BACKGROUND, AIM, AND SCOPE: Fishery wastewater treatment can be compromised due to seasonal production. The use of sequencing batch reactors is not completely successful, despite flexibility being one of the principal advantages. Most research on activated sludge is performed using synthetic wastewater to ensure a stable and constant feed. The current work compared biomass morphology and settling ability using image analysis of synthetic and real fishery wastewaters, with and without NaCl addition. RESULTS: The final effluent presented higher turbidity for both wastewaters after NaCl addition, and lower SVI values. For synthetic wastewater, NaCl addition led to the total aggregates' area (TA) increase from 1.46 to 2.09 mm2/μL, alongside the growth of intermediate aggregates into larger aggregates. The addition of NaCl to the fishery wastewater led to a decrease of the TA from 4.43 to 1.72 mm2/μL. The biomass composition decreased in larger and intermediate structures, opposite to the smaller aggregates' area percentage increase. DISCUSSION: NaCl addition to synthetic wastewater incited flocculation increasing sludge settling ability. A slight aggregate disruption was responsible for a turbidity increase. A strong deflocculation was identified in fishery wastewater with NaCl from the decrease of intermediate and large aggregates. This contrasted with pinpoint flocs release, which increased the turbidity levels. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: It could be established that synthetic wastewater biomass flocculation and fishery wastewater biomass deflocculation, observed during 0.5% NaCl experiments, were related to sludge settling and effluent turbidity changes. Furthermore, the biomass changes obtained with synthetic wastewater cannot be extrapolated to fishery wastewater.

Background, aim, and scope A rapid increase in anthropogenic nitrogen inputs has a strong impact on terrestrial and aquatic ecosystems. We have estimated net anthropogenic nitrogen accumulation (NANA) as an index of nitrogen (N) pollution potential in the Beijing metropolitan region, China. Our research provides a basis for understanding the potential impact of anthropogenic N inputs on environmental problems, such as nation-wide water quality degradation under the current rapid urban expansion in modern China. Methods The NANA estimation is based on an inventory of atmospheric N deposition, N fertilizer use, consumption of human food and animal feed, N fixation, and riverine N import and export. We calculated N accumulation values for the years 1991, 1997, 2003, and 2007. Results and discussion The average NANA values for the urban and suburban areas from 1991 to 2007 were 24,038 and 13,090 kg N km⁻² year⁻¹, respectively. NANA is higher in eastern and southern areas than in northern and western areas, and higher in the urban area than in the suburban area. The overall average NANA in Beijing has a downward trend from 15,187 kg N km⁻² year⁻¹ in 1991 to 11,606 kg N km⁻² year⁻¹ in 2007, but is still two to five times as that of developed countries. N input from nitrogenous fertilizer is the largest source of NANA, accounting for 44.4% (6,764 kg N km⁻² year⁻¹) of the total N input, followed by atmospheric N deposition and N in human food and animal feed. NANA is closely related to land use, on average 23,140 kg N km⁻² year⁻¹ in densely populated developed land, 17,904 kg N km⁻² year⁻¹ in agricultural land, and 10,445 kg N km⁻² year⁻¹ in forest land. Human population density is the best single predictor of NANA.

PURPOSE: We tested the genetic diversity in wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of asbestos. Hazardous effects of deposited asbestos persist in the environment because of low rate of fiber disintegration. The upper layers of the soil in the vicinity of a former asbestos factory are nearly “saturated” with asbestos fibers and dust. Natural populations of mice dwell in this area and are constantly exposed to asbestos fibers. METHODS: We measured the microsatellites genetic diversity of wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of this environmental toxin. RESULTS: The six tested microsatellites were highly polymorphic, revealing 111 different alleles for the two sampled populations. Effective number of alleles was slightly higher in the polluted population relative to the control population, while observed heterozygosity was lower. The chromatographic profile of the polluted population exhibited a significantly higher number of bands, probably resulting from somatic mutations, in addition to the ordinary microsatellite band profiles. CONCLUSIONS: Long-term exposure to asbestos fibers significantly elevates the level of somatic mutations. It also leads to a relatively high level of observed homozygosity, a phenomenon that may be associated with loss of heterozygosity. Based on the mice population, our data suggest elevated health risks for humans living in an asbestos-polluted area.

INTRODUCTION: Effluent organic matter from biological wastewater treatment plants is composed of degradation products and soluble microbial products (SMP). Protein, polysaccharide, humic acid, and DNA were major biomolecules of SMP. Little is known about the effects of SMP as microbially derived precursors on disinfection byproduct formation and speciation in biologically treated wastewater. In addition, there has never been any attempt to directly chlorinate the major biomolecules of SMP. MATERIALS AND METHODS: In this study, model compounds (bovine serum albumin, starch, DNA, and humic acid) and SMP collected from a sequencing batch reactor (SBR) were chlorinated to verify the trihalomethane and haloacetic acid species that were produced from them. RESULTS AND DISCUSSION: The results showed that chloroform, dichlorobromomethane, dichloroacetic acid, and trichloroacetic acid were generated from the chlorination of SMP in the SBR, and there was a close relationship between the species predicted from the model chemical compounds and those obtained from the SMP.

Introduction Balya and its associated villages which is a town of the Balikesir region of Turkey have very rich zinc, lead, and manganese mines. These mines have been operating since the thirteenth century and now there is heavy metal contamination in both the soil and natural waters in these areas. Materials and methods Soils were collected from Sarı su, Enverpaşa, and Hastanetepe which are in Balya town and Kadıköy, Kaşıkcı, Müstecap, Patlak, Çakallar, and Bengiler which are the villages near Balya and the mine areas. Nine trace analytes (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) were determined using an acid extraction procedure as well as from PBET in vitro gastro-intestinal experiments using ICP-OES. Results and discussion The results showed that high As, Ba, Pb, Zn, and Cd concentrations were found in these soils. The amounts ingested by pica behavior of children at the rate of 10 g day⁻¹ are calculated using the results of in vitro intestinal bio-accessibility experiments. Conclusion The results showed that the amount of As, Pb, Ba, and Cd levels ingested by pica behavior are substantially higher than tolerable daily intake values in most of the soils. When normal ingestion is taken into account, the tolerable daily limits are only exceeded for one element (Pb) and even then, only at two sites.

BACKGROUND AND PURPOSE: More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation. METHODS: Seawater samples were collected from five sites: 1, sea areas adjacent to the power plant; 2, near discharge outlets; 3, the aeration pool of the power plant; and 4 and 5, two reference sites. The total gaseous Hg was determined in situ with a Tekran 2537B. Analyses of total Hg (TM) followed the USEPA methods. RESULTS: In most part of the study area, TM concentrations were close to the reference values and Hg transfer from the seawater into the sediment and biota was not obvious. However, in the aeration pool and near the waste discharge outlets, atmospheric and surface seawater concentrations of TM were much higher, compared with those at a reference site. The concentration ranges of total gaseous Hg and TM in seawater were 3.83–8.60 ng/m3 and 79.0–198 ng/L near the discharge outlets, 7.23–13.5 ng/m3 and 186–616 ng/L in the aeration pool, and 2.98–4.06 ng/m3 and 0.47–1.87 ng/L at a reference point. CONCLUSIONS: This study suggested that the Hg in the flue gas desulfurization waste seawater was not only transported and diluted with sea currents, but also could possibly be transferred into the atmosphere from the aeration pool and from the discharge outlets.

Background The impact of shipping emissions on urban agglomerations close to major ports and vessel routes is probably one of the lesser understood aspects of anthropogenic air pollution. Little research has been done providing a satisfactory comprehension of the relationship between primary pollutant emissions, secondary aerosols formation and resulting air quality. Materials and methods In this study, multi-year (2003-2007) ambient speciated PM₁₀ and PM₂.₅ data collected at four strategic sampling locations around the Bay of Algeciras (southern Spain), and positive matrix factorisation model were used to identify major PM sources with particular attention paid to the quantification of total shipping emissions. The impact of the emissions from both the harbour of Algeciras and vessel traffic at the Western entrance of Mediterranean Sea (Strait of Gibraltar) were quantified. Ambient levels of V, Ni, La and Ce were used as markers to estimate PM emitted by shipping. Results and discussion Shipping emissions were characterised by La/Ce ratios between 0.6 and 0.8 and V/Ni ratios around 3 for both PM₁₀ and PM₂.₅. In contrast, elevated La/Ce values (1-5) are attributable to emissions from refinery zeolitic fluid catalytic converter plant, and low average V/Ni values (around 1) result mainly from contamination from stainless steel plant emissions. The direct contribution from shipping in the Bay of Algeciras was estimated at 1.4-2.6 μg PM₁₀/m³ (3-7%) and 1.2-2.3 μg PM₂.₅/m³ (5-10%). The total contribution from shipping (primary emissions + secondary sulphate aerosol formation) reached 4.7 μg PM₁₀/m³ (13%) and 4.1 μg PM₂.₅/m³ (17%).

Background and purpose Regeneration of spent activated carbon assumes paramount importance in view of its economic reuse during adsorptive removal of organic contaminants. Classical thermal, chemical, or electrochemical regeneration methods are constrained with several limitations. Microbial regeneration of spent activated carbon provides a synergic combination of adsorption and biodegradation. Methods Microorganisms regenerate the surface of activated carbon using sorbed organic substrate as a source of food and energy. Aromatic hydrocarbons, particularly phenols, including their chlorinated derivatives and industrial waste water containing synthetic organic compounds and explosives-contaminated ground water are the major removal targets in adsorption-bioregeneration process. Popular mechanisms of bioregeneration include exoenzymatic hypothesis and biodegradation following desorption. Efficiency of bioregeneration can be quantified using direct determination of the substrate content on the adsorbent, the indirect measurement of substrate consumption by measuring the carbon dioxide production and the measurement of oxygen uptake. Modeling of bioregeneration involves the kinetics of adsorption/desorption and microbial growth followed by solute degradation. Some modeling aspects based on various simplifying assumptions for mass transport resistance, microbial kinetics and biofilm thickness, are briefly exposed. Results Kinetic parameters from various representative bioregeneration models and their solution procedure are briefly summarized. The models would be useful in predicting the mass transfer driving forces, microbial growth, substrate degradation as well as the extent of bioregeneration. Conclusions Intraparticle mass transfer resistance, incomplete regeneration, and microbial fouling are some of the problems needed to be addressed adequately. A detailed techno-economic evaluation is also required to assess the commercial aspects of bioregeneration.