Secukinumab demonstrates high sustained efficacy and a favourable safety profile in patients with moderate-to-severe psoriasis through 5 years of treatment (SCULPTURE Extension Study)

BACKGROUND

Secukinumab, a fully human monoclonal antibody that selectively neutralizes IL-17A, has been shown to have significant efficacy and a favourable safety profile in the treatment of moderate-to-severe psoriasis and psoriatic arthritis.

OBJECTIVE

To assess the efficacy and safety of secukinumab through 5 years of treatment in moderate-to-severe psoriasis.

METHODS

In the core SCULPTURE study, Psoriasis Area and Severity Index (PASI) 75 responders at Week 12 continued receiving subcutaneous secukinumab until Year 1. Thereafter, patients entered the extension phase and continued treatment as per the core trial. Treatment was double-blinded until the end of Year 3 and open-label from Year 4. Here, we focus on the 300 mg fixed-interval (every 4 weeks) treatment, the recommended per label dose. Efficacy data are primarily reported as observed, but multiple imputation (MI) and last observation carried forward (LOCF) techniques were also undertaken as supportive analyses.

RESULTS

At Year 1, 168 patients entered the extension study and at the end of Year 5, 126 patients completed 300 mg (every 4 weeks) treatment. PASI 75/90/100 responses at Year 1 (88.9%, 68.5% and 43.8%, respectively) were sustained to Year 5 (88.5%, 66.4% and 41%). PASI responses were consistent regardless of the analysis undertaken (as observed, MI, or LOCF). The average improvement in mean PASI was approximately 90% through 5 years compared with core study baseline. DLQI (dermatology life quality index) 0/1 response also sustained through 5 years (72.7% at Year 1 and 65.5% at Year 5). The safety profile of secukinumab remained favourable, with no cumulative or unexpected safety concerns identified.

CONCLUSION

Secukinumab 300 mg treatment delivered high and sustained levels of skin clearance and improved quality of life through 5 years in patients with moderate-to-severe psoriasis. Favourable safety established in the secukinumab phase 2/3 programme was maintained through 5 years.

Comparison of palygorskite and struvite supported palygorskite derived from phosphate recovery in wastewater for in-situ immobilization of Cu, Pb and Cd in contaminated soil

A phosphorus-bearing product S-PAL obtained from nutrient-rich wastewater was reused as ameliorant for Cu, Pb and Cd immobilization in contaminated soil with three different rates (1%, 5% and 10% w/w). The 0.01 mol/L CaCl₂ -extractability of metals significantly reduced with increasing rate of PAL and S-PAL in the first 7-day immobilization and insignificantly changed after 14-day immobilization. Compared with PAL, the lower metal extractability was observed after S-PAL addition. The BCR sequential extraction results showed that both of amendments were beneficial to transform acid soluble fraction to residual fraction. The XRD patterns of soil samples after immobilization evidenced that the formation of metal-bearing phosphate precipitates and the combination between functional groups such as Si-OH and metals played a key role for metal immobilization by S-PAL and PAL. Dominant phyla across all samples were Fusobacteria, Proteobacteria and Actinobacteria, and the relative abundance of Fusobacteria decreased under S-PAL treatment. The pH-dependent leaching test indicated that the metal release at a defined pH was not affected by the presence of PAL. Compared with S-PAL, the metals amended by PAL in soil were easier to release at acidic pH since the combination between functional groups and metals instead the formation of new metal-bearing precipitate.

Influencing characteristics of short-time aerobic digestion on spatial distribution and adsorption capacity of extracellular polymeric substances in waste activated sludge

The spatial distribution and adsorption capacity of extracellular polymeric substances (EPS) were systematically investigated for waste activated sludge (WAS) treated by a short-time aerobic digestion (STAD) process.

New insights into the plasmonic enhancement for photocatalytic H2 production by Cu–TiO2 upon visible light illumination

Cu nanoparticles were deposited on the surface of commercial TiO₂ nanoparticles (Cu–TiO₂) using different methods aiming at the production of highly efficient visible light photocatalysts.

Assessing membrane biofouling and its gel layer of anoxic/oxic membrane bioreactor for megacity municipal wastewater treatment during plum rain season in Yangtze River Delta, China

This study assessed membrane biofouling and its gel layer of anoxic/oxic membrane bioreactor (A/O-MBR) for megacity municipal wastewater treatment during plum rain season, which was continuous rainy weather, in Yangtze River Delta, China. A laboratory-scale A/O-MBR was operated to treat the municipal wastewater from Quyang wastewater treatment plant, which located at the typical megacity of Shanghai in Yangtze River Delta, from April to July accompanying with plum rain season. As reactor performance showed, COD_Cr, NH₄⁺-N, TN, TP of the influent gradually decreased during plum rain season, and inhibited pollutant removal due to organic carbon shortage. However, dissolve inorganic carbon and inorganic components in mixed liquid had an obvious increase under rainy weather. Membrane filtration results indicated that plum rain season enhanced pore blocking behavior, further leading to the serious membrane biofouling but inhibiting gel layer formation. Additionally, gel layer analysis predicted that plum rain season led to plenty of inorganic components and precipitate flew into A/O-MBR reactor. Inorganic components with elements of Ca, Mg Ba, Fe, Al and Si seriously blocked membrane pores. Those components also accumulated into gel layer in the form of SiO₂, CaCO₃, CaSiO₃, MgNH₄PO₄, BaCO₃, AlPO_4, etc. Consequently, plum rain season enhanced pore blocking behavior and led to severe membrane biofouling but with the inhibition of gel layer formation.

How myristyltrimethylammonium bromide enhances biomass harvesting and pigments extraction from Synechocystis sp. PCC 6803

Myristyltrimethylammonium bromide (MTAB) is a cationic surfactant used to improve biomass harvesting and pigment extraction form microalgae, but the mechanisms underlying its effectiveness are poorly defined. We document the mechanisms for enhanced harvesting and pigment extraction for the cyanobacterium Synechocystis sp. PCC 6803 using measurements from flow cytometer, zeta potential, release of soluble components, and microscopy. Harvesting efficiency increased as the MTAB/Biomass dose increased from 0 to 40%. A low MTAB dose (≤ 8%) mainly brought about coagulation and flocculation, which led to aggregation that improved harvesting, but 40% MTAB had the highest harvesting efficiency, 62%. Adding MTAB above a MTAB/Biomass dose of 8% also increased cell-membrane permeability, which allowed the solvent (ethyl acetate) to pass into the cells and resulted in a large increase in extraction efficiency of pigments: An MTAB/Biomass ratio of 60% for 180 min achieved the highest extraction efficiencies of chlorophyll and carotenoids, 95% and 91%, respectively. Combining harvesting and extraction performances with results from flow cytometry, zeta potential, release of soluble components, and microscopy lead to the following mechanistic understandings. MTAB dose from 8% to 40% solubilized EPS, which lowered the biomass's negative charge, but caused breakup of the large aggregates. An increase of cell permeability also in this stage allowed ethyl acetate to pass into the cells and achieve better pigment extraction. MTAB >40% led to cell lysis and a large increase in soluble organics, but complete cell lysis was not required to achieve the maximum extraction efficiency. The MTAB/Biomass % ratio for optimizing harvest efficiency and pigment extraction lay in the range of 40%-60%.

New insights into comparison between synthetic and practical municipal wastewater in cake layer characteristic analysis of membrane bioreactor

In previous studies, cake layer analysis in membrane bioreactor (MBR) was both carried out with synthetic and practical municipal wastewater (SMW and PMW), leading to different results. This study aimed to identify the comparison between SMW and PMW in cake layer characteristic analysis of MBR. Two laboratory-scale anoxic/oxic MBRs were operated for over 90days with SMW and PMW, respectively. Results showed that PMW led to rough cake layer surface with particles, and the aggravation of cake layer formation with thinner and denser cake layer. Additionally, inorganic components, especially Si and Al, in PMW accumulated into cake layer and strengthened the cake layer structure, inducing severer biofouling. However, SMW promoted bacterial metabolism during cake layer formation, thus aggravated the accumulation of organic components into cake layer. Therefore, SMW highlighted the organic components in cake layer, but weakened the inorganic functions in practical MBR operation.

Enhancement mechanisms of short-time aerobic digestion for waste activated sludge in the presence of cocoamidopropyl betaine

Cocoamidopropyl betaine (CAPB), which is a biodegradable ampholytic surfactant, has recently been found to dramatically enhance the aerobic digestion of waste activated sludge (WAS) in short-time aerobic digestion (STAD) systems. Therefore, it is important to understand the mechanisms in which CAPB enhances WAS aerobic digestion performance. Results showed that CAPB could dramatically enhance the solubilization of soluble proteins (PN), polysaccharides (PS), nucleic acids (NA) and humic-like substances (HS) in the STAD system within the initial 2 h. Then PN, PS and NA gradually decreased, while HS showed only minor decease. In addition, CAPB increased the proportion of low MW fractions (<20 kDa) from 4.22% to 39.4%, which are more biodegradable. Specific oxygen uptake rates and dehydrogenase enzyme activity results indicated that CAPB markedly improved the aerobic microorganism activities. Microbial community analyses and principle coordinate analyses (PCoA) revealed that CAPB increased the proportion of some functional microorganisms, including Proteobacteria, Planctomycetales, Acinetobacter, Pseudomonas and Aeromonas. The changes driven by CAPB could explain the enhanced performance of the STAD system for WAS aerobic treatment.

DHX15 promotes prostate cancer progression by stimulating Siah2-mediated ubiquitination of androgen receptor

Androgen receptor (AR) activation is critical for prostate cancer development and progression, including castration-resistance. The nuclear export signal of AR (NES^AR) plays an important role in AR intracellular trafficking and proteasome-dependent degradation. Here, we identified the RNA helicase DHX15 as a novel AR co-activator using a yeast mutagenesis screen and revealed that DHX15 regulates AR activity by modulating E3 ligase Siah2-mediated AR ubiquitination independent of its ATPase activity. DHX15 and Siah2 form a complex with AR, through NES^AR. DHX15 stabilized Siah2 and enhanced its E3 ubiquitin ligase activity, resulting in AR activation. Importantly, DHX15 was upregulated in prostate cancer specimens and its expression was correlated with Gleason scores and PSA recurrence. Furthermore, DHX15 immunostaining correlated with Siah2. Finally, DHX15 knockdown inhibited the growth of C4-2 prostate tumor xenografts in mice. Collectively, our data argue that DHX15 enhances AR transcriptional activity and contributes to prostate cancer progression through Siah2.

The distribution of phosphorus and its transformations during batch growth of Synechocystis

Phosphorus (P) is an essential nutrient that affects the growth and metabolism of microalgal biomass. Despite the obvious importance of P, the dynamics of how it is taken up and distributed in microalgae are largely undefined. In this study, we tracked the fate of P during batch growth of the cyanobacterium Synechocystis sp. PCC 6803. We determined the distribution of P in intracellular polymeric substances (IPS), extracellular polymeric substances (EPS), and soluble microbial products (SMP) for three initial ortho-phosphate concentrations. Results show that the initial P concentration had no impact on the production of biomass, SMP, and EPS. While the initial P concentration affected the rate and the timing of how P was transformed among internal and external forms of inorganic P (IP) and organic P (OP), the trends were the same no matter the starting P concentration. Initially, IP in the bulk solution was rapidly and simultaneously adsorbed by EPS (IP_EPS) and taken up as internal IP (IP_int). As the bulk-solution's IP was depleted, desorption of IP_EPS became the predominant source for IP that was taken up by the growing cells and converted into OP_int. At the end of the 9-d batch experiments, almost all P was OP, and most of the OP was intracellular. Based on all of the results, we propose a set of transformation pathways for P during the growth of Synechocystis. Key is that EPS and intracellular P pool play important and distinct roles in the uptake and storage of P.

[Liposuction combined with lymphatico-venous anastomosis for treatment of secondary lymphedema of the lower limbs: a report of 49 cases]

Objective: To study the clinical effects of liposuction combined with lymphatico-venous anastomosis for treatment of secondary lymphedema of the lower limbs. Methods: A retrospective analysis was performed for 49 patients who had undergone liposuction combined with lymphatico-venous anastomosis to treat secondary lymphedema of the lower limbs at Department of Lymph Surgery, Beijing Shijitan Hospital from November 2013 to February 2015.All patients were female aging from 31 to 70 years with median age of (52±10)years.All patients had history of pelvic surgery.There were 32 cases with cervical carcinoma, 11 cases with endometrial cancer, 1 case with ovarian cancer who accepted radical hysterectomy, 2 cases with benign tumor who accepted resection, 2 cases accepted inguinal lymph node dissection, 1 case with rectal cancer accepted radical resection.There were 30 cases with history of radiation therapy and 23 cases with history of erysipelas recurrent((2.1±3.9)/year). The limb swelling degree in preoperative and postoperative patients was explored using one-way analysis of variance with replicate measures and paired sample t-test. Meanwhile the incidence of lymphogenous infection was used as an evaluation of operation efficacy. Results: The mean lower limb circumference difference at 7 days, 6 months and 12 months was (0.17±1.36)cm, (1.25±1.62)cm and(1.58±1.56)cm, respectively, which was significantly decreased compared with preoperative((4.92±2.16)cm) (t=-5.712, -5.777, -5.765; all P<0.01). The mean lower limb volume difference at 7 days, 6 months and 12 months was (522±799)ml, (726±973)ml and (889±895)ml, respectively, which was significantly decreased compared with preoperative((2 729±1 335) ml)(t=-5.905, -6.093, -5.777; all P<0.01). The incidence of erysipelas was 0.0(0.0, 0.0)/6 months within 6 months after operation and 0.0(0.0, 0.0)/6 months within 6-12 months after operation, which was significantly lower than that before operation(0.0(0.0, 2.0)/year). The feeling of tightness and heaviness of the limb was significantly improved compared with preoperative. Conclusion: Liposuction combined with lymphatico-venous anastomosis is an effective method for the treatment of secondary lymphedema of the lower limbs.

New and practical mathematical model of membrane fouling in an aerobic submerged membrane bioreactor

This study aimed to develop a practical semi-empirical mathematical model of membrane fouling that accounts for cake formation on the membrane and its pore blocking as the major processes of membrane fouling. In the developed model, the concentration of mixed liquor suspended solid is used as a lumped parameter to describe the formation of cake layer including the biofilm. The new model considers the combined effect of aeration and backwash on the foulants' detachment from the membrane. New exponential coefficients are also included in the model to describe the exponential increase of transmembrane pressure that typically occurs after the initial stage of an MBR operation. The model was validated using experimental data obtained from a lab-scale aerobic sponge-submerged membrane bioreactor (MBR), and the simulation of the model agreed well with the experimental findings.

Biodecolorization of textile azo dye using Bacillus sp. strain CH12 isolated from alkaline lake

Textile azo dye decolorizing bacteria were isolated from alkaline Lakes Abaya and Chamo using Reactive Red 239 (RR239) dye. Through subsequent screening process, strain CH12 was selected to investigate the effects of nutrient supplement, DO, pH, temperature, dye concentration and types on decolorization. Based on 16S rRNA gene sequence analysis, strain CH12 was identified as Bacillus sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) supplements. Complete decolorization was also observed under anoxic and anaerobic conditions, and at the temperature of 30 °C and the pH of 10. However, the azo dye decolorization efficiency of strain CH12 was significantly reduced when NaNO₃ (1-8%) was supplemented or under aerobic culturing condition (≤6%), indicating that RR239 was less preferred electron acceptor. Overall, strain CH12 can be a promising candidate for decolorization applications due to its potential to effectively decolorize higher RR239 concentrations (50-250 mg/L) and six additional dyes.

Butyrate and retinoic acid imprint mucosal-like dendritic cell development synergistically from bone marrow cells

Accumulating data show that the phenotypes and functions of distinctive mucosal dendritic cells (DCs) in the gut are regulated by retinoic acid (RA). Unfortunately, the exact role of butyrate in RA-mediated mucosal DC differentiation has not been elucidated thoroughly to date. Mucosal-like dendritic cell differentiation was completed in vitro by culturing bone marrow cells with growth factors [granulocyte-macrophage colony-stimulating factor (GM-CSF/interleukin (IL)-4], RA and/or butyrate. The phenotypes, cytokine secretion, immune functions and levels of retinal dehydrogenase of different DCs were detected using quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. The results showed that RA-induced DCs (RA-DCs) showed mucosal DC properties, including expression of CD103 and gut homing receptor α₄ β₇ , low proinflammatory cytokine secretion and low priming capability to antigen-specific CD4⁺ T cells. Butyrate-treated RA-DCs (Bu-RA-DCs) decreased CD11c, but increased CD103 and α₄ β₇ expression. Moreover, the CD4⁺ T priming capability and the levels of retinal dehydrogenase of RA-DCs were suppressed significantly by butyrate. Thus, butyrate and retinoic acid have different but synergistic regulatory functions on mucosal DC differentiation, indicating that immune homeostasis in the gut depends largely upon RA and butyrate to imprint different mucosal DC subsets, both individually and collectively.

[The value of DCE-MRI in assessing the course of thyroid associated ophthalmopathy]

Objective: To explore the feasibility of the semi-quantitative rectus extraocular muscle (EOM) parameters of dynamic contrast-enhanced magetic resonance imaging (DCE-MRI) in assessing the clinical course of thyroid associated ophthalmopathy (TAO). Methods: It was a retrospective case series study. A total of 136 cases of TAO were recruited from March 2011 to October 2012 in the Tianjin the first center hospital including 63 males and 72 females, aged 24.0-65.0 years, with an average age of (40.5±10.9) years. Forty healthy volunteers were recruited as control group (CG). According to clinical activity score (CAS), all TAO patients were divided into 2 groups, activity group (AG) and inactivity group (IAG). MRI and DCE-MRI orbit scan were performed in each subject. Drew time-intensity curves (TIC) by Siemens 3.0 MR (syngo) post-processing workstation. The semi-quantitative parameters of DCE-MRI were calculated. The semi-quantitative paramters based on TIC include early enhancement coefficient (EEC), maximum enhancement coefficient (Emax) and wash-out coefficient (WC(5min)). Kruskal-Wallis H rank test was used for comparing signal intensity among 3 groups, and Nemenyi test for pairwise comparison between groups. The DCE-MRI parameters (EEC, Emax, WC(5 min)) among groups were compared by one-way ANOVA, and Bonferroni t test is for pairwise comparison between groups. The diagnostic value of mean EEC, mean Emax, WC(5min) for assessment of the clinical course in TAO was analyzed by ROC curve. Results: There were significant difference in signal intensity (SI) of rectus EOM on T(2)WI among CG, AG and IAG, which is significantly different in 88 cases of AG including 45 cases of high intensity 51.1%, 23 cases of moderate intensity 26.1%, and 20 cases of low intensity 22.7%,compared with CG and IAG. EEC (P<0.05), Emax and WC5min values of rectus EOM of TAO group were significantly lower than those of CG(P<0.05), which values of rectus EOM of TAO active group of EEC are 0.63±0.06、0.61±0.05、0.56±0.09、0.57±0.09, and values of rectus EOM of TAO inactive group of EEC are 0.49±0.05、0.50±0.08、0.57±0.10、0.55±0.09. The values of rectus EOM of TAO active group of Emax are 1.35±0.09、1.28±0.09、1.21±0.17、1.25±0.10, and the values of rectus EOM of TAO inactive group of Emax are 1.04±0.06、1.05±0.10、1.20±0.19、1.16±0.11. The values of rectus EOM of TAO active group of WC(5 min) are 0.13±0.03、0.13±0.03、0.13±0.06、0.13±0.03 and the values of rectus EOM of TAO inactive group of WC5min are 0.08±0.02、0.79±0.03、0.11±0.06、0.09± 0.03. EEC (χ(2)=9.20, P<0.05), Emax and WC(5min) values of rectus EOM of TAO group were significantly lower than those of CG (P<0.05). EEC, Emax and WC(5min) values of medial rectus and inferior rectus EOM of IAG were significantly lower than those of AG(P<0.05). WC(5min) values of superior rectus EOM of IAG were significantly lower than those of AG (P<0.05). There were no differences in EEC and Emax values of lateral rectus and superior rectus EOM between IAG and AG (P>0.05). There were no differences in WC(5min) values of lateral rectus EOM between IAG and AG (P>0.05). The area under the curve (AUC) were 0.771, 0.879, 0.898 for mean EEC, mean Emax, and mean WC(5min), respectively. Conclusion: The semi-quantitative paramters of DCE-MRI can show the clinical activity of TAO patients and can be considered as the quantitative index of TAO activity staging. (Chin J Ophthalmol, 2017, 53: 430-435).

Potential effects of loading nano zero valent iron discharged on membrane fouling in an anoxic/oxic membrane bioreactor

A laboratory-scale submerged anoxic-oxic membrane bioreactor for municipal wastewater was operated to investigate the potential effects of loading suspended nano zero valent iron (nZVI, 25 and 50 mg/L) discharged on the membrane fouling. nZVI transformed rapidly into Feⁿ⁺, generated reactive oxygen species (ROS) and caused oxidative stress. This result rapidly led to the cell lysis and bacteria death, and further resulted in the decrease of biomass and extracellular polymeric substances (EPS). nZVI also thinned the membrane fouling layer. But nZVI had no obvious effects on activated sludge particle size, EPS molecule weight distribution and VOCs constitution of membrane foulant. Additionally, nZVI released Feⁿ⁺ and mitigated the inorganic (mainly Si element) fouling through Feⁿ⁺ flocculation. Consequently, membrane fouling mitigation with nZVI discharged was mainly due to oxidative stress to bacteria and Feⁿ⁺ flocculation of nZVI.

Simultaneous Bioreduction of Multiple Oxidized Contaminants Using a Membrane Biofilm Reactor

  This study tests a hydrogen-based membrane biofilm reactor (MBfR) to investigate simultaneous bioreduction of selected oxidized contaminants, including nitrate (<inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm01.gif"/>-N), sulfate (<inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm15.gif"/>), bromate (<inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm26.gif"/>), chromate (Cr(VI)) and para-chloronitrobenzene (p-CNB). The experiments demonstrate that MBfR can achieve high performance for contaminants bioreduction to harmless or immobile forms in 240 days, with a maximum reduction fluxes of 0.901 g <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm37.gif"/>-N/m2·d, 1.573 g <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm48.gif"/>/m2·d, 0.009 g <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm59.gif"/>/m2·d, 0.022 g Cr(VI)/m2·d, and 0.043 g p-CNB/m2·d. Increasing H2 pressure and decreasing influent surface loading enhanced removal efficiency of the reactor. Flux analysis indicates that nitrate and sulfate reductions competed more strongly than <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="00178-ilm70.gif"/>, Cr(VI) and p-CNB reduction. The average H2 utilization rate, H2 flux, and H2 utilization efficiency of the reactor were 0.026 to 0.052 mg H2/cm3·d, 0.024 to 0.046 mg H2/cm2·d, and 97.5% to 99.3% (nearly 100%). Results show the hydrogen-based MBfR may be suitable for removing multiple oxidized contaminants in drinking water or groundwater.

Fabrication of HA/PEI-functionalized carbon dots for tumor targeting, intracellular imaging and gene delivery

Carbon quantum dots (CDs) as emerging carbon nano-materials have attracted tremendous attention in biomedical fields due to unique properties.

Biofouling and control approaches in membrane bioreactors

Membrane fouling (especially biofouling) as a critical issue during membrane reactor (MBR) operation has attracted much attention in recent years. Although previous review papers have presented different aspects of MBR's fouling when treating various wastewaters, the information related to biofouling in MBRs has only simply or partially reviewed. This work attempts to give a more comprehensive and elaborate explanation of biofilm formation, biofouling factors and control approaches by addressing current achievements. This also suggests to a better way in controlling biofouling by developing new integrated MBR systems, novel flocculants and biomass carriers.

New insight into adsorption characteristics and mechanisms of the biosorbent from waste activated sludge for heavy metals

The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb(2+) and Zn(2+) in aqueous single-metal solutions. A pH value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients (above 0.99 for both metal ions) and insignificant lack of fit (p=0.0838 and 0.0782 for Pb(2+) and Zn(2+), respectively). Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation (between -NH2, -CN and metal ions) and ion-exchange (between -COOH and metal ions). The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.

Targeting 6-phosphogluconate dehydrogenase in the oxidative PPP sensitizes leukemia cells to antimalarial agent dihydroartemisinin

The oxidative pentose phosphate pathway (PPP) is crucial for cancer cell metabolism and tumor growth. We recently reported that targeting a key oxidative PPP enzyme, 6-phosphogluconate dehydrogenase (6PGD), using our novel small molecule 6PGD inhibitors Physcion and its derivative S3, shows anti-cancer effects. Notably, humans with genetic deficiency of either 6PGD or another oxidative PPP enzyme, glucose-6-phosphate dehydrogenase (G6PD), exhibit non-immune hemolytic anemia upon exposure to aspirin and various anti-malarial drugs. Inspired by these clinical observations, we examined the anti-cancer potential of combined treatment with 6PGD inhibitors and anti-malarial drugs. We found that stable knockdown of 6PGD sensitizes leukemia cells to anti-malarial agent dihydroartemisinin (DHA). Combined treatment with DHA and Physcion activates AMP-activated protein kinase, leading to synergistic inhibition of human leukemia cell viability. Moreover, our combined therapy synergistically attenuates tumor growth in xenograft nude mice injected with human K562 leukemia cells and cell viability of primary leukemia cells from human patients, but shows minimal toxicity to normal hematopoietic cells in mice as well as red blood cells and mononucleocytes from healthy human donors. Our findings reveal the potential for combined therapy using optimized doses of Physcion and DHA as a novel anti-leukemia treatment without inducing hemolysis.

Reaching the Surveillance-Response Stage of Schistosomiasis Control in The People's Republic of China: A Modelling Approach

With the goal set to eliminate schistosomiasis nationwide by 2020, The People's Republic of China has initiated the surveillance-response stage to identify remaining sources of infection and potential pockets from where the disease could reemerge. Shifting the focus from classical monitoring and evaluation to rapid detection and immediate response, this approach requires modelling to bridge the surveillance and response components. We review here studies relevant to schistosomiasis modelling in a Chinese surveillance-response system with the expectation to achieve a practically useful understanding of the current situation and potential future study directions. We also present useful experience that could tentatively be applied in other endemic regions in the world. Modelling is discussed at length as it plays an essential role, both with regard to the intermediate snail host and in the definitive, mammal hosts. Research gaps with respect to snail infection, animal hosts and sectoral research cooperation are identified and examined against the prevailing background of ecosystem and socioeconomic changes with a focus on coexisting challenges and opportunities in a situation with increasing financial constraints.

Utilizing a one-dimensional multispecies model to simulate the nutrient reduction and biomass structure in two types of H2-based membrane-aeration biofilm reactors (H2-MBfR): model development and parametric analysis

In this study, a one-dimensional multispecies model (ODMSM) was utilized to simulate NO3(-)-N and ClO4(-) reduction performances in two kinds of H2-based membrane-aeration biofilm reactors (H2-MBfR) within different operating conditions (e.g., NO3(-)-N/ClO4(-) loading rates, H2 partial pressure, etc.). Before the simulation process, we conducted the sensitivity analysis of some key parameters which would fluctuate in different environmental conditions, then we used the experimental data to calibrate the more sensitive parameters μ1 and μ2 (maximum specific growth rates of denitrification bacteria and perchlorate reduction bacteria) in two H2-MBfRs, and the diversity of the two key parameters' values in two types of reactors may be resulted from the different carbon source fed in the reactors. From the simulation results of six different operating conditions (four in H2-MBfR 1 and two in H2-MBfR 2), the applicability of the model was approved, and the variation of the removal tendency in different operating conditions could be well simulated. Besides, the rationality of operating parameters (H2 partial pressure, etc.) could be judged especially in condition of high nutrients' loading rates. To a certain degree, the model could provide theoretical guidance to determine the operating parameters on some specific conditions in practical application.

Scum sludge as a potential feedstock for biodiesel production from wastewater treatment plants

The main goal of this study was to compare the component and yield of biodiesel obtained by different methods from different sludge in a wastewater treatment plant. Biodiesel was produced by ex-situ and in-situ transesterification of scum, primary and secondary sludge respectively. Results showed that scum sludge had a higher calorific value and neutral lipid than that of primary and secondary sludge. The lipid yield accounted for one-third of the dried scum sludge and the maximum yield attained 22.7% under in-situ transesterification. Furthermore the gas chromatography analysis of fatty acid methyl esters (FAMEs) revealed that all sludge contained a significant amount of palmitic acid (C16:0) and oleic acid (C18:1) regardless of extraction solvents and sludge types used. However, the difference lay in that oleic acid methyl ester was the dominant component in FAMEs produced from scum sludge while palmitic acid methyl ester was the dominant component in FAMEs from primary and secondary sludge. In addition, the percentage of unsaturated fatty acid ester in FAMEs from scum sludge accounted for 57.5-64.1% of the total esters, which was higher than the equivalent derived from primary and secondary sludge. In brief, scum sludge is a potential feedstock for the production of biodiesel and more work is needed in the future.

Effects of potassium diformate on the gastric function of weaning piglets

Potassium diformate (KDF), as an acidifier, has been shown to improve growth performance in pigs, but it is not yet known whether KDF regulates gastric function. Thus, the objective of the present study was to investigate the effects of dietary KDF on gastric function in weaning piglets. One hundred and eighty Landrace × Large White piglets (bodyweight = 5.80 ± 0.15 kg) were weaned at 28 days old and randomly allocated into two groups, with six pens in each group and 15 piglets in each pen. Piglets in the control group were fed the basal diet, whereas the KDF-treated group was fed the basal diet supplemented with 10 g/kg KDF. After 35 days of feeding, the KDF treatment improved the bodyweight (P = 0.034) and reduced the relative weight of stomach (P = 0.050), decreased the hydrochloric acid concentration (P = 0.016) in the gastric digesta and the pepsin activity in the gastric oxyntic mucosa (P = 0.001) and increased the lactic acid concentration (P = 0.001) in the gastric digesta. Furthermore, KDF treatment increased the level of somatostatin (SS) (P = 0.009), but did not change the concentration of gastrin (P = 0.497) and the activity of H+-K+-ATPase (P = 0.575) in the gastric oxyntic mucosa. However, KDF treatment downregulated the expression of SS mRNA in the gastric oxyntic mucosa (P = 0.031) and upregulated the mRNA expression of gastrin (P < 0.001) and H+-K+-ATPase (P < 0.001) in the gastric oxyntic mucosa. These results suggest that the effects of KDF on weaning piglets may be related to the regulation of gastric function gene expression.

Supplemental lipoic acid relieves post-weaning diarrhoea by decreasing intestinal permeability in rats

Lipoic acid (LA) is a naturally existing substance which widely distributed in the cellular membranes and cytosol of animal cells. Its intracellular functions include quenching of free radicals and repairing oxidized proteins. The purpose of this study was to evaluate the effects of LA on post-weaning diarrhoea using a rat model. Sixty weaned rats were fed either a basal diet or a LA-supplemented diet, or a zinc oxide (ZnO)-supplemented diet as a positive control. Rats in the LA and ZnO groups had better performance and reduced incidence of diarrhoea (p < 0.05). Both LA and ZnO treatments enhanced intestinal homeostatic and architecture, significantly decreased urinary lactulose to mannitol ratios (p < 0.05) and increased the expression of the intestinal mucosal tight junction proteins occludin (OCLN) and zonula occludens protein-1 (ZO-1) (p < 0.05). LA significantly increased the activities of antioxidant enzymes, and reduced glutathione while decreasing the levels of oxidative glutathione and malondialdehyde in the intestinal mucosa (p < 0.05). Furthermore, an in vitro study indicated that supplementation with LA in IEC-6 intestinal epithelial cells significantly enhanced the expression of OCLN and ZO-1 under hydrogen peroxide-induced oxidative stress. Collectively, these results suggest that LA relieves post-weaning diarrhoea by reducing intestinal permeability and improving antioxidant indices.

Putative suppressing effect of IgG Fc-conjugated haemagglutinin (HA) stalk of influenza virus H7N9 on the neutralizing immunogenicity of Fc-conjugated HA head: implication for rational design of HA-based influenza vaccines

The emergence of influenza A H7N9 in infection has posed a great threat to public health globally. Poor immunogenicity of H7N9 haemagglutinin (HA) is a major obstacle to the development of an effective H7N9 vaccine. Here, we found that the vaccine containing the H7HA head conjugated with IgG Fc (Hd-Fc) induced strong neutralizing antibody responses and protection against H7N9 infection, whilst the Fc-conjugated H7HA stalk (St-Fc)-based vaccine could not induce neutralizing antibodies, although the St-Fc-immunized mice were partially protected. The vaccines containing the full-length extracellular domain of HA conjugated with Fc and the mixture of Hd-Fc plus St-Fc induced significantly lower neutralizing antibody and haemagglutination inhibition titres than the Hd-Fc-based vaccine. These results suggest that the St-Fc may have inhibitory effects on the neutralizing immunogenicity of Hd-Fc. Therefore, the neutralizing domain(s), such as the receptor-binding domain, in the HA head should be kept and the non-neutralizing domain(s) in the HA stalk with the ability to potentially suppress the neutralizing immunogenicity of HA head should be removed from Fc-conjugated HA-based influenza vaccines to increase the neutralizing antibody response.

Structure and distribution of inorganic components in the cake layer of a membrane bioreactor treating municipal wastewater

A laboratory-scale submerged anoxic-oxic membrane bioreactor treating municipal wastewater was operated to investigate the structure and distribution of the inorganic cake layer buildup on the membrane. BCR (European Community Bureau of Reference) sequential extraction, X-ray photoelectron spectroscopy (XPS), and both map and line scan of energy-dispersive X-ray analysis (EDX) were performed for cake layer characterization. BCR results showed that Si, Al, Ca, Mg, Fe, and Ba were the predominant inorganic elements in the cake layer, and they occurred mostly as crystal particles. Crystal SiO2 was the dominant inorganic compound while Ca in the form of CaSO4 (dominant) and CaCO3 were also present, but exerted little effect on the cake layer structure because most of these compounds were deposited as precipitates on the reactor bottom. EDX results indicated that Si and Al accumulated together along the cross-sectional cake layer in the form of Si-Al (SiO2-Al2O3) crystal particles.

Probable aerosol transmission of severe fever with thrombocytopenia syndrome virus in southeastern China

Some clusters of severe fever with thrombocytopenia syndrome virus (SFTSV) infection were reported in China as of 2010. However, to date, there has been no epidemiologic evidence of aerosol transmission of SFTSV. Epidemiologic investigations were conducted after a cluster of 13 cases of SFTSV in May 2014. A total of 13 cases, including 11 confirmed cases and one clinically diagnosed case, were identified besides the case of the index patient. The index patient experienced onset of SFTSV on 23 April and died on 1 May. The patients with secondary cases had onset from 10 to 16 May, peaking on 13 May. Moreover, eight secondary cases occurred in family members of the index patient, and the other five cases occurred in neighbors of the index patient. According to epidemiologic investigations, patients 1, 3, 4, 5, 6, 7, 9 and 12 contracted the disease through contact with blood of the index patient. Notably, patients 8 and 10 did not have a history of contact with the blood of the index patient, but they stayed in the mourning hall for hours. SFTSV could be transmitted from person to person by direct contact and/or aerosol transmission, and it is important to consider aerosol transmission as a possible transmission route.

Bioreduction of vanadium (V) in groundwater by autohydrogentrophic bacteria: Mechanisms and microorganisms

As one of the transition metals, vanadium (V) (V(V)) in trace amounts represents an essential element for normal cell growth, but becomes toxic when its concentration is above 1mg/L. V(V) can alter cellular differentiation, gene expression, and other biochemical and metabolic phenomena. A feasible method to detoxify V(V) is to reduce it to V(IV), which precipitates and can be readily removed from the water. The bioreduction of V(V) in a contaminated groundwater was investigated using autohydrogentrophic bacteria and hydrogen gas as the electron donor. Compared with the previous organic donors, H2 shows the advantages as an ideal electron donor, including nontoxicity and less production of excess biomass. V(V) was 95.5% removed by biochemical reduction when autohydrogentrophic bacteria and hydrogen were both present, and the reduced V(IV) precipitated, leading to total-V removal. Reduction kinetics could be described by a first-order model and were sensitive to pH and temperature, with the optimum ranges of pH7.5-8.0 and 35-40°C, respectively. Phylogenetic analysis by clone library showed that the dominant species in the experiments with V(V) bioreduction belonged to the β-Proteobacteria. Previously known V(V)-reducing species were absent, suggesting that V(V) reduction was carried out by novel species. Their selective enrichment during V(V) bioreduction suggests that Rhodocyclus, a denitrifying bacterium, and Clostridium, a fermenter known to carry out metal reduction, were responsible for V(V) bioreduction.

Effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances from waste activated sludge

The effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances (EPSs) from waste activated sludge (WAS) was investigated. Bioflocculation of the EPS was found to be enhanced by 2∼6 h of WAS aerobic digestion under the conditions of natural sludge pH (about 7), high sludge concentration by gravity thickening, and dissolved oxygen of about 2 mg/L. With the same EPS extraction method, the total suspended solid content reduction of 0.20 and 0.36 g/L and the volatile suspended solid content reduction of 0.19 and 0.26 g/L were found for the WAS samples before and after aerobic digestion of 4 h. It indicates that more EPS is produced by short-time aerobic digestion of WAS. The scanning electron microscopy images of the WAS samples before and after aerobic digestion of 4 h showed that more EPS appeared on the surface of zoogloea by aerobic digestion, which reconfirmed that WAS aerobic digestion induced abundant formation of EPS. By WAS aerobic digestion, the flocculating rate of the EPS showed about 31 % growth, almost consistent with the growth of its yield (about 34 %). The EPSs obtained before and after the aerobic digestion presented nearly the same components, structures, and Fourier transform infrared spectra. These results revealed that short-time aerobic digestion of WAS enhanced the flocculation of the EPS by promoting its production.

Biofilm architecture in a novel pressurized biofilm reactor

A novel pure-oxygen pressurized biofilm reactor was operated at different organic loading, mechanical shear and hydrodynamic conditions to understand the relationships between biofilm architecture and its operation. The ultimate goal was to improve the performance of the biofilm reactor. The biofilm was labeled with seven stains and observed with confocal laser scanning microscopy. Unusual biofilm architecture of a ribbon embedded between two surfaces with very few points of attachment was observed. As organic loading increased, the biofilm morphology changed from a moderately rough layer into a locally smoother biomass with significant bulging protuberances, although the chemical oxygen demand (COD) removal efficiency remained unchanged at about 75%. At higher organic loadings, biofilms contained a larger fraction of active cells distributed uniformly within a proteinaceous matrix with decreasing polysaccharide content. Higher hydrodynamic shear in combination with high organic loading resulted in the collapse of biofilm structure and a substantial decrease in reactor performance (a COD removal of 16%). Moreover, the important role of proteins for the spatial distribution of active cells was demonstrated quantitatively.

Removal and mechanism of Cu (II) and Cd (II) from aqueous single-metal solutions by a novel biosorbent from waste-activated sludge

The removal and mechanism of Cu(2+) and Cd(2+) from aqueous single-metal solutions were investigated by using a novel biosorbent from waste-activated sludge. A series of adsorption experiments was designed to disclose the effects of the key factors on the adsorption capacity of the biosorbent for the metal ions. The mass ratio of the biosorbent to metal ion was optimized as 2 to balance the adsorption capacity and the removal efficiency. A right shaking speed (150 r/min) not only ensured enough contact frequency between the sorbent and the adsorbate but also reduced the mass transfer resistance. The natural pH value (about 5.5) of the metal solutions benefited a high adsorption capacity of the biosorbent and avoided the consumption of acid or base for pH adjustment. The adsorption reactions belonged to the endothermic process between 15 and 45 °C. As the scanning electron microscopy (SEM) images showed, the meshy structure with long chains and many branches was ideal for the biosorbent to quickly capture the metal ions. The energy-dispersive X-ray (EDX) spectra confirmed that the adsorbed metal ions lay in the precipitates of the adsorption reactions. According to the FTIR analyses, the functional groups responsible for Cu(2+) adsorption majorly consisted of O-H, N-H, COOH, CONH2, and the groups containing sulfur and phosphorus, while those for Cd(2+) adsorption contained O-H, N-H, COOH, and CONH2. The differences in the responsible functional groups explained the phenomenon that the adsorption capacity of the biosorbent for Cu(2+) was higher than that for Cd(2+).

A comparison study on membrane fouling in a sponge-submerged membrane bioreactor and a conventional membrane bioreactor

This study compared membrane fouling in a sponge-submerged membrane bioreactor (SSMBR) and a conventional membrane bioreactor (CMBR) based on sludge properties when treating synthetic domestic wastewater. In the CMBR, soluble microbial products (SMP) in activated sludge were a major contributor for initial membrane fouling and presented higher concentration in membrane cake layer. Afterwards, membrane fouling was mainly governed by bound extracellular polymeric substances (EPS) in activated sludge, containing lower proteins but significantly higher polysaccharides. Sponge addition could prevent cake formation on membrane surface and pore blocking inside membrane, thereby alleviating membrane fouling. The SSMBR exhibited not only less growth of the biomass and filamentous bacteria, but also lower cake layer and pore blocking resistance due to lower bound EPS concentrations in activated sludge. Less membrane fouling in SSMBR were also attributed to larger particle size, higher zeta potential and relative hydrophobicity of sludge flocs.

The effect of solids retention times on the characterization of extracellular polymeric substances and soluble microbial products in a submerged membrane bioreactor

In this study, the effect of solids retention times (SRTs) on extracellular polymeric substances (EPS) and soluble microbial products (SMPs) were investigated in a membrane bioreactor (MBR) at SRTs of 10, 5 and 3 days. The results showed that more carbohydrates and proteins were accumulated at short SRT, which can due to the higher biomass activity in the reactor. The molecular weight (MW) distribution analysis suggested that macromolecules (MW>30 kDa) and small molecules (MW<1 kDa) were the dominant fraction of EPS and SMP, respectively. The reactor at shorter SRT had more small molecules and less macromolecules of carbohydrates. The MW distribution of total organic carbon (TOC) suggested that other organic moieties were exuded by microbes into the solution. The shorter SRT had more undefined microbial by-product-like substances and different O − H bonds in hydroxyl functional groups.

Removal and fate of micropollutants in a sponge-based moving bed bioreactor

This study investigated the removal of micropollutants using polyurethane sponge as attached-growth carrier. Batch experiments demonstrated that micropollutants could adsorb to non-acclimatized sponge cubes to varying extents. Acclimatized sponge showed significantly enhanced removal of some less hydrophobic compounds (log D<2.5), such as ibuprofen, acetaminophen, naproxen, and estriol, as compared with non-acclimatized sponge. The results for bench-scale sponge-based moving bed bioreactor (MBBR) system elucidated compound-specific variation in removal, ranging from 25.9% (carbamazepine) to 96.8% (β-Estradiol 17-acetate) on average. In the MBBR system, biodegradation served as a major removal pathway for most compounds. However, sorption to sludge phase was also a notable removal mechanism of some persistent micropollutants. Particularly, carbamazepine, ketoprofen and pentachlorophenol were found at high concentrations (7.87, 6.05 and 5.55 μg/g, respectively) on suspended biosolids. As a whole, the effectiveness of MBBR for micropollutant removal was comparable with those of activated sludge processes and MBRs.

New insight into the effects of Ca(II) on cake layer structure in submerged membrane bioreactors

The effects of Ca(II) on the structure of the cake layer in submerged membrane bioreactors (SMBRs) were investigated in this study. Three parallel laboratory-scale SMBRs were operated with synthetic municipal wastewater with three Ca(II) levels (82, 208 and 410 mg l(-1)). As the Ca(II) concentration increased, the sludge floc size increased and the molecular weight of the soluble microbial products (SMP) in the bulk liquid decreased. These observations were attributed to the neutralization and bridging function of Ca(II). Furthermore, Ca(II) addition did not change the thickness of the cake layer, but inhibited the deposition of other elements, such as Al, Si, Mg, and Fe. As a result of Ca(II) addition, the cake layer became less compact and more porous. The interspaces among the flocs in the cake layer helped to reduce the membrane fouling potential.

Enhanced struvite recovery from wastewater using a novel cone-inserted fluidized bed reactor

The feasibility of struvite recovery at low (12.5 mg/L) and high (120 mg/L) phosphorus concentrations was studied by constructing a novel fluidized bed reactor with cones (FBRwc) and without cones (FBRwoc). The crystallization process was continuously operated for 133 days under different hydraulic retention times (HRT = 1-10 hr), pH (7.5-10), and molar ratios of Mg/P (0.75-1.75), N/P (1-10) and Ca/Mg (0-2). The optimum operating conditions of HRT, pH, Mg/P and N/P molar ratios were found to be 2 hr, 9, 1.25, and 7.5, respectively. Under these optimum conditions, the phosphorus precipitation efficiencies of FBRwc were 93% for low and 98% for high phosphorus influent; however, the efficiencies were 78% and 81% for FBRwoc, respectively. Due to crystal losses at each junction (17%-31%), the crystal recovery efficiency of FBRwoc was relatively low (47%-65%) for both influent concentrations. However, the losses were minimal in FBRwc, which showed 75% and 92% crystal recovery for low and high phosphorus concentrations, respectively. At low calcium concentration, crystal chemical analysis showed the product to be pure struvite (> 99%). The scanning electron microscope and X-ray diffraction results further confirmed that the crystal recovered from FBRwc contained pure struvite, which could be considered a high quality fertilizer. Except HRT, all parameters (pH, Mg/P, N/P and Ca/Mg) were found to be influencing factors for FBRwc performance. Overall, inserting cones in each part of the reactor played a significant role in enhancing struvite recovery from a wide range of phosphorus-containing wastewater.

Effect of intermittent aeration cycle on nutrient removal and microbial community in a fluidized bed reactor-membrane bioreactor combo system

Effect of intermittent aeration cycle (IAC=15/45-60/60min) on nutrient removal and microbial community structure was investigated using a novel fluidized bed reactor-membrane bioreactor (FBR-MBR) combo system. FBR alone was found more efficient for removing PO4-P (>85%) than NH4-N (<40%) and chemical oxygen demand (COD<35%). However, in the combo system, COD and NH4-N removals were almost complete (>98%). Efficient nitrification, stable mixed liquor suspended solid and reduced transmembrane pressure was also achieved. Quantitative real-time polymerase chain reaction results of total bacteria 16S rRNA gene copies per mL of mixed-liquor varied from (2.48±0.42)×10(9) initial to (2.74±0.10)×10(8), (6.27±0.16)×10(9) and (9.17±1.78)×10(9) for 15/45, 45/15 and 60/60min of IACs, respectively. The results of clone library analysis revealed that Proteobacteria (59%), Firmicutes (12%) and Bacteroidetes (11%) were the dominant bacterial group in all samples. Overall, the combo system performs optimum nutrient removal and host stable microbial communities at 45/15min of IAC.

Arsenic removal from groundwater by acclimated sludge under autohydrogenotrophic conditions

Arsenic in the environment is attracting increasing attention due to its chronic health effects. Although arsenite (As(III)) is generally more mobile and more toxic than arsenate (As(V)), reducing As(V) to As(III) may still be a means for decontamination, because As(III) can be removed from solution by precipitation with sulfide or by adsorption or complexation with other metal sulfides. The performance of As(V) bio-reduction under autohydrogenotrophic conditions was investigated with batch experiments. The results showed that As(V) reduction was a biochemical process while both acclimated sludge and hydrogen were essential. Most of the reduced arsenic remained in a soluble form, although 20% was removed with no addition of sulfate, while 82% was removed when sulfate was reduced to sulfide. The results demonstrated that the reduced arsenic was re-sequestered in the precipitates, probably as arsenic sulfides. Kinetic analysis showed that pseudo first-order kinetics described the bio-reduction process better than pseudo second-order. In particular, the influences of pH and temperature on As(V) reduction by acclimated sludge under autohydrogenotrophic conditions and total soluble As removal were examined. The reduction process was highly sensitive to both pH and temperature, with the optimum ranges of pH 6.5-7.0 and 30-40 degrees C respectively. Furthermore, Arrhenius modeling results for the temperature effect indicated that the As(V) reduction trend was systematic. Total soluble As removal was consistent with the trend of As(V) reduction.

Copper (II) adsorption by the extracellular polymeric substance extracted from waste activated sludge after short-time aerobic digestion

The extracellular polymeric substance (EPS) extracted from waste activated sludge (WAS) after short-time aerobic digestion was investigated to be used as a novel biosorbent for Cu(2+) removal from water. The EPS consisted of protein (52.6 %, w/w), polysaccharide (30.7 %, w/w), and nucleic acid (16.7 %, w/w). Short-time aerobic digestion process of WAS for about 4 h promoted the productivity growth of the EPS for about 10 %. With a molecular weight of about 1.9 × 10(6) Da, the EPS showed a linear structure with long chains, and contained carboxyl, hydroxyl, and amino groups. The sorption kinetics was well fit for the pseudo-second-order model, and the maximum sorption capacity of the EPS (700.3 mg Cu(2+)/g EPS) was markedly greater than those of the reported biosorbents. Both Langmuir model and Freundlich model commendably described the sorption isotherm. The Gibbs free energy analysis of the adsorption showed that the sorption process was feasible and spontaneous. According to the complex results of multiple analytical techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy, etc., the adsorption process took place via both physical and chemical sorption, but the electrostatic interaction between sorption sites with the functional groups and Cu(2+) is the major mechanism.