Advanced Materials Research Vols. 1073-1076

Abstract: An aerobic benzene-degrading heterotrophic nitrifying strain Pseudomonas sp.BN5 was isolated from the well domesticated microbes. Growth and nitrification characteristics were investigated with the benzene as the sole carbon and energy source and the NH+4-N as nitrogen source under aerobic condition. It was demonstrated that the favorite C/N ratio, temperature and speed of Pseudomonas sp.BN5 was 10, 30°C and 180rpm, respectively. About 70.86% of ammonium and 100% of benzene was removed after 72 h of incubation at initial benzene and ammonium concentration of 52.37mg/L and 16.13mg/L, respectively. Only trace accumulation of nitrate was observed during the process.

Abstract: The fine particulate matter (PM_2.5) has become the primary pollutant of atmospheric environment of Beijing now, therefore to know the spatial distribution characteristics and to make accurate and refined forecast of PM_2.5 is very important. In this study, the spatial distribution characteristics of PM_2.5 concentration in summer in Beijing was derived by using Kriging interpolation method based on the data from 30 air quality monitoring stations all over Beijing during June, July and August 2014. In general, the PM_2.5 pollution is higher in the south and east, and is lower in the north and west, but when there is south or southeast wind blowing, the situation could be totally the opposite. Based on the hourly PM_2.5 concentration data from one representative air quality monitoring station and the meteorological data from a nearby meteorological station during June, July and August 2014, the hourly PM_2.5 concentration was forecasted up to 168 hours ahead by using BP (Error-back propagation) and RBF (Radial basis function) neural network methods. The results show RBF neural network method is more efficient, the curve trends of the forecasted values are similar with the curve trends of the monitored values and the forecasted values have significant linear relationship with the monitored values, which demonstrates the possibility of hourly forecast for PM_2.5 pollution.

Abstract: The current governance for air pollutants presents problems, such as the singleness of administration body，slack law enforcement of the environment protection departments and the ineffective coordination among the different departments. The synergy governance can mobilize the plural stakeholders to participate in a joint effort to improve the air quality. The paper analyzes the status of governance for air pollutants in China. Also, based on flue gas desulphurization (FGD) franchise pilot project in the thermal power plant, the paper summarizes the connotation of franchise and progresses made in flue gas desulphurization. Finally, the mode of synergic governance for air pollutants emission is presented.

Abstract: The furfural wastewater is kind of highly concentrated organic wastewater. According to its quality and quantity characteristics, this process of micro-electrolysis - photosynthetic bacterial oxidation - biological contact oxidation - biological carbon has been used for treating furfural wastewater. Under the condition that, the mass concentration of influent COD, BOD₅ and SS were 8337~15692, 2100~4030, 100~300mg/L respectively, the pH value was 2~3, the effluent water after the treatment met the specification for grade 1 in Integrated Wastewater Discharge Standard GB(8978-1996), which practical proved that, the effect of the treatment process had a high efficiency, impact load is strong and stable operation; using it in furfural wastewater treatment, other high concentration wastewater treatment would be application reference.

Abstract: Utilize cement specific surface area is larger and neutralizes the acidic aqueous ,which can adsorb heavy metal,properties and can precipitate heavy metal.Study on removal rate of Cu²⁺,Pb^{2 +}, Zn^{2 +}, Cd^{2 +}. By study the properties of the cement and analyzing the experimental data on the cement dosage,the ion concentration,PH and the stirring time, the results show that cement has better adsorption and the effect of precipitation on the above four kinds of ion, removal rate increased with increasing PH,the mount of dosage and stirring time.

Abstract: Industrial boilers are important thermal power equipments. Soot, SO_x and NO_x, etc. generated from Industrial boilers are main sources of PM_2.5. Based on the analysis of sources of PM_2.5 emissions from industrial boilers, PM_2.5 control technologies for industrial boilers such as dedusting technology, desulfurization technology and denitration technology are introduced and analyzed. According to the characteristics of current PM_2.5 control technology and industrial boilers, technical route of PM_2.5 emissions control for industrial boilers is recommended.

Abstract: The influence factors on alkalization-ceramic flat membranes combination craft in manganese removal are studied in this experiment. The results show that pH value has a great influence on the treatment effect of this method, and the best effect is when the PH value is 7.70 in the conditions of alkaline. But the influent flow and dissolved oxygen (DO) value have little influence. Overcome economic considerations,the best influent flow is between the 9 ~ 12ml/min and DO at 2.3mg / L is optimal.

Abstract: Supercritical water gasification (SCWG) of food waste was carried out to investigate the effects of increasing alkali catalysts (NaOH, KOH, Ca (OH)₂, Na₂CO₃, NaHCO₃ and K₂CO₃) concentration on hydrogen yield. Food waste containing twenty-eight different Chinese food items was gasified at a temperature of 400°C (held for 10mins) and pressure of 24MPa. The basicity of the reacting medium was an underlying factor influencing the effects of the different alkali catalysts concentrations on the hydrogen yield. In this study, KOH generally had the highest catalytic effects on hydrogen yield. Additionally, increasing the concentration of alkali catalysts significantly suppressed the CO₂ content in the product gases. Suppression of CO₂ by NaOH and KOH was due to their catalytic effects during the water gas shift reaction (WGSR) in order to increase the hydrogen yield. Suppression of CO₂ by carbonates on the other hand was due to their catalytic effects on the methanation reaction, thereby hindering the WGSR and resulting in lower hydrogen yields. Finally, increasing NaOH concentrations was very effective to decarbonize the product gas of the various reactions. This study seeks to discriminate the effects of increasing alkali catalysts concentration on hydrogen yield during the SCWG of food waste.

Abstract: The amounts of municipal solid waste (MSW) are increasing dramatically in metropolis, such as Shanghai in China, due to rapid economic development and urbanization, and it has brought a significant challenge to ecological situation of the city. It is concerned to establish an innovated management system for MSW reducing, recycling, and reusing (3Rs). Thus, information technologies are introduced with the objectives to establish an integrated, and cost-effective solid waste management system. In this system, Radio Frequency Identification (RFID) technology is applied to collection, transportation, and disposal of MSW. Meanwhile, source separation is also combined as a best practice for management of trash and recyclable materials. The paper infers that the establishment of information management system of MSW will offer opportunities to MSW management by reducing secondary pollution and improving efficiency of collection and transportation.

Abstract: The influence of Na₂CO₃ on RF4-type waste printed circuit board (PCB) thermal degradation process in air atmosphere was studied with thermogravimetric analysis, and the reaction kinetics was calculated based on the Coats – Redfern method. It is shown that the weight loss process of WPCB in air atmosphere includes three stages. Addition of Na₂CO₃ decreases the initial temperature of the first weight loss stage of WPCB, which indicates the enhancement effect on the decomposition of the flame retardant. Addition of Na₂CO₃ increases the initial temperature of the second and third weight loss stage of WPCB, which indicates the obstruction effect on oxidation reaction. From the different mechanism function, the optimal mechanism function is f (α)=2/3(1-α)[-ln (1-α) ]³ and the range of activation energy is 30~185 kJ /mol.