Characteristics of ashes from different locations at the MSW incinerator equipped with various air pollution control devices

The characteristics of ashes from different locations at a municipal solid waste incinerator (MSWI) equipped with a water spray tower (WST) as a cooling system, and a spray dryer adsorber (SDA), a bag filter (BF) and a selective catalytic reactor (SCR) as air pollution control devices (APCD) was investigated to provide the basic data for further treatment of ashes. A commercial MSWI with a capacity of 100 tons per day was selected. Ash was sampled from different locations during the normal operation of the MSWI and was analyzed to obtain chemical composition, basicity, metal contents and leaching behavior of heavy metals. Basicity and pH of ash showed a broad range between 0.08-9.07 and 3.5-12.3, respectively. Some major inorganics in ash were identified and could affect the basicity. This could be one of the factors to determine further treatment means. Partitioning of hazardous heavy metals such as Pb, Cu, Cr, Hg and Cd was investigated. Large portions of Hg and Cd were emitted from the furnace while over 90% of Pb, Cu and Cr remained in bottom ash. However 54% of Hg was captured by WST and 41% by SDA/BF and 3.6% was emitted through the stack, while 81.5% of Cd was captured by SDA/BF. From the analysis data of various metal contents in ash and leach analysis, such capturing of metal was confirmed and some heavy metals found to be easily released from ash. Based on the overall characteristics of ash in different locations at the MSWI during the investigation, some considerations and suggestions for determining the appropriate treatment methods of ash were made as conclusions.     

Approaches to Evaluate Water Quality Model Parameter Uncertainty for Adaptive TMDL Implementation1

Abstract: The National Research Council recommended Adaptive Total Maximum Daily Load implementation with the recognition that the predictive uncertainty of water quality models can be high. Quantifying predictive uncertainty provides important information for model selection and decision‐making. We review five methods that have been used with water quality models to evaluate model parameter and predictive uncertainty. These methods (1) Regionalized Sensitivity Analysis, (2) Generalized Likelihood Uncertainty Estimation, (3) Bayesian Monte Carlo, (4) Importance Sampling, and (5) Markov Chain Monte Carlo (MCMC) are based on similar concepts; their development over time was facilitated by the increasing availability of fast, cheap computers. Using a Streeter‐Phelps model as an example we show that, applied consistently, these methods give compatible results. Thus, all of these methods can, in principle, provide useful sets of parameter values that can be used to evaluate model predictive uncertainty, though, in practice, some are quickly limited by the “curse of dimensionality” or may have difficulty evaluating irregularly shaped parameter spaces. Adaptive implementation invites model updating, as new data become available reflecting water‐body responses to pollutant load reductions, and a Bayesian approach using MCMC is particularly handy for that task.     

Inhibition of Murine Norovirus and Feline Calicivirus by Edible Herbal Extracts

Human noroviruses (HuNoVs) cause foodborne and waterborne viral gastroenteritis worldwide. Because HuNoV culture systems have not been developed thus far, no available medicines or vaccines preventing infection with HuNoVs exist. Some herbal extracts were considered as phytomedicines because of their bioactive components. In this study, the inhibitory effects of 29 edible herbal extracts against the norovirus surrogates murine norovirus (MNV) and feline calicivirus (FCV) were examined. FCV was significantly inhibited to 86.89 ± 2.01 and 48.71 ± 7.38% by 100 μg/mL of Camellia sinensis and Ficus carica, respectively. Similarly, ribavirin at a concentration of 100 μM significantly reduced the titer of FCV by 77.69 ± 10.40%. Pleuropterus multiflorus (20 μg/mL) showed antiviral activity of 53.33 ± 5.77, and 50.00 ± 16.67% inhibition was observed after treatment with 20 μg/mL of Alnus japonica. MNV was inhibited with ribavirin by 59.22 ± 16.28% at a concentration of 100 μM. Interestingly, MNV was significantly inhibited with 150 µg/mL Inonotus obliquus and 50 μg/mL Crataegus pinnatifida by 91.67 ± 5.05 and 57.66 ± 3.36%, respectively. Treatment with 20 µg/mL Coriandrum sativum slightly reduced MNV by 45.24 ± 4.12%. The seven herbal extracts of C. sinensis, F. carica, P. multiflorus, A. japonica, I. obliquus, C. pinnatifida, and C. sativum may have the potential to control noroviruses without cytotoxicity.     

Application of titania from Ti-Salt flocculated sludge for UHPC

Journal of Material Cycles and Waste Management - In this paper, Ultra High Performance Concrete (UHPC) specimens using Titania extracted from Ti-Salt agglomerated sludge analyzed both the...     

Characteristics of products and PCDD/DF emissions from a pyrolysis process of urethane/styrofoam waste from electrical home appliances

A plastic fraction consisting mainly of polyurethane/styrofoam waste is generated after separating valuable spare parts and metals from used electrical home appliances. In Korea, such waste is currently incinerated in cement kilns or is landfilled. However, owing to its high volatile matter content, conversion into gaseous or liquid pyrolysis products is a preferable alternative. A pyrolysis process of polyurethane and styrofoam waste from electrical home appliances was evaluated by characterizing the products generated at 500°–800°C. The para meters determined were the yields of gas, oil, and char; the characteristics of the remaining char; and the con centration of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzo-furans in the product gas. As expected, the char yield decreased at higher temperatures, whereas gas and oil yields showed increasing tendency. The oil products could be used as storable fuels with a calorific value of 6000–8000 kcal/kg. Fine pores were observed in the char. The adsorption and decolorizing ability of the char were almost the same as those of activated carbon, so that pyrolysis char has potential for use as a sorbent. Further feasibility studies will be needed before utilizing pyrolysis technology to recover either fuels or usable products from polyurethane/styrofoam waste.     

Variability of nitrous oxide and carbon dioxide emissions continuously measured in solid waste incinerators

Nitrous oxide and carbon dioxide were continuously measured and variability of emission factors (EFs) was evaluated in five municipal waste incinerators (MWIs) and four industrial waste incinerators (IWIs) from 24 to 86 days between 2008 and 2011. N₂O EFs were calculated by Monte Carlo simulation and mean N₂O EFs were 7.1, 107, 127, 219 g N₂O/ton waste combusted in MWIs with selective catalytic reduction (SCR) for NOx control, MWIs with selective non-catalytic reduction (SNCR), IWIs with SNCR, and a MWI using fluidized bed with SNCR, respectively. Climate-relevant CO₂ EFs ranged from 0.45 to 0.72 ton CO₂/ton waste combusted in MWIs. Maximum values of upper limit for 95% confidence intervals (CIs) of N₂O EFs estimated in each MWIs with SCR, MWIs with SNCR, IWIs with SNCR were 185, 94, 101% of mean N₂O EFs, respectively. Meanwhile, maximum values of upper limit for 95% CIs of CO₂ EFs were much lower as between 18 and 36% in those facilities. 84% CIs of mean N₂O EFs in MWIs with SNCR and IWIs with SNCR were overlapped indicating those values are not significantly different.     

Practices in dioxin emission reduction by special regulatory enforcement and utilizing advanced control technologies for incinerators in Korea

This study strives to estimate the emission of dioxin and furthermore attempts to find the best technological control methods available for waste incinerators by investigating the emission status thereof. In order to incorporate the Stockholm Convention, a particular stringent law was promulgated in Korea and in recent years incinerators were forced to utilize better technological control. After the enforcement of special dioxin emission regulation in 2003, the average concentration of dioxin emitted from municipal and industrial waste incinerators decreased from 15.25 and 12.86 ng TEQ Nm(-3) to 5.53 and 4.96 ng TEQ Nm(-3) in 2001 and 2004, respectively. Based on test results at commercial plants, several best arranged sets of air pollution control devices (APCDs) were suggested in order to provide guidelines to help operators. These sets included combinations of spray dry absorbers, bag type filters, wet scrubbers, selective catalytic reductions and electrostatic precipitators. Different suggestions and real installations of APCD arrangement were investigated during the years around the regulation in effective. The results were presented depending on the capacity of the incinerators and different waste streams to observe the efforts to reduce dioxin emission by operators of incineration plants. The annual amount of dioxin emission from the incinerators is expected to be 212.5 g-TEQ in 2011 and 234.3g-TEQ in 2015, respectively, compared to 891.6g-TEQ recorded in 2001. The enforcement of new regulation and the installation of better APCDs showed the significant effect on such reduction. This reduction in dioxin emission from incinerators confirmed the nation's commitment to the regulatory requirement set by the Stockholm Convention.     

Analysis of the effects diclofenac has on Japanese medaka (Oryzias latipes) using real-time PCR

The expression levels of cytochrome P450 1A, p53 and vitellogenin were investigated in three different tissues of male medaka fish after exposure to diclofenac that is one of the main concerns among pharmaceuticals frequently found in sewage treatment plant (STP) effluents. The results showed that cytochrome P450 1A, p53 and vitellogenin were highly expressed in tissue-specific gene expression patterns after exposure to 8 mg/l and 1 μg/l of diclofenac. These elevated expression levels of three biomarkers suggested that diclofenac has potential to cause cellular toxicity, p53-related genotoxicity and estrogenic effects. It is also noteworthy that diclofenac has the potential to cause these effects even at an environmentally relevant concentration of diclofenac, 1 μg/l.