Jian She Liu

Survey of Rural Domestic Sewage Treatment Systems of Songjiang District in Shanghai, China

Due to the relatively unprogressive economic and social development of Songjiang rural areas of Shanghai city in China, the degree of rural domestic sewage treatment was relatively weak and hysteretic. The rural sewage treatment systems of Songjiang district were investigated through field survey. Finally, the systems of soil infiltration-constructed wetland and combinatorial biofilter, with obvious advantages, were proposed to popularize in Songjiang rural areas more suitably.

Multiwall Carbon Nanotubes-Modified Glassy Carbon Electrode for Square-Wave Stripping Voltammetric Determination of Aqueous Antimony (III) Ion

A glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNTs) for electrochemical square-wave stripping voltammetric (SWV) determination of antimony (III) was introduced. Various experimental parameters, such as the amounts of carbon nanotubes, the deposition potential and time, the electrolyte solution, etc, were thoroughly optimized and discussed. Under the optimum experimental conditions, the MWCNTs-modified GCE exhibited well linear behaviour in the antimony(III) concentration range from 0.04 to 0.26 mg/L (R=0.9983) with a detection limit of 3.20×10-4 mg/L (S/N=3) under a 360 s accumulation. The proposed electrode also exhibited encouraging properties for measurements of simulated water samples.

Isolation, Characterization and Phylogenetic Analysis of Acidiphilium-Like Bacteria from Acid Mine Drainage

The acidophilic heterotrophic bacteria Acidiphilium spp. were considered as a ministrant of Leptospirillum spp., Acidithiobacillus spp. and other autotrophic bacteria in acid mine drainage (AMD). 25 Acidiphilium-like bacterial strains were isolated from eight different mines in China and their physiology was characterized. Their marmatite-bioleaching ability has been investigated and compared with that of a mixed culture of Acidiphilium sp. and Acidithiobacillus ferrooxidans. The results indicated that some Acidiphilium-like strains exhibited a high marmatite-bioleaching ability, which was even higher than that of Acidithiobacillus ferrooxidans. The leaching efficiency was not higher in mixed than in pure culture. The phylogenetic relationship of the 25 Acidiphilium-like strains was analyzed by 16S rRNA sequencing, GyrB sequencing and rep-PCR genomic fingerprinting. The 25 strains and other eight species of Acidiphilium spp. were clustered into three groups.

Degradation of Hydroquinone by Pulsed Corona Discharge Combined with Ozone Process

Owing to toxicity of pharmacy wastewater to microbe, commonly used biodegradation is often limited in application; accordingly exploiting new ways of the wastewater treatment with high efficiency is a hot topic. As a new efficient advanced oxidation, pulsed corona discharge combining with ozone is attracting more and more attention. In this study, a special reactor was designed, in addition, the removal of TOC(Total Organic Carbon) and COD (Chemical Oxygen Demand)of simulant pharmacy wastewater containing hydroquinone (500mg/L) by pulsed corona discharge combining with ozone were investigated . It was showed that the TOC and COD removal (53.8% and 72.3%) by the combined technology was much higher than by using the two techniques in series when all the samples were treated 40mins.The two methods in combination have a synergistic effect. TOC and COD removal could be improved obviously when NaCl feed concentration increased from 0 to1000 mg/L, yet further increase in NaCl feed led to a markedly decrease removal efficiency of TOC and COD.

Biooxidation of Refractory Gold Ores by Mixed Moderate Thermophiles in Airlift Bioreactor

Bacterial preoxidation of refractory gold ore has showed many advantages, such as lower operation cost and environmental friendly. In this paper, biooxidation of refractory gold ore by mixed moderate thermophiles culture in airlift bioreactor has been well studied. Firstly, a laboratory scale airlift bioreactor unit has been designed for bacterial preoxidation of refractory gold ore, a mixed moderate thermophilic culture was incubated. The orthogonal experiment was performed to investigate the effects of particle size, pulp density, aeration rate and initial pH. The results showed that when particle size 37micrometer，pulp density 5%，aeration rate 4 dm3•s-1 and initial pH 1.2, the arsenic leaching rate achieved to 93.5%. On the base of the airlift bioreactor unit, a continuous airlift bioreactor was designed. The preoxidation of refractory gold ore by a mixed culture of moderately thermophilic bacteria also was investigated in this equipment. The results showed that, under the conditions of pulp density 8% and stay time 60h, it can deal with 0.256 kg refractory gold ore per day, and the arsenic leaching rate can reach to 95.25%. During the experiment, some leaching liquor has been sampled from the second sect the fourth column of the continuous airlift bioreactor. The composition of microbial communities in this sample has been investigated using culture-independent 16S rDNA based cloning approach- restriction fragment length polymorphism. The phylogenetic analysis revealed that Leptospirillum ferriphilum and Acidithiobacillus caldus are the main organisms in this system. Both of them are moderate thermphilic bacteria and can resist relatively high concentration of arsenic ion.

Microbial Communities in Acid Mine Water from Two Different Copper Mines in China

Microorganisms such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans are the most studied acid mine drainage (AMD) organisms, they catalyze ferrous iron oxidization, thus determine the rate of metal sulfide dissolution, and play very important roles in AMD generation. To present a more complete picture of microbially mediated AMD production, the composition of microbial communities in five AMD samples was determined using a culture-independent 16S rDNA based cloning approach. Three samples, named SX1, SX2 and SX3, were obtained from three separate AMD sites of the Zhong Tiaoshan copper mine in Shanxi Province, China. The other two samples, named K1 and K2, were obtained from two separate bioleaching systems of the Tong Shankou copper mine, Hubei Province, China. Phylogenetic analysis revealed that the bacteria in these five samples fell into four major groups: Proteobacteria (α-, β-, γ-, δ-proteobacteria), Nitrospira (Leptospirillum), Firmicutes and Bacteroidetes. Proteobacteria such as A. ferrooxidans and A. albertensis dominated in the samples SX2, SX3, K1 and K2, but were scarce in sample SX1; Nitrospira such as Leptospirillum ferrooxidans, Leptospirillum ferriphilum and Leptospirillum group lll, were prevalent in the samples SX1, SX3, K1 and K2, but scarcely occurred in sample SX2; Firmicutes were only found in the samples SX3 and K1; Bacteroidetes were only found in the sample SX3. Archaea were only detected in the two samples K1 and K2 from the Tong Shankou copper mine. Thermoplasma and Ferroplasma lineages were detected abundantly in these two samples. Unexpectedly, sequences affiliated with Sulfolobales and the genus Methanothermus were also detected in small numbers. The results of a PCA (Principal Component Analysis) suggested that biogeochemical properties of the samples correlated with the microbial community structure in these samples. Additionally, the concentrations of some elements such as S, Fe, Cu, Zn and Ag seemed to be key factors resulting in the diverse distribution of typical iron-oxidizers (such as Acidithiobacillus ferrooxidans and Leptospirillum species) in different water samples. The fluorescence in situ hybridization (FISH) method was also used to investigate microbes in the samples K1 and K2. The variation in the intensity of the hybridization signals from different probes (such as CY3 labeled probe TF539, FAM labeled probe LF655, CY3 labeled probe FER656, FAM labeled ARCH915 and CY5 labeled ACD840) indicated the difference of microbes’ distribution in different environments, which may prove some results revealed by RFLP. Advanced Materials Research Online: 2007-07-15 ISSN: 1662-8985, Vols. 20-21, pp 577-577 doi:10.4028/www.scientific.net/AMR.20-21.577

Influence of Astaxanthin on Pearl Oyster Pinctada martensii

In the study, through the addition astaxanthin into the bait for the pearl oyster Pinctada martensii for 3 months, we studied the accumulation and existence form of astaxanthin in pearl oyster through qualitative and quantitative analysis which adopted High Performance Liquid Chromatography method; the transmission of astaxanthin in shells was detected by Micro-Raman spectrometry. The results showed: 6.870±1.356μg/g of astaxanthin existed in the control group of Pinctada martensii, and 74.799±5.907μg/g of astaxanthin existed in the experimental group, some of them were existent in the form of astaxanthin esters. Weak carotenoid characteristic peak occurred in the control group, while the carotenoid characteristic peaks intensity enhanced obviously in the experimental group, which illustrated remarkable increase of carotenoid content in the shell. These findings will not only provide the basis for colorful pearl cultivation via food-borne transmission but also lay a foundation for further artificial regulation and control of pearl color.

Degradation of Disperse Blue 2BLN Dye Wastewater by Pulsed Corona Discharge Combined with Ozone Process

Waste water discharged from dye plant contains high sanity ,high chroma and high CODcr (Chemical Oxygen Demand), commonly used biodegradation is often limited in application; As a new efficient advanced oxidation, pulsed corona discharge combining with ozone is attracting more and more attention. A special reactor was designed, in addition, the removal of COD and decoloration of stimulant dye wastewater containing disperse blue 2BLN dye (100mg/L) by pulsed corona discharge combining with ozone were investigated . It showed that in alkaline solution, the maximum COD removal and decoloration rate(58.8% and 99.1%) was observed ,which demonstrated that ozone and pulsed discharge was more efficient on COD removal and decolouration in alkalin than in neutral solution when all the samples were treated for13mins. After being treated, B/C increased from 0.2 to 0.45. Decoloration efficiency and COD removal could be improved obviously when oxygen feed increased from 40 to80L /h，yet further increase in oxygen feed led to a markedly decrease of decolouration efficiency and COD removal.

Biogenic Jarosite: A Friendly Adsorbent for the Removal of Chromate from Aqueous Solution

Ferric hydrosulfate minerals are commonly byproducts of biotic oxidation of Fe (II) in acid mine drainage and biohydrometallurgy like biogenic jarosite. In this study, adsorption of Cr (VI) on jarosite was a rapid process and the optimum pH for Cr (VI) adsorption was found at 7.0. The variation of Cr (VI) adsorbed on jarosite fitted the Langmuir adsorption isotherm models and the maximum adsorption capacity was 3.23 mg/g. It was evident that anion exchange mechanism was responsible for Cr (VI) adsorption on jarosite based on the sulfate leaching data and optimum pH experiments.

Electrospun Porous Ta 3 N 5 Nanorods with Enhanced Visible Light Photocatalytic Activity

In this study, porous Ta3N5 nanorods were sucessfully fabricated via electrospinning-calcination-nitridation method. The porous Ta3N5 nanorods are composed of Ta3N5 nanoparticles with diameters ranging from 30 nm to 80 nm. The porous Ta3N5 nanorods show significantly enhanced photocatalytic activity for the degradation of Methyl blue (MB) under visible light than commercial Ta3N5. Importantly, The porous Ta3N5 nanorods can be used as an easily recyclable photocatalyst with wide visible-light response.