Advanced Materials Research Vols. 781-784

Abstract: According to the problem of polymeric compound appearing in oil field produced water, following by the changes of water quality characteristics that result in the polymeric compound accumulated in the filter tank which lead to the poor regeneration, being partly hardened and the losing, and the over standard of water quality, the study uses the technology of axial dynamic backwashing to back wash and regenerate the dual-media filter of walnut shell/quartz sand. The removal rate of oil content for filter materials reaches above 90% after backwashing. Simultaneously, cleaning the granular filter materials in filter bed achieves high removal rate of oil and suspended substance content, the average removal rate of oil content being 96.0% while the suspended substance 77.81% which greatly improved the water quality index.

Abstract: The regeneration of Analginum-saturated powdered activated carbon (PAC) using solvent extraction and thermal regeneration was investigated in detail to get the optimal conditions. In the solvent extraction step, various influence factors, such as pH of solvent, treatment time, and temperature were studied respectively. In addition, the optimal conditions of thermal regeneration were determined to be 500 °C, 120 min, with blowing N₂ gas at 80 mL/min. Under the optimized conditions, the regeneration efficiency of spent PAC reached as high as 95.1%. This study provides a useful reference of regeneration method for other spent activated carbons.

Abstract: Ferrite material is a kind of special ferromagnetic mental oxide with Fe3+ as a main component. Based on the assumption that the reduction of Fe3+ and the magnetic variations could produce potential active impacts on degradation of organic pollutants under anaerobic conditions, we took water and sediment samples from Chongming east intertidal flat, a typical coastal wetland, to investigate the effects of exogenetic addition of ferrite on the removal of toluene in sediments during an 11-day incubation. Ferrite (Fe₁₂O₁₉·Sr, M.W. 1061.75, Nanosized spherical material 800 nm, the purity >98%) was added into sediment samples by proportions of 0.0, 5.0, 10.0, 20.0 g/kg with 0.0, 0.2, 0.5, 1.0 ml/kg toluene, respectively. It is found that the rate of toluene removal is the highest when the ferrite added is 10.0 g/kg with toluene recovery rates of 0.24%, 20.79%, 30.36% for treatments of 0.2, 0.5, 1.0 ml/kg toluene addition by the end of 11th day of incubation, respectively. In contrast, the recovery rates are 1.85%, 50.05%, 55.68%, respectively, when ferrite content rises to 20.0 g/kg. In addition, all toluene recovery rates are less than 2% after 11 day incubations under the condition of 0.2 ml/kg toluene, indicating that the removal rate of toluene depends on the contents of toluene in sediments. In summary, it confirm that application of exogenetic ferrite material can effectively enhance the removal of toluene from the sediment.

Abstract: Biofiltration systems have become effective and inexpensive alternatives to conventional treatment systems. In this study, a functional bioreactor, e.g. the biotrickling filter was evaluated for its efficiencies in treating ammonia in the wastewater treatment plant at different loadings and its performance were studied. The experimental results showed that the influent ammonia can be efficiently removed in the biotrickling filter. The removal efficiency was above 90.7% when the inlet ammonia concentrations varied from 20 to 300 mg/m³and the flow rates were adjusted to from 0.61 to 1.06 m³/h.The results in microbial analyses indicated that the ammonia oxidizing bacteria and nitrite oxidizing bacteria were dominant in the biotrickling filter.

Abstract: An air sweep vacuum membrane distillation process was used to treat brackish water desalination. The only operating parameter of the apparatus is the sweeping air flow rate. The effect of sweeping air flow rate on desalination was observed. The produced/condensed water rate was about 2.5 g/h for the PP module. The conductivity of produced water was about 92 μs·cm^-1, the salt rejection was above 95%.

Abstract: This article shows the results of research on finding ways to purify waste water produced by alkaline hydrolysis of rice waste - rice husk. Two methods were used: baromembrane filtration and electrochemical oxidation of organic substances. It was found that in the results of baromembrane processing of hydrolyzate on the membranes mainly stay silicon compounds partially sorbing organic substances contained in the feedstock. Through the membranes there pass the major part of microbiologically oxidated organic matter, so its difficult to reach the required waste water treatment stage. The use of electrochemical oxidation of organic substances extracted by alkaline hydrolysis of rice husks into a solution allows more qualitatively treat the solution. A range of indicators (chemical oxygen demand, permanganate demand, polyphenols) evaluating the content of organic compounds in the desilicated solution showed that in order to remove them effectively enough electrolyte concentration of sodium chloride is 4 g L^-1, formed by the desilication and dilution of the solution with the distilled water 1:10.

Abstract: Power stations provide a huge influence on the environment. This influence can be diverse and integrated: (1) land avulsion, (2) dusting from the open storage spaces of fuel, ash and slags, (3) huge amounts of ash-slug wastes containing toxic metals. The aim of the research is to evaluate the effect of ash-slug wastes of the coal-burning power station Partizanskaya on the ecological state of soils and water bodies. The waters of the Lozoviy Stream are polluted mostly with the residual iodine, bromine, silicium compounds and sulphides. Ash-slags of the coal-burning power station Partizanskaya can be an environmental hazard. The obtained information about the properties of the abiotic components of the industrial area of the coal-burning power station Partizanskayaash-slags, soils and water bodiesare the first step in studying the environmental situation in this area. One of the possible solutions aimed to improve the environmental situation in the industrial area of the coal-burning power station Partizanskaya is recultivation of the ash dump and development of the technologies for the usage of the ash in the household economy.

Abstract: Biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor was applied to treat high ammonium content urban landfill leachate. Inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on nitrifying bacteria activity was used to achieve nitrogen removal via nitrite pathway in the A/O. Results demonstrated that removed efficiencies of COD, total nitrogen (TN) and NH₄⁺-N were 95.3%, 84.6 %and 99.2%, respectively. Stable nitrite pathway with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Moreover, Fluorescence in situ hybridization (FISH) analysis showed that AOB was dominant microorganism.

Abstract: Crosslinked carboxymethyl tamarind (CCMTKP) with degree of substitution (DS) 0.42, 0.64 and 0.88 were prepared through reaction of sodium monochloroacetic acid (SMCA), epichlorohydrin (ECH) and tamarind kernel polysaccharide (TKP) and used to adsorb Cu²⁺ from aqueous solution. The appropriate range for pH was 2-6. The adsorption capacity rapidly reached equilibrium within 15 min and adsorption followed second-order kinetic equation. The adsorption of Cu²⁺ is well followed as the Langmuir isotherm and the maximum adsorption capacity (Q_m) was 68.03 mg/g. The regeneration study indicates that CCMTKP could be used repeatedly without significantly changing their adsorption capacities.

Abstract: Methylene blue (MB) was examined for oxidation decoloration. Results indicated that the use of ferrate resulted in effectively removal of chroma which has been explained by oxidation and flocculation interactions. Reaction conditions were optimized concerning ferrate addition mass, reaction temperature and dye concentration. The optimization mass of ferrate and the optimization reaction temperature was observed with decoloration of methylene blue wastewater.