Dejesusguldbrandsen1899

A process for the continuous extraction of ammonia from anaerobic digesters is proposed. In this process, a portion of the sludge treated in the digesters is continuously withdrawn and transferred to a thin film evaporator (TFE) unit, where the ammonia is stripped through a biogas stream. The ammonia-rich biogas is treated with a sulfuric acid/water solution in a reactive absorption unit, with production of ammonium sulphate. The chemistry of a CH4/CO2/NH3 gas phase in thermodynamic equilibrium with a liquid sulfuric acid/water solution is investigated theoretically, with focus on the simultaneous absorption of CO2 and NH3 into the liquid phase. Pilot plant experimental data confirm the theoretical results. Further pilot plant experimental results obtained during on-off cycles of the stripping equipment demonstrate that, when the TFE unit is off, ammonia concentration in the digestate rises quickly, while, when the stripping equipment is turned on again, ammonia concentration drops down. On average, during the 180 days of pilot plant experimentation, 4.1 g N-NH4 per kg of sludge fed to the digester, i.e. 19.3 g N-NH4 per kg of total solids (TS) fed to the digester, are stripped from digestate and recovered as ammonium sulphate, demonstrating the feasibility of the proposed concept. The integration of one anaerobic reactor in the mainstream (AMSR) of a pre-denitritication-MBR was evaluated with the aim to achieve simultaneous sludge minimization and phosphorous removal. The excess sludge production was reduced by 64% when the AMSR was operated under 8 h of hydraulic retention time (HRT). The highest nutrients removal performances referred to organic carbon (98%), nitrogen (90%) and phosphorous (97%) were obtained under 8 h of HRT. In contrast, prolonged anaerobic-endogenous conditions were found to be detrimental for all nutrients removal performances. Similarly, the lowest membrane fouling tendency (FR = 0.65∙1011 m-1 d-1) was achieved under 8 h of HRT, whereas it significantly increased under higher HRT. The highest polyphosphate accumulating organisms kinetics were achieved under HRT of 8 h, showing very high exogenous P-release (46.67 mgPO4-P gVSS-1 h-1) and P-uptake rates (48.6 mgPO4-P gVSS-1 h-1), as well as a not negligible P-release rate under endogenous conditions at low COD/P ratio (≈1). Waste from drilling operations of oil and gas wells in the event of poor management, in addition to imposing costs, can lead to environmental problems. This research was aimed at providing a suitable model for collecting, transferring, and recycling the drilling wastes produced in the operational areas of the Iranian offshore oil company. Data analysis was performed using the Expert Choice and template selection using the analytical hierarchy process method. Based on the results of this study, the method of collecting waste in a cutting skip (weight = 0.576) was identified as a suitable option in the waste-collecting sector. read more In the waste transfer sector, the waste shipments from the west of the Persian Gulf to Kharg Island (weight 0.623) and the transfer of waste from the Eastern areas to Lavan island (weight 0.625) were selected as suitable options. Among the waste recycling options, the thermal method with of 0.433 was chosen as a top priority. Large volume of wastewater consisting complex forms of organics, lipids and nutrients, is discharged from the abattoir (red meat) processing industry. In this study, nutrient rich pre-Anaerobic Membrane Bioreactor (AnMBR) treated abattoir effluent was fed to a struvite (MgNH4PO4.6H2O) precipitator to evaluate the possibility of developing an innovative environmentally sustainable treatment technology to produce nutrient free high-quality treated effluent. A series of continuous and batch experiments were conducted to investigate the influence of pH and presence of Ca2+ on struvite precipitation. The study found that Mg2+Ca2+ molar ratio of 0.8 (or high Ca2+) impacts on the production and quality of struvite significantly. Pre-AnMBR treated abattoir wastewater with negligible Ca2+ (Mg2+Ca2+ molar ratio > 20) showed over 80% removal of phosphorus via struvite precipitation. The highest removal rates of both nitrogen and phosphorus were achieved at pH 9.5 with Mg2+PO43- molar ratio of 21. Crown All rights reserved.The steel industry is the largest consumer of energy in the world among industrial sectors. It is generally acknowledged that energy and environment are intimately related. Steel production is an energy intensive process that has a significant environmental impact. This paper reviews the progress made on energy consumption, carbon dioxide emissions and water consumption in the steel industry worldwide. The reduction in the availability of fresh water resources combined with the effects of global warming and climate change have increased pressure on industries, especially steel, to reduce its overall pollution, and specifically its water and carbon footprint. The implications of these effects on the value chain is discussed in this review. The contribution of new emerging technologies of iron and steelmaking is also reviewed. Finally, the important issues that contribute to define a sustainable industrial activity such as the recycling of steel and of by-products of steel production are studied. The history of steel industry is full of lessons, one of which is the need to keep the dreams alive. There are indeed expectations to solve problems created by technical progress. Three different organic substrates, K-medium, sterilized activated sludge (SAS), and methanol, were examined for utility as substrates for enriching manganese-oxidizing bacteria (MnOB) in an open bioreactor. The differences in Mn(II) oxidation performance between the substrates were investigated using three down-flow hanging sponge (DHS) reactors continuously treating artificial Mn(II)-containing water over 131 days. The results revealed that all three substrates were useful for enriching MnOB. Surprisingly, we observed only slight differences in Mn(II) removal between the substrates. The highest Mn(II) removal rate for the SAS-supplied reactor was 0.41 kg Mn⋅m-3⋅d-1, which was greater than that of K-medium, although the SAS performance was unstable. In contrast, the methanol-supplied reactor had more stable performance and the highest Mn(II) removal rate. We conclude that multiple genera of Comamonas, Pseudomonas, Mycobacterium, Nocardia and Hyphomicrobium play a role in Mn(II) oxidation and that their relative predominance was dependent on the substrate.