Improper disposal and spills of spent engine oil into the environment can result in contamination, which eventually affects humans through the food chain. Mycoremediation is an effective and inexpensive alternative to clean up spent engine oil contamination. In recent work, the potential effectiveness of fungi for degrading spent engine oil was confirmed, with the species identified through molecular identification. Fungi that were able to grow in Bushnell Haas Broth supplied with spent engine oil were identified with the potential to utilize spent engine oil as a carbon source. Six species of fungi namely Penicillium simplicissimum, Aspergillus nidulans, Aspergillus niger, Trichoderma longibrachiatum, Aspergillus ustus, and Aspergillus flavus were successfully identified in this study. Over a course of seven days, P. simplicissimum (21.11 percent) was identified as the most effective fungi in degrading spent engine oil, followed by A. nidulans (17.75 percent), A. niger (15.85 percent), T. longibrachiatum (15.12 percent), A. ustus (15.02 percent), and A. flavus (11.80 percent). As these species of fungi were isolated from the natural environment in Peninsular Malaysia, the potential of using these fungi as mycoremediation of spent engine oil was therefore confirmed. 相似文献
Nitrogen pollution of waters has sometimes caused severe eutrophication, leading to the death of fishes and most aquatic life. There is therefore a need for efficient and cost-effective methods to remove nitrogen from ammonium-rich wastewaters. Anaerobic ammonium oxidation (ANAMMOX) is a promising process to remove nitrogen because this process directly oxidizes ammonium (NH4+) to dinitrogen gas (N2) under anoxic condition. Nonetheless, a challenge of this process is that chemolithoautotrophic Anammox bacteria grow slowly at the beginning, thus resulting in low Anammox biomass and instability of reactors. Such issues can be overcome by granulation of the Anammox sludge. Here, we review the characteristics of the Anammox bacteria, and the formation, structure and flotation of Anammox granules under high hydraulic loadings. We also evaluate the performances of full-scale granular Anammox processes. The major points are: 1) Anammox bacteria secrete a large amount of extracellular polymeric substances (EPS), up to 415 mg g?1 of volatile suspended solids (VSS), containing many hydrophobic functional groups that facilitate biomass granulation. 2) Granulation enhances the sludge settling property and retention time, which contributes to the extremely high nitrogen removal rate of 77 kg m?3 d?1 of Anammox upflow reactors. 3) Flotation of Anammox granules frequently occurs under nitrogen removal rate higher than 10 kg m?3 d?1, which is mainly due to the overproduction of EPS under high hydraulic conditions. 相似文献
In this study, a multi-level-factorial risk-inference-based possibilistic-probabilistic programming (MRPP) method is proposed for supporting water quality management under multiple uncertainties. The MRPP method can handle uncertainties expressed as fuzzy-random-boundary intervals, probability distributions, and interval numbers, and analyze the effects of uncertainties as well as their interactions on modeling outputs. It is applied to plan water quality management in the Xiangxihe watershed. Results reveal that a lower probability of satisfying the objective function (θ) as well as a higher probability of violating environmental constraints (qi) would correspond to a higher system benefit with an increased risk of violating system feasibility. Chemical plants are the major contributors to biological oxygen demand (BOD) and total phosphorus (TP) discharges; total nitrogen (TN) would be mainly discharged by crop farming. It is also discovered that optimistic decision makers should pay more attention to the interactions between chemical plant and water supply, while decision makers who possess a risk-averse attitude would focus on the interactive effect of qi and benefit of water supply. The findings can help enhance the model’s applicability and identify a suitable water quality management policy for environmental sustainability according to the practical situations.