Advanced Materials Research Vols. 726-731

Abstract: A consortium of bioflocculant-producing bacteria (BPA), mainly consisting of previously enriched Devosia hwasunensis and Tetrasphaera elongata, was inoculated into a sequencing batch airlift reactor during aerobic granular sludge cultivation to determine the effects of BPA on the formation of aerobic granular sludges. The results indicate that granulation time was substantially shortened from 56 to 28 days with the addition of BPA. Microbial community analysis of granular sludge based on denaturing gradient gel electrophoresis revealed diversity. Dominant populations belonged to Actinobacteria and α-and γ-proteobacteria. The added bacterial species, D. hwasunensis and T. elongata, which have been proposed to secrete extracellular polysaccharide mucus, played an important role in particle formation and in the maintenance of the stability and physicochemical properties of the granular sludge.

Abstract: Coagulation process enhanced with floatation was applied to treat dyeing wastewater generated from the production process of textile. The efficiency was mainly evaluated in terms of the chemical oxygen demand (COD) removal of mixed wastewater. Comparing the coagulation experiment with coagulation-floatation experiment on the performance of COD removal for the dyeing wastewater, we can find that floatation promote the effect of coagulation. The results show that: the COD removal of the dyeing wastewater in the coagulation-floatation experiment can reach 68% after floatation with the speed of 1.2 L/min for 4 min and maintaining standstill for 90 min, which is 17% more than the result appeared in coagulation experiment, under the conditions of the dosage of AlCl₃ and PAM is 100 mg/L and 15 mg/L, respectively.

Abstract: Carbide slag is adopted as flue gas desulfurization agent in Ning Xia Western Thermal Power Plant.During the operation process,flue gas desulfurization efficiency and slurry dewatering efficiency can not meet the requirement at the same time. Through the analysis of the main influence factors,the work in the laboratory is going to improve calcium sulrite oxidation effect .The experimental results are characterized by crystal diffraction and scanning electron microscope. Through the orthogonal experiment,the optimun conditions are obtained:pH of the limestone slurry is 5.1,temperature is 40°C,the oxidation air volume is 45L/min,solid content of the slurry is 11%.On this condition,not only the flue gas desulfurization efficiency can be guaranteed,but the calcium sulfite is good to calcium sulfate conversion,then the problem of slurry dewatering efficiency is resolved.Application to engineering practice,very good results are achieved

Abstract: In order to analyze the hydraulic properties of municipal solid waste (MSW), laboratory tests on the soil-water characteristic curves of 6 groups of MSW samples with different void ratios and organic contents are performed by means of the unsaturated consolidation apparatus. The filter paper method is also employed to determine their soil-water characteristic curves. The distribution indexλof void size of the samples is analyzed. The results show that the air-entry value of the MSW samples is very small and about 1kPa, and it increases owing to the action of loading. The value ofλ decreases with the increase of the initial void ratio and increases with the increase of the organic content in the samples. For measuring the soil-water characteristic curves of MSW by means of the filter paper method, the values at high suction phase are more rational and significant.

Abstract: For the purpose of recycling acid sludge of lubricant oil from refinery, on the conditions that the dilution factor is 20 and the actual addition amount of calcium carbonate and calcium hydroxide is respectively 1.15 and 1.1 times of the theoretical value, neutralization method is used to process acid sludge. By means of removing post-reaction organic phase, evaporating, drying, igniting at 650°C for 80 min, dissolving, crystallizing, calcium sulfate product is obtained. The conversion rate of SO₄^2- in acid sludge is more than 75% in the product. The purified product meets the national quality standards for similar products.

Abstract: In this study a new and environmental biopolymer membrane has been synthesized by incorporating β-cyclodextrin polymers as the reagent and using vinyltriethoxysilane (JH-V151) as crosslinking agent. The FT-TR and SEM were used to characterize the functional groups, morphology and pore-size. The results indicated that the prepared membranes exhibited relatively large pores, and the average pore size was 5μm. The study of adsorption behavior demonstrated that the prepared membranes could be considered as an efficient adsorbent for the removal of acid dyes from the wastewater.

Abstract: Heavy metal pollution is a serious threat to human health. Because of the development of nanotechnology, removal of heavy metal is more convenient and effective. nanozero valent iron (Fe⁰) particles have high activity and specific surface area. At present, Fe⁰ nanoparticles have been used in the processing of refractory organics, heavy metals, inorganic salts, soil restoration, and other areas of the environment. But the dispersion and stability of the Fe⁰ nanoparticles are poor. We can improve physical and chemical properties of Fe⁰ by adding carrier materials to make iron nanoparticles have better stability, dispersion and the treatment effect. This paper mainly introduced the situation of removing heavy metals by the Fe⁰ nanoparticles and hybridized Fe⁰ particles. Hybridized Fe⁰ has good performance and high removal efficiency to heavy metals. We also discussed what are inadequate and need to be further researched.

Abstract: To accomplish rapidly the granulation process of digestion sludge for the treatment of actual coking wastewater and meanwhile achieve high COD, phenol, SCN^- and CN^- removal, the EGSB reactor was employed with two operation stages. StageI: Granular sludge was formed from digestion sludge using brewery wastewater as substrate in the anaerobic way (meanwhile adding little granules, which were 1/7 of the total biomass). StageII: Granular sludge was acclimatized with the actual coking wastewater through continuous micro-oxygenation way. The experimental results showed that the granular sludge could quickly form in 10d in the EGSB reactor seeded with digestion sludge and little loose granules. It took only about 6 months for the successful micro-aerobic acclimating of the granular sludge by the actual coking wastewater. The removal efficiencies of COD, phenol, SCN^- and CN^- were 72.9, 99.5, 95.7 and 97.5%, respectively, at 12.1h hydraulic retention time (HRT) and for 631-922, 12.8-37.7, 66.7-232.7 and 0.3-57.8mg.L^-1 influent COD, phenol, SCN^- and CN^- concentration.

Abstract: This paper deals with the wastewater from solid propellant production containing high level of ammonia nitrogen. The chemical treatment had been made in laboratory, by the selected process, the removal rate of NH₃-N is above 92%.

Abstract: Summarized the traditional and mechanisms of sewage treatment methods ,and then studied several typical and widely research methods in detail .Actuality of development of sewage treatment technology were introduced.