Freshwater alga Raphidocelis subcapitata undergoes metabolomic changes in response to electrostatic adhesion by micrometer-sized nylon 6 particles

Environmental Science and Pollution Research - Nylon powders are a type of microplastic (MP) used in personal care products such as cosmetics and sunscreens. To determine the effects of nylon...     

Vulnerability assessment of sea-level rise in Viti Levu, Fiji Islands

Fiji is expected to come under increasing pressure and risk from various threats resulting from climate change and sea-level rise (SLR). Fiji consists of 332 islands and thus has a predominant and large coastline. Viti Levu is the largest and most important of the islands, harboring Fiji’s capital city and most of the major towns concentrated around its coast. The objectives of this study were to evaluate the extent of possible sea-level rise using GIS, and to identify high-risk locations. Potential sea level rise was shown graphically as an output to determine where inundation or flooding would take place. This analysis allowed important areas facing risk to be highlighted for future action. Flooding/inundation can be classified into two kinds: ‘permanent inundation’, which is the result of sea-level rise with tide; and ‘temporary flooding’, also including occasional storm surge events. The inundated area was displayed under different projections and quantified. The results produced output maps showing the distribution of inundation/flooding around the island of Viti Levu as well as the extent of flooding. Six scenarios for sea-level rise were used (0.09, 0.18, 0.48, 0.50, 0.59, 0.88 m). Six scenarios for storm surge were used with return intervals of 1, 2, 5, 10, 25, 50 years. High risk and priority locations are identified as Fiji’s capital Suva, the major tourist center and arrival port of Nadi, and Fiji’s second city Lautoka. Future action, adaptation and response strategies in these identified locations must occur to reduce risk from climate change.     

低浓度臭氧在含钴盐硅胶上的吸附研究

常压下对含钴盐硅胶进行低浓度臭氧的吸附实验，吸附达到饱和后用氮气作为载气加热解吸。结果显示，含钴盐的硅胶对臭氧具有较强的吸附能力；臭氧解吸量随着解吸温度的上升而增加；吸附了臭氧的含钴硅胶粒子在常温(313．15K)下可在60min内不问断解吸出臭氧。     

Wastewater treatment with multilayer media of waste and natural indigenous materials

Wastewater treatment using waste materials (refuse concrete, waste paper and charcoal) and natural indigenous rocks (andesite, limestone, granite and nitrolite) in the form of multilayer media was investigated. The removal of suspended solids (SS), phosphate ion, nitrate ion, ammonium ion, toxic metals and chemical oxygen demand (COD) were evaluated for the multilayer wastewater treatment system. Effective removal of heavy metals such as cadmium, chromium, mercury and lead was demonstrated. SS and phosphate ion were removed with relatively high efficiency and the COD after treatment was lessened using certain combinations of media. The present wastewater treatment system is simple, convenient and low cost. Therefore, this method can be applied in small scale plants for wastewater treatment in local and nonexclusive areas.     

Do corals select zooxanthellae by alternative discharge?

Loss of zooxanthellae (dinoflagellate Symbiodinium) from corals will sometimes lead to mass mortality of corals. To detect and quantify Symbiodinium released from corals, we developed a zooxanthellae “trap” and a quantitative PCR (qPCR) system with Symbiodinium clades A–F-specific primer sets. The trap was attached to a branch or the surface of several wild stony corals, and the water samples within the traps, including released Symbiodinium, were subjected to qPCR. All tested corals released clade C Symbiodinium at estimates of ~5,900 cells h⁻¹ cm⁻² of coral surface. Although all tested Pocillopora eydouxi harboured both clades C and D, some of these colonies released only clade C or released a lesser amount of clade D than that in the tissues. Our Symbiodinium quantification system revealed that wild hermatypic corals constantly release Symbiodinium to the environment. Our result suggests that some corals may discharge certain clades of Symbiodinium alternatively.     

Improvement of an efficient separation method for chemicals in diesel exhaust particles: analysis for nitrophenols

GOAL, SCOPE, AND BACKGROUND: Diesel exhaust is believed to consist of thousands of organic constituents and is a major cause of urban pollution. We recently reported that a systematic separation procedure involving successive solvent extractions, followed by repeated column chromatography, resulted in the isolation of vasodilatory active nitrophenols. These findings indicated that the estimation of the amount of nitrophenols in the environment is important to evaluate their effect on human health. The isolation procedure, however, involved successive solvent extractions followed by tedious, repeated chromatography, resulting in poor fractionation and in a significant loss of accuracy and reliability. Therefore, it was crucial to develop an alternative, efficient, and reliable analytical method. Here, we describe a facile and efficient acid-base extraction procedure for the analysis of nitrophenols. MATERIALS AND METHODS: Diesel exhaust particles (DEP) were collected from the exhaust of a 4JB1-type engine (ISUZU Automobile Co., Tokyo, Japan). Gas chromatography-mass spectrometry (GC-MS) analysis was performed with a GCMS-QP2010 instrument (Shimadzu, Kyoto, Japan). RESULTS: A solution of DEP in 1-butanol was extracted with aqueous NaOH to afford a nitrophenol-rich oily extract. The resulting oil was methylated with trimethylsilyldiazomethane and subsequently subjected to GC-MS analysis, revealing that 4-nitrophenol, 3-methyl-4-nitrophenol, 2-methyl-4-nitrophenol, and 4-nitro-3-phenylphenol were present in significantly higher concentrations than those reported previously. DISCUSSION: Simple acid-base extraction followed by the direct analysis of the resulting extract by GC-MS gave only broad peaks of nitrophenols with a poor detection limit, while the GC-MS analysis of the sample pretreated with (trimethylsilyl)diazomethane gave satisfactorily clear chromatograms with sharp peaks and with a significantly lowered detection limit (0.5 ng/ml, approximately 100 times). CONCLUSION: The present method involving an acid-base extraction, in situ derivatization, and GC-MS analysis has shown to be a simple, efficient, and reliable method for the isolation and identification of the chemical substances in DEP.     

Human intake of PCDDs, PCDFs, and dioxin like PCBs in Japan, 2001 and 2002

PCDDs, PCDFs, and dioxin like PCBs (dioxin) surveillance results derived from regular environmental monitoring as well as other dioxin surveys by national and local governmental bodies in Japan were collected and analyzed. Several thousand data for air and soil in fiscal year 2001 (from 01/04/2001 to 31/03/2002) and 2002, water (from the sea, rivers and lakes), sediment (from the sea, rivers and lakes), ground water, aquatic organisms, purified water from water purification plants, raw water from water purification plants, human breast milk, and human blood in fiscal 2001, and total diet study (TDS) and various kinds of foodstuff in fiscal 1998-2002 were collected. Average human uptake of dioxin in Japan in fiscal 2001 was estimated at 1.68 pg-TEQ/kg-bw/day, while uptake in fiscal 2002 was estimated at 1.52 pg-TEQ/kg-bw/day. Diet accounted for more than 90% of the total intake. Contributions of inhalation and soil ingestion were relatively small. Age-group-specific contribution of various foodstuff to total dietary intake was also estimated. The estimates of intake through fish and shellfish accounted for approximately 45-70% of total dietary intake in each age group. Monte Carlo simulation was conducted, using the data of the air and soil concentrations in fiscal 2001 and the total diet study data in fiscal 1998-2001, in order to obtain information on the variability of dioxin intake; The estimated average, median, 5th percentile and 95th percentile of the intake distribution were 1.78, 1.69, 0.95 and 2.91 pg-TEQ/kg-bw/day, respectively. This study found that the average total intake estimates in Japan in both fiscal 2001 and 2002 were estimated to be below tolerable daily intake level (TDI) defined by the Ministry of Health, Labour and Welfare, Japan (i.e. 4 pg-TEQ/kg-bw/day). The 95th percentile of the dioxin intake distributions estimated with Monte Carlo simulation using the data of the air and soil concentrations in fiscal 2001 and TDS data in fiscal 1998-2001 was also below the Japanese TDI.     

偏振激光雷达在沙尘暴观测中的数据解析

阐述了日本国立环境研究所(NIES)研制的双波长偏振激光雷达的工作原理和主要工作参数,探讨了激光雷达方程在沙尘暴监测中的应用条件,并对激光雷达获取的各种信息进行直观图视化处理.分别用光学强度、后向散射强度、退偏振率、消光系数以及双波长信号比等对沙尘天气的污染特征进行了解析,并对垂直方向沙尘浓度的分布进行了计算.研究表明:退偏振率大于10%时,即可判断为沙尘天气;双波长信号比(P(1 064)/P(532))大于0.4,则表示该期间为沙尘天气;利用消光系数表示气溶胶浓度时,NIES激光雷达观测沙尘气溶胶消光系数超过0.3 km-1(ρ(TSP)约为500　μg/m3),且持续时间超过3　h的沙尘天气现象即可判断为一次沙尘事件.根据激光雷达特有物理量对沙尘气溶胶的不同判定标准,对沙尘事件的强度、持续时间、沙尘云厚度以及沙尘天气的污染特征进行了解析和探讨.