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151.
Use of modelling for optimization and upgrade of a tropical wastewater treatment plant in a developing country. 总被引:1,自引:0,他引:1
D Brdjanovic M Mithaiwala M S Moussa G Amy M C M van Loosdrecht 《Water science and technology》2007,56(7):21-31
This paper presents results of a novel application of coupling the Activated Sludge Model No. 3 (ASM3) and the Anaerobic Digestion Model No.1 (ADM1) to assess a tropical wastewater treatment plant in a developing country (Surat, India). In general, the coupled model was very capable of predicting current plant operation. The model proved to be a useful tool in investigating various scenarios for optimising treatment performance under present conditions and examination of upgrade options to meet stricter and upcoming effluent discharge criteria regarding N removal. It appears that use of plant-wide modelling of wastewater treatment plants is a promising approach towards addressing often complex interactions within the plant itself. It can also create an enabling environment for the implementations of the novel side processes for treatment of nutrient-rich, side-streams (reject water) from sludge treatment. 相似文献
152.
The problem of managing water scarcity by resorting to complex interconnected multi-source water systems needs to utilize
management optimization techniques analyzing aspects of water quantity and quality in a common strategy. In the southern regions
of Mediterranean Europe, the greater part of water resources for supply systems are derived from artificial reservoirs and
water systems can become quite complex since they interconnect several sources and demand centers, as indeed occurs in the
Region of Sardinia (Italy). A simplified approach to the requirement to insert water quality aspects in the mathematical optimization
model can be achieved by examining the trophic conditions of reservoirs. Trophic State Indexes (TSI) based on Carlson’s (1977) make it possible to insert quality constraints in the water management optimization model also considering complex multi-reservoir
and multi-user systems. Model formalization and implementation by the optimization toolkit WARGI (Water Resource system optimization
aided by Graphical Interface) (Sechi and Zuddas 2000; Manca et al. 2004; Salis et al. 2005) is illustrated in this paper. The usefulness of a mixed quantity–quality optimization approach has been confirmed by WARGI
application to a real multi-reservoir water resources system in southern Sardinia. The optimization model remains computationally
efficient dealing with this complex multi-reservoir system and the obtained results can be seen as a reference target in a
subsequent simulation phase. 相似文献
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Sebouh Aintablian Patricia A. Mcgraw Gordon S. Roberts 《Journal of Business Finance & Accounting》2007,34(1-2):389-401
Abstract: Loan announcement effects for 152 Canadian companies are examined to investigate the efficiency of monitoring by banks facing lender environmental liability. Market reaction to the announcement of bank debt to 'environmental' firms is more positive and significant than for 'non-environmental' firms and, for firms in industries with a higher likelihood of experiencing spill events, is more positive and significant, reinforcing earlier results that establish a relationship between specific loan/borrower characteristics and announcement period excess returns and providing further evidence on the 'uniqueness' of bank loans by demonstrating the superior ability of banks to monitor corporate borrowers exposed to environmental liability. 相似文献
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Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l. 相似文献