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Liu J.,Chongqing University | Li D.,Chongqing University | Li D.,Key Laboratory of the Exploitation of Southwest Resources | Li D.,State and local joint engineering laboratory
Research Journal of Chemistry and Environment

In this paper, Anaerobic Baffled Reactor (ABR) was applied to treat the synthetic wastewater in the matrix of starch and glucose. Tlie reactor was started using low loading start-up, VLR controlled at 0.59 ∼ 11.05kgCOD/m 3.d. Some granular sludge appeared after running 18 days. The figure and size of granular sludge in each compartment revealed different characteristics due to the changing of OLRs and shear force between gas and liquid in each compartment. The COD removal efficiency was higher than 90% and steady when the reactor's start-up finished. When the anaerobic granular sludge appeared in the reactor, the VLR was 1.29kg COD/(m 3-d), COD removal efficiency was 83 %, hydraulic surface loading was 0.078m 3/m 2.h and an HRT was 30h The VLR had remarkable influence on COD removal efficiency, VFA, pH and ALK. When VLR was 5.57kgCOD/(m 3.d), COD removal efficiency and ALK were the minimum, VFA in the outflow exceeded lOOOmg/L, reactor's efficiency decreased. The reactor recovered after adjusting VLR and ALK value. Compared with the third and fourth compartments, the first and second compartments were less sensitive to changing of VFA. When pH deviated from adapt range, the COD removal efficiency decreased obviously, so pH value was kept in range of 6.2 to 6.5 for the later stage of experiments. Source

Lili L.,Chongqing University | Dongwei L.,Chongqing University | Dongwei L.,Key Laboratory of the Exploitation of Southwest Resources | Zhu F.,Chongqing University
Research Journal of Chemistry and Environment

Different chemical morphological of heavy metals have different activity and harmfulness. Migration and Utilization of heavy metals were decided by the existent form of heavy metals in the soil, which influenced Bioactivity and Toxicity. This paper analyses the forms of heavy metals(Zn, Pb, Cd and As) of the Smelting Slag for Lead and Zinc,. using BCR sequential extraction. The results show that the main forms of Zn and Cd are oxidizable. Pb mainly occurred in oxidizable and Reducible fraction. However, As mainly occurred in residual fraction, which the percentage of reach 99.56%. According to the percentage of fractions extracted in total content(As is 0.44%, Zn is 14.7%, Pb is 85.98%, Cd is 48.86%), the latent ecological risk of heavy metals varied in the descending order of Pb, Cd, Zn and As. Source

Wang Q.,Chongqing University | Li D.,Chongqing University | Li D.,Key Laboratory of the Exploitation of Southwest Resources | Li D.,State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam | Chen G.,Chongqing University
Applied Mechanics and Materials

Everyone knows heavy metals are inorganic pollutants with strong toxicity and typical pollutant needing preferentially control. In the metal mines of China, the tails that were piled up on the ground already have reached more than 4 billion tons, and this number increased 2 ×108 tons every year. The characteristics of metal mine tails mainly include: (1) the grain size is extremely fine; (2) The quantity in weight was very large; (3) the toxicity is very strong; (4) Transporting concentration is very low. The migration of heavy metals would impact the local environment, the safety of the downriver resident and the plowland, the food safety of livestock as well as the solid's safety. Based on the characteristics of mine tailings impacting to environment, this paper estimates the pollution property, as well as studies the harm for the outside environment through the experiment of the gross analysis and the infusion toxicity analysis. This research takes Longdu tailings of Dahong Mountain for example to know the harm of heavy metal ion. © (2011) Trans Tech Publications. Source

Li D.,Chongqing University | Li D.,Key Laboratory of the Exploitation of Southwest Resources | Zhang S.,Chongqing University | Wang K.,Chongqing University
Research Journal of Chemistry and Environment

The technology of two phase anaerobic digestion (TPAD) is different from the other new anaerobic reactors. It focuses on the changes of technologies, not on the reshape of reactors' structure. The phase-separation is the essential characteristic of this treatment system. Two-phase anaerobic digestion process fixes the acid-producing bacteria and methanogens respectively in two separate reactor in tandem and provide the own best conditions. The twophase anaerobic digestion has several advantages over conventional one-phase processes, such as selection and enrichment of different bacteria in each phase, increased stability of the process, higher organic loading rates (OLR) and shorter hydraulic retention times (HRT). Furthermore, two-phase anaerobic digestion system has given the best performances concerning methane productivity, so this technology is helpful to alleviate current solution of the energy shortage and explore the new ways for clean energy. Source

Li D.,Chongqing University | Li D.,Key Laboratory of the Exploitation of Southwest Resources
Research Journal of Chemistry and Environment

The hydrometallurgy industry discharges large numbers of heavy metal wastewater annually in China, especially during the production of Germanium extracted from Lead and Zinc oxide ore. The effluent contains Pb(II), Zn(II) and Cd(II) and the concentration is 7.0, 50.0 and 4.12mg/L respectively. In this research, the XRD was introduced to detect the ferrite generated in chemical coprecipitation. The crystal structure of ferrite may play a important role in parceling heavy metal ions. The hydrometallurgical effluent quality treated by chemical coprecipitation and ferrite combined process was excellent. The extraction toxicity of ferrite was far below the allowed standard concentration. It was also found that the removal efficiency is optimal when the pH is from 8.86 to 9.24 and the temperature is from 40°C to 60°C. Source

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