Applied Mechanics and Materials Vols. 295-298

Abstract: An anaerobic membrane bioreactor (UBF) with a total capacity of 3L was employed for treatment of sulfide and nitrate containing wastewater with elemental sulfur as terminal product. The effect of HRT and pH on substrate removal and elemental sulfur accumulation was researched when S/N ratio at 2.5. The influent concentration of S^2-/HS^- and NO₃^--N were 110mg•L^-1 and 20mg•L^-1, respectively, during autotrophic denitrification. When HRT was between 7.41h and 6.83h and pH was between 6 and 7.5, HRT and pH has no effect on NO₃^--N and sulfide removal ratios, and at 97% and 100%, respectively, but elemental sulfur accumulation ratio was increased to 61% with HRT shorten. And low pH (pH at 7) was conducive to elemental sulfur accumulation with the ratio up to 62%. But further to reduce the pH would lead marginal increase in elemental sulfur accumulation ratio at 65%.

Abstract: In the pilot research for treatment of the purified terephthalic acid (PTA) wastewater with the functional strain Fhhh in the carrier activated sludge process (CASP) effectively, control of the value of COD: TN: TP and the concentrations of Cu, Mn, Se and Zn were conducted to improve the manganese peroxidase (MnP) level. When the value of COD:TN:TP was 100:0.36:0.15 and the concentrations of Cu, Mn, Se and Zn were 0.54, 5.07, 0.00 and 0.08mg/L, the specific activity value of MnP reached a higher level being 689 units while the sludge loading rate was 1.09 d-1. This value of the sludge loading rate was those of 4-7fold of the other processes reported. The data suggested that improving MnP level could enhance the degradability for Fhhh. And the potentials for Fhhh in the PTA wastewater CASP will be also discussed in this paper.

Abstract: In this paper, the chrome plating wastewater of a tin factory in Zhongshan City was taken as research object. In order to offer help for enlarging technique, we studied the pilot plant test of disposing and reclaiming chrome plating wastewater with ion exchange technique and optimized the technological conditions of ion exchange.

Abstract: Used slaughter wastewater treatment engineering of some food industry group in Liaoning Anshan as example. Introduced process characteristics, design parameters, treatment effect and operation cost of treating slaughter wastewater by regulation pool/ hydrolysis acidification/ contact oxidation process. The project of water treatment capacity is 8000m3/d, the average concentration of COD、BOD、NH3-N and oil respectively was 2000mg/L、1200 mg/L、120mg/L and 200 mg/L respectively. The treated water concentration can reach 44mg/L、8 mg/L、6 mg/L and 5 mg/L respectively. Good treatment effects can be achieved by regulation pool/ hydrolysis acidification/ contact oxidation process, the effluent can meet requirement of Comprehensive Wastewater Discharge Standard (DB21/1627-2008), and the process has the advantages of low operating cost, treatment costs of each ton water is 1.78 Yuan/t.

Abstract: The arsenic-containing rural drinking groundwater was treated by adsorption method in the paper. It was studied that the varieties and dosages of adsorbents, pH value and adsorption time have an effect on removal of arsenic. The experimental results indicated that the rate of arsenic removal is able to reach 91.39% at room temperature and under the condition of neutral pH values, 2.0 g of zeolite as adsorbent and 1 h of adsorption time. The content of arsenic in the treated drinking groundwater can be up to the current national hygiene standards of rural drinking water (<0.05mg /L).

Abstract: Phytoremediation is a low cost and eco-friendly emerging technology for treatment of contaminated soils with the use of green plants. In this study, the accumulation potential to heavy metals by two biofuel crops (maize and sunflower) and two metal accumulator plants (Elsholtzia splendens (ES), Tagetes patula L. (TP)) was studied with pot culture filled with a heavy metal contaminated soil, in order to compare their suitability for phytoremediation of contaminated soils. Sunflower showed the highest accumulation level for Cu (150 ug/pot) and Zn (10893 ug/pot) in the shoot part compared to other three plants. Maize showed a similar accumulation level for Cu (104 ug/pot) and Zn (7454 ug/pot) to TP, but a much higher level than ES. TP showed noticeable accumulation levels for Pb (196 ug/pot) and Cd (637 ug/pot). ES generally had the lowest accumulation capacity for Cu (38.5 ug/pot), Zn (2784 ug/pot), Pb (35.4 ug/pot) and Cd (18.2 ug/pot). Therefore, the two biofuel plants had higher or similar phytoremediation potential of heavy metals compared to the two accumulator plants. This study provided useful data for considering biofuel plants as potential economic crops for phytoremediation.

Abstract: The effects of arsenic uptake by Pteris vittata L. and Polystichum craspedosorum were examined. Pteris vittata L. were exposed hydroponically to 4Italic textItalic text.8 mg/L As(V) for 16 d and 4.05 mg/L As(V) for 24 h. Arsenic concentration in solution respectively decreased to 1.61 mg/L and 3.86mg/L. TF after 24 h was 0.81(1). Polystichum craspedosorum were exposed hydroponically to 3.26 mg/L As(V) for 20 days. As concentration decreased to 2.83mg/L after 16d and then increased slowly in the later four days. As contents in roots and fronds of Polystichum craspedosorum were 147 mg/kg and 90mg/kg. The results indicated that Polystichum craspedosorum was not good candidate for removal As(V) from water compared with Pteris vittata L..

Abstract: In this experiment the main corrosion factors of produced water in Changqing Oil Field concentrated treatment station was studied. In terms of ion component analysis, dissolved oxygen detection, bacteria content measurement, corrosion rate determination, as well as Gray Relational Analysis (GRA) method. And the corrosion products Scanning Electron Microscope Energy Dispersive X-ray analysis(SEM/EDX) were conducted. The results showed that the TGB content, pH value, S2-content, HCO3-, and dissolved oxygen content were the main corrosion factors. This study indicated that the corrosion rate of the system could be reduced from 0.0872mm/a to 0.0074mm by increasing pH value of oilfield produced water appropriately, strengthening the intensity of sulfur removal, controlling the bacterial content by adding fungicides etc.