一种简便方法评价空气净化产品除氨率性能

通过搭建装置,模拟《QB/T 2761-2006室内空气净化产品净化效果测定方法》,测定被动式空气净化产品的除氨效果。该装置由氨气发生装置、除氨装置和氨气收集装置组成。实验时在氨气发生装置中加入5.0 mL浓度为25%的浓氨水作为氨源,用滤纸作为样品载体,取3.0 g样品加于滤纸上,通过附有样品的滤纸吸收氨气后,采集剩余氨气并使用酸碱滴定法测定被吸收氨气量,通过计算空白样品和待测样品吸收氨气量的差异,从而得到样品除氨率。分析测试4个不同样品,结果稳定性良好且与行标方法接近。该方法具有设备简单,占地面积小,氨含量测定时不需要用到有毒有害物质,分析结果准确等特点。

Effect Research of Immobilized Algae-bacteria Removal Ammonia Nitrogen of Aquaculture Wastewater and Proposed Model

Applied Immobilized algae bacteria (ABI) to remove ammonia of freshwater aquaculture wastewater. Temperature (T),PH,light intensity (I),dissolved oxygen (DO) and filling rate five factors plays important role in the process of ammonia nitrogen removal ,related data between ammonia removal and five factors was received through multi-factor orthogonal test,and established relations model between the five factor and nitrogen removal. The results show that five-factors had significant effect on AR,and the best combinations for removing AR was temperature 30 ℃,pH=7.0,light intensity 6 000 lux,dissolved oxygen 5.0 mg/L and the fill rate 10%. According to the experimental data,equation model was proposed and coefficient of determination R2 =0.864 8,P<0.05. Samples T-test was done between the model predictions and the actual measured values.Test results showed that the significant difference of overall mean value sig. (2-tailed) was 0.978 (P>0.05),it Shows that had no significant difference between model predictions and the actual measured value,and model had a high degree of fitting.

Ammonia nitrogen removal from aqueous solution using zeolite modified by microwave-sodium acetate

The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal performance.The ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after modification.Compared to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 nm.The cation exchange capacity(CEC)of SMMZ is higher than that of the natural zeolite.And the ammonia nitrogen removal rate is consistent with the change of CEC.The SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm model.The adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.

Combination of Ozonation Process and Absorption through Membrane Contactor Using Natural Hot Spring Water as Absorbent to Remove Ammonia from Wastewater

Ammonia in wastewater is a major pollutant produced in industrial and agricultural wastewaters. Ammonia is often removed by conventional technologies such as pack tower aeration, biological treatment or adsorption as ammonium ion onto zeolites. In many cases, conventional methods are very costly and inefficient, and therefore there is a need for an alternative separation technique for more efficient removal of ammonia from wastewaters. The aim of this study is to investigate the performance of combination of ozonation and absorption through membrane processes to remove ammonia from wastewater using NHSW （natural hot spring water） as absorbent. Experimental results show that hollow fiber membrane contactor has potential application for ammonia removal from wastewater. Operating variables such as time and pH of absorbent solution are found to remarkably influence the removal process efficiency.. Based on experimental results ozonation can improve ammonia removal efficiency through hollow fiber membrane contactor. Ammonia removal efficiencies and overall mass transfer coefficients increase with decreasing pH of absorbent solution.

Removal of Microcystin-LR in Water by Chlorine Dioxide

Microcystins （ MCs ） are well known as hepatotoxins produced by blooms of toxic cyanobacteria （blue-green algae） abundant in surface water used as drinking water resource and have drawn attention of environmentalists world over by leading to adverse health effects. A study on efficiency and reaction kinetics of microcystin-LR （ MC-LR ） degradation by CIO2 was performed. Experimental results indicated that MC-LR was removed by CIO2 effectively and the residual concentration of MC-LR could meet the national guideline（GB5749 - 2006） （1.0 μg · L^-1）, the efficiency of removal was in positive correlation to CIO2 dosage and reaction time and in negative correlation to initial concentration of MC-LR and pH value, whereas it was affected by temperature slightly. CIO2 dosage was the most important reaction factor on base of the orthogonal test results. The reaction was second order overall and first order with respect to both CIO2 and MC- LR, and had an activation energy of 78.81 kJ · mo1^-1 . The reaction rate constant was 4.74× 10-^2 L/（mol · min） at 10 ℃. Therefore, oxidation of CIO~ could be taken as an effective technology for removing MC-LR from drinking water resources in traditional drinking water supplies.

Experimental Research on Coke Wastewater Treatment by Hybrid Biological Reactor

Phase hybrid biological reactor （HBR） was used in treating coke wastewater by adding submerging fiber-ball fillers in suspended growth activated sludge. The optimum operation parameters for the highest performance were determined. It was found that the hybrid biological reactor worked well for the coke wastewater treatment in terms of Chemical Oxygen Demand （COD）, NH4＋ -N and other refractory organic compounds removal efficiencies. Compared with conventional activated sludge system, the removal rate of COD and NH4＋ -N and the nitrating rate were higher and more stable in the hybrid biological reactor. COD of effluent was less than 75 mg/L and the removal rate of COD and NH4＋ -N could be up to 95.0% and 92.5% when COD of influent and NH4＋ -N were less than 700 mg/L and 300 rag/L, respectively. In this way, the quality of effluent concentration could reach the first class of integrated wastewater discharge standard （GB8978-1996） （COD ≤100 mg/L）.

Effects of main factors on remedying northern landscaping water by hybrid ecological filter

Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants' removal efficiency of the hybrid ecological filter.The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH4+-N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficiency of TN is decreased,the removal efficiency of NH4+-N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%.When the temperature declines,the temporal removal efficiency of NH4+-N is reduced,but the removal efficiency of 24 h and 48 h is remained.The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently.The retention time plays an important role in NH4+-N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal.

Transformation and performance of granular sequence batch reactor under conventional organic loading rate condition

Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.

Ammonia Removal from Wastewater through Combination of Absorption Process in the Membrane Contactor and Advance Oxydation Process in Hybride Plasma-Ozone Reactor

Wastewater containing high concentrations of ammonia can be harmful to aquatic life and degrade the water quality. Wastewater containing ammonia is usually removed by conventional methods such as aeration in towers, biological treatment and adsorption of the ammonium ion to the zeolite surface. However, these methods are less effective and relatively expensive. Therefore there is a need for alternative technologies that can improve the efficiency of ammonia removal from wastewater. This study aims to obtain the process of ammonia removal through a combination of absorption in the membrane contactor and the advance oxidation process in the hybrid plasma-ozone reactor. Wastewater containing ammonia used in the study was a synthetic wastewater with a concentration of about 800 ppm. In the experiment, the wastewater fi＇om the reservoir was firstly passed into the membrane contactor on the shell side, and then mixed with ozone from the ozonator befbre entering the plasma reactor, and finally was circulated back to the reservoir. Meanwhile, the absorbent solution was sent to the lumen fiber in membrane contactor. Experimental results showed that the ammonia removal efficiency increases with increasing in circulation rate and temperature of the wastewater. The highest efficiency of ammonia removal obtained from the experimental results was 77%.

A comparable study of microbial community in aerobic granular sludge and activated sludge for wastewater treatment

Effect of ammonia at different concentrations on aerobic granular sludge and activated sludge was investigated in this study. Meanwhile, bacterial diversity variation and ammonia oxidizing bacterium （AOB） quantification within both kinds of sludge were monitored by terminal restriction fragment length polymorphism （T-RFLP） and real-time PCR （RT-PCR） technique, respectively. The results showed that the COD removal of both kinds of sludge changed slightly when the ammonia removal efficiency decreased gradually with the ammonia concentration increased from 100 mg L^-1 to 500 mg L^-1 Furthermore, activated sludge demonstrated higher ammonia removal ability than that of aerobic granular sludge （10%- 16%）. As revealed by T-RFLP, activated sludge was of higher ammonia removal ability and more abounding bacterial diversity than that of aerobic granular sludge, suggesting that the bacterial diversity was probably relevant to the ammonia removal. The RT-PCR results indicated that the AOB population size of activated sludge and aerobic granular sludge were 2.80× 10^4-3.44× 10^4cells （g dried sludge）^-1 and 7.83×10^4-1.18×10^5cells （g dried sludge）^-1, respectively. There is no obvious positive correlation between the ammonia removal ability and number of AOB in both kinds of sludge.