XELOX (capecitabine plus oxaliplatin) plus bevacizumab (anti-VEGF-A antibody) with or without adoptive cell immunotherapy in the treatment of patients with previously untreated metastatic colorectal cancer: a multicenter, open-label, randomized, controlled, phase 3 trial.

Fluoropyrimidine-based combination chemotherapy plus targeted therapy is the standard initial treatment for unresectable metastatic colorectal cancer (mCRC), but the prognosis remains poor. This phase 3 trial (ClinicalTrials.gov: NCT03950154) assessed the efficacy and adverse events (AEs) of the combination of PD-1 blockade-activated DC-CIK (PD1-T) cells with XELOX plus bevacizumab as a first-line therapy in patients with mCRC. A total of 202 participants were enrolled and randomly assigned in a 1:1 ratio to receive either first-line XELOX plus bevacizumab (the control group, n = 102) or the same regimen plus autologous PD1-T cell immunotherapy (the immunotherapy group, n = 100) every 21 days for up to 6 cycles, followed by maintenance treatment with capecitabine and bevacizumab. The main endpoint of the trial was progression-free survival (PFS). The median follow-up was 19.5 months. Median PFS was 14.8 months (95% CI, 11.6-18.0) for the immunotherapy group compared with 9.9 months (8.0-11.8) for the control group (hazard ratio [HR], 0.60 [95% CI, 0.40-0.88]; p = 0.009). Median overall survival (OS) was not reached for the immunotherapy group and 25.6 months (95% CI, 18.3-32.8) for the control group (HR, 0.57 [95% CI, 0.33-0.98]; p = 0.043). Grade 3 or higher AEs occurred in 20.0% of patients in the immunotherapy group and 23.5% in the control groups, with no toxicity-associated deaths reported. The addition of PD1-T cells to first-line XELOX plus bevacizumab demonstrates significant clinical improvement of PFS and OS with well tolerability in patients with previously untreated mCRC.

[Accounting Methods of VOCs Emission Associated with Production Processes in a Fine Chemical Industrial Park].

Volatile organic compounds (VOCs) are one of the key atmospheric pollutants associated with great impact on air quality. Industrial sources have become the most important source of VOCs emissions in China, of which the chemical industry accounts for a large part. At present, more than half of chemical manufacturers are clustered in chemical industrial parks (CIPs), thus the control of VOCs in CIPs is crucial. This study analyzed the production processes of the fine chemical industry and the principle of VOCs production, and then proposed an accounting model of VOCs emissions associated with production processes, based on a typical fine chemical industrial park:Hangzhou Bay Shangyu Economic and Technological Development Area (HSEDA). The quantity of VOCs generation in the main production processes, such as feeding, heating, chemical reaction gas take-off, cleaning, vacuum pumping, pressure release, and evaporating, were calculated. Meanwhile, the chemical process simulation software Aspen was also employed to simulate the VOCs generation in these processes. The methods were applied to 14 representative products in HSEDA and the feature of VOCs generation in the chemical processes mentioned above, and components were revealed. The results of the two methods were compared, and the difference between the two methods was within±22% except for the pressure release process. The model and accounting methods proposed in this study will have sound applicability in accounting for VOCs emissions in fine chemical industrial parks underpinned by quantitative chemical industry production parameters.

Clinical significance of IFIT2 expression in human renal cancer tissues.

BACKGROUND: Interferon (IFN)-induced protein with tetratricopeptide repeats 2 (IFIT2) is an important member of the IFN-stimulated gene (ISG) family. It has been demonstrated that IFIT2 is important in the physiopathological processes of antiviral and antitumor activities. We previously demonstrated that IFIT2 was highly expressed in paracarcinoma tissues compared with gastric cancer tissues, and its expression level was positively correlated with a superior postoperative prognosis of the patients. METHODS: We performed immunohistochemical staining of IFIT2 in human clear cell renal cell carcinoma (ccRCC) tissues by using a tissue microarray. RNAseq data of kidney clear cell carcinoma (KIRC) samples from The Cancer Genome Atlas (TCGA) were used to perform the enrichment analyses based on the genes that were highly correlated with IFIT2. RESULTS: Weak staining of IFIT2 was located on the cytoplasm and cell membrane surface of the cancer cells, while positive staining of IFIT2 was located mainly on adjacent normal tissues. Survival analysis showed that patients with higher IFIT2 expression had better overall survival than patients with lower IFIT2 expression (P=0.030). The Cox model further demonstrated that age (P=0.002), pathological stage (P=0.000), TNM stage (P=0.005) and IFIT2 expression (P=0.003) could be used as independent prognostic predictors for ccRCC patients. Additionally, the enrichment analysis based on ccRCC expression profile data extracted from TCGA revealed that the genes highly correlated with IFIT2 were mainly related to the biological processes of virus response, T cells and the innate immune response (GO:0009615, GO:0042110, and GO:0045088) and the pathways of NLR signaling, chemokine signaling, and TLR signaling (hsa04621, hsa04062, and hsa04620). CONCLUSIONS: IFIT2 could serve as a potential prognostic marker for ccRCC patients, and the mechanism of decreased IFIT2 expression in the progression of ccRCC merits further investigation.

[Distribution Characteristics of Antibiotic Resistance Genes in Wastewater Treatment Plants].

Wastewater treatment plants (WWTPs) are regarded as the main source for antibiotic resistant genes (ARGs). To explore the features regarding the distribution of ARGs in wastewater with complicated composition in treatment plants, wastewater samples from a chemical industry park that produced antibiotics were selected. qPCR was applied to detect the type and abundance of ARGs in the wastewater flows from the WWTPs. The results indicated that 16 types of ARGs were detected from the wastewater from the WWTPs, among which sulfonamide resistance genes and tetracycline resistance genes were the dominant ARGs that appeared in the wastewater. Additionally, intI 1 was detected and its abundance was correlated with that of sulfonamide resistance genes. This indicated that intI 1 may promote the migration and transformation of sulfonamide resistance genes. The pharmaceutical factories in the park mainly synthesize macrolide antibiotics. Because of the selective pressure, the absolute abundance of ermB in the wastewater was much higher than that in the other industrial wastewater. The total ARGs decreased by 1.16 log via traditional biological treatment process, and the total ARGs decreased by 2.46 log via the Fenton process. The results showed that the removal effects of deep treatment processes on ARGs were better than that of biological treatment in this wastewater treatment process. Highly abundant and movable ARGs already exist in the water body, and their release from WWTPs without effective treatment poses high risks to the environment.

[Nitrification and Bioaugmentation of Biological Treatment System of Sewage Treatment Plant at High Temperature in Summer].

The influence of temperature (30-45℃) and ammonia-nitrogen volume load on the nitrification function and microbial community of activated sludge in an aerobic tank of a sewage treatment plant were investigated under simulated high-temperature stress in the summer. Meanwhile, the bioaugmentation effectiveness of the middle-temperature-enriched nitrifying sludge (with or without acclimation) was evaluated in two biological treatment systems under high-temperature shock. The results showed that the ammonium-nitrogen (NH4+-N) removal efficiency and the nitrifying bacteria content of the aerobic activated sludge at 30-40℃ were above 90% and up to 4.55% and decreased to 40% and 1.97% at 45℃, respectively. To quickly recover the nitrification function of the biological system under high-temperature shock in the summer, the middle-temperature-enriched nitrifying sludge was acclimated at 40℃ for 61 d and achieved (60±5) mg·(L·h)-1 nitrification activity. Then, its bioaugmentation efficiency was compared with that of the middle-temperature-enriched nitrifying sludge. In the bioaugmentation test, 10% of NH4+-N was removed in the reactor inoculated with 5% (volume fraction) of the acclimated nitrifying sludge, while the reactor needed inoculate with 10% (volume fraction) of the middle-temperature-enriched sludge to achieve the same removal efficiency. The results suggested that middle-temperature-enriched nitrifying sludge, after acclimating at 40℃, has a better enhancement effect under a high-temperature shocking load.

microRNA-181b suppresses the metastasis of lung cancer cells by targeting sex determining region Y-related high mobility group-box 6 (Sox6).

BACKGROUND: The aim of the study was to measure the expression of microRNA (miR)-181b in patients with lung cancer, investigate its biological function and elucidate the underlying mechanisms associated with the development of lung cancer. METHODS: miR-181b expression in tissues was measured via RT-qPCR. After A549 cells were transfected with miR-181b mimic or si-Sox6, the proliferation, migration and cell cycle distribution of A549 were evaluated using cell counting kit-8 assay, transwell assay and flow cytometry. The levels of cell cycle-related proteins and Sox6 were analyzed by western blotting. Gene targets of miR-181b were predicted via bioinformatics analysis and verified using a dual-luciferase reporter gene assay. RESULTS: Expression of miR-181b was significantly downregulated in lung cancer tissues (P < 0.05), and was inversely correlated with the degree of cell differentiation and clinical stages of lung cancer (both P < 0.05). Additionally, the expression of miR-181b was significantly lower in adenocarcinoma compared with squamous cell carcinoma in the lungs (P < 0.05). Overexpression of miR-181b significantly decreased the protein level of Sox6 and significantly suppressed the cell proliferation and metastasis (both P < 0.05); this effect was also observed in A549 cells transfected with si-Sox6. The luciferase activity of a Sox6 3'-untranslated region-based reporter construct was significantly lower when transfected with miR-181b (P < 0.05), which suggests that Sox6 is a direct target of miR-181b. CONCLUSION: The results of the present study suggest that miR-181b may function as a tumor inhibitor in the development of lung cancer via targeting Sox6 to decrease the proliferation and metastasis of lung cancer cells.

[Distribution and Removal of Antibiotic Resistance Genes in Two Sequential Wastewater Treatment Plants].

Wastewater treatment plants (WWTPs) have been regarded as important point-sources of antibiotic resistance genes (ARGs) in aquatic environments. To investigate the distribution and removal of ARGs in WWTPs, a pharmaceutical wastewater treatment plant (PWWTP) and an integrated wastewater treatment plant (IWWTP) in a fine-chemical industrial park were chosen, and polymerase chain reaction (PCR) and real-time PCR techniques were used to determine the occurrence and abundances of ARGs along the treatment processes. Ten and fifteen ARGs were detected initially in the influents of PWWTP and IWWTP respectively, in which tetracycline and sulfonamide resistance genes were frequently reported, while dfrA13 was first reported in WWTPs. The most abundant ARGs in the influents were sul Ⅰ and sul Ⅱ, followed by dfrA13, tetQ, floR, tetO, and tetW. The total ARGs increased by 0.21 log after the treatment by PWWTP, whose effluent contributed 0.87% to the inflow yet 5.05% to the total ARGs of IWWTP. Finally the total ARGs removed by IWWTP was 1.03 log, with the remaining ARGs then transported within the final effluent to the nearby coastal area. The authors concluded that the environmental and other impacts from the spread of ARGs on the microbial communities of the coastal environment needed further study.

[Pilot-scale Experiment on Enrichment of Nitrifying Activated Sludge and Its Application in Enhancing a Wastewater Biological Treatment System Against Ammonia Shocking Loads].

Nitrifying activated sludge (NAS) was enriched in a membrane bioreactor (MBR) with pre-treated municipal wastewater and additional ammonium sulfate as the culture medium. The influences of temperature, dissolved oxygen (DO), ammonia nitrogen volumetric load, free ammonia (FA), and free nitrite (FNA) on the enrichment of NAS were investigated, the cost of the process was evaluated, and then NAS's application in enhancing a wastewater biological treatment system against ammonia shocking loads was attempted. The results showed that after 182 days of cultivation in an MBR, NAS had a nitrification activity of 98.41 mg·(L·h)-1, which was 30-times higher than that of the seeding sludge. The yield of NAS was 14.96 mg·(L·d)-1, costing 3.52 Yuan for 1 kg. Temperature was found to be a key factor affecting the sludge nitrification activity. The sludge nitrification activity was decreased to 1/3 of the maximum value at temperatures below 15.0℃, while lowering the ammonium volumetric load retarded the decrease in the sludge nitrification activity to some extent. In addition, dissolved oxygen deficiency resulted in nitrite accumulation, and thereby slowed down the NAS enrichment rate. The enriched NAS was then applied to a wastewater biological treatment pilot equipment, which had just been exposed to an ammonium shocking load. The removal rate of ammonia nitrogen in the biological system increased from 29.4% to 88.4% after 2.0% of NAS was inoculated. The enhanced biological system retained ammonia removal rates of as high as 99.0%, even as the temperature dropped to 13.3℃±1.6℃ afterwards. The above pilot-experiment results suggested that enriched nitrifying sludge is suitable for quickly increasing the start-up or recovery rates of the nitrifying function in a biological system.

[Influence of Ciprofloxacin on the Microbial Community and Antibiotics Resistance Genes in a Membrane Bioreactor].

A membrane bioreactor (MBR) was used to treat ciprofloxacin (CIP)-contaminated artificial wastewater. The microbial community structure and the abundance of antibiotic resistant genes (ARGs) in the MBR were studied at four CIP dosages (0, 5 mg·L-1, 10 mg·L-1, and 15 mg·L-1). The results showed that Proteobacteria and Bacteroidetes remained the dominant phylum, with relative abundances of 57.5% and 12.7%, respectively, as the dosage of CIP was increased from 0 mg·L-1 to 15 mg·L-1. Rhodocyclaceae, Chitinophagaceae, and Comamonadaceae became the dominant family with abundances of 29.96%, 5.44%, and 6.60%, respectively. Methyloversatilis, Ferruginibacter, Zoogloea, and Comamonas became the dominant genus, with relative abundances of 21.70%, 7.56%, 5.24%, and 4.15%, respectively. The decrease of Chao1, ACE, and Shannon and the increase of Simpson indicated a decrease in microbial abundance and diversity. The relative abundances of Nitrosomonas, Nitrospira, Alcaligenes, and Nitrobacter decreased, which caused a decrease in the NH3-N removal rate. A CIP-ARGs analysis revealed that the relative abundances of gyrA, gyrB, and parC were increased, beginning after the sludge was dosed with 5 mg·L-1of CIP for 33 days, which augmented the risk for microbial drug-resistance.

[Removal and Influence of Ciprofloxacin in a Membrane Bioreactor].

A membrane bioreactor (MBR) was used to treat ciprofloxacin (CIP)-contaminated artificial wastewater. The pollutant removal performance and the microbial community structure of the MBR were studied at three different CIP dosages (0 mg·L-1, 5 mg·L-1, and 10 mg·L-1). The results showed that the sludge concentration in the reactor decreased and then levelled off as the dosage of CIP was increased from 0 mg·L-1 to 5 mg·L-1 and further to 10 mg·L-1. The mean removal of TOC and COD decreased from 98.40% and 97.80% to 84.20% and 94.10%, respectively, indicating that the CIP negatively influenced the organic removal but the effect was minor. In contrast, the ammonium removal was greatly influenced by the dosage of CIP. When the CIP dosage increased from 0 mg·L-1 to 5 mg·L-1 and further to 10 mg·L-1, the ammonium removal efficiency decreased from 96.91% to 84.14% and then to 77.80%, and the activity of Nitrosomonas, Alcaligenes, Nitrospira, and Nitrobacter were greatly inhibited. The CIP removal initially increased and then decreased. The mass balance revealed that the removal of CIP in the MBR was principally attributed to biodegradation and sludge adsorption, which accounted for 30.13% and 0.25%, respectively, at a CIP dosage of 5 mg·L-1 and 7.55% and 1.81% at a CIP dosage of 10 mg·L-1.

AOX contamination in Hangzhou Bay, China: Levels, distribution and point sources.

The parameter AOX (adsorbable organic halogens) indicates the total amount of organic halogens in an environment. Seawater and surface sediment samples from 12 sample sites in the Hangzhou Bay (HZB), China, were analyzed for AOX to investigate its contamination status. In this study, the AOX concentration ranged from 140.6 ±â€¯45.6 µg/L to 716.1 ±â€¯62.3 µg/L in seawater of the HZB, and from 11.3 ±â€¯2.4 mg/kg to 112.7 ±â€¯7.2 mg/kg in the sediment. Ocean currents, fluvial currents and the Yangtze River exerted profound influences on the distribution of AOX in the HZB. The point sources around the HZB, represented by wastewater treatment plants, discharged at least 645.4 t AOX into the HZB every year, most of which was generated by industrial activities rather than the human daily activities.

[Ozone-Biological Activated Carbon for Advanced Removal of Typical Persistent Organic Pollutants from Micro-Polluted Source Water in the Yangtze Delta Region].

Ozone-biological activated carbon (O3-BAC) was studied for the advanced removal of organics from micro-polluted source water in the water supply plant P located in J City in the Yangtze Delta Region. The results show that 19.2% of the permanganate index, 10.4% of total organic carbon, and 23.0% of UV254 were removed by the advanced treatment of O3-BAC. Eight types of polycyclic aromatic hydrocarbon (PAH), 16 types of organochlorinated pesticides (OCPs), and five types of haloacetic acids (HAAs) were detected in the source water. The total concentrations were 53.9-100.0, 6.5-41.8, and 2.5×103-1.1×104 ng·L-1, respectively. The advanced O3-BAC treatment removed 32.5% of PAHs and 25.9% of OCPs, greatly improving the effluent of the conventional water supply process. However, HAAs were mainly removed with the conventional process, with a removal rate of 33.8%-87.0%. After the advanced treatment with O3-BAC, the amount of chloroacetic acid slightly decreased, while the concentration of bromoacetic acid slightly increased.

[Cultivation of Spirulina platensis in Digested Piggery Wastewater Pretreated by SBR with Operating Conditions Optimization].

Digested piggery wastewater(DPW) contains high concentrations of nitrogen and phosphorus which could be used as a cost-effective culture medium for Spirulina platensis. However, Spirulina platensis would be limited by many factors in the complex composition of DPW, especially the high concentration of ammonium. In this paper, a traditional sequencing batch reactor(SBR) was used to remove these inhibitors in DPW. The retention of nitrate and nitrite in the effluent, which was used as nitrogen source for cultivating Spirulina platensis, was studied at different ratios of chemical oxygen demand(COD) to total nitrogen(TN) in the influent. By comparing the growth of Spirulina platensis in the related effluents, the operation condition of SBR was optimized. The lab-scale cultivation results showed that Spirulina platensis possessed a high biomass yield of 0.084 g·(L·d)-1 in the effluent when the COD/TN ratio of SBR influent was 3.0. In particular, the concentrations of ammonium, nitrate and nitrite in the effluent were 51.2 mg·L-1, 91.6 mg·L-1and 213.1 mg·L-1, respectively. Furthermore, the aforementioned effluent was also used to culture Spirulina platensis in a 120 L outdoor raceway pond, and the growth rate of Spirulina platensis reached(0.075±0.003)g·(L·d)-1 after 10-day culture. The protein content of Spirulina platensis was approximately 60% and the removal efficiency of ammonium was 99%. This study provides an alternative method for the utilization of DPW.

[Life Cycle Assessment of Traction Lead-acid Batteries for Electric Bikes in China].

This research undertook a life cycle assessment (LCA) for lead-acid batteries (LABs) used in electric bikes, the fastest growing LABs in China. A cradle-to-grave LCA model was established to identify the key materials or processes that contribute most to environmental impacts within the life cycle of LABs, including material production, battery manufacture, transportation, use, and end-of-life. A large amount of primary data obtained from enterprisers and a Chinese LCA database were used in this research to reflect the status of technology and environmental management for the related industries in China. The results indicate that material production and LAB use dominate in resource consumption and environmental impacts during the life cycle of LABs. Material production is the most important driver of such impacts as abiotic resources depletion (699%), eutrophication (89%), photochemical smog production (98%), ozone depletion (117%), total human toxicity (159%), and ecological toxicity (484%). Battery use is responsible for 83% of primary energy use and contributes the highest potentials to the impacts related to energy, including global warming potential (86%) and acidification potential (70%). Recovery of materials at the end-of-life stage will significantly mitigate the overall life cycle impacts by reducing virgin material consumption. Based on the findings, there are several substantial opportunities to reduce the overall environmental impacts of batteries, such as prolonging the lifetime of batteries, reducing the metal consumption in batteries, and improving the technology and management in recovery of end-of-life batteries.

[Coking Wastewater Treatment Efficiency and Comparison of Acute Toxicity Characteristics of the AnMBR-A-MBR and A2-MBR Processes].

Coking wastewater contains high-strength refractory organic pollutants and is commonly treated by biological treatment processes. To improve the efficiency of biological treatment, two laboratory scale processes, anaerobic membrane bioreactor/anoxic/aerobic membrane bioreactor (AnMBR-A-MBR) and anaerobic/anoxic/aerobic membrane bioreactor (A2-MBR), were developed for coking wastewater treatment. The removal of main pollutants and the stability of different pollutant loadings were compared under the optimum operating conditions. Acute toxicity distribution, variations, and toxic matter characteristics of the two processes were investigated by solid-phase extraction, components separation, the luminous bacteria Q67 test, and three-dimensional fluorescence spectrometry. The results showed that the organic pollutant removal rate of AnMBR was 15.3%, which was significantly higher than the anaerobic stage of the A2-MBR system (3.4%), and the AnMBR-A-MBR system had greater resistance to pollutant loading. Acute toxicity of AnMBR-A-MBR system in each stage effluent was lower than the A2-MBR system and the total toxic unit removal rate of both were 85.2% and 79.2%, respectively. The acute toxicity of the polar component in each stage effluent was the highest, and the polar and mid-polar components contributed to the majority of the toxicity. The toxicity of each stage effluent mainly originated from Region Ⅱ aromatic protein analogues, which could be the main acute toxicity substances of the polar component.

[Abundance of Cell-associated and Cell-free Antibiotic Resistance Genes in Two Wastewater Treatment Systems].

For revealing the characteristics of antibiotic resistance genes (ARGs) in wastewater treatment systems, real-time PCR was adopted to investigate the variation of abundances of cell-associated ARGs and cell-free ARGs, in a municipal wastewater treatment system (M for short) and a coking wastewater treatment system (C for short). In system M, the absolute abundances of the cell-associated ARGs, sul Ⅱ,tetC,blaPSE-1, and ermB, were much higher than those of the cell-free fractions in the influent. The biological treatment process did not enrich antibiotic resistance bacteria (ARBs) and membrane filtration of the MBR effectively reduced both cell-associated and cell-free DNA in water. The total ARGs removal was 2.54-4.95 logs. In system C, the biological treatment process enriched the sul Ⅱ -carried ARBs; however, the relative and absolute abundances of cell-free sul Ⅱ were decreased. The succeeding process, coagulation-sand filtration, decreased the absolute abundance of cell-associated sul Ⅱ, but increased the absolute abundance of cell-free sul Ⅱ in water. The proportion of cell-free sul Ⅱ in total sul Ⅱ gene increased from 0.05% in the biological treatment effluent to 1.33% in the sand filtration effluent and further increased to 9.31% after the effluent was kept at 25℃ and at dark for five days. The ratio of cell-free ARGs to total ARGs increased with deep removal of ARBs and lysis of residual cells. The risk of ARG proliferation by cell-free DNA in the effluent needs further evaluation.

[Stability of Short-cut Nitrification Nitrogen Removal in Digested Piggery Wastewater with an Intermittently Aerated Sequencing Batch Reactor].

Stability of short-cut nitrification nitrogen removal performance was studied in a step-feeding, intermittently aerated sequencing batch reactor (IASBR) at 30°C to treat digested piggery wastewater. Results showed that the nitrogen removal was greatly influenced by the ratio of chemical oxygen demand (COD) to total nitrogen (TN) in the influent. Nitrite nitrogen kept accumulating up to 800 mg · L⁻1 when the influent COD/TN ratio was 0.8 ± 0.2, and the removal rates of TN, ammonium nitrogen and total organic carbon (TOC) were only 18.3% ± 12.2%, 84.2% ± 10.3% and 60.7% ± 10.7%, respectively. By contrast, as the influent COD/ TN ratio was increased to 2.4 ± 0.5, the accumulated concentration of nitrite nitrogen sharply decreased from 800 mg · L⁻¹ to below 10 mg-L⁻¹, and the removal rates of TN, ammonium nitrogen and TOC were increased to over 90%, 95% and 85%, respectively. Gradually shortened hydraulic retention time ( HRT) reveales that the ammonia load is a restricting factor for nitrogen removal. The ammonia load should be controlled at no more than 0.30 kg · (m³ · d) ⁻¹, or else, the removal rates of TN, ammonium and TOC would be greatly decreased. The nitrite accumulation rate over the whole run was 74.6%-97.8% and the TN removal rate in the stable phase was over 90%. With efficient and stable short-cut nitrification-denitrification in a low COD/TN, moreover, and unnecessary for addition of alkaline, IASBR shows great advantage for treating wastewater with high concentration of ammonia while low COD/TN ratio.

[Removal of AOX and Chroma in Biologically Treated Effluent of Chemical Dyestuff Wastewater with Nanoscale Ni/Fe].

Nanoscale Ni/Fe was applied to biologically treated effluent of chemical dyestuff wastewater. The removal rates of absorbable organic halogens (AOX) and chroma were investigated at different Ni loadings (0-5%), initial wastewater pH (4.1-10.0), Ni/Fe dosage (1-5 g x L(-1)) and reaction time (0.5-96 h). The results showed that the removal rates of AOX and chroma firstly increased and then decreased with the increase of the Ni loading, while continuously increased with the decrease of the initial wastewater pH and the increase of Ni/Fe dosage. The optimal condition was Ni loading of 1%, initial wastewater pH of 4.1 and Ni/Fe dosage of 3 g x L(-1), under which 29.2% of AOX and 79.6% of chroma were removed after 24 h reaction, and 50.6% of AOX and 80.7% of chroma were removed after 96 h reaction. GC-MS analysis revealed that toxicants such as chlorinated anilines, p-nitroaniline, 4-methoxy-2-nitroaniline and halogenated hydrocarbons were efficiently removed.

[Removal of AOX, Chroma and TOC in Chemical Dyestuff Wastewater with Iron Scraps-Fenton-Coagulation Combined Process].

Iron scraps-Fenton-coagulation process was applied to chemical dyestuff wastewater. The removal performance of absorbable organic halogens(AOX), chroma and total organic carbon (TOC) was investigated at different molar ratios of Fe2+ to H2O2 (1:3-1:15), iron scraps reaction time (2-5 h) and Fenton reaction time (20-80 min). The results showed that the removal ratios of AOX, chroma and TOC firstly increased and then decreased with the decrease of the molar ratio of Fe2+ to H2O2, while continuously increased with the increase of iron scraps and Fenton reaction time. The optimal condition was determined as Fe2+:H2O2 ratio of 1:8, iron scraps reaction time of 4 h and Fenton reaction time of 60 min, under which 94.2% of AOX, 93.7% of chroma and 27.2% of TOC were removed. A comparison study revealed that the iron scraps-Fenton-coagulation combined process could achieve much better removal of AOX, chroma and TOC than any other single or combined processes of iron treatment, Fenton oxidation and coagulation. GC-MS analysis revealed that halogenated compounds and anilines were efficiently removed, as well as nitrobenzenes, phenols, benzaldehydes, ethers, nitriles and heterocyclic compounds.·OH was found to devote much in the Fenton reaction according to the tert-butyl alcohol trapping hydroxyl radicals test.

[Removal of AOX in Activated Sludge of a Chemical Pharmaceutical Industry with Fenton Oxidation].

This study aimed to remove AOX (adsorbable organic halogens) with Fenton oxidation from activated sludge in a chemical pharmaceutical industry. The influences of H2O2 dosage, Fe2+ dosage and reaction time were investigated, based on which the reaction conditions for AOX removal were optimized, and the reaction mechanism was discussed. The optimized reaction conditions were as follows:0.90 mol·L-1 of H2O2, 0.045 mol·L-1 of Fe2+[n (Fe2+):n (H2O2) of 1:20] and reaction time of 2 h. Under the optimized conditions, 70.7% of AOX in the sludge and 78.5% of AOX in the supernatant were removed. GC-MS analysis revealed that eleven organic halides were detectable in the original sludge. After Fenton reaction, only three organic halides were detectable, and their peak areas were reduced by 40%-50%. Toxic and hazardous non-AOX organic matters such as xylene, diisobutyl phthalate were also effectively removed.