Particle size distribution based evaluation of biodegradation and treatability for leachate from organic waste

BACKGROUND: The study evaluated the relationship between particle size distribution (PSD) of chemical oxygen demand (COD) and treatability of leachate generated by organic waste. PSD determinations were performed together with physico‐chemical and biological treatability studies. Leachate biodegradation was also evaluated by means of oxygen uptake rate (OUR) profiles and experimental results were used for calibration of the adopted mathematical model. RESULTS: The leachate was characterized by a COD content of 80 000 mg L^?1 in summer. PSD analysis showed a bimodal distribution with around 60% of the COD below 2 nm and 25% above 1600 nm. Chemical treatment by lime and alum provided limited COD removal (30‐35%). The extent of COD removal was higher than the particulate COD fraction above 1600 nm, it also occurred in the soluble range below 2 nm through adsorption. A modeling study indicated three major COD fractions that could be correlated with PSD analysis: readily biodegradable COD and slowly biodegradable COD in the soluble range and hydrolyzable COD fraction in the particulate range. CONCLUSION: PSD‐based COD fractionation adequately explained limitations of chemical treatment efficiency; it was also a reliable complement to the currently used respirometric tests for biodegradation, providing insight to the fate of different COD fractions included in the soluble range (<2 nm) and yielding concrete supporting information on the generation of soluble residual microbial products. Copyright © 2011 Society of Chemical Industry     

Preparation of amidoximated poly(glycidyl methacrylate) microbeads

Poly(glycidyl methacrylate) (PGMA) microbeads were synthesized by a simple suspension polymerization of glycidyl methacrylate and ethylene glycol dimethacrylate. The epoxy groups of the microbeads were firstly modified with 3,3′‐iminodipropionitrile (IDPN) and the resulting nitrile groups were then converted to amidoxime. From scanning electron microscopy studies, the average size of the PGMA microbeads was determined as 170 µm, which was not changed by the modification processes. For the modification of epoxy groups with IDPN, the intensity of the C≡N absorption band at 2249 cm^?1 increased proportionally with reaction time; for the conversion of nitrile groups to amidoxime, it decreased. Attenuated total reflectance Fourier transform infrared spectroscopy measurements clearly showed the disappearance of the original nitrile groups and the formation of amidoxime groups through treatment with hydroxylamine under the reaction conditions specified. The microbeads possessed good thermal and morphological properties and chemical stability suitable for practical use. Therefore, the amidoximated PGMA microbeads could be used in batch and continuous processes for the adsorption of uranyl ions from seawater or aqueous media. Copyright © 2010 Society of Chemical Industry     

Treatability of Organic Constituents in the Paşaköy Wastewater Treatment Plant Effluent by O3 and O3/H2O2

Effluent from the Pa?aköy Wastewater Treatment Plant was oxidized by using O₃ and O₃/H₂O₂. DOC, COD, UV₂₅₄, total coliform, dissolved ozone and some endocrine disrupting compounds were monitored during oxidation. Results showed that O₃ provided superior disinfection, however, lower reductions in DOC, COD and endocrine disrupting compounds were exhibited compared to O₃/H₂O_2. The highest removal efficiency of DOC, COD and endocrine disrupting compounds were achieved at 0.5 molar ratio of O₃/H₂O_2. The benefit of H₂O₂ addition for advanced oxidation reduced significantly when the mole ratio was increased to 2. Therefore, the mole ratio of H₂O₂ to O₃ is a critical parameter for the design of wastewater oxidation by O₃/H₂O₂.     

Forecasting of CO2 emissions from fuel combustion using trend analysis

The accelerating use of fossil fuels since the Industrial Revolution and the rapid destruction of forests causes a significant increase in greenhouse gases. The increasing threat of global warming and climate change has been the major, worldwide, ongoing concern especially in the last two decades. The impacts of global warming on the world economy have been assessed intensively by researchers since the 1990s. Worldwide organizations have been attempting to reduce the adverse impacts of global warming through intergovernmental and binding agreements. Carbon dioxide (CO₂) is one of the most foremost greenhouse gases in the atmosphere. The energy sector is dominated by the direct combustion of fuels, a process leading to large emissions of CO₂. CO₂ from energy represents about 60% of the anthropogenic greenhouse gas emissions of global emissions. This percentage varies greatly by country, due to diverse national energy structures. The top-25 emitting countries accounted 82.27% of the world CO₂ emissions in 2007. In the same year China was the largest emitter and generated 20.96% of the world total. Trend analysis is based on the idea that what has happened in the past gives traders an idea of what will happen in the future. In this study, trend analysis approach has been employed for modelling to forecast of energy-related CO₂ emissions. To this aim first, trends in CO₂ emissions for the top-25 countries and the world total CO₂ emissions during 1971–2007 are identified. On developing the regression analyses, the regression analyses with R² values less than 0.94 showing insignificant influence in statistical tests have been discarded. Statistically significant trends are indicated in eleven countries namely, India, South Korea, Islamic Republic of Iran, Mexico, Australia, Indonesia, Saudi Arabia, Brazil, South Africa, Taiwan, Turkey and the world total. The results obtained from the analyses showed that the models for those countries can be used for CO₂ emission projections into the future planning. The calculated results for CO₂ emissions from fitted curves have been compared with the projected CO₂ emissions given in International Energy Outlook 2009 of U.S. Department of Energy calculated from “high economic growth case scenario”, “reference case scenario” and “low economic growth case scenario” respectively. Agreements between calculated results and the projected CO₂ emissions from different scenarios are in the acceptable range.     

Implementing a data mining solution for enhancing carpet manufacturing productivity

In recent years, knowledge has received significant attention in manufacturing to built a competitive advantage in the sector. Knowledge induction from data is an important issue in manufacturing to find the failure of the process then predict and improve the future system performance.This research examines the improvement of manufacturing process via data mining. Not only do we detect and isolate machine breakdowns in carpet manufacturing, but also we propose a C4.5 decision tree model. In addition, we use attribute relevance analysis to select the qualitative attribute’s variables. Consequently, manufacturing process is redeveloped.     

Lot streaming in a two-machine mixed shop

Most classical scheduling models overlook the fact that products are often produced in job lots and assume that job lots are indivisible single entities, although an entire job lot consists of many identical items. However, splitting an entire lot (process batch) into sublots (transfer batches) to be moved to downstream machines allows the overlapping of different operations on the same product while work needs to be completed on the upstream machine. This approach is known as lot streaming in scheduling theory. In this study, the lot streaming problem of multiple jobs in a two-machine mixed shop where there are two different job types as flow shop and open shop is addressed so as to minimize the makespan. The optimal solution method is developed for the mixed shop scheduling problem in which lot streaming can improve the makespan.     

Ambient response of a unique performance‐based design tall building with dynamic response modification features

A 64‐story, performance‐based design building with reinforced concrete core shear walls and unique dynamic response modification features (tuned liquid sloshing dampers and buckling‐restrained braces) has been instrumented with a monitoring array of 72 channels of accelerometers. The responses of the building to ambient motions from ground or wind were recorded and analyzed to identify modes and associated frequencies and damping. Not unexpectedly, the low‐amplitude dynamic characteristics are considerably different than those computed from design analyses. Nonetheless, these computed values serve as a baseline against which to compare future strong shaking responses. Such studies help to improve our understanding of the effectiveness of the response modification features at various levels of shaking, to evaluate the predictive capabilities of the design analysis tools and to improve similar designs in the future. Copyright © 2013 The Authors. The Structural Design of Tall and Special Buildings published by John Wiley & Sons Ltd.     

Laboratory comparison of the crumb-rubber and SBS modified bitumen and hot mix asphalt

The use of crumb rubber (CR) recycled from waste tires using an ambient grinding process was evaluated at two stages in asphalt formulation. First, bitumen modified with crumb rubber was evaluated by rotational viscometery (RV), dynamic shear rheometry (DSR) and conventional binder tests. Hot asphalt mixtures including crumb-rubber-modified bitumen were then evaluated by determining the permanent and fatigue characteristics and stiffness moduli of control and modified mixtures. The properties of the crumb-rubber-modified bitumen and asphalt mixtures were compared to different contents of styrene–butadiene–styrene (SBS) modified-bitumen and asphalt mixtures. The tests showed that to achieve the same performance, as with SBS-modification, the CR-content must be used at much higher than SBS. 8%-CR modification was determined as the most suitable content according to both binder and mixture tests.