Rapid start-up of PN/A process and efficient enrichment of functional bacteria: A novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS).

Reactor configuration, control strategy and inoculation method were key factors affecting the rapid start-up of partial nitrification/anammox (PN/A) process and the efficient enrichment of functional bacteria (anammox and ammonia oxidizing bacteria). At present, PN/A process was generally operated through single factor rather than forming a system. In this study, a novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS) was constructed, which consisted of a multi-stage aerobic-biofilm/anaerobic-granular baffle reactor (MOABR) and a control strategy on pH/aeration time. PN process was started within 10d, and PN/A process was started on the basis of stable PN process within 41d. The simultaneous enrichment of functional bacteria was achieved by combining the advantages of single-stage and two-stage PN/A process. The results of high-throughput sequencing showed that Candidatus Kuenenia (20.42 ± 15.88%) was highly enriched in each compartment at day 98, and the relative abundance of Candidatus Kuenenia in the anaerobic compartment R4 was as high as 43.13%.

High-rate partial denitrification via effluent residual nitrate controlling and microbial mechanism of nitrite accumulation by carbon dosage optimization.

The high-rate partial denitrification (PD) via effluent residual nitrate controlling by carbon dosage optimization was investigated based on the analysis of microbial mechanism of nitrite accumulation in this study. When the COD/N was changed from 4.0 to 1.8 and the effluent nitrate was above 8.48 mg/L, the nitrate accumulation ratio (NAR) and nitrate removal ratio (NRR) achieved 60 and 90%, respectively. With the electron donor starvation (EDS) strategy, nitrite accumulation was increased, which is related to the reduced utilization of carbon sources. In addition, the rapid increase of Thauera (0.21% to 53.29%) and inhibition of Others and Unclassified (96.93% to 16.99%), and the significantly different expression between reductase genes contributed to nitrite production (narG, 1,727.44 copies/mg) and nitrite reduction (nirS, 208.27 copies/mg; nirK, 203.94 copies/mg) commonly involved in PD start-up and stable operation. Another reactor can be quickly started by controlling effluent residual nitrate within 19 days.

Grafting of R4N+-Bearing Organosilane on Kaolinite, Montmorillonite, and Zeolite for Simultaneous Adsorption of Ammonium and Nitrate.

Modification of aluminosilicate minerals using a R4N+-bearing organic modifier, through the formation of covalent bonds, is an applicable way to eliminate the modifier release and to maintain the ability to remove cationic pollutants. In this study, trimethyl [3-(trimethoxysilyl) propyl] ammonium chloride (TM) and/or dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DMO) were used to graft three aluminosilicate minerals, including calcined kaolinite (Kaol), montmorillonite (Mt), and zeolite (Zeol), and the obtained composites were deployed to assess their performance in regard to ammonium (NH4+) and nitrate (NO3-) adsorption. Grafting of TM and/or DMO had little influence on the crystal structures of Kaol and Zeol, but it increased the interlayer distance of Mt due to the intercalation. Compared to Kaol and Zeol, Mt had a substantially greater grafting concentration of organosilane. For Mt, the highest amount of loaded organosilane was observed when TM and DMO were used simultaneously, whereas for Kaol and Zeol, this occurred when only DMO was employed. 29Si-NMR spectra revealed that TM and/or DMO were covalently bonded on Mt. As opposed to NO3-, the amount of adsorbed NH4+ was reduced after TM and/or DMO grafting while having little effect on the adsorption rate. For the grafted Kaol and Zeol, the adsorption of NH4+ and NO3- was non-interfering. This is different from the grafted Mt where NH4+ uptake was aided by the presence of NO3-. The higher concentration of DMO accounted for the larger NO3- uptake, which was accompanied by improved affinity. The results provide a reference for grafting aluminosilicate minerals and designing efficient adsorbents for the co-adsorption of NH4+ and NO3-.

Synthesis of Fe3O4@Phoslock® composites and the application in adsorption of phosphate from aqueous solution.

Assisted with an organosilane, Fe3O4@Phoslock® composites with different constituents were synthesized to separate phosphate from aqueous solution. The experimental adsorption data of kinetics and isothermal studies by the composites were well fitted by pseudo-second order and Freundlich models, respectively, suggesting the chemical and heterogeneous adsorption process, i.e., ligand exchange and precipitation. After loading of Fe3O4, Phoslock® became magnetic at the expense of the certain decrease of phosphate uptake from 10.4 to 8.1 mg P/g when [P]0 = 1.0 mmol/L and the solid/liquid ratio of 1.0 g/L were applied. However, compared with the original Fe3O4 nanoparticles, Fe3O4@Phoslock® showed more favorable phosphate uptake and stability against pH variation. The inhibitory influence of anionic ions on phosphate adsorption by three composites followed the order: HCO3- > humate > SiO32- > NO3- ≈ Cl- ≈ SO42-, while the facilitating effect of cations followed the order: Ca2+ > Mg2+ > NH4+. The regeneration rate was higher than 50% for all composites after recycled for 5 times by NaOH, and two of the composites successfully removed 75% phosphate from the landfill leachate treated by the Anammox process with the solid/liquid ratio of 5.0 g/L. This suggests that Fe3O4@Phoslock® composites would be a competitive adsorbent for phosphate removal from real wastewater.

Immobilization of W(VI) and/or Cr(VI) in soil treated with montmorillonite modified by a gemini surfactant and tetrachloroferrate (FeCl4-).

The coexistence of highly toxic chromium (Cr) and the emerging contaminant tungsten (W) in the soil adjacent to W mining areas is identified. Immobilization of W and/or Cr is vital for the safe utilization of contaminated soil. In this study, the cationic gemini surfactant (butane-1,4-bis(dodecyl dimethyl ammonium bromide)) and tetrachloroferrate (FeCl4-)-modified montmorillonite (FeOMt) was applied to investigate the retention performance of W and/or Cr in the soil. Regardless of the initially spiked amount of WO42- and/or CrO42-, the W and/or Cr leached in soil solution was rapidly immobilized within 5 min. The immobilization rates of W and/or Cr in the single and binary soil systems were stably maintained against the variations in pH and coexisting anion. FeOMt showed more favorable performance in the retention of W and/or Cr with respect to the precursors (i.e., the original Mt and surfactant-modified Mt) and efficiently inhibited the phytotoxicity and bioaccumulation of W and/or Cr in mung beans. Due to the ion exchange, complexation, reduction, and flocculation, the addition of FeOMt transformed W and/or Cr from exchangeable/carbonate species to reducible/oxidizable fractions, reducing the environmental risk. FeCl4- complex, as a byproduct of the steel pickling process in industry, plays the pivotal role in the efficient retention of W and Cr. Based on the facile synthesis procedure and the efficient performance, the use of FeOMt for the amendment of W- and/or Cr-contaminated soil is feasible and promising.

Delivery of curcumin using a zein-xanthan gum nanocomplex: Fabrication, characterization, and in vitro release properties.

This study aimed to use xanthan gum as a stabilizer to improve the stability of zein nanoparticles. Zein-xanthan gum composite nanoparticles were prepared via anti-solvent precipitation at pH 4.0. The particle size, zeta potential, and stability of the system were related to the amount of xanthan gum added. When 20 mg of xanthan gum was added, spherical nanoparticles with a small particle size (179 ± 2.1 nm) and sufficient negative zeta potential (-42 ± 1.6 mV) were obtained. The zeta potential and Fourier transform infrared spectroscopy results indicated that electrostatic attraction was the main driving force, followed by hydrogen bonding and hydrophobic interactions. Composite nanoparticles were coated by xanthan gum and remained stable over a wide pH range and at high temperatures and salt concentrations; they did not precipitate or aggregate after 30 days of storage. Moreover, the addition of xanthan gum considerably improved the encapsulation efficiency and loading capacity of nanoparticles containing high curcumin amounts, which facilitated slow and sustained release of curcumin in simulated intestinal fluid. Therefore, zein-xanthan gum nanoparticles can be used for the delivery of biologically active compounds in food and pharmaceutical preparations.

Adaptation, restoration and collapse of anammox process to La(III) stress: Performance, microbial community, metabolic function and network analysis.

During the mining of rare earth mineral, the use of lanthanum-containing fertilizers, and the disposal of lanthanum-containing electronic products, the content of lanthanum (La(III)) in typical ammonia wastewater with low carbon to nitrogen ratio is increasing day by day. Here, effects of La(III) on anammox process in performance, microbial community structure, metabolic function, and microbial co-occurrence network were investigated. The results shown that the nitrogen removal efficiency was declines briefly and then gradually recovers after low dosage (1-5 mg/L) La(III) treatment and the decrease to low level (24.25 ± 1.74%) under high La(III) dosage (10 mg/L). La(III) in the range of 1-5 mg/L significantly promoted the relative abundance of Anammoxoglobus (0.024% to 9.762%). The blocking of key metabolic pathways was confirmed to cause the breakdown of anammox by PICRUSt. Furthermore, network analysis revealed that lack of cooperation bacteria limits the activity of Anammoxoglobus.

Exploring potential impact(s) of cerium in mining wastewater on the performance of partial-nitrification process and nitrogen conversion microflora.

Cerium Ce(III) is one of the major pollutants contained in wastewater generated during Ce(III) mining. However, the effect(s) of Ce(III) on the functional genera responsible for removing nitrogen biologically from wastewater has not been studied and reported. In this study, the effects of Ce(III) on aspects of partial-nitritation-(PN) process including ammonia oxidation rate (AOR), process kinetics, and microbial activities were investigated. It was found that the effect of dosing Ce(III) in the PN system correlated strongly with the AOR. Compared to the control, batch assays dosed with 5 mg/L Ce(III) showed elevated PN efficiency of about 121%, an indication that maximum biological response was feasible upon Ce(III) dose. It was also found that, PN performance was not adversely affected, given that Ce(III) dose was ≤20 mg/L. Process kinetics investigated also suggested that the maximum Ce(III) dose without any visible inhibition to the activities of ammonium oxidizing bacteria was 1.37 mg/L, but demonstrated otherwise when Ce(III) dose exceeded 5.63 mg/L. Compared to the control, microbes conducted efficient Ce(III) removal (averaged 98.66%) via biosorption using extracellular polymeric substances (EPS). Notably, significant deposits of Ce(III) was found within the EPS produced as revealed by SEM, EDX, CLSM and FTIR. 2-dimensional correlation infrared-(2DCOS-IR) revealed ester group (uronic acid) as a major organic functional group that promoted Ce(III) removal. Excitation-emission matrix-(EEM) spectrum and 2DCOS-IR suggested the dominance of Fulvic acid, hypothesized to have promoted the performance of the PN process under Ce(III) dosage.

Effects of heavy rare earth element (yttrium) on partial-nitritation process, bacterial activity and structure of responsible microbial communities.

Yttrium (Y(III)) is mined commercially for industrial purposes due to its excellent physical properties. However, the effects of Y(III) in mining-wastewater on the performance of partial-nitritation process and ammonia-oxidizing bacteria (AOB) have not been explored. To elucidate Y(III) effects on biological mechanisms, kinetics was conducted to establish a correlation between Y(III) dosage and specific-oxygen-uptake-rate (SOUR). The mechanism(s) demonstrated by bacterial population to resist against toxic effects from Y(III) dose was also investigated using scanning electron microscopy-(SEM), energy-dispersive X-ray spectroscopy-(EDS), confocal laser scanning microscopy-(CLSM)，Fourier transform infrared-(FTIR) spectroscopy, and 2-dimensional correlation infrared-(2DCOS-IR) approach. The study revealed a strong correlation between ammonium oxidation rate (AOR) and Y(III) dosage. AOR promotion was more pronounced when Y(III) concentration was ≤20 mg/L (maximum AOR of 12.39 mgN/L/h, at 5 mg/L), whereas inhibition when Y(III) in influent was >20 mg/L (minimum AOR of 7.34 mgN/L/h, at 500 mg/L). Aiba model demonstrated high-performance (R2 = 0.962) when Y(III) concentration ranged 0-20 mg/L, whereas linear model fitted well (R2 of 0.984) to experimental data when Y(III) dose ranged 20-500 mg/L. The maximum change in SOUR (Vmax), half-rate constant (Km), and inhibition constant (Ki) reached 1.04 d-1, 20.12 mg/L, and 4.87 mg/L, respectively, an indication that dosage of Y(III) could affect the partial-nitritation process. SEM-EDS showed that the content of extracellular polymeric substances (EPS) increased along with increasing Y(III) dosage. When 20 mg/L of Y(III) was dosed, the fraction of Y(III) within the surface elemental composition of the sludge increased gradually whereas that of calcium decreased. To further comprehend the EPS production, CLSM results further revealed ß-polysaccharide as the dominant component in the EPS. FTIR/2DCOD-IR showed that the chelation of polyguluronic sections within ß-polysaccharide, together with hydrazine might be the main pathways of cell resistance, but ß- glucan, may have caused the hormesis.

[Marine fish bone collagen oligopeptide combined with calcium aspartate increases bone mineral density in obariectomized rats].

OBJECTIVE: To investigate the effect of marine fish collagen oligopeptide and calcium aspartate alone or in combination on bone mineral density in ovariectomized rats. METHODS: Sixty three-month-old SPF Wistar female rats were randomly divided into 6 groups according to their body weight: sham operation group, model control group(ovariectomy), calcium aspartate group(ovariectomy), marine fish collagen oligopeptide group(ovariectomy), aspartate calcium + marine fish collagen oligopeptide group(ovariectomy) and calcium carbonate control group(ovariectomy), 10 rats in each group. The sham operation group and the model control group were given the same volume of pure water by gavage, and the other groups were intragastrically administered with calcium aspartate(116. 7 mg/kg), marine fish collagen oligopeptide(250 mg/kg), calcium aspartate(116. 7 mg/kg) + marine fish collagen oligopeptide(250 mg/kg), calcium carbonate(35. 6 mg/kg), and the test substance was continuously administered for 90 days. After 90 days, the animals were sacrificed, and the liver and kidney of the rats were taken to calculate the organ coefficient and pathological examination. The rat femurs were taken to measure bone mineral density and bone calcium content and rat serum was used to determine serum calcium, phosphorus concentration and alkaline phosphatase(ALP) activity. RESULTS: Bone mineral density and bone calcium content in the model group were significantly lower than those in the sham operation group(P<0. 05), indicating that the osteoporosis model was successfully established by oophorectomy. There was no significant difference in the organ index of each group(P>0. 05), liver/kidney HE staining microscopic examination showed no abnormal changes, indicating the safety of the test substances. The bone mineral density of the aspartate calcium + marine fish collagen oligopeptide group was significantly greater than that of the model group(P<0. 05). The bone mineral density of the aspartate calcium group and the marine fish collagen oligopeptide group was larger than that of the model group, but there was no significant difference(P>0. 05). Compared with that in the model group, the calcium content of calcium aspartate + marine fish collagen oligopeptide group was significantly higher(P<0. 05). Compared with that in the calcium aspartate group, the calcium content of calcium aspartate + marine fish collagen oligopeptide group was higher(P<0. 05), there was no significant difference in serum calcium concentration between groups(P>0. 05). Compared with that in the model group, serum phosphorus concentration in the aspartate calcium group, marine fish collagen oligopeptide group, aspartate calcium + marine fish collagen oligopeptide group was significantly higher(P<0. 05) and ALP activity was significantly reduced(P<0. 05). CONCLUSION: The combination of calcium aspartate and marine fish collagen oligopeptide has a significant effect on increasing bone mineral density, also indicating that marine fish bone collagen oligopeptide could promote absorption of calcium aspartate.

High-rate partial-nitritation and efficient nitrifying bacteria enrichment/out-selection via pH-DO controls: Efficiency, kinetics, and microbial community dynamics.

Conventional nitrification/denitrification process is gradually being replaced with partial-nitritation/anammox (PN/A) processes due to its installation and running cost. However, high ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing (anammox) bacteria activity as well as optimum out-selection of nitrite-oxidizing bacteria (NOB) are necessary to achieving efficient PN/A process. Consequently, to enhance PN process via nitrifying bacteria enrichment/out-selection within psychrophilic environment, a novel pH-DO (dissolved oxygen) control strategy was proposed and the response of PN, kinetics, AOB enrichment, and NOB out-selection efficiency was investigated during start-up and long-term operation. With DO of 0.7 mg/L and pH of 7.5-7.9, quick start-up of the PN process was established within 34d as NO2--N accumulation ratio (NAR) reached 90.08 ±â€¯1.4%. Again, when NLR was elevated to 0.8 kg/m3·d (400mgNH4+-N/L), DO curtailed to 0.2 mg/L, pH maintained at 7.7 and free ammonium at 6.5 mg/L, NAR and NH4+-N removal rate could still reach 97.04 ±â€¯2.4% and 97.84 ±â€¯1.5%, respectively. After optimum control factors had been established, real nitrogen-rich-mine-wastewater was fed (DO, 0.2 mg/L, pH, 8.9, and free ammonia, 6.5 mg/L) and NAR and NH4+-N removal rate reached was 97.33 ±â€¯0.5% and 97.76 ±â€¯1.1%, respectively. Estimated kinetic parameters including maximum degradation rate (Vmax = 1.58/d), half-rate constant (Km = 33.8 mg/L), and inhibition constant (Ki = 201.6 mg/L) suggested that inhibition on NH4+-N oxidation was most feasible at higher concentration of NH4+-N. To elucidate biological mechanisms, 16S rRNA high-throughput revealed that AOB (Nitrosomonas) enrichment had increased from 0.08% to 49% whereas NOB (Nitrospira) abundance reduced from 1% to 0.034%, indicating pH-DO control efficiently enriched AOB and out-selected NOB. Conversely, when influent NH4+-N was curtailed to about 200 mg/L and free ammonia concentration maintained at 6.5 mg/L, the population of AOB was observably reduced by 6% within a period of 14 days, indicating control strategies including pH-DO control and substrate availability were the key factors which substantially influenced and promoted the activities and growth of AOBs in the present SBR.

Modeling the performance of Single-stage Nitrogen removal using Anammox and Partial nitritation (SNAP) process with backpropagation neural network and response surface methodology.

Two novel feedforward backpropagation Artificial Neural Networks (ANN)-based-models (8:NH:1 and 7:NH:1) combined with Box-Behnken design of experiments methodology was proposed and developed to model NH4+ and Total Nitrogen (TN) removal within an upflow-sludge-bed (USB) reactor treating nitrogen-rich wastewater via Single-stage Nitrogen removal using Anammox and Partial nitritation (SNAP) process. ANN were developed by optimizing network architecture parameters via response surface methodology. Based on the goodness-of-fit standards, the proposed three-layered NH4+ and TN removal ANN-based-models trained with Levenberg-Marquardt-algorithm demonstrated high-performance as computations exhibited smaller deviations-(±2.1%) as well as satisfactory coefficient of determination (R2), fractional variance-(FV), and index of agreement-(IA) ranging 0.989-0.997, 0.003-0.031 and 0.993-0.998, respectively. The computational results affirmed that the ANN architecture which was optimized with response surface methodology enhanced the efficiency of the ANN-based-models. Furthermore, the overall performance of the developed ANN-based models revealed that modeling intricate biological systems (such as SNAP) using ANN-based models with the view to improve removal efficiencies, establish process control strategies and optimize performance is highly feasible. Microbial community analysis conducted with 16S rRNA high-throughput approach revealed that Candidatus Kuenenia was the most pronounced genera which accounted for 13.11% followed by Nitrosomonas-(6.23%) and Proteocatella-(3.1%), an indication that nitrogen removal pathway within the USB was mainly via partial-nitritation/anammox process.

Performance, microbial community evolution and neural network modeling of single-stage nitrogen removal by partial-nitritation/anammox process.

Single-stage nitrogen removal by anammox/partial-nitritation (SNAP) process was proposed and explored in a packed-bed-EGSB reactor to treat nitrogen-rich wastewater. With dissolved oxygen (DO) maintained within 0.2-0.5 mg/L, reactor performance and microbial community dynamics were evaluated and reported. To ascertain whether control/prediction of the SNAP process was feasible with mathematical modeling, a novel 3-layered backpropagation-artificial-neural-network-(BANN) was also developed to model nitrogen removal efficiencies. When NLR of 300 gN/m3·d and DO of <0.3 mg/L was employed, the SNAP-process demonstrated autotrophic nitrogen removal pathways with NH4+-N and TN removal of 91.1% and 81.9%, respectively. Microbial community succession revealed by 16S rRNA high-throughput gene-sequencing indicated that Candidatus-Kuenenia-(33.83%), Nitrosomonas-(3.4%) Armatimonadetes_gp5-(1.39%), Ignavibacterium-(1.80%), Thiobacillus-(1.33%), and Nitrospira-(1.17%) were the most pronounced genera at steady-state. The proposed BANN-model demonstrated high-performance as computational results revealed smaller deviations (±3%) and satisfactory coefficient of determination-(R2 = 0.989), fractional variance-(FV = 0.0107), and index of agreement-(IA = 0.997). Thus, forecasting the efficiency of a SNAP-process with neural-network modeling was highly feasible.

[Long-term efficacy of laparoscope-assisted transanal total mesorectal excision for rectal cancer].

OBJECTIVE: To investigate the long-term outcome of laparoscope-assisted transanal total mesorectal excision (taTME) for rectal cancer. METHODS: Clinicopathological data of 29 patients with mid-low rectal cancer undergoing laparoscope-assisted taTME at Department of Gastrointestinal Surgery, the First Affiliated Hospital of Guangzhou Medical University from May 2010 to December 2015 were collected for the retrospective case-series study. All the operations were performed with transabdominal and transanal procedure simultaneously or sequentially. Perioperative presentations, pathological examinations, and oncologic outcomes were retrospectively analyzed. Long-term recurrence, metastasis and survival were assessed during follow-up. Outpatient clinic and telephone survey were used for follow-up. The follow-up time ended in December 2018. The overall survival (OS) rate and disease-free survival (DFS) rate were calculated by the Kaplan-Meier method. RESULTS: The average intra-operative blood loss was (75.9±9.5) ml (range,20 to 200). The average operating time was (223.6±4.1) minutes (range, 165 to 280). The average number of harvested lymph node was 22.3±2.0. The average length of pathological specimen was (13.1±0.6) cm. The average distal resection margin was (2.9±0.2) cm. 89.7% (26/29) of specimens was complete and 10.3% (3/29) near complete. Two cases (6.9%) had positive cutting circumferential margin. Median follow-up was 56 (range, 22 to 91) months. Local recurrence rate, distant metastasis rate, 3-year OS rate, 3-year DFS rate, 5-year OS rate, 5-year DFS rate were 10.3% (3/29), 20.7%(6/29), 96.6%, 83.2%, 87.6% and 79.6%, respectively. No incisional hernia or adhesive intestinal obstruction was found. CONCLUSION: Long-term outcomes of mid-low rectal cancer patients undergoing laparoscope-assisted taTME are satisfactory.

Accelerated start-up, long-term performance and microbial community shifts within a novel upflow porous-plated anaerobic reactor treating nitrogen-rich wastewater via ANAMMOX process.

The anaerobic ammonium oxidation (anammox) process has gained much popularity in recent years following its success in nitrogen removal. However, not much has been reported on techniques to promote anammox bacteria immobilization and associated microbial community evolution. In this study, a novel upflow porous-plate anaerobic reactor (UPPAR) was developed and explored to promote biomass (anammox) retention and growth. To comprehend the performance of the UPPAR, its nitrogen removal efficiencies, as well as the microbial community dynamics involved in the nitrogen removal process, was evaluated and reported. When NLR ranging 0.98-1.08 kg m-3 d-1 was introduced at various stages of the UPPAR operation, a rapid start-up was achieved in 63 d, and the overall nitrogen removal rate could reach 90-95%. By the end of the start-up period, it was revealed that Proteobacteria abundance had reduced by 43.92% as opposed Planctomycetes which increased from 2.95% to 43.52%. Conversely, after the UPPAR had been operated for 124 d, thus at steady-state, the most pronounced phylum observed was Planctomycetes (43.52%) followed by Proteobacteria (26.63%), Chloroflexi (5.87%), Ignavibacteriae (5.55%), and Bacteroidetes (4.9%). Predominant genera observed included Candidatus Kuenenia - (25.46%) and Candidatus Brocadia - (3.15%), an indication that nitrogen removal mechanism within the UPPAR was mainly conducted via autotrophic anammox process. Scanning electron microscopy (SEM) revealed that sludge samples obtained at steady-state were predominantly in granular form with sizes ranging between 2 mm to 5 mm. Granules surfaces were dominated with normal to coccoid-shaped cells as revealed by the SEM.

Enhanced removal of refractory pollutant from aniline aerofloat wastewater using combined vacuum ultraviolet and ozone (VUV/O3) process.

Aerofloats, such as aniline aerofloat ((C6H5NH)2PSSH), are extensively employed for collection activities in wastewater particularly in cases where minerals are in flotation. Although this aniline aerofloat has efficient collection properties, they are ordinarily biologically persistent chemicals in which case their residual, as well as their byproducts, pose great environmental risks to water and soils. In this study, the removal efficiency of aniline aerofloat (AAF) by a combined vacuum ultraviolet (VUV) and ozone (O3) process (VUV/O3) was evaluated. Furthermore, the impacts of pH, O3, the concentration of AAF and coexisting ions (SiO3 2-, CO3 2-, Cl- (Na+), SO4 2-, Ca2+) were systematically studied. The experiments revealed that, with an initial AAF of 15 mg/L, AAF removal >88% was feasible with a reaction time of 60 min, pH of 8 and O3 of 6 g/h. The order of influence of the selected coexisting ions on the degradation of AAF by VUV/O3 was Ca2+ > CO3 2- > SiO3 2- > Cl- (Na+) >SO4 2-. Compared with VUV and O3 in terms of pollutant degradation rate, VUV/O3 showed a remarkable performance, followed by O3 and VUV. Additionally, the degradation kinetics of AAF by the VUV/O3 process agreed well with first-order elimination kinetics.

Effect of Active Videogames on Underserved Children's Classroom Behaviors, Effort, and Fitness.

OBJECTIVE: The purpose of this study was to examine the effect of active videogames (AVGs) on underserved minority children's on-task classroom behavior, academic effort, and fitness. MATERIALS AND METHODS: A one group pre- and posttest repeated measures design was used. In Fall 2013, 95 fourth grade children (57 boys, 38 girls; 96% of minority) from three classes at an underserved urban elementary school participated in teacher-supervised AVG activities (e.g., Wii Sports, Xbox Just Dance). Specifically, students participated in a 50-minute weekly AVG program at school for 6 weeks. Children's academic effort was evaluated by classroom teachers using a validated scale that assessed activity, attention, conduct, and social/emotional behavior. Moreover, children's classroom behavior was observed immediately before and after each AVG session by trained researchers. Finally, cardiovascular fitness was also measured. RESULTS: A paired t-test was used to assess teacher-rated student effort, while one-way (gender) analysis of variance (ANOVA) with repeated measures was performed to analyze children's on-task classroom behavior. There was a significant effect on children's effort between the first (mean = 3.24, SD = 0.75) and last week (mean = 3.41, SD = 0.73) assessments, t = 2.42, P = 0.02. In addition, there was a significant effect on classroom behavior, F = 33.103, P < 0.01. In detail, children scored significantly higher on on-task behavior during the post-AVG observation (mean = 81.4, SD = 12.3) than seen during the pre-AVG observation (mean = 69.8, SD = 14.9). However, no main effect was indicated for gender, F = 0.39, P = 0.54. No significant improvement in cardiovascular fitness was observed, although slight improvements were seen. CONCLUSION: Offering an AVG program at school could improve underserved minority children's classroom on-task behavior and academic effort. Future studies may include a control group to further confirm the effectiveness of AVG activities. Practical implications for educators and other stakeholders are provided.

[Measurements of density distribution of high energy electrons by emission spectroscopy in pulsed discharge reactor].

Pulsed streamer discharge can generates high energy electrons with energy higher than 11. 03 eV and enough to excite N2 to its C3 pi(u) state from the ground state, so the density of the high energy electrons can be obtained by diagnosing the relative emission spectrum intensity of the N2 (C 3 pi(u) --> B 3 pi(g)) emitted from the pulsed streamer discharge. In the present paper, the density distributions of high energy electrons in the wire-plate DeSO2 reactor with pulsed streamer discharge were studied in air at room temperature and 1 atm, and the influences of pulsed voltage and wire-to-wire spacing on the density distributions of high energy electrons were also studied. The experimental results show that high-energy electrons mainly centralize around the discharge wire of the wire-plate reactor, and the electron density reduces with the increase of the distance from the discharge wire. The pulse voltage has a great influence on the high energy electron density, and the high energy electron density increases linearly with increasing the pulsed voltage. Under a fixed wire-to-plate spacing, when the wire-to-wire spacing is 0. 6-1 times the wire-to-plate spacing, the density distributions of the high energy electrons are more uniformity.