污水灌溉的研究进展

科学合理地利用污水灌溉,可以缓解日益紧张的水资源供需矛盾,充分利用污水的水肥资源,提高经济效益,保护生态环境.总结了国内外污水灌溉的发展概况和研究进展,包括污水灌溉对土壤理化特性的影响、对植物生长的影响以及对地下水的影响,并针对中国污水灌溉存在的问题,探讨了污水灌溉技术的发展方向.     

Performance and role of N-acyl-homoserine lactone (AHL)-based quorum sensing (QS) in aerobic granules

The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1（1.0065 g/mL）. The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.     

Effects of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the swimming behavior,population growth and reproduction of the rotifer Brachionus plicatilis

Polybrominated diphenyl ethers (PBDEs) are new kinds of persistent organic pollutants (POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE (BDE-47) and deca-BDE (BDE-209) were applied, and their toxic effects on the swimming behavior, population growth and reproduction of Brachionus plicatilis were investigated. The results showed that: (1) The actual concentrations of BDE-47 and -209 in the seawater phase measured by GC–MS (Gas Chromatography−Mass Spectrometer) were much lower than their nominal concentrations. (2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209. (3) Both BDE-47 and -209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females (OF/NOF), the ratio of mictic females/amictic females (MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and -209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.     

Macroscale and microscale analysis of Anammox in anaerobic rotating biological contactor

Inoculated with conventional anaerobic activated sludge, the Anammox process was successfully developed in an anaerobic rotating biological contactor (AnRBC) fed with a low ratio of C/N synthetic wastewater. Operated in a single point feed mode, the AnRBC removed 92.1% (n = 126) of the influent N at the highest surface load of 12 g/(m².day). The biomass increased by 25% and 17.1 g/(m².day) of maximum N removal surface load was achieved by elevating flow rate with another feed point. Fluorescence in situ hybridization and polymerase chain reaction analysis indicated that the Anammox genus Candidatus Kuenenia stuttgartiensis dominated the community. Both Anammox and denitrifying activity were detected in biofilm by the application of microelectrodes. In the outer layer of the biofilm (0-2500 μupm), nitrite and ammonium consumed simultaneously in a ratio of 1.12/1, revealing the occurrence of Anammox. In the inner layer (> 2500 μupm), a decrease of nitrate was caused by denitrification in the absence of nitrite and ammonium.     

南京外秦淮河河岸带原生植被初步调查

对南京外秦淮河河岸带原生植被进行了初步调查.外秦淮河河岸带原生植被共有28科、50属、53种,其中漂浮植物4种,占7.55%,沉水植物1种,占1.89%,挺水和湿生植物13种,占24.53%,陆生草本和藤本植物24种,占45.28%,乔木和灌木11种,占20.75%.在概括外秦淮河自然环境和分析原生植被主要特征的基础上,提出在进行河岸带植被群落重建时应注重闸下段河岸带植被群落的重建,增加沉水植物、浮叶植物和观赏性植物的种植.另外,植被群落可按河道垂向的常水位以下区域、变化水位区域和洪水位以上区域来构建.     

T3WS便携式水质快速检测仪在环境监测中的应用研究

便携式水质快速检测仪具有测量速度快、体积小、重量轻、便于携带等特点,特别适用于水质现场快速测定.在T3WS快速检测仪30余个项目中选择六价铬、甲醛、砷、氨氮、硫化物等五项常用指标,进行试管一致性、校准曲线斜率、截距、相关系数、检出限、测定范围、精密度、准确度以及与实验室分析方法比对等试验.结果表明,T3WS快速检测仪测试标准样品测试结果均在允许误差范围内,标准样品及地袁水、废水样品测试结果的相对偏差均小于10％,与实验室分析结果之间最大相对误差分别为-6.1％、15.9％、15％、-7.2％、-21.0％,T3WS便携式水质快速检测仪用于水质现场快速测定结果的精密度与准确度是可以接受的.     

Emissions of parent, nitrated, and oxygenated polycyclic aromatic hydrocarbons from indoor corn straw burning in normal and controlled combustion conditions

Emission factors （EFs） of parent polycyclic aromatic hydrocarbons （pPAHs）, nitrated PAHs （nPAHs）, and oxygenated PAHs （oPAHs） were measured for indoor corn straw burned in a brick cooking stove under different burning conditions. The EFs of total 28 pPAHs, 6 nPAHs and 4 oPAHs were （7.9 ±3.4）, （6.5 ±1.6）×10^-3, and （6.1 ±1.4）×10^-1mg/kg, respectively. Fuel charge size had insignificant influence on the pollutant emissions. Measured EFs increased significantly in a fast burning due to the oxygen deficient atmosphere formed in the stove chamber. In both restricted and enhanced air supply conditions, the EFs of pPAHs, nPAHs and oPAHs were significantly higher than those measured in normal burning conditions. Though EFs varied among different burning conditions, the composition profiles and calculated isomer ratios were similar, without significant differences. The results from the stepwise regression model showed that fuel burning rate, air supply amount, and modified combustion efficiency were the three most significant influencing factors, explaining 72%-85% of the total variations.     

Impact of ambient temperature on life loss per death from cardiovascular diseases: a multicenter study in central China

Environmental Science and Pollution Research - In the context of global climate change, studies have focused on the ambient temperature and mortality of cardiovascular diseases (CVDs). However,...     

Precipitation projection over Daqing River Basin (North China) considering the evolution of dependence structures

Environmental Science and Pollution Research - Understanding dynamic future changes in precipitation can provide prior information for nonpoint source pollution simulations under global warming....     

Current research scenario for biological effect of exogenous factors on microcystin synthesis

Environmental Science and Pollution Research - In natural water bodies, numerous cyanobacteria have the potential to intracellularly synthesize cyanotoxins, among which microcystin (MC) is the...