The Gulf of Aqaba is of significant strategic and economic value to all gulf-bordering states, particularly to Jordan, where it provides Jordan with its only marine outlet. The Gulf is subject to a variety of impacts posing imminent ecological risk to its unique marine ecosystem. We attempted to investigate the status of metal pollution in the coastal sediments of the Jordanian Gulf of Aqaba. The distribution of Cd, Cr, Zn, Cu, Pb, Al, Fe, and Mn concentrations were determined in trapped and bottom-surface sediments at three selected sites at different depths. In addition, monthly sedimentation rates at varying water depths were also estimated at each sampling site using sediment traps. The high concentrations of Cd, Cr, Zn were recorded at the Phosphate Loading Birth (PLB) site followed by the Industrial Complex (IC) site indicating their dominant anthropogenic source (i.e., the contribution of industrial activities). However, Fe, Al, and Mn contents were related to inputs from the terrigenous (crustal) origin. Except for Al, Fe and Mn at the PLB site, the concentrations of metals exhibited a decreasing trend with increasing water depth (distance from the shoreline). The PLB site also showed the highest sedimentation rate which decreased with increasing water depth. The Enrichment factors (EFs) showed that Cd was the most enriched element in the sediment (indicating that Cd pollution is widespread), whereas the least enriched metal in sediments was Cu. EF values suggested that the coastal area is impacted by a combination of human and natural sources of metals, where the anthropogenic sources are intense in the PLB site (north of Gulf of Aqaba). The MSS area is potentially the least polluted, consistent with being a marine reserve. The IC sediments have been found to be impacted by human activities but less intensely compared to the PLB area. These results suggested that there are two sources of metals in sediments; the primary source is likely closer to PLB, while the secondary is nearby the IC.

Metals are non-degradable in the aquatic environment and play a vital role in estuarine biogeochemistry but could also be detrimental to associated biota. A comparative evaluation of the trace metal concentrations (Fe, Mn, Zn, Cu, Ni, and Co) was carried out in the Zuari estuary, Goa during the post-monsoon season of 2013 at six locations, each representing three mangrove and three mudflat regions. In addition, fractionation of trace metals in sediments was performed to provide information on the mobility, distribution, bioavailability and toxicity. Special attention was paid to the marine mollusks viz. bivalves and gastropods that are extensively used as bio-indicators in coastal pollution. Considering the percentage of metals in the sequentially extracted fractions, the order of mobility from most to least bioavailable forms was Mn > Zn > Cu > Ni > Co > Fe. Mn maintained high bioavailability (average around 60%) in Fe–Mn oxide and carbonate bound forms indicating that Mn is readily available for biota uptake. The bioavailability of Fe was on an average of around 6% whereas other metals like Cu, Zn, Ni and Co were around 19% to 34%. When the bioavailable values were compared with standard Screening Quick Reference Table (SQUIRT), Zn showed higher toxicity level and bioavailability in the lower estuary. On the basis of calculated Bio Sediment Accumulation Factors (BSAF's), overall trend in bioaccumulation was in the order of Cu > Zn > Mn > Ni > Co > Fe. Metal Pollution Index (MPI) computed was higher for gastropods than bivalves.

European maritime companies have adopted programs to limit operational impacts on the environment. For maritime companies in North America, the Green Marine Environmental Program (GMEP) offers a framework to establish and reduce environmental footprints. Green Marine (GM) participants demonstrate annual improvements of specific environmental performance indicators (e.g., reductions in air pollution emissions) to maintain certification. Participants complete annual self-evaluations with results determining rankings for performance indicators on a 1-to-5 scale. Self-evaluations are independently verified every two years to ensure rigor and individual results are made publicly available annually to achieve transparency. GM benefits the marine industry across North America by encouraging sustainable development initiatives. GM's credibility is reflected through a diverse network of environmental groups and government agencies that endorse and help shape the program. Merits of this relatively new maritime certification (not previously described in the academic literature), are discussed.

Symbiotic associations are complex partnerships that can lead to new metabolic capabilities and the establishment of novel organisms. The diversity of these associations is very broad and there are still many mysteries about the origin and the exact relationship between the organisms that are involved in a symbiosis. The aim of the present study is to find symbiotic crude-oil degrading bacteria in the mussels that collected from the Persian Gulf. Fifteen crude-oil degrading bacteria were isolated from Mactra stultorum mussel that collected from oil contaminated area at Persian Gulf. According to high growth rate on crude oil five strains were selected from 15 isolated strains for more study. Determination of the nucleotide sequence of the gene encoding 16S rRNA show that these isolated strains belong to: Alcanivorax dieselolei strain BHA25, Idiomarina baltica strain BHA28, A. dieselolei strain BHA30, Alcanivorax sp. strain BHA32 and Vibrio azureus strain BHA36. Analysis of remaining of crude oil by Gas Chromatography (GC) confirmed that these strains can degrade: 64%, 63%, 71%, 58% and 75% of crude oil respectively.

Animal agricultural activities can be a significant source of pollutants affecting the health of farmers and neighboring communities. The main objective of this research was to improve the air quality by reducing the interior concentrations of emitting pollutants such as particulate matter (PM) and ammonia (NH3) within forced-ventilated fattening pig barns in order to improve the working conditions for human and the living conditions for animals as well as to have less impact on the surrounding environment. The mitigation techniques were a recirculating air scrubber and spraying of a water-oil mixture. The reduction efficiencies of the two mitigation techniques for PM and NH3 concentrations inside the barns were investigated. Two air scrubbers were mounted in a barn occupied with 515 pigs. A water-oil mixture spraying system with two different nozzles geometries was installed in a barn with 680 pigs. The data obtained from the mitigation system was compared with that obtained from a control barn with the same animal capacity and conditions. The results indicated that the average reduction efficiencies were 63% for total PM, 61% for PM10 and 32% for NH3. The results indicated that the average reduction efficiencies of the spraying system for the whole periods were 74% for total PM, 72% for PM10 and 19.5% for NH3 when using small nozzles and 44% for total PM, 39% for PM10 and 16% for NH3 when using large nozzles. The spraying system reduced the germs and fungal spore concentrations by 14 and 58%, respectively.

In this study, two composting strategies (not turned and turned windrows) of pig slurry solid fraction (SF) were evaluated and compared in terms of their suitability to obtain a composted manure appropriate for further pelletizing (i.e., moisture content <40%). The effect of the two composting strategies on carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions were also investigated.Six identical SF windrows of approximately 4 m3 and 1800 kg were set up outside, on a concrete pad in an open-sided, roofed facility, and composted for a period of 72 days. During the experimental period, three SF windrows were composted unturned (NTW), while the others three SF windrows were turned (TW) six times: at day 7, 16, 28, 35, 50 and 57. Carbon dioxide, methane, nitrous oxide and ammonia emissions were measured three times a week for the first 3 weeks and twice per week thereafter for the 72 days of composting. In correspondence of each turning operation, gases emissions rates from TW, were evaluated two times: before and immediately after turning. Due to the production of heat generated during the composting process, high losses of water occurred from both NTW and TW. However, at the end of the trial the average moisture content in composted manure from NTW and from TW resulted, respectively, 46.7% and 34.6%. Therefore, under the specific conditions adopted in this study, composting of pig slurry SF in NTW did not give a suitable product for further pelletizing. In addition, composted manure from NTW resulted in significantly (p < 0.05) lower total nitrogen (2.9% vs 3.4%) and NO3–N (714 mg kg−1 vs 1358 mg kg−1) content. However, in terms of CO2-eq, total gaseous emissions recorded over 72 days of trial from TW (120.4 kg CO2-eq. t−1) were approximately 95% higher as compared to those (64.7 kg CO2-eq. t−1) obtained from NTW.

A novel aerobic denitrification and biomineralization strain CN86 was isolated from the Qu Jiang artificial lake. Based on phylogenetic characteristics, the isolated strain was identified as Acinetobacter species. Strain CN86 was confirmed to have the ability to perform simultaneous denitrification and biomineralization. Exponential decay equation was used for the matching of kinetic processes on denitrification and biomineralization. A highest nitrate removal rate was achieved at the pH7.0, organic concentration of 1.5g/L and temperature of 30°C. An optimal hardness removal rate was obtained at the pH9.0, organic concentration of 2.0g/L and temperature of 30°C. Strain CN86 is a suitable candidate for the simultaneous removal of nitrate and hardness in groundwater treatment.

The characteristics of dissolved organic matter (DOM) extracted from sediments with four particle sizes (<25, 63–25, 200–63 and >200μm) in the Yangtze Estuary were compared. The differences in their binding capacities for individual fluorescent components with As/Sb were studied using fluorescence-quenching titrations combined with excitation–emission matrix (EEM) spectra. The results indicated that the particle size influenced the quality and quantity of extracted DOM. With increasing particle size, the extracted DOM content, value of UV280 and acidic functional group content of the DOM decreased. Three protein-like components (C2, C3 and C4) and one humic-like component (C1) were identified using the parallel factor analysis (PARAFAC) model. Wherein, protein-like material dominated in DOM on different particle-size fractions and possessed a stronger complex capacity with As/Sb. A significant positive correlation between the complexation capacity of extracted DOM from samples, as well as with the acidic functional group content, was observed.

Microplastics are known to be an increasing component found within both marine sediments and the water column. This study carried out an initial assessment of the levels of microplastics present within the Solent estuarine complex, focusing specifically on the water column. A plankton net trawl survey was carried out, with samples analysed using visual observation and Fourier Transform Infrared Spectroscopy (FT-IR). The study identified significant quantities of plastics, ranging in shape, with hot spots found at confluence points within the estuary. Though the FT-IR analysis was inconclusive, the nature of the samples indicates the effect of oceanographic conditions on the prevalent types of microplastics found, which in turn identifies key local sources such as wastewater treatment plants and the plastics industry as being the dominant inputs.

Mercury (Hg) contamination is an issue of a growing environmental and public health concern. Atmospheric chemistry transport models for Hg are a critical tool for understanding the sources, processes, and fate of Hg. Uncertainties in multiple aspects of atmospheric Hg models, however, limit their application for policy evaluation and for monitoring global trends in atmospheric Hg concentrations. This review aims to identify uncertainties in atmospheric Hg modeling that are relevant in the context of policy and for informing decision-making. We focus on specific requirements of the Minamata Convention on Mercury, a global treaty signed in 2013 to protect human health and the environment from Hg, to demonstrate how existing uncertainties in atmospheric Hg modeling can influence our ability to evaluate source-receptor relationships. Modeling studies of source attribution suggest that major uncertainties in atmospheric Hg modeling arise from anthropogenic emissions, biogeochemical cycling, and atmospheric chemistry. Uncertainties in these aspects of modeling are expected to increase under the Convention, with regulation of anthropogenic emissions, changes in atmospheric conditions, and legacy and natural Hg source contribution to the global biogeochemical cycle. These uncertainties can interact with one another and with the current Hg species measurement capability and pose challenges to effectively monitoring trends in atmospheric Hg. Developing additional means to attribute simulated atmospheric Hg trends and improve source-receptor relationships in atmospheric Hg models would improve our ability to evaluate the Convention’s effectiveness.