Experimental Study on Purification Efficiency of Air Purifier for the Indoor Total Volatile Organic Compounds

By using total volatile organic compounds （TVOC） as the objective volatile pollutant, the purification efficiency of some representative air purifiers bought in the market was determined under the relatively independent and stable environmental conditions supplied by the self-made multi- functional environmental test chamber. Various evaluation parameters of TVOC were calculated based on the tested results, such as purification ef- ficiency and removal rate. The results showed that the TVOC purification efficiency increased with enhancing the temperature or lessening the rela- tive humidity, but this effect is not obvious. The air purifiers which use photocatalytic technology have higher TVOC purification efficiency than those which only use some adsorption technology. The purification efficiency and removal rate can be more accurate to evaluate the purification efficiency of air purifiers.

Chemical characterization of volatile organic compounds (VOCs) emitted from multiple cooking cuisines and purification efficiency assessments

Cooking process can produce abundant volatile organic compounds(VOCs),which are harmful to environment and human health.Therefore,we conducted a comprehensive analysis in which VOCs emissions from multiple cuisines have been sampled based on the simulation and acquisition platform,involving concentration characteristics,ozone formation potential(OFP)and purification efficiency assessments.VOCs emissions varied from 1828.5 to 14,355.1μg/m^(3),with the maximumand minimumvalues fromBarbecue and Family cuisine,respectively.Alkanes and alcohol had higher contributions to VOCs from Sichuan and Hunan cuisine(64.1%),Family cuisine(66.3%),Shandong cuisine(69.1%)and Cantonese cuisine(69.8%),with the dominant VOCs species of ethanol,isobutane and n-butane.In comparison,alcohols(79.5%)were abundant for Huaiyang cuisine,while alkanes(19.7%),alkenes(35.9%)and haloalkanes(22.9%)accounted for higher proportions from Barbecue.Specially,carbon tetrachloride,n-hexylene and 1-butene were the most abundant VOCs species for Barbecue,ranging from 8.8%to 14.6%.The highest OFP occurred in Barbecue.The sensitive species of OFP for Huaiyang cuisine were alcohols,while other cuisines were alkenes.Purification efficiency assessments shed light on the removal differences of individual and synergistic control technologies.VOCs emissions exhibited a strong dependence on the photocatalytic oxidation,with the removal efficiencies of 29.0%–54.4%.However,the high voltage electrostatic,wet purification and mechanical separation techniques played a mediocre or even counterproductive role in the VOCs reduction,meanwhile collaborative control technologies could not significantly improve the removal efficiency.Our results identifiedmore effective control technologies,which were conductive to alleviating air pollution from cooking emissions.

Comparison on Purification Effect of Two Macroalgae Species on Prawn Tailwater

[Objectives]This study was conducted to investigate the purification effects of two common large seaweeds on the tail water of prawn farming in greenhouses,and to determine the best culture density of seaweeds.[Methods]Two large seaweed species,Gracilaria lichevoides and Ulva lactuca,were selected to set four culture densities of 0.5,2,4 g/L and a blank control group,respectively.The seaweeds were cultured in 100 L white polyethylene buckets,each of which contained 50 L of tail water from prawn culture.[Results]After 5 d,the nutrient removal rates of the two seaweeds were directly proportional to the density.There was no significant difference in NH_(4)-N removal rate between G.lichevoides and U.lactuca(P>0.05)by two-way analysis of variance,and the NH_(4)-N removal rate of the latter was higher.The removal rates of NO_(3)-N,TN and TP by G.lichevoides were significantly higher than those by U.lactuca(P<0.05).The specific growth rates of seaweeds were negatively correlated with their culture densities.The specific growth rates of G.lichevoides were 5.73%,1.654%and 0.48%,respectively,and those of U.lactuca were 2.01%,1.187%and 0.138%,respectively,when the culture densities were 0.5,2.0 and 4.0 g/L.Two-factor analysis of variance showed that the former was significantly higher than the latter,when the culture density of the two species of seaweeds was 0.5 g/L(P<0.05).The two-way analysis of variance showed that when the culture density of the two kinds of seaweeds was 0.5 g/L,the specific growth rate of G.lichevoides was significantly higher than that of U.lactuca(P<0.05).Based on the above research,the two macroalgae could reduce the nutrients in the wastewater to a large extent,but the culture density determined the scale and economic benefits of seaweed cultivation and further affected the normal growth,metabolism and quality of the seaweeds.[Conclusions]This study provides some theoretical basis for large-scale seaweed farming and biological selection of in-situ ecological restoration of eutrophic seawater.

Efficient Expression and Purification of Fc-fragment-binding Domain and Its Application to Immunoglobulin G Purification

The number of therapeutic monoclonal antibodies used in clinical trials has recently increased dramatically, leading to the development of optimized downstream purification processes[1]. Staphylococcal protein A （SPA）, a cell-wall protein of Staphylococcus aureus, has been developed as a universal ligand for immunoglobulin G （IgG） purification because it binds specifically to the Fc portion of the IgG molecule of many mammals[2]. However, certain characteristics of SPA severely restrict the advancement of the antibody industry.

Effects of live rock on removal of dissolved inorganic nitrogen in coral aquaria

Maintaining stable water quality is one of the key processes for recirculating coral aquaculture. Traditional aquarium systems which mainly utilized a nitrification of nitrifying bacteria attached to the surface of massive artificial filter material are difficult to maintain the oligotrophic conditions necessary for coral aquaculture. This study investigated the removal effects of dissolved inorganic nitrogen（ammonia and nitrate） by live rock（LR）, a key component in the ＂Berlin system＂ coral aquarium. The expression levels of bacterial functional genes, AOA3,amo A and nos Z, were measured on the exterior and interior of LR. The nitrifying and denitrifying bacterial abundance on LR was quantified and the nitrogen nutrient regulatory effects of LR were evaluated. The results demonstrated that LR mainly removed ammonium（NH_4~＋） from the water with a mean efficiency of 0.141 mg/（kg·h）, while the removal of nitrate（NO_3~–） was not significant. Bacterial diversity analysis showed that ammonia-oxidizing bacteria（AOB） were the most common bacteria on LR, which accounted for 0.5%–1.4% of the total bacterial population, followed by denitrifying bacteria, which accounted for 0.2% of the total population, and the ammonia-oxidizing archaea（AOA） were the least common type（〈0.01%）. The low abundance of denitrifying bacteria may be responsible for the poor nitrate（NO_3~–） removal of LR. Thus, other biological filtration methods are needed in coral aquaria to control nitrates generated from nitrification or biological metabolism.

Efficient purification of 1,3-butadiene

Subject Code:B01With the support by the National Natural Science Foundation of China,the research team led by Prof.Zhang Jiepeng(张杰鹏)at the MOE Key Laboratory of Bioinorganic and Synthetic Chemistry,School of Chemistry,Sun Yat-Sen University,recently reported a new adsorptive separation mechanism for

Environmental and energy requirements for different production biomass of Nile tilapia(Oreochromis niloticus)in recirculating aquaculture systems(RAS)in Kenya

Recirculating Aquaculture Systems(RAS)offers a better option to increase aquaculture production with limited land and water resources while minimizing water pollution.The biggest challenges in RAS is to maintain favorable water quality for the fish to thrive.The practice of RAS in Kenya is minimal with the improper matching of RAS components and production densities for the existing few and in most cases,leading to a system failure.This study aimed at evaluating environmental and energy requirements for different production biomass of Nile tilapia in a RAS established in a controlled environment.Both production densities and water flow rates were varied while at the same time,the water quality parameters(dissolved oxygen,ammonia,pH,electrical conductivity and temperature)were monitored.The energy consumed for pumping and aeration was also monitored.Tilapia stocking biomass varied from 2.3 kg/m^(3) to 10 kg/m^(3) while flow rate was varied from 2.0 L/min and increased at intervals of 1.0 L/min to the maximum attainable flow rate of 10.0 L/min.Crushed pumice rock packed in a 1000 L tank and equipped with a bell siphon was used as the biofilter.Ammonia removal reduced with increasing flow rate with removal rates of 75%at 2.0-3.0 L/min to 9%at 8.0-10.0 L/min.The water pH increased with increasing flow rate with R^(2) ranging from 0.4 to 0.9.Electrical conductivity increased with flow rate from 112 mg/L to as high as 209 mg/L.Dissolved oxygen increased with flow rate and ranged from 1.0 mg/L to 7.0 mg/L.Energy consumption increased with flow rate and raged from 0.4 kW h at 2.3 kg/m^(3) stocking biomass to 2.4 kW h at 10 kg/m^(3)stocking biomass.High stocking densities and flow rates resulted to lower purification efficiencies and higher power consumptions than low stocking densities and flow rates.In order to maintain good RAS water quality,increased production and profits among farmers using RAS in Kenya,there is need to give proper advice on the right combination of stocking biomass,power,and water flow rate.In addition,similar studies should be carried out for other common fish species such as the African catfish.