₂O₃ incrustations after 3-4 weeks. Similar crustose deposits of smaller sizes were observed on Cladophora plants growing near rusty chains in a harbour at some distance from the ore terminal. Cladophora would seem to be a useful factor monitoring organism for iron ore dust spillage in the sea.     

Ferric Oxide Incrustations on Cell Walls of the Green Alga Cladophora rupestris Growing near an Iron Ore Unloading Terminal

Cladophora rupestris plants growing near an iron ore unloading terminal bore red-brown cell wall incrustations. These were shown to be of ferric oxide by histochemical tests. Iron-free Cladophora plants transplanted to this same location developed Fe₂O₃ incrustations after 3–4 weeks. Similar crustose deposits of smaller sizes were observed on Cladophora plants growing near rusty chains in a harbour at some distance from the ore terminal. Cladophora would seem to be a useful factor monitoring organism for iron ore dust spillage in the sea.