Comparative study on the treatment of swine wastewater by VFCW-MFC and VFCW: Pollutants removal, electricity generation, microorganism community.

Swine wastewater, characterized by high organic and nutrient content, poses significant environmental challenges. This study aims to compare the effectiveness of two treatment technologies, namely Vertical Flow Constructed Wetland-Microbial Fuel Cell (VFCW-MFC) and Vertical Flow Constructed Wetland (VFCW), in terms of pollutant removal, electricity generation, and microorganism community dynamics. The results showed that the average removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TN), total phosphorus (TP) and sulfadiazine antibiotics (SDZ) by VFCW-MFC were as high as 94.15%, 95.01%, 42.24%, 97.16% and 82.88%, respectively, which were all higher than that by VFCW. Both VFCW-MFC and VFCW have good tolerance to SDZ. In addition, VFCW-MFC has excellent electrical performance, with output voltage, power density, coulombic efficiency and net energy recovery up to 443.59 mV, 51.2 mW/m3, 52.91% and 2.04 W/(g·s), respectively, during stable operation. Moreover, the microbial community diversity of VFCW-MFC was more abundant, and the species abundance distribution in cathode region was more rich and even than in anode region. At phylum level, the dominant microorganisms in VFCW-MFC included Proteobacteria, Bacteroidota, Firmicutes and Actinobacteriota, which showed good degradation effect on SDZ. Proteobacteria and Firmicutes are also involved in electricity production. Chloroflexi, Proteobacteria and Bacteroidota play a major role in nitrogen reduction.

Real-Time Deep Image Retouching Based on Learnt Semantics Dependent Global Transforms.

Although artists' actions in photo retouching appear to be highly nonlinear in nature and very difficult to characterize analytically, we find that the net effects of interactively editing a mundane image to a desired appearance can be modeled, in most cases, by a parametric monotonically non-decreasing global tone mapping function in the luminance axis and by a global affine transform in the chrominance plane that are weighted by saliency. This allows us to simplify the machine learning problem of mimicking artists in photo retouching to constructing a deep artful image transform (DAIT) using convolutional neural networks (CNN). The CNN design of DAIT aims to learn the image-dependent parameters of the luminance tone mapping function and the affine chrominance transform, rather than learning the end-to-end pixel level mapping as in the mainstream methods of image restoration and enhancement. The proposed DAIT approach reduces the computation complexity of the neural network by two orders of magnitude, which also, as a side benefit, improves the robustness and generalization capability at the inference stage. The high throughput and robustness of DAIT lend itself readily to real-time video enhancement as well after a simple temporal processing. Experiments and a Turing-type test are conducted to evaluate the proposed method and its competitors.

Insight into sludge dewatering by advanced oxidation using persulfate as oxidant and Fe2+ as activator: Performance, mechanism and extracellular polymers and heavy metals behaviors.

This study established a Fe2+/persulfate oxidation system to dewater sludge in WWTPs. Dewatering performance, persulfate consumption and the variations of sludge pH, TN and TP during dewatering process were monitored. EPS and ζ-potential behaviors for ameliorating sludge dewatering was investigated. Transformation, leaching toxicity and environmental risk of heavy metals in sludge during dewatering were determined. Results demonstrated that after treated by Fe2+/persulfate oxidation system with 0.6 mmol/g-VS of persulfate at Fe2+/persulfate molar ratio 0.6, WC decreased to 53.5% and SCST increased to 4.15, which implied an excellent improvement of sludge dewatering. The fast persulfate consumption, the decrease of sludge pH and the increase of TN illustrated the positive effects of Fe2+ in activating persulfate and the decomposition of EPS by the activation products, SO4•- and •OH. Another product (Fe3+) generated during persulfate activation could decrease the content of phosphorus-containing matter (released from EPS decomposition) through the precipitation reaction with PO43-. The decrease of TOC and UV-254 happened in HPO-A, HPO-N and TPI-A organic substance of EPS (mainly contained in TB-EPS fraction) indicated that the destruction of hydrophobic organic matter of EPS would stimulate the release of bound water, which was beneficial to dewater sludge. The largest protein loss in TB-EPS (from 24.5 to 10.7 mg/L) indicated that the effective decomposition of TB-EPS could significantly ameliorate sludge dewatering. The increase of ζ-potential indicated the degradation of organic matter in EPS with negative charge. To sum up, the destruction of protein-like substances in hydrophobic organic matter of TB-EPS was the main mechanism for improving sludge dewatering by Fe2+/persulfate oxidation system. 3D-EEM fluorescence spectroscopy analysis proved that these protein-like substances were mainly tryptophan protein and humic acid. Moreover, due to the disruption of EPS, the contents of heavy metals in sludge, and their leaching toxicity and environmental risk were reduced. Therefore, Fe2+/persulfate oxidation system has potential and application prospects to improve sludge dewatering and optimize sludge management in WWTPs.

Enhancement of ethylbenzene removal from contaminated gas and corresponding mechanisms in biotrickling filters by a biosurfactant from piggery wastewater.

This study prepared a biosurfactant by using piggery wastewater to enhance ethylbenzene removal from contaminated gas in a biotrickling filter (BTF). Experiments were conducted to investigate the enhancement of ethylbenzene removal and the biofilm characteristics in present of the biosurfactant. Results demonstrated that the optimal biosurfactant concentration was 0.1 CMC and the corresponding ethylbenzene removal rate was 87.2%, much higher than that (68.9%) achieved in free of biosurfactant. The inlet ethylbenzene concentration and the empty bed residence time (EBRT) affected ethylbenzene removal as well. In present of 0.1 CMC of biosurfactant, ethylbenzene removal rate decreased from 87.2% to 72.2% with the increasing inlet ethylbenzene from 1000 to 2200 mg/m3, and decreased from 91.1% to 42.7% with the EBRT shorten from 30 to 7.5 s. For the enhancement mechanisms of ethylbenzene removal in BTF, the biosurfactant changed the contents of extracellular polymers (EPS) and decreased negative surface charge of the biofilm in the BTF, which improved the mass transfer of ethylbenzene to biofilm and facilitated the aggregation of microbes, and further improved the removal of ethylbenzene. All in all, the biosurfactant would be a feasible way to enhance the removal of ethylbenzene by the BTF.

Insight into the improvement of dewatering performance of waste activated sludge and the corresponding mechanism by biochar-activated persulfate oxidation.

A novel activator, corn biochar, was produced to activate persulfate to dewater waste activated sludge (WAS). Results demonstrated that the biochar-activated persulfate oxidation can effectively improve the dewatering performance of WAS. After treating WAS by biochar-activated persulfate oxidation (biochar dosage: 2.1 g/L, persulfate concentration: 7.5 mM) at the original WAS pH, standardized-capillary suction time (SCST) increased to 4.21 times and moisture content (MC) decreased to 43.4%, indicating an excellent performance of WAS dewatering. The decrease of residual persulfate with the increasing biochar dosage during WAS dewatering process illustrated that the role of persulfate in improving WAS dewatering was because of the biochar activation. The behaviors of extracellular polymers (EPS) proved that the protein in tightly bound EPS (TB-EPS) linked to WAS dewatering, and its content significantly reduced to 10.5 mg/g-volatile solids (VS) after WAS treatment. Three-dimensional fluorescence spectroscopy for EPS once again proved that the disintegration of tryptophan protein and humic acid (hydrophobic organic substances in EPS) was responsible for the improvement of WAS dewatering. To sum up, the biochar-activated persulfate oxidation was a feasible application in improving WAS dewatering.

Insight into dewatering behavior and heavy metals transformation during waste activated sludge treatment by thermally-activated sodium persulfate oxidation combined with a skeleton builder-wheat straw biochar.

This work focused on dewatering performance and heavy metals (HMs) transformation during waste activated sludge (WAS) treatment by employing thermally-activated sodium persulfate (SPS) oxidation combined with a biochar made of wheat straw (WS-BC). Results demonstrated that the combined treatment was an efficient way to improve WAS dewatering, especially when SPS and WS-BC dosages were adjusted to 120 and 150 mg/g-volatile solids (VS), respectively. After being treated at 70 °C without pH adjustment, standardized-capillary suction time (SCST) was increased to 5.03, centrifuged weight reduction (CWR) was increased to 86.8% and moisture content (MC) was decreased to 42.6%, indicating an excellent dewatering performance. The underlying mechanism identified were: (1) SPS oxidation disintegrated extracellular polymers (EPS) at high temperature, thereby releasing EPS-bound water; (2) WS-BC acted as a skeleton builder conducive to form porous structure and provide free water release channels in WAS, which was favorable to improve dewatering properties of WAS; (3) thermally-activated SPS oxidation significantly improved the solubilization and reduced the leaching toxicity of HMs in WAS; and (4) the following WS-BC treatment further reduced the leaching toxicity of HMs in WAS. Therefore, the combined technology might be a promising strategy to improve WAS dewatering and reduce HMs risks in WAS.

Mapping and identification of CsUp, a gene encoding an Auxilin-like protein, as a putative candidate gene for the upward-pedicel mutation (up) in cucumber.

BACKGROUND: Pedicel orientation can affect the female flower orientation and seed yield in cucumber. A spontaneous mutant possessing upward growth of pedicels was identified in the wild type inbred strain 9930 and named upward-pedicel (up). The morphological and genetic analyses of up were performed in this study. In order to clone the up gene, 933 F2 individuals and 524 BC1 individuals derived from C-8-6 (WT) and up were used for map-based cloning. RESULTS: up was mapped to a 35.2 kb physical interval on chromosome 1, which contains three predicted genes. Sequencing analysis revealed that a 5-bp deletion was found in the second exon of Csa1G535800, and it led to a frameshift mutation resulting in a premature stop codon. The candidate gene of CsUp (Csa1G535800) was further confirmed via genomic and cDNA sequencing in biparental and natural cucumber populations. Sequencing data showed that a 4-bp deletion was found in the sixth exon of Csa1G535800 in CGN19839, another inbred line, and there was also a mutation of an amino acid in Csa1G535800 that could contribute to the upward growth of pedicels in CGN19839. Moreover, it was found that Csa1G535800 exhibited strong expression in the pedicel of WT, suggesting its important role in development of pedicel orientation. Thus, Csa1G535800 was considered to be the candidate gene of CsUp. CONCLUSIONS: CsUp encodes an Auxilin-like protein and controls pedicel orientation in cucumber. The identification of CsUp may help us to understand the mechanism of pedicel orientation development and allow for investigation of novel functions of Auxilin-like proteins in cucumber.