Background and aim Many rivers have to receive treated or untreated wastewater as the main water sources in the world, especially in the countries facing with water shortage. For instance, the Haihe and Huaihe River Basin, which are among areas facing crises for water resources in China, receive 33,400 million tons of wastewater per year. As the sediment has large capacity for sorbing hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), it can act as a natural repository for the contaminants. This means pollutants can release into water phase again under some conditions, such as resuspension, sediment dredging, etc. The objective of this research was to study the trends of PAH release from sediments in rivers receiving much wastewater, such as Yongding New River (YD), Northsewer (NS), and Southsewer (SS) from Haihe River Basin. These rivers received most of the wastewater from Tianjin, China and merge into Bohai Bay finally. Methods Sediments (namely YD, NS, and SS) were collected from Yongding New River, Northsewer, and Southsewer, respectively. The physical and chemical properties of the sediments, including particle size distribution, total organic carbon (TOC) and black carbon (BC) contents, elemental compositions, organic functional groups analyzed from Fourier transformed infrared (FTIR), and nuclear magnetic resonance (NMR) spectra, were characterized. PAH desorption from the sediments was measured with the Tenax shaken slurry desorption method. Results The NS sediment had a greatly higher TOC and BC contents, while lower BC-to-TOC ratio than YD and SS sediments. NMR and FTIR analysis showed that aliphatic carbons were more abundant in NS sediment than SS sediment. The desorption experiments showed that PAHs desorbed more rapidly from YD and NS sediments than from SS sediment. PAH fraction desorbed after each interval during the experiment except 0.8 day was significantly correlated with PAH properties among all the three sediments. Discussion The higher BC-to-TOC ratio in SS sediment corresponded to slower desorption rate and less desorption extent of PAHs from SS sediment among the three sediments. This probably could be explained by the extremely strong sorption ability of BC. It also proved that the sequestration of PAHs in sediment was not simply the result of higher organic carbon content. Conclusions Considering the physical and chemical characterization of the sediments and PAH desorption properties comprehensively, BC-to-TOC ratio was a more important factor controlling the behavior of PAHs in sediments than absolute TOC or BC content.

BACKGROUND, AIM, AND SCOPE: Ferro-cyanide is one of the commonly found species at cyanide-contaminated soils and groundwater. Unlike botanical metabolism of KCN via the β-cyanoalanine pathway, processes involved in the plant-mediated assimilation of ferro-cyanide are still unclear. The objective of this study was to investigate a possible mechanism involved in uptake and assimilation of ferro-cyanide by plants. MATERIALS AND METHODS: Detached roots of plants were exposed to ferro-cyanide in a closed-dark hydroponic system amended with HgCl2, AgNO3, LaCl3, tetraethylammonium chloride (TEACl), or Na3VO4, respectively, at 25 ± 0.5°C for 24 h. Total CN, free CN-, and dissolved Fe2+ were analyzed spectrophotometrically. Activity of β-cyanoalanine synthase involved in cyanide assimilation was also assayed using detached roots of plants in vivo. RESULTS: Dissociation of ferro-cyanide [FeII(CN)6]-4 to free CN- and Fe2+ in solution was negligible. The applied inhibitors did not show any significant impact on the uptake of ferro-cyanide by soybean (Glycine max L. cv. JD 1) and hybrid willows (Salix matsudana Koidz × alba L.; p > 0.05), but rice (Oryza sativa L. cv. JY 98) was more susceptible to the inhibitors compared with the controls (p < 0.05). However, TEACl had the most severe effect on the assimilation of ferro-cyanide by soybean, hybrid willows, and maize (Zea mays L. cv. PA 78; p < 0.01), whereas AgNO3 was the most sensitive inhibitor to rice (p < 0.01). No measurable difference in β-cyanoalanine synthase activity of roots exposed to ferro-cyanide was observed compared with the control without any cyanides (p > 0.05), whereas roots exposed to KCN showed a considerable increase in enzyme activity (p < 0.05). CONCLUSIONS: Plants take up Fe2+ and CN- as a whole complex, and in vivo dissociation to free CN- is not prerequisite during the botanical assimilation of ferro-cyanide. Ferro-cyanide is likely metabolized by plants directly through an unknown pathway rather than the β-cyanoalanine pathway.

INTRODUCTION: Illicit drug use is a largely hidden phenomenon, and population measures are notoriously problematic. Reliable and valid data for local, regional, and national public health and other interventions are needed. METHODS: To address this information, we examined temporal trends within and across weeks in methamphetamine (MA) in a single location in order to inform a sampling plan for understanding long-term trends in MA use based on sampling raw influent to wastewater treatment plants. The measured concentrations in the wastewater are used to estimate the total mass of MA consumed rather than the number of doses due to the uncertainty surrounding methamphetamine purity, mass of MA per dose, and the number of doses used per day. RESULTS: Results from a region with high levels of MA use indicate that MA levels do not differ significantly between weekdays and weekends (p = 0.1), consistent with a predominately regular, daily use pattern use. The potential contribution of legal sales of D: - and L: -MA to the mass of MA consumed within the community was estimated to range from 3–8%. Limitations and uncertainties associated with estimating the mass of MA consumption include small contributions of prescription and over-the-counter drugs that are metabolized to MA as well as measurement and sampling variability.

In the present work, two types of artificial neural network (NN) models using the multilayer perceptron (MLP) and the radial basis function (RBF) techniques, as well as a model based on principal component regression analysis (PCRA), are employed to forecast hourly PM₁₀ concentrations in four urban areas (Larnaca, Limassol, Nicosia and Paphos) in Cyprus. The model development is based on a variety of meteorological and pollutant parameters corresponding to the 2-year period between July 2006 and June 2008, and the model evaluation is achieved through the use of a series of well-established evaluation instruments and methodologies. The evaluation reveals that the MLP NN models display the best forecasting performance with R ² values ranging between 0.65 and 0.76, whereas the RBF NNs and the PCRA models reveal a rather weak performance with R ² values between 0.37-0.43 and 0.33-0.38, respectively. The derived MLP models are also used to forecast Saharan dust episodes with remarkable success (probability of detection ranging between 0.68 and 0.71). On the whole, the analysis shows that the models introduced here could provide local authorities with reliable and precise predictions and alarms about air quality if used on an operational basis.

Background, aim and scope This paper presents a preliminary study of the water profile with reference to microbiological parameters, required by Directive 2006/07/EC (European Community 2006) concerning the management of bathing water quality, in the coastal belt of the Province of Venice (Italy, Northern Adriatic Sea). A historical database has been implemented with monitoring data for the period 2000-2006 (data on rivers, bathing and marine coastal waters and on the characterization of Wastewater Treatment Plant (WWTP) discharges) from the institutional activity of Veneto Regional Environmental Prevention and Protection Agency (ARPAV). An integrated areal analysis for the microbiological investigation of homogeneous stretches along the coast of the Province of Venice was performed for a preliminary characterization of the bathing water profile considering water quality status and existing pressure sources. Materials and methods ARPAV is the institutional body responsible for environmental monitoring and control activities. Data were produced from monitoring and controls made available by the Regional Environmental Informative System and extracted and elaborated for the period of interest (2000−2006). Sampling and analysis of microbiological parameters were executed following the official Italian methods in accordance with international procedures (APHA et al. 1998). For the purpose of this study, the coast was divided into eight stretches, which were considered to be homogeneous according to their physical and geographical characteristics. An ANOVA statistical assessment has been performed on stretches I, V and VIII. Results and discussion From the integrated areal analysis of microbiological parameters in the homogeneous stretches along the coast of all the investigated matrices, high mean levels of faecal contamination were found in some cases. The most critical situation amongst the stretches evaluated is to be found in stretch VIII--Ca' Roman, Sottomarina and Isola Verde shores (Southern part of the Province). These results can be widely attributed to pressure sources from the Brenta and Adige rivers, rather than to local contributions. Stretches VI and VII, which correspond to the area from Punta Sabbioni (Cavallino shore N-E) to the Pellestrina shore (S-W), present the best conditions for faecal contamination parameters (low pollution levels). These situations can probably be explained given that WWTPs 7 and 8 have two submarine outfalls at a distance of about 4 km from the coastline and therefore a discharge point which is distant from the bathing and marine coastal monitoring stations; there are also no river mouths in these two stretches. Due to lack of data, it was not possible to implement seasonal assessments. Conclusions This study aimed to develop an integrated areal analysis for biological parameters along the coast over the period 2000-2006 for the identified homogeneous stretches in order to develop a preliminary approach for the characterization of the water profile, as requested by directive 2006/7/EC. From the integrated analysis of the stretches, it is evident that in some cases there are high levels of faecal contamination along the coast which can be caused by river flows which heavily condition the quality of coastal waters as verified with the statistical assessment. Recommendations and perspectives From the preliminary analysis, the submarine outfalls seem to be the best solution to guarantee good bathing water quality on the coast. Nevertheless, it must be observed that this solution cannot overlook the possible impact of the discharges on seawaters intended for a specific use, such as mussel farms with reference to coastal hydrodynamics. Therefore, a sound wastewater dispersion analysis on the discharges of the WWTPs for the identification of the interested area and the level of contamination must be performed; a modelling study on pollution dispersion is complementary to this study (Scroccaro et al. 2009). This analysis highlights the critical stretches as being numbers II and, above all, VIII with particular correlation with the main river mouths. Thus, it is evident that the issue of microbiological impact must be studied following a river basin approach according to the influence of river loads on coastal areas.

INTRODUCTION: The influence of sintering temperature on the physico-mechanical characteristics (such as water absorption, apparent porosity, bulk density, weight loss on ignition, firing shrinkage, and compressive strength), leachability, and microstructure of shale brick containing oil well-derived drilling waste (DW) was investigated. METHODS: The experiments were conducted at a temperature ranging from 950°C to 1,050°C with 30% DW addition. RESULTS: The results indicate that increasing the sintering temperature decreases the water absorption and apparent porosity and increases the shrinkage, density, and compressive strength of sintered specimens. Moreover, the physico-mechanical properties of samples sintered at 1,050°C meet the requirements of the MU20 according to GB/T 5101-2003 (in China). The heavy metal concentrations of the leachate are much lower than the current regulatory limits according to GB16889-2008. CONCLUSION: The results from XRD and SEM show that increasing sintering temperature results in an increase of the high temperature liquid phase, which may have a significant effect on the densification process of the samples.

INTRODUCTION: This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge. MATERIALS AND METHODS: The results showed that the continuous addition of 20 mg/L Cu(II) seriously inhibited the removal of sodium benzoate (provided as a model organic pollutant) by activated sludge in a SBR. RESULTS AND DISCUSSION: After 40 days of acclimation, the removal efficiency presented a slight but unsteady recovery and the settling and dewatering properties improved, indicating that sludge bulking had been inhibited. Additionally, the proportion of loosely bound EPS in the total EPS increased with time and the relative composition of the total organics was polysaccharide > humic substances > protein > DNA. CONCLUSION: The effects of copper on the composition of EPS and the settling and dewatering properties of bulking activated sludge were also discussed for the first time in this paper.

INTRODUCTION: Two hundred twenty-five precipitation samples were collected at high- (summit, 1,534 m ASL) and low-elevation (base, 218 m ASL) sites between 2005 and 2008 in eastern China. The present work focused on the roles of long-range transport and under-cloud/boundary layer scavenging on chemical composition of precipitation collected at the two sites. METHODS: Ionic and trace species were analyzed in 225 precipitation samples. A total of 72 precipitation events occurring simultaneously at the summit and base sites were further examined. Positive matrix factorization (PMF) and backward air mass trajectories were used to identify the sources of precipitation pollutants. RESULTS: Low pH and high concentrations of ionic and trace species were measured at both sites. Inter-correlations for the simultaneous samples at the two sites were poor for trace elements (−0.07~0.47). A several fold increase in major ion (122~546%) and trace element (261~3,302%) concentrations occurred as the rain fell. Approximately 89% of the air masses responsible for the summit precipitation events were of distance origin. Marine salt, crustal material, fossil fuel burning plus secondary products, and metallic-industry-related factors were identified by PMF, contributing 9.7%, 22.8%, 41.8%, and 25.6%, respectively, to the precipitation pollutants at the summit and 13.3%, 31.9%, 39.6%, and 15.2%, respectively, at the base. CONCLUSIONS: Long-range atmospheric transport primarily influenced the high and the low site precipitation was strongly influenced by the under-cloud scavenging process of local boundary layer pollutants. Crustal material and fossil fuel burning plus secondary products were the predominant pollution sources in this region.

The potential RDX contamination of food chain from polluted soil is a significant concern in regards to both human health and environment. Using a hydroponic system and selected soils spiked with RDX, this study disclosed that four crop plant species maize (Zea mays), sorghum (Sorghum sudanese), wheat (Triticum aestivum), and soybean (Glycine max) were capable of RDX uptake with more in aerial parts than roots. The accumulation of RDX in the plant tissue is concentration-dependent up to 21 mg RDX/L solution or 100 mg RDX/kg soil but not proportionally at higher RDX levels from 220 to 903 mg/kg soil. While wheat plant tissue harbored the highest RDX concentration of 2,800 μg per gram dry biomass, maize was able to remove a maximum of 3,267 μg RDX from soil per pot by five 4-week plants at 100 mg/kg of soil. Although RDX is toxic to plants, maize, sorghum, and wheat showed reasonable growth in the presence of the chemical, whereas soybeans were more sensitive to RDX. Results of this study facilitate assessment of the potential invasion of food chain by RDX-contaminated soils.

Introduction Water contamination is a notable environmental problem of the Niger Delta, Nigeria. The present work is an improved attempt at a scientific discourse of water-quality issues in the Niger Delta of Nigeria with respect to heavy metal levels in surface water in view of the hitherto dearth of scientific data. Materials and methods We have looked at the Fe, Mn, Cu, Cd, Cr, Pb, Ni, Zn (quantified by atomic absorption spectrophotometry) profiles and some physicochemical properties (pH and salinity) of some surface water used by the local population in the mid Niger Delta. Surface water samples were collected from these surface waters in the dry and rainy seasons. Results Akiplai wellhead stream and Etebde River had the highest level of iron. In Delta State, high levels of cadmium were found in Ijala creek, Ubeji creek, Jeddo River, and Ekpan River, respectively. High lead levels were seen in Jeddo River, Ekurede-Itsekiri Creek, and Ughelli River. In River State, Tombia River had the highest levels of chromium, lead, and nickel. Ijala creek, Eja-Etan, Ifie-Kporo, Ubeji Creek, Jeddo, Ekpan Rivers, and Ekurede-Itsekiri Creek, all in Delta State, presented highest salinity levels. Orash River, Ughewhe stream, and Egbo stream have a lowest pH of 5.22, 5.32, and 5.53, respectively, while Ifie-Kporo River have a highest pH of 8.18. Conclusion Most of the metal levels were above US EPA Maximum Contaminant Level MCL indicative of water pollution which may be of public health importance, and we, therefore, recommend water-quality monitoring.