Transferral of HMs pollution from road-deposited sediments to stormwater runoff during transport processes

Ratio of turbidity and TSS (Tur/TSS) was used to characterize PSD of stormwater particles. Pb and Zn preferred to accumulate in finer RDS, while Cu, Cr and Ni in coarser RDS. HMs pollution in stormwater particles increased linearly with Tur/TSS. Dissolvability of HMs and PSD variations contribute to the differences between RDS and stormwater. Stormwater runoff, derived from the wash-off of road-deposited sediments (RDS), contains elevated heavy metal (HM) concentrations and, thus, imposes an increasing threat to urban aquatic ecosystems. In-depth understanding of the variations of HMs pollution from RDS to stormwater during transport processes facilitates the development of effective RDS and stormwater control strategies. Toward this end, the distribution of HMs (Cu, Pb, Zn, Cr, and Ni) in RDS and stormwater were investigated simultaneously. The results show a preferential accumulation of Pb and Zn in the finer (<38.5 μm) RDS, and Cu, Cr and Ni in the coarser (38.5–150 μm) RDS. For stormwater, n.d.~48.6% of HMs fractionated into the dissolved phase, and stormwater particles constitute the primary carriers of HMs. Furthermore, the accumulation of HMs in stormwater particles increased linearly with finer particle size distributions (PSD). Geoaccumulation index (I_geo) highlighted the predominant pollution of both RDS and stormwater particles by Cu, Pb and Zn. Nonetheless, Cu, Pb, and Ni mostly contributed the potential ecological risk of RDS, whereas Cu, Pb, and Zn mainly contributed that of stormwater particles. Moreover, contamination by Cu, Pb and Zn was significantly higher in stormwater particles than that in RDS. These differences are attributable to the solubility and size-dependent accumulation of HMs in RDS, as well as the PSD variations during transport processes. The study outcomes highlight the importance of very fine (nano- and submicron- scale) RDS in stormwater pollution and the necessity of control.     

The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing

The spreading of extended-spectrum β-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and bla_TEM+CTx-M was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes.     

自来水污泥堆肥化研究

研究了自来水污泥脱水防粘预处理技术、高温好氧堆肥技术及其应用于园林种植效果。机械组成测定和电镜扫描结果表明,调理剂QS可以显著改善自来水污泥的粘结性及脱水性能;堆肥实验结果表明,预处理的自来水污泥与枯枝落叶按体积比3∶7混匀,加入尿素调节碳氮比,27 d后,可达腐熟,EM菌可以加快堆肥物料腐熟,19 d后,即可达腐熟要求;桉树盆栽实验结果表明,自来水污泥经堆肥化处理后,保水性提高,促进桉树生长,而且堆肥过程中添加EM菌可以进一步促进桉树生长。     

催化臭氧氧化染料溶液的研究

采用催化臭氧化技术降解染料废水,以甲基紫溶液为目标污染物,研究了过渡型金属离子的类型,Fe2+的浓度,溶液初始pH值,染料浓度和正丁醇等因素对其降解率的影响。实验结果表明:臭氧氧化甲基紫溶液的过程中,加入一定浓度的过渡型金属离子对甲基紫的去除具有促进作用;当臭氧浓度为16 mg/L,一定浓度范围内,Fe2+催化臭氧化的效果随着浓度的增加而增加,但Fe2+浓度为13 mg/L时,甲基紫的降解率下降;在酸性范围时,pH值增大其降解率会减小;染料浓度增加,甲基紫的降解率减小,但是其绝对降解值会增加;正丁醇的加入抑制氧化反应的进行,甲基紫的降解率下降,说明催化臭氧化过程中有羟基自由基产生。染料降解过程符合一级反应动力学规律。     

含二甲胺工业废水的回收及再利用技术研究

为了消除工业二甲胺废水带来的巨大污染,使其达到回收利用的目的,利用精馏技术,采用BH型高效填料作为分离介质,连续从废水中脱除二甲胺,并将塔顶二甲胺提浓。结果表明,采用本技术可使塔顶二甲胺提浓至47%(质量百分含量),达到满足40%二甲胺水溶液质量要求的目的;塔釜二甲胺含量降低至≤50 mg/L,此水可作皮革工业生产回用水。由于含二甲胺废水经处理后可以全部回收利用,表明该高效精馏技术用于清洁生产中具有可靠性和实用性。     

A Routing and Scheduling System for Infectious Waste Collection

Most hospitals and clinics in Taiwan do not have on-site treatment facilities for their infectious waste and must rely on outside agencies for their collection and treatment. The problem of optimally routing and scheduling the collection of medical waste from a disperse group of facilities is recognized as a periodic vehicle routing problem. This study develops a computer system to solve the resulting optimization problem based on a two-phased approach proposed earlier. The first phase solves a standard vehicle routing problem to determine a set of individual routes for the collection vehicles. The second phase uses a mixed integer programming method to assign routes to particular days of the week. The computer system is user-friendly and consists of several Visual Basic programs while the geographical information system is incorporated to facilitate input and output interface and database management. An illustrative example for the infectious waste of 348 hospitals in the Tainan City area demonstrates the effectiveness of the system.     

论环境监测站在污染源监测中的作用

对环保局所属监测站在污染源监测管理中的作用、监测市场化运作及地位与作为等方面进行了探讨。     

Particulate composition characteristics under different ambient air quality conditions

Particulate compositions including elemental carbon (EC), organic carbon (OC), water-soluble ionic species, and elemental compositions were investigated during the period from 2004 to 2006 in southern Taiwan. The correlation between the pollutant standard index (PSI) of ambient air quality and the various particle compositions was also addressed in this study. PSI revealed a correlation with fine (r = 0.74) and coarse (r = 0.80) particulate matter (PM). PSI manifested a significant correlation with the amount of analyzed ionic species (r approximately 0.80) in coarse and fine particles and a moderate correlation with carbon content (r = 0.63) in fine particles; however, it showed no correlation with elemental content. Although the ambient air quality ranged from good to moderate, the ionic species including chloride (Cl-), nitrate (NO3-), sulfate (SO4(2-)), sodium (Na+), ammonium (NH4+), magnesium (Mg2+), and calcium (Ca2+) increased significantly (1.5-3.7 times for Daliao and 1.8-6.9 times for Tzouying) in coarse PM. For fine particles, NO3-, SO4(2-), NH4+, and potassium (K+) also increased significantly (1.3-2.4 times for Daliao and 2.8-9.6 times for Tzouying) when the air quality went from good to moderate. For meteorological parameters, temperature evidenced a slightly negative correlation with PM concentration and PSI value, which implied a high PM concentration in the low-temperature condition. This reflects the high frequency of PM episodes in winter and spring in southern Taiwan. In addition, the mixing height increase from 980 to 1450 m corresponds to the air quality condition changing from unhealthy to good.     

Real-time reverse transcription PCR analysis of trichloroethylene-regulated toluene dioxygenase expression in Pseudomonas putida F1

Toluene dioxygenase (tod) is a multicomponent enzyme system in Pseudomonas putida F1. Tod can mediate the degradation of Trichloroethylene (TCE), a widespread pollutant. In this study, we try to explore the TCE-regulated tod expression by using real-time qRT-PCR. The minimal culture media were supplemented with glucose, toluene, or a mixture of glucose/toluene respectively as carbon and energy sources. The TCE was injected into each medium after a 12-hour incubation period. The TCE injection severely affected bacterial growth when cultured with toluene or toluene/glucose mixtures. The cell density dropped 61 % for bacteria growing in toluene and 36 % for bacteria in the glucose/toluene mixture after TCE injection, but the TCE treatment had little effect on bacteria supplied with glucose alone. The decrease in cell number was caused by the cytotoxicity of the TCE metabolized by tod. The results from the real-time qRT-PCR revealed that TCE was capable of inducing tod expression in a toluene-dependent manner and that the tod expression level increased 50 times in toluene and 3 times in the toluene/glucose mixture after 6 hours of TCE treatment. Furthermore, validation of the rpoD gene as a reference gene for P. putida F1 was performed in this study, providing a valuable foundation for future studies to use real-time qRT-PCR in the analysis of the P. putida F1 strain.     

Levels and patterns of polycyclic aromatic hydrocarbons (PAHs) in soils after forest fires in South Korea

Introduction  

To investigate the influence of biomass burning on the levels of polycyclic aromatic hydrocarbons (PAHs) in soils, temporal trends and profiles of 16 US Environmental Protection Agency priority PAHs were studied in soil and ash samples collected 1, 5, and 9 months after forest fires in South Korea.