All

Sludge is the ultimate by product of all traditional and conventional wastewater treatment processes. Conversion of the treatment sludge into new products is a significant disposal alternative for these wastes. In this study, branches, leaves and the organic and inorganic trash coming out from the aerated sand trap unit have all been mixed up with determined mixing ratios and composting has been realised by windrow-composting technique. The present study was conducted to investigate the effects of 4 different treatment sludge composts and chemical fertilizer on soil characteristics and plant (oat and grass) yields. Experiments were conducted in randomized black design with 3 replications in a plastic high-tunnel greenhouse. The sludge composts of sample1 (S1) and sample2 (S2) were applied at rates of 4 t/da and 6 t/da. Chemical fertilizer was applied in the form of N₈P₆. Grass was sown in a rate of 20 gr m^-2. Oat was sown in pots at a rate of 60 seeds per pot and then thinned to have 40 plants in each pot. Sludge composts in grass and oat culture significantly improved soil characteristics and increased the plant yields. It was concluded that sludge composts could be used as an alternative soil amendment.

This study aims to model the dispersion of two pollutants: nitrogen oxides (NO_x) and sulfur dioxide (SO₂) from an onsite biogas fueled generator by using CALPUFF modeling system. CALPUFF is a non-steady state puff simulating software that takes into account, meteorological data, terrain data and land use data, to effectively simulate dispersion from a given source. These data are taken from the different governmental and accredited organizations and used in conjunction with CALPUFF. Results showed a wider dispersion of both pollutants in January as supposed to June. This was due to rapid changes of wind’s speed and directionin the month of January. It was also discovered that the emission results were well below the point of impregnation (POI) limits set by the Ministry of Environment for its 24 hour, 1 hour and 30 minute averaging time periods of exposure. The findings of this study reveal that the proposed facility’s operation is in compliance with the Ontario regulations and that it should be able to operate in accordance with them, in the winter and summer seasons.

Aniline is a harmful substance that pollutes the environment and seriously endangers human health. In the present study five different bacteria were enriched and isolated from the soil around Shiraz refinery (Iran) as aniline degrading bacteria. They were identified as Enterobacter ludwigii KH-5, Raoultella planticola KH-A2, Alcaligenes faecalis KH-A3, Serratia marcescens KH-A4 and Microbacterium barkeri KH-A1 based on 16S rDNA gene sequencing. The highest aniline degradation rate (96%) was observed by E. ludwigii KH-A5. This strain with the greatest amount of minimum inhibitory concentration (MIC) was the most aniline resistant bacterium. The optimum pH and temperature that supported biodegradation of aniline by strain KH-A5 were 7.0 and 28-35 °C, respectively. The maximum growth and biodegradation of aniline by KH-A5 were observed at the initial aniline concentration of 100 mg l^-1. The strain could growth on aniline up to concentration of 700 mg l^-1 with the degradation rate of 11%. Further studies demonstrated that the addition of 0.5 g l^-1 glucose or potassium nitrate as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 96.0% to 99.0%. However, even more addition of glucose or potassium nitrate could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain KH-A5. It could be concluded that these new strains, particularly E. ludwigii KH-A5, have a potential use for bioremediation of the site contaminated with aniline.