Direct Cr (VI) bio-reduction with organics as electron donor by anaerobic sludge

Industrial activities produce lots of Cr (VI)-containing wastewater. This study presented a detailed work on direct Cr (VI) bio-reduction (i.e. Cr (VI) is reduced with organics as electron donor directly) by anaerobic sludge through both batch and long-term experiments. Effects of pH and initial Cr (VI) concentrations on direct Cr (VI) bio-reduction activity were evaluated. The highest direct Cr (VI) bio-reduction rate was achieved at pH 8.0 at 104\ua0mg Cr (VI)/g MLVSS/d (MLVSS: mixed liquor volatile suspended solids), corresponding to the highest protein release (124\ua0mg/g MLVSS) and cell viability (71%). In contrast, the direct Cr (VI) bio-reduction rates were 46, 70 and 82\ua0mg Cr (VI)/g MLVSS/d, respectively, at pH 6.0, 7.0 and 9.0. Also, the direct Cr (VI) bio-reduction activity decreased by 74% when initial Cr (VI) concentration increased from 10\ua0mg/L to 50\ua0mg/L. The contribution of chemical adsorption to Cr (VI) removal was found to be negligible, whereas biosorption played a role in Cr (VI) removal although its role was insignificant. Indirect Cr (VI) bio-reduction (i.e. Cr (VI) is chemically reduced by sulfide produced from biological sulfate reduction) rate (990\ua0mg Cr (VI)/g MLVSS/d) was faster than that (210\ua0mg Cr (VI)/g MLVSS/d) of direct Cr (VI) bio-reduction, indicating that indirect Cr (VI) bio-reduction would dominate the Cr (VI) bio-reduction pathway if both Cr (VI) and sulfate were present. The direct Cr (VI) bio-reduction was then successfully demonstrated in an up-flow anaerobic sludge bed (UASB) reactor, where the Cr (VI) was completely removed with a Cr (VI) removal rate of 1.0\ua0mg Cr (VI)/L/h. 454 pyrosequencing results revealed that direct Cr (VI) bio-reduction related genera were Desulfovibrio, Ochrobactrum and Anaerovorax

Molecular cloning and characterization of a new peroxidase gene (OvRCI) from Orychophragmus violaceus

A new peroxidase gene from Orychophragmus violaceus was cloned. The full-length cDNA of O.violaceus peroxidase gene (OvRCI, GenBank. Acc. No. AY428037) was 1220 bp and contained an 1128 bp open reading frame encoding a protein of 375 amino acids. Homology analysis and molecularmodeling revealed that OvRCI strongly resembled other peroxidase genes. Quantitative real-time PCR analysis revealed that it was a constitutively salt-inducible gene and its transcript level was most abundant after 24 h treatment with 200 mmol.L-1 sodium chloride. Our studies suggested that OvRCI was a new member of the family of recently cloned peroxidase genes

The Application of Solar Indirect System in Passive House in Cold Region and Severe Cold Region of CHINA

AbstractThis paper, the future developing prospect of application of passive house in China was provided,solar indirect system combined with fresh air ventilation system with heat recovery was used in designing to provide heat to meet fresh air load in the passive house, taking the Xining city as an example. The aperture areas of solar collector in different conditions were calculated by changing the influence factors such as the tilt angle of the collector and the solar fraction. This paper analyzed the relationship of the solar collector aperture area with the tilt angle of the collector and the solar fraction. On the basis of the analysis, it is safe to draw a conclusion that the program of using solar indirect system combined with fresh air ventilation system with heat recovery in passive house in cold region and severe cold region of China is economically feasible

Total Cerebral Small Vessel Disease Score and Cerebral Bleeding Risk in Patients With Acute Stroke Treated With Intravenous Thrombolysis

OBJECTIVE: The aim of this study was to investigate the association of total cerebral small vessel disease (cSVD) score with the risk of intracerebral hemorrhage (ICH) in patients with acute ischemic stroke who received intravenous thrombolysis (IVT) using recombinant tissue-plasminogen activator (rt-PA). METHODS: We retrospectively reviewed clinical data from two stroke registries of patients with acute ischemic stroke treated with IVT. We assessed the baseline magnetic resonance (MR) visible cSVD markers and total cSVD score (ranging from 0 to 4) between patients with and without ICH after IVT. Logistic regression analysis was used to determine the association of total cSVD score with the risk of ICH after IVT, adjusted for cofounders selected by least absolute shrinkage and selection operator (LASSO). We additionally performed an E-value analysis to fully explain away a specific exposure-outcome association. Receiver operating characteristic (ROC) curve analysis was used to quantify the predictive potential of the total cSVD score for any ICH after IVT. RESULTS: Among 271 eligible patients, 55 (20.3%) patients experienced any ICH, 16 (5.9%) patients experienced a symptomatic ICH (sICH), and 5 (1.85%) patients had remote intracranial parenchymal hemorrhage (rPH). Logistic regression analysis showed that the risk of any ICH increased with increasing cSVD score [per unit increase, adjusted odds ratio (OR) 2.03, 95% CI 1.22–3.41, P = 0.007]. Sensitivity analyses using E-value revealed that it would need moderately robust unobserved confounding to render the exposure-outcome (cSVD-any ICH) association null. ROC analysis showed that compared with the National Institutes of Health Stroke Scale (NIHSS) score alone, a combination of cSVD and NIHSS score had a larger area under the curve for any ICH (0.811, 95% CI 0.756–0.866 vs. 0.784, 95% CI 0.723–0.846, P = 0.0004). CONCLUSION: The total cSVD score is associated with an increased risk of any ICH after IVT and improves prediction for any ICH compared with NIHSS alone

Free sulfurous acid (FSA) inhibition of biological thiosulfate reduction (BTR) in the sulfur cycle-driven wastewater treatment process

A sulfur cycle-based bioprocess for co-treatment of wet flue gas desulfurization (WFGD) wastes with freshwater sewage has been developed. In this process the removal of organic carbon is mainly associated with biological sulfate or sulfite reduction. Thiosulfate is a major intermediate during biological sulfate/sulfite reduction, and its reduction to sulfide is the rate-limiting step. In this study, the impacts of saline sulfite (the ionized form: HSO + SO ) and free sulfurous acid (FSA, the unionized form: HSO) sourced from WGFD wastes on the biological thiosulfate reduction (BTR) activities were thoroughly investigated. The BTR activity and sulfate/sulfite-reducing bacteria (SRB) populations in the thiosulfate-reducing up-flow anaerobic sludge bed (UASB) reactor decreased when the FSA was added to the UASB influent. Batch experiment results confirmed that FSA, instead of saline sulfite, was the true inhibitor of BTR. And BTR activities dropped by 50% as the FSA concentrations were increased from 8.0 × 10to 2.0 × 10mg HSO-S/L. From an engineering perspective, the findings of this study provide some hints on how to ensure effective thiosulfate accumulation in biological sulfate/sulfite reduction for the subsequent denitrification/denitritation. Such manipulation would result in higher nitrogen removal rates in this co-treatment process of WFGD wastes with municipal sewage

Enrichment and characteristics of ammonia-oxidizing archaea in wastewater treatment process

High purity ammonia-oxidizing archaea (AOA) culture containing a single AOA strain was enriched from the filtering materials of biological aerated filter. The concentration of AOA reached 3.27\ua0×\ua010\ua0copies/mL, while its proportion was 91.40%. The AOA amoA gene sequence belonged to Nitrososphaera cluster. Ammonia concentration significantly influenced the growth of AOA in culture, while total organic carbon (TOC) concentration had no obvious effect. The optimum ammonia concentration, temperature, pH and DO concentration for growth of AOA were 1\ua0mM, 30\ua0°C, 7.5 and 2.65\ua0mg/L, respectively. Under the optimum growth conditions, the AOA abundance and ammonia oxidation rate were 3.53\ua0×\ua010\ua0copies/mL and 2.54\ua0×\ua010\ua0mg/(copies·d)

Repetitive sequence analysis and karyotyping reveal different genome evolution and speciation of diploid and tetraploid Tripsacum dactyloides

In the subtribe Maydeae, Tripsacum and Zea are closely related genera. Tripsacum is a horticultural crop widely used as pasture forage. Previous studies suggested that Tripsacum might play an important role in maize origin and evolution. However, our understanding of the genomics and the evolution of Tripsacum remains limited. In this study, two diploids, T. dactyloides var. meridionale (2n = 36, MR) and T. dactyloides (2n = 36, DD), and one tetraploid, T. dactyloides (2n = 72, DL) were sequenced by low-coverage genome sequencing followed by graph-based cluster analysis. The results showed that 63.23%, 59.20%, and 61.57% of the respective genome of MR, DD, and DL were repetitive DNA sequence. The proportions of different repetitive sequences varied greatly among the three species. Fluorescence in situ hybridization (FISH) analysis of mitotic metaphase chromosomes with satellite repeats as the probes showed that the FISH signal patterns of DL were more similar to that of DD than to that of MR. Comparative analysis of the repeats also showed that DL shared more common repeat families with DD than with MR. Phylogenetic analysis of internal transcribed spacer region sequences further supported the evolutionary relationship among the three species. Repetitive sequences comparison showed that Tripsacum shared more repeat families with Zea than with Coix and Sorghum. Our study sheds new light on the genomics of Tripsacum and differential speciation in the Poaceae family

Re-Thinking LiDAR-Stereo Fusion Frameworks (Student Abstract)

In this paper, we present a 2-step framework for high-precision dense depth perception from stereo RGB images and sparse LiDAR input. In the first step, we train a deep neural network to predict dense depth map from the left image and sparse LiDAR data, in a novel self-supervised manner. Then in the second step, we compute a disparity map from the predicted depths, and refining the disparity map by making sure that for every pixel in the left, its match in the right image, according to the final disparity, is the local optimum