Manganese (Mn) in drinking water can cause aesthetic and operational problems. Mn removal is necessary and often has major implications for treatment train design. This review provides an introduction to Mn occurrence and summarizes historic and recent research on removal mechanisms practiced in drinking water treatment. Manganese is removed by physical, chemical, and biological processes or by a combination of these methods. Although physical and chemical removal processes have been studied for decades, knowledge gaps still exist. The discovery of undesirable by-products when certain oxidants are used in treatment has impacted physical–chemical Mn removal methods. Understanding of the microorganisms present in systems that practice biological Mn removal has increased in the last decade as molecular methods have become more sophisticated, resulting in increasing use of biofiltration for Mn removal. The choice of Mn removal method is very much impacted by overall water chemistry and co-contaminants and must be integrated into the overall water treatment facility design and operation.

Size distributions of particulate matter and twelve constituent elements were measured at a high traffic site in New Delhi, India during winter 2013. While PM was found to be trimodal, individual elements showed varying size distribution patterns. Three key types of size distributions were observed including unimodal with peaks either in the coarse (Al, Si) or fine (Pb) modes, bimodal with peaks in the fine range (S) and multimodal with peaks in accumulation and coarse (Cu, Sb) modes. Elements such as Al, Si and Fe were found to be in predominantly in the coarse range while Cu, Zn, Pb and Sb were found to be in the fine size range. Two modes dominate the size distribution. One is coarse (ca. 3 μm) and contains mainly crustal elements and hence arises from sources such as soil, road dust, construction dust and possible coal fly ash. The other, more intense mode is fine (ca. 0.6 μm) and appears to comprise sulphate and anthropogenic trace metals which have entered the droplet mode through hygroscopic particle growth in the very high humidity conditions of the Delhi winter. A third, less intensive mode ca. at 0.2 μm probably arises from relatively fresh anthropogenic emissions which have not grown into the droplet mode.

Extended use of GC–FID and GC–MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC–FID and GC–MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.

A new accurate, sensitive, rapid and convenient measurement for the determination of nitrogen oxides in the air was established. After being oxidized by chromium trioxide (CrO3), nitrogen oxides in the air existed in the form of NO2, then forming nitrite and nitrate after being absorbed by the alkaline aqueous solution. Under acidic condition, the diazo reaction is specific to the nitrite and primary aromatic amine. In this paper, the structure of diazo and coupling compounds were selected and tested through the experiments. The relationship between the azo compound's molecular structure and the sensitivity of the method as well as the electronic flow direction in the conjugated system of azo compounds were studied. A theory that conjugated system's electron cloud in azo compound's molecule flowed from coupling compounds to diazo compounds through nitrogen and nitrogen double bond was proposed. This theory had a guiding function for exploiting highly sensitive chromogenic agents. Furthermore, the conditions and methods of diazo reaction and coupling chromogenic reaction were investigated. A spectrophotometry that p-aminobenzenesulfonic acid as diazo compound and 2-amino-5-naphthol-7-sulfonic acid (J acid) as coupling compound for the determination of nitrogen oxides in the air was established. The maximum absorption wavelength of p-aminobenzenesulfonic acid-J acid azo compound was at 480 nm. And the molar absorptivity was 4.01 × 104 L mol−1 cm−1 with recovery of 98.5%–100.9% and R.S.D. of 1.82%. In addition, the determination limit of measurement was 0.017 mg m−3 nitrogen oxides and the determination range was 0.027–2.0 mg m−3 nitrogen oxides. This method can be easily applied to the determination of the nitrogen oxides in the air.

A circadian rhythm of the dinoflagellate Peridinium quadridentatum was studied at a time-series station in the southwestern Gulf of Mexico, in May 2007. Different substrates (water column, the seagrass Thalassia testudinum, macroalgae, coral rubble and sandy sediment surface) were sampled at the site at 1.5–3.5m depth. In the samples of coral rubble, P. quadridentatum was scarce. In the water column, the species showed an abundance peak at 15:00. The cell abundance of P. quadridentatum in Thalassia samples increased from 15:00 until 18:00 (1.81×104cells/gsubstratewet weight), and then continuously decreased until 06:00. Changes in P. quadridentatum cell abundance on macroalgae followed the same trend as on Thalassia, with the maximal value at 18:00. The higher abundance of P. quadridentatum (up to 1.40×104cells/gSWW) in macroalgae samples showed the preference for seaweeds. P. quadridentatum has a neritic tropical–boreal distribution. A new combination is proposed: Peridinium quadridentatum var. trispiniferum.

There are problems associated with dismantling vessels that have reached the end of their life, when pollution problems associated with the process need to be addressed. The first problem in “end-of-life vessels” (EOLV) is to define their legal frameworks. The second problem is their dismantlement for recycling of ships. In order to reduce the effects of pollution caused by EOLV dismantling, the International Maritime Organization (IMO) adopted the Hong Kong Convention on 15 May 2009. While preparing for implementing the obligations under the Hong Kong Convention, China shall make effort on five aspects: (i) establish an ISRT for the safe and environmentally sound recycling of ships, (ii) improve the competitiveness of ship dismantling plants, (iii) strengthen international exchanges, (iv) amend the domestic laws and regulations, and (v) support from the China Classification Society.

Beijing and Kanpur are two cities identified as high aerosol optical thickness (AOT) and complex composition of aerosols in Asian monsoon regions. Detail knowledge of key aerosol types in these two countries would be helpful for clarifying the mechanisms of aerosol radiative forcing and improving the accuracy of satellite remote sensing in these two countries. This study examines the characteristics of aerosol types over Beijing and Kanpur derived from a 12-year dataset from Aerosol Robotic Network (AERONET) stations and compares them via cluster analysis of optical and microphysical properties. Aerosols in Beijing are more complex than in Kanpur. Four fine-size dominated aerosol types (including two types of moderately absorbing aerosols, one highly absorbing aerosol type and one non-absorbing aerosol type) and one coarse-size dominated aerosol type are identified over Beijing. In Kanpur, two fine-sized dominated aerosol types (one high absorbing aerosol type and one non-absorbing aerosol type) and one coarse-sized dominated aerosol type are obtained. Compared to Beijing, the average SSAs of non-absorbing and high-absorbing aerosols are lower for the four wavelengths (440 nm, 676 nm, 869 nm, 1020 nm) in Kanpur. High absorbing aerosols usually occur in the months December to February (DJF) for both sites. The proportion in Kanpur (14%) is about twice that in Beijing (7%). Non-absorbing aerosols are usually observed in the months June to August (JJA) for both sites. Their proportion in Kanpur (31%) is ∼3 times larger than that in Beijing (11%). Coarse aerosols are frequently observed in the months March to May (MAM) for both sites. Their proportion in Kanpur (54%) is two times larger than in Beijing (21%).

Air pollution is a basic problem nowadays and it requires special concern. In India, the air pollution is a growing problem because of the enhanced anthropogenic activities such as burning fossil fuels involving industrial processes and motor vehicles. We study airborne dust particles collected at the height of 7 m in roadside and land area from thirty-eight cities in the state of Tamil Nadu. The collection involves a total of 111 samples concerning vehicular, industrial and residential areas, and allows us to assess the spatial distribution of magnetic particles produced and emitted on a short period of time (about one month). Magnetic properties of these air suspended particles were determined by techniques of environmental magnetism, revealing the presence of magnetite and hematite. We found the overall average of mass-specific magnetic susceptibility χ of 589.0 × 10−8 m3 kg−1 and saturation of remanent magnetization SIRM of 68.1 × 10−3 A m2 kg−1; as well as χ and SIRM values higher than 900.0 × 10−8 m3 kg−1 and 700.0 × 10−3 A m2 kg−1, respectively, corresponding to the most impacted zones in industrial/vehicular areas and in cities located in the central/eastern region respectively (e.g.: Hosur, Krishnagiri, Salem, Dharapuram, Ranipet, Ayanavaram, Cuddalore and Chidambaram). We analyzed the relationship between magnetic parameters, between areas and possible grouping of cities using multivariate statistical analysis. The SEM-EDS observations and grain size estimations reveal the presence of trace elements (Sb, Zn, Co, Ni, As and V) and fine particles (1–5 μm) that can be inhaled and therefore are dangerous to human health.

To investigate the long-term weathering of oil from the Deepwater Horizon (DWH) incident, oil-soaked sand patties were collected from Gulf of Mexico beaches from Florida to Alabama over a three-year period from 2012 to 2014. Analysis of oil residues by gas chromatography with flame ionization detection (GC-FID), thin-layer chromatography with flame ionization detection (TLC-FID), and Fourier transform infrared spectroscopy (FT-IR) indicated uniformity in their chemical composition. Some variability within and between samples was observed, arising from differences in exposure to light and water, which increase the amount of weathering. Oxygenated hydrocarbons (OxHC) produced by weathering processes dominate the majority of oil residues. These OxHC have continued recalcitrance in the environment, and increase in relative abundance over time. Analyses of the bulk characteristics of oil residues via TLC-FID and FT-IR should be continued as these techniques provide important insight into the weathering state of oil residues.

Superstorm Sandy generated huge quantities of debris in the Long Island, NY coastal zone. However, little appears to have been washed offshore to eventually be returned to Long Island's beaches as marine debris wash-ups. Information for our analysis includes debris collection statistics, very high resolution satellite images, along with wind and sea level data. Rigorous debris collection efforts along with meteorological conditions following the storm appear to have reduced the likelihood of debris wash-ups.