Nomogram to predict postoperative cognitive dysfunction in elderly patients undergoing gastrointestinal tumor resection.

Objective: To establish a nomogram model for the prediction of postoperative cognitive dysfunction (POCD) in elderly patients undergoing gastrointestinal tumor resection. Methods: A total of 369 elderly patients scheduled for elective gastrointestinal tumor resection under general anesthesia were included. The cognitive function of each participant was assessed by the Mini-Mental State Examination (MMSE) 1 day before surgery and 7 days after surgery for the diagnosis of POCD. According to the results, patients were divided into a POCD group and a non-POCD group. The differences in hospitalization data and examination results between the two groups were compared. A logistic regression model was used to explore the risk factors for POCD in elderly patients undergoing gastrointestinal tumor resection, and a nomogram was then constructed based on these factors. The diagnostic performance of the nomogram was evaluated using the area under the receiver operating characteristic curve (AUROC) and a calibration plot. The clinical usefulness of the nomogram was estimated using decision curve analysis (DCA). Results: Among the 369 patients undergoing gastrointestinal tumor resection, 79 patients had POCD, with a positive rate of 21.4%. The nomogram model comprised the following variables: age, body mass index (BMI), history of cerebrovascular disease, preoperative white blood cell (WBC) count, preoperative hemoglobin (Hb) level, intra-operative blood loss, and operation time. The model showed good discrimination, with an area under the curve (AUC) of 0.710 (95% CI = 0.645-0.775), and good calibration (Hosmer-Lemeshow test, χ2 = 5.133, p = 0.274). Internal validation also maintained ideal discrimination and calibration. Decision curves indicated that when the threshold probability was above 0.1, the nomogram achieved more benefit than both the treat-all and treat-none policies. Conclusion: This scoring system is the first nomogram model developed for the prediction of POCD in elderly patients undergoing gastrointestinal tumor resection. It has good efficacy in the prediction of POCD risk and could provide an important reference for the prevention, management, and treatment of POCD.

COL5A1 Promotes the Progression of Gastric Cancer by Acting as a ceRNA of miR-137-3p to Upregulate FSTL1 Expression.

MicroRNAs (miRNAs) and their target genes have been shown to play an important role in gastric cancer but have not been fully clarified. Therefore, our goal was to identify the key miRNA-mRNA regulatory network in gastric cancer by utilizing a variety of bioinformatics analyses and experiments. A total of 242 miRNAs and 1080 genes were screened from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), respectively. Then, survival-related differentially expressed miRNAs and their differentially expressed target genes were screened. Twenty hub genes were identified from their protein-protein interaction network. After weighted gene co-expression network analysis was conducted, we selected miR-137-3p and its target gene, COL5A1, for further research. We found that miR-137-3p was significantly downregulated and that overexpression of miR-137-3p suppressed the proliferation, invasion, and migration of gastric cancer cells. Furthermore, we found that its target gene, COL5A1, could regulate the expression of another hub gene, FSTL1, by sponging miR-137-3p, which was confirmed by dual-luciferase reporter assays. Knockdown of COL5A1 inhibited the proliferation, invasion, and migration of gastric cancer cells, which could be rescued by the miR-137-3p inhibitor or overexpression of FSTL1. Ultimately, bioinformatics analyses showed that the expression of FSTL1 was highly correlated with immune infiltration.

PTBP3 modulates P53 expression and promotes colorectal cancer cell proliferation by maintaining UBE4A mRNA stability.

The RNA binding protein PTBP3 was recently reported to play a critical role in multiple cancers, and the molecular mechanisms involved RNA splicing, 3' end processing and translation. However, the role of PTBP3 in colorectal cancer (CRC) remains poorly explored. Herein, PTBP3 was upregulated in CRC and associated with a poor prognosis. PTBP3 knockdown in colorectal cancer cell lines restricted CRC proliferative capacities in vitro and in vivo. Mechanistically, PTBP3 regulated the expression of the E3 ubiquitin ligase UBE4A by binding the 3' UTR of its mRNA, preventing its degradation. UBE4A participated in P53 degradation, and PTBP3 knockdown in colorectal cancer cell lines showed increased P53 expression. UBE4A overexpression rescued PTBP3 knockdown-induced inhibition of CRC cell proliferation and P53 expression. Our results demonstrated that PTBP3 plays an essential role in CRC cell proliferation by stabilizing UBE4A to regulate P53 expression and may serve as a new prognostic biomarker and effective therapeutic target for CRC.

Gas chromatography/mass spectrometry analysis of organic acid profiles in human serum: A protocol of direct ultrasound-assisted derivatization.

RATIONALE: Low-molecular-weight organic acids that generally contain one to three carboxyl groups are involved in many important biological processes; therefore, it is important to develop a quantitative method for analyzing organic acids in serum in order to allow an evaluation of metabolic changes. In this study, we evaluated a protocol for detecting 26 organic acids in serum based on ultrasound-assisted derivatization by gas chromatography/mass spectrometry (GC/MS). METHODS: Serum samples were prepared using ultrasound-assisted silane derivatization before GC/MS analysis to quantify concentrations of organic acids. Additionally, we investigated the variables affecting derivatization yields, including the extraction solvent, derivatization reagents, and derivatization conditions (reaction temperature, duration, and sonication parameters). The protocol was ultimately applied to detect organic acid profiles related to obesity. RESULTS: We used acetone as the extraction solvent and determined suitable derivatization conditions, as follows: BSTFA + 1% TMCS, 50°C, 10 min, and 100% ultrasound power. The protocol showed satisfactory linearity (r = 0.9958-0.9996), a low limit of detection (0.04-0.42 µmol/L), good reproducibility (coefficient of variation (CV) %: 0.32-13.76%), acceptable accuracy (recovery: 82.97-114.96%), and good stability within 5 days (CV%: 1.35-12.01% at room temperature, 1.24-14.09% at 4°C, and 1.01-11.67% at -20°C). Moreover, the protocol was successfully applied to obtain the organic acid profiles from obese and healthy control subjects. CONCLUSIONS: We identified and validated a protocol for ultrasound-assisted derivatization prior to GC/MS analysis for detecting 26 kinds of organic acids in serum. The results suggest the efficacy of this protocol for clinical applications to determine metabolic changes related to fluctuations in organic acid profiles.

Fine particulate matter PM2.5 generated by building demolition increases the malignancy of breast cancer MDA-MB-231 cells.

OBJECTIVES: This study investigates the effects of water-extracted PM2.5 on a triple-negative breast cancer (TNBC) cell line, MDA-MB-231, by sampling suspended particulates around a building demolition site. METHODS: PM2.5 particles were obtained using a high-flow TISCH sampler. Water-soluble PM2.5 were extracted by an ultrasonic oscillator and then freeze-dried. The heavy metal components of soluble PM2.5 was analyzed by ICP-MS. Cell viability was evaluated by MTT assay for cells that were exposed to PM2.5 (200, 400 and 600 µg/mL). Wound healing and transwell cell migration and invasion assays were used to measure cell motility and the invasiveness of cancer cells that had been exposed to PM2.5 into a chemo-attractant substance. Interrelated mechanisms of cancer malignancy were analyzed by Western blot analysis. RESULTS: Nearby PM2.5 concentrations increased significantly during the deconstruction of buildings, and the Cd, Cu, Pb, Zn and Cr contents of soluble PM2.5 also significantly increased. Following exposure to PM2.5, the survival rate of breast cancer cells was significantly higher than that of the control group. Soluble PM2.5-treated cells had a higher migration capacity. The signaling pathway of FAK/PI3K/AKT proteins was more activated in PM2.5-treated cells than the control group. Increased levels of Aurora B and Bcl-2 were associated with cell proliferation. Elevated levels of cathepsins D, ß-catenin, N-cadherin, vimentin and MMP-9 were associated with breast cancer cell metastasis. CONCLUSION: Soluble PM2.5 from building demolition may promote/progress in surviving TNBC cells, increasing the malignancy of breast cancer. This study offered evidence of a link between demolition PM2.5 and cancer progression.

Derivation and Validation of a Risk Stratification System for Predicting Postoperative Cognitive Impairment.

BACKGROUND: To establish and validate a risk stratification scoring system (we name it as PreOp-BFS, which represents Pre-Operative Brain Fragility Score) for postoperative cognitive impairment containing postoperative cognitive dysfunction (POCD) and postoperative delirium (POD) in elderly patients undergoing non-cardiac surgery. METHODS: We searched for relevant literatures and reviews reported in PubMed and ScienceDirect databases from January 1994 to December 2017. We performed a preoperative risk factor for cognitive impairment in elderly patients (age ≥ 60 years) who underwent non-cardiac surgery, and finally constructed a risk scoring system to predict postoperative cognitive impairment. RESULTS: The test data included 49 patients with postoperative cognitive impairment and 31 patients without postoperative cognitive impairment. The postoperative risk scale score ranged from 0 to 8 points. The incidence of postoperative cognitive impairment was 16.2%, 62.9% and 96.2% in the low (0-2 scores), medium (3-4 scores) and high (5-8 scores) risk groups, respectively. In addition, the risk of postoperative cognitive impairment was significantly higher in high and medium risk groups than in low risk group. Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of the risk scoring system was 0.862 [95% CI 0.784-0.941]. CONCLUSIONS: The preoperative risk stratification scoring system (PreOp-BFS) established in this study had a good prediction effect, which was helpful for rapid identification and screening of high-risk susceptible patients with early postoperative cognitive impairment, and for performing targeted perioperative prevention.

Identification and Validation of Ferroptosis-Related LncRNA Signatures as a Novel Prognostic Model for Colon Cancer.

Background: Ferroptosis is a newly defined form of programmed cell death that plays an important role in many cancers. However, ferroptosis-related lncRNAs (FRLs) involved in the regulation of colon cancer are not thoroughly understood. This study aimed to identify a prognostic FRL signature in colon cancer and explore its potential molecular function. Methods: RNA-seq data and relevant clinical information were obtained from The Cancer Genome Atlas (TCGA) database, and a list of ferroptosis-related genes was extracted from the FerrDb website. Analysis of differentially expressed FRLs was performed using the 'limma' package in R software. By implementing coexpression analysis and univariate Cox analysis, we then identified prognostic FRLs. Using Cox regression analysis with the least absolute shrinkage and selection operator (LASSO) algorithm, we constructed a prognostic model based on 4 FRLs. We evaluated the prognostic power of this model using Kaplan-Meier (K-M) survival curve analysis and receiver operating characteristic (ROC) curve analysis. Moreover, the relationships between the signature and immune landscape, somatic mutation and drug sensitivity were explored. Finally, in vitro experiments were conducted to validate the functions of AP003555.1 and AC000584.1. Results: A 4-FRL signature was constructed. Two risk groups were classified based on the risk score calculated by this signature. The signature-based risk score exhibited a more powerful capacity for survival prediction than traditional clinicopathological features in colon patients. Additionally, we observed a significant difference in immune cells, such as CD4+ and CD8+ T cells and macrophages, between the two groups. Moreover, the high-risk group exhibited lower IC50 values for certain chemotherapy drugs, such as cisplatin, docetaxel, bleomycin or axitinib. Finally, the in vitro experiments showed that ferroptosis processes were suppressed after AP003555.1 and AC000584.1 knockdown. Conclusion: The proposed 4-FRL signature is a promising biomarker to predict clinical outcomes and therapeutic responses in colon cancer patients.

Real-time dengue forecast for outbreak alerts in Southern Taiwan.

Dengue fever is a viral disease transmitted by mosquitoes. In recent decades, dengue fever has spread throughout the world. In 2014 and 2015, southern Taiwan experienced its most serious dengue outbreak in recent years. Some statistical models have been established in the past, however, these models may not be suitable for predicting huge outbreaks in 2014 and 2015. The control of dengue fever has become the primary task of local health agencies. This study attempts to predict the occurrence of dengue fever in order to achieve the purpose of timely warning. We applied a newly developed autoregressive model (AR model) to assess the association between daily weather variability and daily dengue case number in 2014 and 2015 in Kaohsiung, the largest city in southern Taiwan. This model also contained additional lagged weather predictors, and developed 5-day-ahead and 15-day-ahead predictive models. Our results indicate that numbers of dengue cases in Kaohsiung are associated with humidity and the biting rate (BR). Our model is simple, intuitive and easy to use. The developed model can be embedded in a "real-time" schedule, and the data (at present) can be updated daily or weekly based on the needs of public health workers. In this study, a simple model using only meteorological factors performed well. The proposed real-time forecast model can help health agencies take public health actions to mitigate the influences of the epidemic.

BIS-guided deep anesthesia decreases short-term postoperative cognitive dysfunction and peripheral inflammation in elderly patients undergoing abdominal surgery.

OBJECTIVES: Postoperative cognitive dysfunction (POCD) is a common clinical complication, with an underlying pathophysiology linked to heightened levels of neuroinflammation. However, it requires clarification as to whether the depth of anesthesia modulates postoperative cognitive dysfunction. This study investigated the association between depth of anesthesia and POCD in elderly patients undergoing abdominal surgery. METHODS: A total of 120 patients aged 60 years or older who were planned for abdominal surgery under total intravenous anesthesia were included in this study. The depth of anesthesia was guided by monitoring Bispectral Index (BIS) data. All study participants completed a battery of nine neuropsychological tests before surgery and at 7 days and 3 months after surgery. POCD was calculated by using the reliable change index. Plasma concentration of C-reactive protein (CRP), interleukin (IL)-1ß, IL-10, S-100ß, and norepinephrine (NE) were measured. RESULTS: The incidence of POCD at 7 days after surgery in the deep anesthesia group was 19.2% (10/52), which was significantly lower (p = 0.032) than the light anesthesia group 39.6% (21/53). The depth of anesthesia had no effect on POCD at 3 months after surgery (10.3% vs 14.6%, respectively, p = 0.558). Similarly, plasma levels of CRP and IL-1ß in deep anesthesia group were lower than that in light anesthesia group at 7 days after surgery (p < 0.05), but not at 3 months after surgery (p > 0.05). There were no significant differences in the plasma concentration of IL-10, S-100ß, and NE between the groups (p > 0.05). CONCLUSIONS: Deep anesthesia under total intravenous anesthesia could decrease the occurrence of short-term POCD and inhibit postoperative peripheral inflammation in elderly patients undergoing abdominal surgery, compared with light anesthesia.

Depletion of the lncRNA RP11-567G11.1 inhibits pancreatic cancer progression.

BACKGROUND: Pancreatic cancer is one of the most lethal malignancies, as demonstrated by its 5-year survival rate of less than 10%. The poor response of pancreatic cancer to conventional therapeutics, especially against cancer stem cells (CSCs), is the primary obstacle to improving patient survival. Emerging evidence indicates that the long non-coding RNA (lncRNA) RP11-567G11.1 is up-regulated in pancreatic cancer tissues and that its expression is associated with poor prognosis. This study aimed to elucidate the mechanism by which RP11-567G11.1 influences survival in pancreatic cancer. METHODS: We evaluated the expression of RP11-567G11.1 in pancreatic cancer tissues via in situ hybridization. We also constructed RP11-567G11.1 knockdown cell models and used CCK8 and flow cytometry to detect the function of this lncRNA. Western blotting and qPCR were used to detect the expression levels of factors related to RP11-567G11.1. RESULTS: The results illustrated that RP11-567G11.1 was significantly up-regulated in poorly differentiated pancreatic cancer tissues as compared to its expression in non-tumor tissues. Additionally, depletion of RP11-567G11.1 in pancreatic cancer cells inhibited proliferation and cell cycle progression, induced apoptosis, suppressed the stem cell-like phenotype, and increased sensitivity to gemcitabine. Also depletion of RP11-567G11.1 in pancreatic cancer cells inhibited factors downstream of the NOTCH signaling pathway. CONCLUSION: RP11-567G11.1 plays a crucial role in pancreatic cancer. Importantly, depletion of RP11-567G11.1 boosts the sensitivity of pancreatic cancer cells to gemcitabine, suggesting that this lncRNA is a promising target for pancreatic cancer treatment.

Evaluation of two-step liquid-liquid extraction protocol for untargeted metabolic profiling of serum samples to achieve broader metabolome coverage by UPLC-Q-TOF-MS.

Untargeted metabolomics studies aim to extract a broad coverage of metabolites from biological samples, which largely depends on the sample preparation protocols used for metabolite extraction. The aim of this study was to evaluate a comprehensive sample pretreatment strategy using two-step liquid-liquid extraction to achieve broader metabolome coverage by ultra-high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (UPLC-Q-TOF-MS). We compared four protocols: (A) methanol protein precipitation, (B) Ostro 96-well plates, (C) two-step extraction protocol of CHCL3-MeOH followed by MeOH-H2O, and (D) two-step extraction protocol of CH2CL2-MeOH followed by MeOH-H2O. The number of extracted features, reproducibility and recovery were the major criteria for evaluation. Our results demonstrated that Protocols B, C and D, with approximately similar number of features, extracted more features than Protocol A. Protocols C and D appeared to have similar extraction reproducibility (low coefficient of variation < 30%) and Protocol D enabled an acceptable recovery of serum metabolites. The two-step extraction Protocol D (CH2CL2-MeOH followed by MeOH-H2O) resulted in the greatest improvement in metabolite coverage, satisfactory extraction reproducibility, acceptable recovery and environmental safety. The selected protocol was applied to an obesity metabolomics study to obtain different metabolites between participants with obesity and the controls, and to investigate complex metabolic alterations in obesity during a 2-h oral glucose-tolerance test. Our results suggested that this protocol was useful for analyzing serum metabolome changes in obese individuals in the fasting and postprandial state.

Fasting serum α­hydroxybutyrate and pyroglutamic acid as important metabolites for detecting isolated post-challenge diabetes based on organic acid profiles.

The aim of this study was to develop a method to detect serum organic acid profiles in patients with isolated post-challenge diabetes (IPD) and to compare the metabolites between IPD patients, type 2 diabetes mellitus (T2DM) and healthy controls. We developed a gas chromatography-mass spectrometry method to detect serum organic acids and validated it using serum from 40 patients with IPD, 47 with newly diagnosed T2DM, and 48 healthy controls. We then analyzed the organic acid profiles by multivariate analysis to identify potential metabolites. This method allowed the fast and accurate measurement of 27 organic acids in serum. Serum organic acid profiles differed significantly among IPD patients, T2DM patients, and healthy controls. IPD samples had significantly higher concentrations of α­hydroxybutyrate and ß­hydroxybutyrate (P < 0.05) and lower pyroglutamic acid concentration (P < 0.05) compared with the healthy controls, and the area under the curve for the combination of α­hydroxybutyrate and pyroglutamic acid was 0.863 for the IPD group. These results provide useful information regarding the changes in organic acid metabolism associated with IPD. Measurement of these metabolites in fasting serum from IPD patients may provide useful diagnostic and/or prognostic biomarkers, as well as helpful markers for the therapeutic monitoring of IPD patients.

Taurine, glutamic acid and ethylmalonic acid as important metabolites for detecting human breast cancer based on the targeted metabolomics.

BACKGROUND: This study investigated the use of serum amino acids and organic acids profiles as the novel metabolites for screening breast cancer (BC) patients. METHODS: A total of 116 subjects as training set were divided into the following three groups: BC patients (n= 34), benign (BE) patients (n= 38) and controls (n= 44). The amino acids profiles from three groups were measured using liquid chromatography-mass spectrometry and organic acids profiles in three groups were studied by gas chromatography-mass spectrometry. The resultant study data set was subjected to multivariate statistical analysis to identify important metabolites related with BC and construct the criteria for discriminating BC patients from BE subjects or controls. A test data set derived from 60 patients (30 BC and 30 BE subjects) and 30 controls was used to validate the stability of the different metabolites. RESULTS: The serum amino acids and organic acids profiles significantly differed between the BC patients, BE patients and the controls. Our results demonstrate that combinations of three candidate metabolites from taurine, glutamic acid and ethylmalonic acid were found to mirror tumour burden, with AUC values ranging from 0.751 to 0.834 when comparing BC patients to the controls. The areas under the curve from the taurine, glutamic acid and ethylmalonic acid in validated study were 0.901, 0.924 and 0.749, respectively. CONCLUSIONS: This study shows that amino acids and organic acids profiles will be a potential screening tool for BC patients. The dysregulated metabolism of amino acids and organic acids in breast cancer might be useful for the diagnosis, therapy, prognosis and understanding the pathogenesis of breast cancer.

Targeted metabolomics analysis reveals the association between maternal folic acid supplementation and fatty acids and amino acids profiles in rat pups.

Maternal diet during pregnancy can influence offspring's health by affecting development and metabolism. This study aimed to analyze the influence of maternal folic acid (FA) supplementation on the metabolism of rat pups using targeted metabolomics. Twenty female rats were randomly assigned to a FA supplementation (FAS group, n = 10) or control group (n = 10), which were fed AIN93G diet with 2 or 10 mg/kg FA, respectively. We then measured amino acids and their derivatives, biogenic amines, and fatty acids in the female rats and their pups by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC/MS-MS) and gas chromatography-mass spectrometry (GC/MS-MS). In maternal rats, the significant changes of three metabolites (proline, γ-aminobutyric acid and esterified octadecatetraenoic acid, P < 0.05) were observed in FAS group. For the rat pups, FAS pups had significantly lower homocysteine and higher FA levels than control pups. The lower levels of amino acids (leucine, isoleucine, serine, proline) were obtained in FAS pups. Furthermore, there were the decreased esterified fatty acids (arachidonic acid, eicosapentaenoic acid, and docosatetraenoic acid) and free fatty acids (oleic acid, linoleic acid, γ-linolenic acid, octadecatetraenoic acid, arachidonic acid, eicosapentaenoic acid and selacholeic acid) in FAS pups. Metabolic changes in the FAS pups were characterized by changes in fatty acids and amino acids. These results suggested that FA supplementation during pregnancy influenced amino acids and fatty acids metabolism in rat pups. This study provides new insights into the regulation of amino acids and fatty acids metabolism during early life.

MicroRNA-296 mediated corneal neovascularization in an animal model of corneal burns after alkali exposures.

Alkali burns of the cornea may lead to permanent visual impairment or complete blindness. In the current study, the role of microRNA 296 (miR-296) was explored in mouse corneal neovascularization induced by alkali burns. An alkali burn model in Balb/c mice was developed to study chemical corneal injuries. The expression of the miR-296 gene was measured by reverse-transcription-quantitative polymerase chain reaction. Fibroblast growth factor 23 (FGF23) protein expression was measured by western blot analysis. Possible impacted pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes pathway analysis. miR-296 gene expression was examined following chemical corneal injury and it was demonstrated that different topical eye medications decreased miR-296 gene expression. miR-296 may participate in cytokine-cytokine receptor interaction pathways to influence corneal inflammatory responses. It was also revealed that FGF23 was expressed following chemical corneal injury and that different treatments with topical eye drops decreased its expression. miR-296 is a novel molecular modulator for alkali burns in the mouse cornea.

[Effect of flavonoids of polygoni orientails fructus on human hepatoma cell line SMMC-7721].

OBJECTIVE: To investigate the inhibitory effects of flavonoids of Polygoni Orientails Fructus on cell cycle and apoptosis of human hepatoma cell line SMMC-7721. METHODS: MTT method was used to study the inhibitory rate and time-dose relationship of flavonoids on SMMC-7721. Flow cytometry PI staining and Annexin V-EGFP/PI double staining were used to measure the DNA concentration and apoptosis rate in SMMC-7721. RESULTS: Flavonoids of Polygoni Orientails Fructus had obvious inhibitory effect and with good linear relationship between time and dose. Flavonoids of Polygoni Orientails Fructus could regulate the G1/S transition in hepatoma cell, which could make the cell in S phase arrest, result in the accumulation of cells in S phase, blocked DNA synthesis and replication of cells, blocked tumor cells into the G2/M phase, so as to restrain the proliferation of tumor cells and induce the apoptosis of SMMC-7721 cells. And this inductive effect showed obvious time-dose-effect relationship. CONCLUSION: The flavonoids of Polygoni Orientails Fructus could inhibit the hepatoma cell line SMMC-7721 in vitro by inhibiting cell proliferation and inducing apoptosis of the cell in a time-dose dependence maner.

Copper emission during thermal treatment of simulated copper sludge.

This study evaluates Cu emissions in air-particulate and gas phases during thermal treatment of simulated copper sludge by a rotary kiln. Influences of operating parameters, including treatment temperature (400-700 degrees C), rotary speed (0.89-2.00 rpm) and copper content in sludge (1% to 5% by weight) on copper emissions were investigated. The toxicity characteristic leaching procedure (TCLP) and scanning electron microscopy (SEM) were also conducted to evaluate copper leaching and the surface structure of thermally treated sludge, respectively. The results indicated that (1) low Cu emissions in air-particulate and gas phases were associated with the two operating conditions of 400-500 degrees C at 0.89-1.39 rpm and 600-700 degrees C at 2.00 rpm; (2) temperatures and rotary speeds did not affect gaseous copper emission, except for the operating condition of 400 degrees C at 2.00 rpm; (3) rising copper content of sludge at 600 degrees C and 2.00 rpm increased the particulate copper emission, but not the gaseous copper emission; (5) the TCLP copper leaching concentrations of sludge treated at 400 degrees C were obviously higher than those treated at 500-700 degrees C; however, all of the thermally treated products agreed with the Taiwan EPA TCLP regulations.

Effect of Cu species on leaching behavior of simulated copper sludge after thermal treatment: ESCA analysis.

The aim of this study is to evaluate the efficiency of thermal treatment on residual copper sludge after separation treatment. The toxicity characteristic leaching procedure (TCLP) concentration, pattern distribution and possible Cu species of simulated copper sludge were analyzed. Parameters such as different reaction time and temperature are also discussed in this study. The TCLP leaching results showed that the TCLP concentration of Cu in thermally treated simulated copper sludge decreased (T=900 degrees C) as the reaction time increased to 4 h. The sequential extraction results showed that the main fraction of raw simulated copper sludge was carbonate. When temperatures were 500 and 700 degrees C, the main fraction of thermally treated simulated copper sludge was also carbonate. The percentage of Fe-Mn oxides and residue increased when T=900 degrees C. Electron Spectroscopy for Chemical Analysis (ESCA) showed that the possible Cu species of raw simulated copper sludge was Cu(OH)(2). The main possible Cu species of thermally treated simulated copper sludge were CuO and Cu(2)O when T was 500 and 700 degrees C, respectively. CuO, Cu(2)O, and Cu(3)O(2) were the possible Cu species in thermally treated simulated copper sludge when T=900 degrees C.

Enhancement of Rhodamine B removal by low-cost fly ash sorption with Fenton pre-oxidation.

The removal of a basic dye, Rhodamine B (RhB), by fly ash adsorption, Fenton oxidation, and combined Fenton oxidation-fly ash adsorption were evaluated. Even though fly ash is a low cost absorbent, a high dose of fly ash was needed to remove RhB. Only 54% of RhB was removed by 80 g L(-1) fly ash. Solution pH did not significantly affect the RhB sorption by fly ash after 8h. Fenton reagents at H(2)O(2) dose of 6 x 10(-3)M and pH 3 rapidly decolorized 97% of RhB within 2 min, and 72% of COD removal was obtained at 30min reaction time. Spectrum analysis result showed that a large area of UV spectrum at 200-400 nm remained after Fenton reaction. The addition of 1gL(-1) fly ash effectively removed COD from Fenton-treated solution, and the UV absorption spectrum at 220-400 nm totally vanished within 2h. COD removal of RhB by the combined Fenton oxidation and fly ash sorption process was 98%. The COD removal capacity of fly ash for Fenton-treated RhB solution was 41.6 times higher than that for untreated RhB solution. The results indicated that the combined process is a potential technique for RhB removal.

Biotoxicity evaluation of fly ash and bottom ash from different municipal solid waste incinerators.

Different types of municipal solid waste incinerator (MSWI) fly and bottom ash were extracted by TCLP and PBET procedures. The biotoxicity of the leachate of fly ash and bottom ash was evaluated by Vibrio fischeri light inhibition test. The results indicate the following: (1) The optimal solid/liquid ratio was 1:100 for PBET extraction because it had the highest Pb and Cu extractable mass from MSWI fly ash. (2) The extractable metal mass from both fly ash and bottom ash by PBET procedure was significantly higher than that by TCLP procedure. (3) The metal concentrations of fly ash leachate from a fluidized bed incinerator was lower than that from mass-burning and mass-burning combined with rotary kiln incinerator. (4) The TCLP and PBET leachate from all MSWI fly ash samples showed biotoxicity. Even though bottom ash is regarded as a non-hazardous material, its TCLP and PBET leachate also showed biotoxicity. The pH significantly influenced the biotoxicity of leachate.