Publications by authors named "Wenlai Xu"

The sp. BN6-4 capable of degrading high concentrations of pyridine was isolated from the coking sludge. The removal rate of BN6-4 to 1,000 mg/L pyridine during 48 h was 97.

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This study aimed to remediate the problems of sludge floating and uneven mass transfer in up-flow partial denitrification/anammox (PDA) reactors and dissect the nitrogen removal mechanism. Two up-flow PDA reactors were operated, whereby in R1 combined biological carriers were added, while in R2 mechanical stirring was applied, the reactors were inoculated with PD sludge and anammox sludge. Results showed the TN removal rates at the end of the operation were 89% (R1) and 92% (R2).

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The continued accumulation of halogenated organic pollutants in soil posed a potential threat to ecosystems and human health. In this study, tetrabromobisphenol A (TBBPA) was used as a typical representative of halogenated organic pollutants in soil, for alkali-thermal activated persulfate (PS) treatment. The results of response surface methodology (RSM) showed a optimal debromination efficiency of TBBPA was 88.

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Partial denitrification granular sludge (PDGS) can provide long-term stable nitrite for anaerobic ammonia oxidation (anammox). The cultivation of ordinary activated sludge from wastewater treatment plants into PDGS can further promote the application of PD in practical engineering. In this study, the feasibility of fast start-up of PDGS was explored by inoculating waste sludge in up-flow anaerobic sludge blanket (UASB) reactor with synergistic control of nitrogen load rate (NLR, 0.

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The long multiplication time and extremely demanding enrichment environment requirements of Anammox bacteria (AAOB) have led to difficult reactor start-ups and hindered its practical dissemination. Few feasibility studies have been reported on the recovery of AAOB activity initiation after inlet substrate disconnection caused by an unfavorable condition, and few factors, such as indicators of the recovery process, have been explored. Therefore, in this experiment, two modified expanded granular sludge bed reactors (EGSB) were inoculated with 1.

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Anaerobic ammonia oxidation (anammox) has potential advantages for nitrogen removal when operating at medium temperatures, but the increased operation costs of heating limit its application. It would be advantageous to start and operate anammox at low temperatures, the feasibility of which was studied here on a lab scale. Two identical expanded granular sludge bed (EGSB) reactors were inoculated at 35 ± 1 °C (A) and 15 ± 3 °C (A).

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Phosphorus is a nonrenewable resource, and the recovery of phosphorus from wastewater containing high concentrations of phosphorus is of great importance. In this work, a novel method for highly efficient treatment of high-concentration phosphorus-containing wastewater (50 mg/L, 100 mg/L and 150 mg/L) with low energy consumption was developed by using the block waste foam concrete (FC) as a potential phosphorus recovery material. The results showed that acid leaching significantly improved the accumulation efficiency of phosphorus in calcium hydroxyphosphate (HAP) via accelerating the release of calcium in wastewater.

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The presence of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) in swine wastewater may present a threat to the environment and public health. Conventional swine wastewater treatment processes generally fail to effectively reduce the content of ARGs. Therefore, it is necessary to develop a highly efficient and low-cost treatment method to solve this environmental problem.

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The organophosphate-mineralizing bacteria (OPB) convert environmental organic phosphorus (P) into soluble P that can be directly absorbed and utilized by organisms. OPB is an important group of microorganisms in lake sediments. The P decomposed and released from the sediments by OPB is an important P-source in eutrophic water bodies.

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Shortcut nitrification is crucial for application of autotrophic nitrogen removal which is beneficial for treating carbon-limited wastewater. In this experiment, rapid start-up of autotrophic shortcut nitrification system was studied in a small sequencing batch reactor (SBR) built in laboratory with intermittent aeration operation mode. The influent was artificially simulated inorganic domestic wastewater (the ammonium nitrogen concentration was 35.

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A theoretical approach was followed to optimize the design of a cylindrical photobioreactor for wastewater treatment based on algal culture. In particular, the problem of uneven light distribution that impairs algal growth was minimized by optimizing the area of uniform illumination distribution for a bioreactor design that can be enlarged without affecting its performance. The theoretical analysis was based on modeled simulations to determine the best configuration and illumination mode.

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Inorganic phosphate-solubilizing bacteria (IPB) are an important component of microbial populations in lake sediments. The phosphate that they decompose and release becomes an important source of phosphorus for eutrophic algae. The IPB strains were screened and isolated from the sediments of Sancha Lake using National Botanical Research Institute's phosphate (NBRIP) plates.

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Reforestation plays an important role in the carbon cycle and climate change. However, knowledge of ecosystem carbon sequestration through reforestation with mixed species is limited. Especially in dry hot valley of the Jinsha River, no studies cover total ecosystem carbon sequestration level in mature mixed plantations for a limited area of mixed plantations and difficulty in the sampling of plant roots and deep soil.

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To study the microbial community structure in sediments and its relation to eutrophication environment factors, the sediments and the overlying water of Sancha Lake were collected in the four seasons. MiSeq high-throughput sequencing was conducted for the V3-V4 hypervariable regions of the 16S rRNA gene and was used to analyze the microbial community structure in sediments. Pearson correlation and redundancy analysis (RDA) were conducted to determine the relation between microbial populations and eutrophic factors.

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The degradation effect, degradation mechanism, oxidation kinetics, and degradation products of Atrazine (ATZ) by Ultrasound/Peroxymonosulfate (US/PMS) in phosphate buffer (PB) under different conditions were studied. It turned out that the degradation rate of US/PMS to ATZ was 45.85% when the temperature of the reaction system, concentration of PMS, concentration of ATZ, ultrasonic intensity, and reaction time were 20 °C, 200 μmol/L, 1.

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Article Synopsis
  • Quinoprotein glucose dehydrogenase (GDH) is crucial for converting glucose into gluconic acid and plays a major role in transforming insoluble phosphate into soluble forms, which can lead to algal blooms.
  • Research conducted on sediments from the eutrophic Sancha Lake revealed high genetic diversity among microbial groups with a strong presence of GDH encoding genes, particularly from the Proteobacteria phylum.
  • The study found temporal and spatial variations in GDH diversity linked to environmental factors like dissolved oxygen and phosphorus levels, indicating that GDH genes significantly contribute to the lake's eutrophication process.
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In this work, the influence of graphene on nitrogen and phosphorus in a batch reactor was studied. The impact of graphene on the removal performance of was investigated in a home-built sewage treatment system with seven identical sequencing batch reactors with graphene contents of 0 mg/L (T1), 0.05 mg/L (T2), 0.

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The activated sludge process of the anaerobic/oxic (A/O) process has a good denitrification performance because it can make full use of the carbon source in the original sewage, and the denitrification can provide alkalinity for aerobic nitrification. The traditional constructed soil rapid infiltration (CSRI) system, on the other hand, has a poor nitrogen removal effect. Dividing the traditional CSRI system into two sections, one performs denitrification as an anoxic section, while the other performs nitrification as an aerobic section and is placed after the anoxic section.

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The aim of this study was to improve the removal of nitrogen pollutants from artificial sewage by a modeled two-stage constructed rapid infiltration (CRI) system. The C/N ratio of the second stage influent was elevated by addition of glucose. When the C/N ratio was increased to 5, the mean removal efficiency of total nitrogen (TN) reached up to 75.

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A constructed rapid infiltration (CRI) system is a new type of sewage biofilm treatment technology, but due to its anaerobic zone it lacks the carbon sources and the conditions for nitrate retention, and its nitrogen removal performance is very poor. However, a shortcut nitrification–denitrification process presents distinctive advantages, as it saves oxygen, requires less organic matter, and requires less time for denitrification compared to conventional nitrogen removal methods. Thus, if the shortcut nitrification–denitrification process could be applied to the CRI system properly, a simpler, more economic, and efficient nitrogen removal method will be obtained.

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Unlabelled: In the rural area of the Tibetan Plateau (RATP), the characteristics of domestic waste, people's environmental awareness, people's willingness to pay and their influence factors were firstly studied by questionnaires, field samplings and laboratory tests. The results showed that, in the RATP, the generation of domestic waste was 85 g•d-1 per capita and it was mainly composed of plastics, inert waste, kitchen waste, glass and paper. The waste bulk density, moisture content, ash, combustible and low calorific value were 65 kg•m-3, 19.

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