Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment

Ambio - Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an...     

Contamination by perfluorinated compounds in water near waste recycling and disposal sites in Vietnam

There are very few reports on the contamination by perfluorinated chemicals (PFCs) in the environment of developing countries, especially regarding their emission from waste recycling and disposal sites. This is the first study on the occurrence of a wide range of PFCs (17 compounds) in ambient water in Vietnam, including samples collected from a municipal dumping site (MD), an e-waste recycling site (ER), a battery recycling site (BR) and a rural control site. The highest PFC concentration was found in a leachate sample from MD (360 ng/L). The PFC concentrations in ER and BR (mean, 57 and 16 ng/L, respectively) were also significantly higher than those detected in the rural control site (mean, 9.4 ng/L), suggesting that municipal solid waste and waste electrical and electronic equipment are potential contamination sources of PFCs in Vietnam. In general, the most abundant PFCs were perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUDA; <1.4–100, <1.2–100, and <0.5–20 ng/L, respectively). Interestingly, there were specific PFC profiles: perfluoroheptanoic acid and perfluorohexanoic acid (88 and 77 ng/L, respectively) were almost as abundant as PFOA in MD leachate (100 ng/L), whereas PFNA was prevalent in ER and BR (mean, 17 and 6.2 ng/L, respectively) and PFUDA was the most abundant in municipal wastewater (mean, 5.6 ng/L), indicating differences in PFC contents in different waste materials.     

Effects of field-applied composted cattle manure and chemical fertilizer on ammonia and particulate ammonium exchanges at an upland field

The present study aimed to investigate the NH₃ volatilization loss from field-applied compost and chemical fertilizer and evaluate the atmosphere–land exchange of NH₃ and particulate NH₄⁺ (pNH₄) at an upland field with volcanic ash soil (Andosol) in Hokkaido, northern Japan. Two-step basal fertilization was conducted on the bare soil surface. First, a moderately fermented compost of cattle manure was applied by surface incorporation (mixing depth, 0–15 cm) at a rate of 117 kg N ha⁻¹ as total nitrogen (T-N) corresponding to 9.9 kg N ha⁻¹ as ammoniacal nitrogen (NH₄–N). Twelve days later, a chemical fertilizer containing 10% (w/w) of NH₄–N as a mixture of ammonium sulfate and ammonium phosphates was applied by row placement (cover depth, 3 cm) at a rate of 100 kg N ha⁻¹ as NH₄–N. The study period was divided into the first-half, beginning after the compost application (CCM period), and the second-half, beginning after the chemical fertilizer application (CF period). The mean air concentrations of NH₃ and pNH₄ (1.5 m height) were 7.6 and 3.0 μg N m⁻³, respectively, in the CCM period; the values were 3.7 and 3.9 μg N m⁻³, respectively, in the CF period. The composition ratios of NH₃ to the sum of NH₃ and pNH₄ (1.5 m height) were 72% and 49% in the CCM and CF periods, respectively. The NH₃ volatilization loss from the compost was 0.8% of the applied T-N (or 9.3% of the applied NH₄–N) and that from the chemical fertilizer was near zero. Excluding the period immediately after the compost application, the upland field acted as a net sink for NH₃ and pNH₄.     

Temporal Trends of Non-sea Salt Sulfate and Nitrate in Wet Deposition in Japan

Temporal trends of non-sea salt (nss-) sulfate and nitrate were analyzed from nationwide precipitation chemistry measurements provided by the Ministry of the Environment (MOE) for the 1988–2002 fiscal years (April–March). The concentrations and deposition of nss-sulfate were found to be decreasing, and those of nitrate were stable or slightly increasing at most sites. These deposition trends were discussed from the viewpoint of emissions of SO₂ and NO_X during the period of interest. Because monitoring techniques have changed in the number of active sites, samplers, and analytical methods during the operation period, the median of all annual depositions measured in Japan in a specific year was selected as the annual representative. The contribution of specific emission sources was also calculated for 1990 on the basis of the nss-sulfate and nitrate deposition in Japan obtained with a model simulation in which the model did not include volcanic emissions from Mt. Oyama, Miyakejima Island, which began to erupt suddenly and violently in 2000. For nss-sulfate, the calculated deposition agrees well with the intensity and trends of the median up to 1999. After 2000, a higher deposition than calculated in the preceding years was evident, which is attributable to the volcanic SO₂ from Mt. Oyama. For nitrate, both the calculated and observed depositions were slightly increasing; however, the calculation was found to exceed the observation.     

Levels of Hg and other chemical elements in volcanic ash fall samples erupted from Mt. Sakurajima,Japan

Mt. Sakurajima is a volcanic island in Japan, and a big city, Kagoshima, is quite close to the active volcano. Samples of volcanic ash fall erupted from Mt. Sakurajima were collected at several locations in Kagoshima City and analyzed for Hg and other elements, including major (Mg, Al, Ca, and Fe) and trace elements (V, Cr, Mn, Co, Ni, Zn, As, and Pb). The concentrations of Hg varied from 6.3 to 124 ng g^?1, with the amounts of ash varying from 13 to 1230 g m^?2 month^?1. The Hg concentrations tended to be higher when the monthly amounts of ash fall were lower; other elements did not show such a tendency.     

Sterol components of coral-reef molluscs

The sterol composition of 23 species of coral-reef molluscs from Tahiti was investigated in relation to habitat and taxonomy. The elucidation of sterol components was performed by both argentation column and gas-liquid chromatographic techniques. Coral-reef molluscs, especially gastropods, seem to be characterised by sterols rich in 24-methylcholesterol.     

A novel mechanical plant compression system for biomass fuel and acquisition of squeezed liquid with water-soluble lignin as anti-virus materials

Journal of Material Cycles and Waste Management - Plant biomass could be a viable alternative renewable resource, but the moisture content must be reduced to use it as fuel. Mechanical compression...