STUDY ON MAXIMUM SPECIFIC SLUDGE ACTIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

The maximum specific sludge activity of granular sludge from large scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

Effect of sulfate on the methanogenic activity of a bacterial culture from a brewery wastewater during glucose degradation

The maximum specific methanogenic activity （SMA） of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading basis. Batch experiments were conducted in serum bottles at pH 7 and 35℃. A comparison of the values indicates that the SMA of this mixed culture was increased and reached its highest level of 0.128 g CH4 gas COD/（g VSS.d） when biomass was in contact with sulfate at a ratio of 1：0.114 by weight.

Nondestructive high-sensitivity measurement method for activation estimation in accelerator room concrete

This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.

Studies on Properties of Lipase Produced from Aspergillus sp. Isolated from Compost Soil

Lipase producing Aspergillus was isolated from soil collected from a refuse dump site located at Awka, Anambra State, Nigeria using standard microbiology and biochemical techniques. Crude extract of lipase was produced after a successful screening of the isolates using mineral broth containing p-NPP through submerged fermentation system with optimized physiologic conditions. Three steps of purification were carried out: Ammonium sulphate, dialysis and gel filtration (sephadex G-150). Crude extract was precipitated by using 70% saturation of ammonium sulphate at pH 6.0 which gave the optimum precipitation of the protein with specific activity of 260.56 U/mg. Precipitation using ammonium sulphate carried out at pH 6.5 and 8.0 gave specific activity of 217 U/mg of the protein. The precipitates were further desalted through dialysis for twelve hours and specific activity of 343.20 U/mg was recorded from the dialysate afterwards. Further purification was done by using sephadex G-150 and specific activity of 490.55 U/mg was recorded from the active pooled fractions. The purification table showed a 2.32 purification folds of lipase was gotten after gel filtration (sephadex G-150) with a lipase percentage yield of 2.00%. The specific activity of lipase increased from 211.81 to 490.55 U/mg. Characterization of β-galactosidase gave optima pH and temperature of the enzyme at 6.0 and 60°C respectively. Kinetic constants: Km and Vmax values were obtained at various concentrations of p-NPP where 0.32 mM and Vmax of 200.00 μmol/min respectively. Ca2+ and Co2+ showed greater effect on lipase activity in a concentration-dependent manner (0.03 - 0.05 M) when compared to Mn2+ and Fe2+. The results from this study have shown that lipase produced from filamentous Aspergillus has a wide range of activity over physiologic conditions in regards to industrial and clinical standard operational procedures.

Radioactive Element Distribution Characteristics of Red Mud based Field Road Cement before and after Hydration

Red mud was firstly used as a raw material in sintering field road cement. Then, the radioactive element distribution characteristics of red mud based field road cement（RFC） before and after hydration were comparatively investigated. The experimental results indicated that the specific activity of ^（226）Ra and ^（232）Th increased after sintering process from raw material to clinker, as a result of concentrating effect on ^（226）Ra and ^（232）Th during sintering process, but the specific activity of ^（40）K decreased after sintering process as a result of volatilization effect. Radionuclide ^（226）Ra mainly distributed in RFC silicate phases（C_xS）, ^（232）Th distributed more in RFC interstitial phases than RFC silicate phases（C_xS）, ^（40）K mainly distributed in RFC interstitial phases. With increasing hydration ages of RFC pastes, the specific activity of ^（226）Ra kept increasing, ^（232）Th remained consistency all the same and ^（40）K declined. The radioactivity of RFC was in the recommended safe limit of Chinese National Standards GB6566-2010 during its preparation and application process.

Comparison between controlled landfill reactor and conditioned landfill bioreactor

Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste(MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature decomposing MSW. The results of waste biodegradation were compared with that of the leachate-recirculated landfill simulator and conservative sanitary landfill simulator. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown. An obvious enhancement of effective disposal from conservative sanitary landfill(CSL) simulator, to the leachate-recirculated landfill(LRL) simulator and to the conditioned bioreactor landfill(CBL) simulator would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.

CELLULAR IMMUNITY EFFECT OF LEUKEMIA VACCINE ON TUMOR BURDEN RAT

Objective To evaluate the effect of the active specific immunotherapy with leukemia vaccine in the malignant hematopoietic diseases. Methods We established the animal models by inoculating C 57 BL/6 rats with FBL 3 erythroleukemia cells and prepared three types of tumor vaccine, which were administered on the rats respectively. The MTT colorimetric assay was adopted 2 and 4 weeks later to test the cytotoxicity of macrophage( M Φ ) and that of cytotoxic T lymphocyte(CTL) derived from the rats injected with tumor vaccines, and compared the results with the control group. Results With the growth of erythroleulemia cells in the rats, the cellular immunity was seriously depressed, and the inhibition of specific cellular immunity was later than that of non specific cellular immunity. The tumor vaccine made from inactivated tumor cells, IFA and cytokines (rGM CSF, rIL 2 and rIL 6), promote the cellular immunity of tumor burden rats, especially the specific cellular immunity more efficiently than that of tumor vaccine made from inactivated tumor cells and IFA, but the third vaccine made from inactivated tumor cells alone has no effect. Conclusion The tumor vaccine made from inactivated tumor cells with addition of IFA and cytokines (rGM CSF, rIL 2 and rIL 6) provides a promising future in the active specific immunotherapy against hematopoietic tumor.

Influence of Pore-expansion Agent on the Structure and Performance of Activated Alumina Synthesized from Waste Aluminum Sludge

The chemical compositions of the sludge after treatment are tested by fully chemical analysis techniques. Its crystalline phase structure changes of the sludge calcined at different temperature are characterized by XRD method. Nitrogen gas isothermal adsorption method （77 K） is applied to measure the influences of ammonium bicarbonate on specific surface area and pore structure of activated alumina synthesized from waste aluminum sludge. The result shows that the amount of Al2O3 in the sludge accounts for more than 94%, and Na2Owt% in a 0.1-0.2% range. By calcining raw sludge at 600℃, monophase γ-Al2O3 is obtained. And this can satisfy the performance requirements of activated alumina adsorbent. The specific surface area of the specimen with NH4HCO3 added has expanded from 179 to 249 m^2/g and the pore volume from 0.25 to 1.11 cm^3/g as well as the average pore diameter from 5.6 to 17.8 nm. All these show that NH4HCO3 is an effective pore-expansion agent to remarkably improve the structure and performance of activated alumina synthesized from waste aluminum sludge.

Mechanism of Suppressing ASR Using Ground Reactive Sandstone Powders instead of Cement

In order to understand the effect of powders ground from reactive sandstone replacing cement on reducing or suppressing alkali-silica reaction（ASR）, and to identify the mechanism of suppressing ASR by this powders, mortar and paste containing reactive sandstone powders of four replacement levels ranging from 10wt% to 40wt% and four specific surfaces areas ranging from 210 m^2/kg to 860 m^2/kg were studied. The experimental results showed that incorporation of 40wt% reactive sandstone powders could suppress ASR effectively except for mortar containing reactive sandstone powders with specific surface area of 610 m^2/kg, which disagreed with the most results reported that the higher reactive powder specific surface area, the smaller ASR expansion. By means of fl ame photometry, Fourier transform infrared spectroscopy（FT-IR） and thermo gravimetric analysis（TG）, the mechanism of reactive sandstone powders on reducing or suppressing ASR was soluble alkalis type of reactive sandstone powders and the competition of liberating and bonding alkali of cement paste containing reactive sandstone powders,when the ability of alkali bonding was greater than the ability of alkali liberation, ASR caused by reactive sandstone was supressed effectively.

Effect of 2-butenal manufacture wastewater to methanogenic activity and microbial community

The synthesis of 2-butenal,which is a vital raw material for the production of sorbic acid as a food preservative,generates some toxic by-products,so it is urgent to seek better detoxification strategies for the treatment of 2-butenal manufacture wastewater.In this study,batch experiments were carried out to investigate the inhibition effect of wastewater on the methanogenic activity.To understand the wastewater toxicity to anaerobic granular sludge,variations of the specific methanogenic activity(SMA)and extracellular polymeric substance(EPS)constituents at various wastewater CODs were investigated.Ultraviolet-visible(UV-vis)spectra and Fourier transform infrared(FT-IR)spectra were employed to analyze the structure of the EPS.The results showed that the inhibitory ratio of 2-butenal manufacture wastewater was less than 8.4%on the anaerobic granular sludge when the CODs were less than 959 mg/L.However,the inhibitory ratio increased from 36.4%to 93.6% when CODs increased from 2396 mg/L to 9585 mg/L,with the SMA decreasing from 39.1 mL CH4/(gVSS·d)to 3.2 mL CH4/(gVSS·d).The diversity of the microbial community under various CODs was researched by Illumina 16S rRNA Miseq sequencing and the results demonstrated that Proteiniphilum、Petrimonas and Syntrophobacter were the dominant bacteria genera in all sample.Regarding archaea,Methanobacterium was the most dominated archaea genera,followed by the Methanosaeta group in all samples.Moreover,the bacterial communities had changed obviously with increasing CODs,which indicated high CODs played a negative impact on the richness and diversity of bacterial community in the sludge samples.

An ultra-highly active nanozyme of Fe,N co-doped ultrathin hollow carbon framework for antibacterial application

In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for researchers. Herein, the Fe,N co-doped ultrathin hollow carbon framework(Fe,N-UHCF) exhibit ultra-high peroxidase-like activity. The specific activity of Fe,N-UHCF nanozyme is as high as 36.6 U/mg,which is much higher than almost all of other reported nanozymes. In practical applications, the Fe,N-UHCF show good antibacterial effects.

Enhanced performance for propane dehydrogenation through Pt clusters alloying with copper in zeolite

Metal alloys have been widely applied for heterogeneous catalysis,especially alkane dehydrogenation.However,the catalysts always suffer from sintering and coke deposition due to the rigorous reaction conditions.Herein,we described an original approach to prepare a catalyst where highly dispersed Pt clusters alloying with copper were encapsulated in silicalite-1(S-1)zeolite for propane dehydrogenation(PDH).The introduction of Cu species significantly enhances the catalytic activity and prolongs the lifetime of the catalyst.0.1Pt0.4CuK@S-1 exhibits a propane conversion of 24.8%with 98.2%selectivity of propene,and the specific activity of propylene formation is up to 32 mol·gPt^(−1)·h^(−1)at 500℃.No obvious deactivation is observed even after 73 h on stream,affording an extremely low deactivation constant of 0.00032 h^(−1).The excellent activity and stability are ascribed to the confinement of zeolites and the stabilization of Cu species for Pt clusters.

Fishbone-like platinum-nickel nanowires as an efficient electrocatalyst for methanol oxidation

Platinum(Pt)-based electrocatalyst with low Pt content and high electrocatalytic performance is highly desired in fuel cell applications.Herein,we demonstrated that platinum-nickel(Pt-Ni)nanowires with an average composition of PtNi3 and a fishbone structure can be readily synthesized and used as an efficient electrocatalyst toward methanol oxidation reaction(MOR).The PtNi3 fishbone-like nanowires(PtNi3-FBNWs)present features such as richer Pt on the surface than in the bulk,high-index facets on the rough surface,and polyhedral facets at the ends of side chains.Such compositional and structural features could be determinative to the enhanced performance in the electrocatalysis of MOR.Compared with commercial 20%Pt/carbon black(Pt/C),the specific activity and mass activity of the PtNi3-FBNWs are enhanced by approximately 4.76 and 3.02 times,respectively.The stability of electrocatalysis is significantly improved as well.Such comprehensive enhancement indicates that the PtNi3-FBNWs would be a promising candidate toward MOR in fuel cells.

Analysis of radiation environmental safety for China's Spallation Neutron Source (CSNS)

The China Spallation Neutron Source（CSNS） is going to be located in Dalang Town,Dongguan City in the Guangdong Province.In this paper we report the results of the parameters related with environment safety based on experiential calculations and Monte Carlo simulations.The main project of the accelerator is an under ground construction.On top there is a 0.5 m concrete and 5.0 m soil covering for shielding,which can reduce the dose out of the tunnel＇s top down to 0.2 μSv/h.For the residents on the boundary of the CSNS,the dose produced by skyshine,which is caused by the penetrated radiation leaking from the top of the accelerator,is no more than 0.68 μSv/a.When CSNS is operating normally,the maximal annual effective dose due to the emission of gas from the tunnel is 2.40×10-3 mSv/a to the public adult,and 2.29×10-3 mSv/a to a child,both values are two orders of magnitude less than the limiting value for control and management.CSNS may give rise to an activation of the soil and groundwater in the nearest tunnels,where the main productions are 3H,7Be,22Na,54Mn,etc.But the specific activity is less than the exempt specific activity in the national standard GB13376-92.So it is safe to say that the environmental impact caused by the activation of soil and groundwater is insignificant.To sum up,for CSNS,as a powerful neutron source device,driven by a highenergy high-current proton accelerator,a lot of potential factors affecting the environment exist.However,as long as effective shieldings for protection are adopted and strict rules are drafted,the environmental impact can be kept under control within the limits of the national standard.

A comparison of process performance during the anaerobic mono-and co-digestion of slaughterhouse waste through different operational modes

The use of consecutive feeding was applied to investigate the response of the microbial biomass to a second addition of substrates in terms of biodegradation using batch tests as a promising alternative to predict the behavior of the process. Anaerobic digestion（AD） of the slaughterhouse waste（SB） and its co-digestion with manure（M）, various crops（VC）, and municipal solid waste were evaluated. The results were then correlated to previous findings obtained by the authors for similar mixtures in batch and semi-continuous operation modes. AD of the SB failed showing total inhibition after a second feeding. Co-digestion of the SB ＋ M showed a significant improvement for all of the response variables investigated after the second feeding, while co-digestion of the SB ＋ VC resulted in a decline in all of these response variables. Similar patterns were previously detected, during both the batch and the semi-continuous modes.