Journal of Material Cycles and Waste Management - Over 60 million tons of aluminium are produced annually, requiring sustainable and eco-friendly recycling methods of aluminium waste. In this work,... 相似文献
The seasonal variations of Cd, Pb, and Cu in the water, sediments, and freshwater fish (Hypophthalmichthys molitrix, Cirrhinus molitorella, and Oreochromis mossambicus) of four lakes in Hanoi, Vietnam, were investigated. Samples for analysis were taken four times from April 2010 to March 2011. The levels in water were lower than the Vietnamese standards, except for Pb, but they were all much higher than the Canadian standards for protection of aquatic life; in the sediments, they were higher than world average levels. Bioaccumulation of the three metals in fish was site-dependent and species-dependent, but correlations of their levels in fish to those in water and sediments were weak. Levels of Pb in fish exceeded those of the UK and the WHO standards, and the recommended values of Vietnam for human consumption. Overall, the results show that the lakes are polluted with these metals, and consumption of high quantities of fish from them may be problematic. The outcome of this research helps to establish background data for future monitoring. 相似文献
This article aims to describe the influence of diffuse pollution on the temporal and spatial characteristics of natural organic matter (NOM) in a stratified dam reservoir, the Daecheong Dam, on the basis of intensive observation results and the dynamic water quality simulation using CE-QUAL-W2. Turbidity is regarded as a comprehensive representation of allochothonous organic matter from diffuse sources in storm season because the turbidity concentration showed reasonable significance in a statistical correlation with the UV absorbance at 254 nm and total phosphorus. CE-QUAL-W2 simulation results showed good consistency with the observed data in terms of dissolved organic matter (DOM) including refractory dissolved organic carbon (RDOC) and labile DOC and also well explained the internal movement of constituents and stratification phenomenon in the reservoir. Instead turbidity and NOM were related well in the upper region of the reservoir according to flow distance, gradually as changing to dissolved form of organic matter, RDOM affected organic matter concentration of reservoir water quality compared to turbidity. To control the increase of soluble organic matters in the dam reservoir, appropriate dam water discharge gate operation provided effective measurement. Because of the gate operation let avoid the accumulation of organic matter within a dam reservoir by shorten of turbid regime retention time. 相似文献
Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen (T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models—artificial neural networks (ANNs) and support vector machines (SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination (R2), Nash–Sutcliff efficiency (NSE), relative efficiency criteria (drel). Additionally, Latin-Hypercube one-factor-at-a-time (LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage. However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process. 相似文献
This study aims to investigate the anaerobic degradation kinetics of reactive dye, C.I. Reactive Red 141 (Evercion Red H-E7B) by partially granulated anaerobic mixed culture using three carbon sources, namely modified starch (MS), polyvinyl alcohol (PVA) and acrylic size (AS) during batch incubation. There is a first-order kinetics reaction in the decolorization processes using MS and PVA as carbon sources, while a zero-order kinetics relationship describes the decolorization process for the AS carbon source. The k values and color removal rate of decolorization with MS carbon source was higher than those of PVA and AS carbon sources. This is because the MS carbon source was well degraded in comparison to AS and PVA, respectively This study also found dye reduction could be enhanced through the addition of MS as a carbon source. The decolorization rates increased with decrease in dye concentrations of RR 141. In contrast, the decolorization rates increased with increase in COD concentration. 相似文献
A number of bench scale laboratory column tests were carried out using a newly designed and developed electrokinetic cell
to investigate the fundamental behavior of zinc-spiked kaolin clay subjected to an electric field. Laboratory investigations
focused on (i) zinc migration by the combined effects of electromigration and electro-osmosis and (ii) the electrically induced
desorption characteristics of zinc-contaminated kaolin that occurred during processing. The correlations of the applied voltage
gradient, electro-osmotic flow rate, and the development of a pH gradient were examined and evaluated. The results showed
that the removal efficiency was high during the early stage of processing due to rapid desorption by electrokinetic effects
in the cathode region. However, the majority of zinc migrating from the anode was precipitated due to the high pH environment
in the cathode region. 相似文献
This work demonstrated a simple, low-cost, rapid, and effective biochemical oxygen demand (BOD) estimation system based on a packed-bed bioreactor that can be easily self-built on-site at a particular wastewater treatment plant for continuous monitoring of the influent and effluent. The use of natural microbial consortium that were collected from the target wastewater and immobilized on a cheap porous carrier simply by adhesion resulted in an acceptable accuracy of over 95%. The newly developed semi-continuous operating mode with peak-type signals was shown to be able to continuously estimate BOD at a high flow rate to overcome the flow dependence of the oxygen electrode, limit clogging issues, enhance the response time, and lower the limit of detection. The resulting packed-bed bioreactors could work continuously for 22 h with a coefficient of variance (CoV) of only 1.8% or for 13 h a day for several days with a maximum CoV of 1.4% and their response was observed to be stable over 80 consecutive measurements. They exhibited stable responses at a wide pH range of 6.5–8.5, which is also the recommended range for aerobic wastewater treatment, emphasizing the greater ease of use of natural microorganisms for BOD estimation.