Shuhu Xiao

Characterization of bacterial communities in hybrid upflow anaerobic sludge blanket (UASB)–membrane bioreactor (MBR) process for berberine antibiotic wastewater treatment

Biodegradation of berberine antibiotic was investigated in upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process. After 118days of operation, 99.0%, 98.0% and 98.0% overall removals of berberine, COD and NH4(+)-N were achieved, respectively. The detailed composition of the established bacterial communities was studied by using 16S rDNA clone library. Totally, 400 clones were retrieved and grouped into 186 operational taxonomic units (OTUs). UASB was dominated by Firmicutes and Bacteroidetes, while Proteobacteria, especially Alpha- and Beta-proteobacteria were prevalent in the MBRs. Clostridium, Eubacterium and Synergistes in the UASB, as well as Hydrogenophaga, Azoarcus, Sphingomonas, Stenotrophomonas, Shinella and Alcaligenes in the MBRs were identified as potential functional species in biodegradation of berberine and/or its metabolites. The bacterial community compositions in two MBRs were significantly discrepant. However, the identical functions of the functional species ensured the comparable pollutant removal performances in two bioreactors.

Combination of upflow anaerobic sludge blanket (UASB) and membrane bioreactor (MBR) for berberine reduction from wastewater and the effects of berberine on bacterial community dynamics.

Berberine is a broad-spectrum antibiotic extensively used in personal medication. The production of berberine results in the generation of wastewater containing concentrated residual berberine. However, few related studies up to date focus on berberine removal from wastewaters. In this study, a lab-scale upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process was developed for berberine removal from synthetic wastewater. The performance of the UASB-MBR system on berberine, COD and NH(4)(+)--N removal was investigated at different berberine loadings. And the effects of berberine on bacterial communities were evaluated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results showed that, as the increase of berberine loadings, UASB performance was affected remarkably, whereas, efficient and stable performance of MBR ensured the overall removal rates of berberine, COD and NH(4)(+)--N consistently reached up to 99%, 98% and 98%, respectively. Significant shifts of bacterial community structures were detected in both UASB and MBR, especially in the initial operations. Along with the increase of berberine loadings, high antibiotic resisting species and some functional species, i.e. Acinetobacter sp., Clostridium sp., Propionibacterium sp., and Sphingomonas sp. in UASB, as well as Sphingomonas sp., Methylocystis sp., Hydrogenophaga sp. and Flavobacterium sp. in MBR were enriched in succession.

An novel identification method of the environmental risk sources for surface water pollution accidents in chemical industrial parks.

The chemical industry is a major source of various pollution accidents. Improving the management level of risk sources for pollution accidents has become an urgent demand for most industrialized countries. In pollution accidents, the released chemicals harm the receptors to some extent depending on their sensitivity or susceptibility. Therefore, identifying the potential risk sources from such a large number of chemical enterprises has become pressingly urgent. Based on the simulation of the whole accident process, a novel and expandable identification method for risk sources causing water pollution accidents is presented. The newly developed approach, by analyzing and stimulating the whole process of a pollution accident between sources and receptors, can be applied to identify risk sources, especially on the nationwide scale. Three major types of losses, such as social, economic and ecological losses, were normalized, analyzed and used for overall consequence modeling. A specific case study area, located in a chemical industry park (CIP) along the Yangtze River in Jiangsu Province, China, was selected to test the potential of the identification method. The results showed that there were four risk sources for pollution accidents in this CIP. Aniline leakage in the HS Chemical Plant would lead to the most serious impact on the surrounding water environment. This potential accident would severely damage the ecosystem up to 3.8 km downstream of Yangtze River, and lead to pollution over a distance stretching to 73.7 km downstream. The proposed method is easily extended to the nationwide identification of potential risk sources.

Phosphorus recovery from fosfomycin pharmaceutical wastewater by wet air oxidation and phosphate crystallization

Fosfomycin pharmaceutical wastewater contains highly concentrated and refractory antibiotic organic phosphorus (OP) compounds. Wet air oxidation (WAO)-phosphate crystallization process was developed and applied to fosfomycin pharmaceutical wastewater pretreatment and phosphorus recovery. Firstly, WAO was used to transform concentrated and refractory OP substances into inorganic phosphate (IP). At 200°C, 1.0MPa and pH 11.2, 99% total OP (TOP) was transformed into IP and 58% COD was reduced. Subsequently, the WAO effluent was subjected to phosphate crystallization process for phosphorus recovery. At Ca/P molar ratio 2.0:1.0 or Mg/N/P molar ratio 1.1:1.0:1.0, 99.9% phosphate removal and recovery were obtained and the recovered products were proven to be hydroxyapatite and struvite, respectively. After WAO-phosphate crystallization, the BOD/COD ratio of the wastewater increased from 0 to more than 0.5, which was suitable for biological treatment. The WAO-phosphate crystallization process was proven to be an effective method for phosphorus recovery and for fosfomycin pharmaceutical wastewater pretreatment.

Variation of dissolved fulvic acid from wetland measured by UV spectrum deconvolution and fluorescence excitation-emission matrix spectrum with self-organizing map

PurposeUV spectrum with deconvolution (UVSD) and fluorescence excitation-emission matrix spectrum (FEEM) with self-organizing map have contributed to soil research by collecting more information from spectroscopic data. The aim of this study is to employ the USVD and FEEM with self-organizing map to determine structural composition and to evaluate the humification level of dissolved fulvic acid (FA) extracted from wetland soils under different types of land use.Materials and methodsSoil samples were collected from different depths in wetland ecosystems along a disturbed-impact gradient in Taihu Lake, China, i.e., Comm. Cinnamomum camphora (CCC), Comm. native grassland (CNG), paddy field (PFD), and green soybean field (SFD).Results and discussionThe Van Krevelen diagram of elemental analysis showed that FA was mainly associated with the surrounding terrestrial vegetation. The presence of characteristic functional groups in the FA was confirmed by Fourier-transformed infrared spectroscopy, consistent with the paradigm of humic substances. By the FEEM with self-organizing map, three fluorescent components were identified, and a fulvic-like material was a representative component in the FA fractions. The investigation of humification parameters deduced from the UVSD and FEEM with self-organizing map indicated that the aromatic content and molecular size of the FA decreased in the order of CCC > CNG > PFD > SFD. Principal component analysis verified that the humification level of the FA within the CCC soil profile was the highest, followed by the CNG, PFD, and SFD. Although an obvious variation occurred in the humification level within a given soil profile, no trend was observed with soil depth increment.ConclusionsThe results of the present study demonstrate that UVSD and FEEM with self-organizing map are useful methods to investigate structural composition and to evaluate the humification level of the FA.

Adsorption Characteristics of Cu2+ onto Zeolite from Pharmaceutical Industrial Wastewater

The adsorption of Cu2+ from pharmaceutical wastewater by zeolite was studied in a batch adsorption system. Factors inflflflfluencing copper adsorption such as pH (1-5), adsorbent dosage (5-50 g/L) and contact time (20-600 min)were investigated. The equilibrium of adsorption process was established in about 480 min, while pH was 5 and adsorbent dosage was 30 g/L. After the adsorption equilibrium was achieved, the removal efficiency of Cu2+ was above 99%. Acomparison of the kinetic models on the overall adsorption rate showed that the adsorption system was best described by the pseudo second-order kinetics. The adsorption equilibrium datafifififit best with the Langmuir isotherm.