The water retention time (sometimes called residence time) in coastal areas is an indicator of coastal hydrodynamics which can be used to quantify the local transportation of dissolved and suspended pollutants. This study has used dynamic and statistical models to explore what governs the water retention time in non-tidal coastal waters of the Baltic Sea. If freshwater input divided by the cross-section area between the coastal water and the sea was below a certain threshold, freshwater had no notable impact on the retention time. Moreover, statistical models were developed for predicting surface water retention time and total water retention time from coastal water volume, cross-section area and freshwater discharge. This study can be useful for managers who need to determine where abatement measures should be focused in order to be as effective as possibly against coastal water pollution.

Plants of the black nightshade (Solanum nigrum L.) Korean ecotype were exposed to a gradient of cadmium (Cd) concentrations (0, 10, 30, 50, and 80 mg kg⁻¹of dry sand). The results showed a significant (p < 0.05) reduction in biomass, root-shoot length, and chlorophyll contents in the plants exposed to Cd compared to the control. Cd concentrations significantly increased in different parts of the plants as indicated by inductively coupled plasma mass spectrometry (ICP-MS) analysis. The amount of Cd accumulated by the plants in the leaves, stems, and roots was 307, 1536, and 3163 mg kg⁻¹of dry matter, respectively, when treated with Cd 80 mg kg⁻¹. The translocation factor (TF) declined with higher Cd concentrations, whereas the bioconcentration factor (BCF) increased with elevated Cd levels. The response to oxidative stress induced by Cd was modulated by the enzymatic activity of peroxidase and polyphenol peroxidase. In terms of non-enzymatic antioxidant biochemicals such as reduced glutathione and polyphenols, its contents in the leaves significantly increased in a dose-dependent manner. The overall increased antioxidant defense response in leaves might have contributed to the higher accumulation and tolerance of plants against Cd-induced oxidative stress. The Korean ecotype of S. nigrum has potential phytoremediation utility for phytostabilization of Cd-contaminated marginal land. However, further genomic insights could contribute to the identification of potential Cd translocation genes.

This work focuses on the effects of two commercial formulations of dispersants on juvenile turbot after 48 h of contamination and 15 days of recovery. Oxidative stress, gill, and immune functions were assessed in seven conditions: exposition to the water-soluble fraction of an oil, mechanical dispersion, two dispersants alone, two types of chemical dispersion and a control group. In the contaminated groups, nominal concentrations of oil and dispersants were 66 and 3.3 mg L⁻¹, respectively. Dispersants alone had weak effects; the soluble fraction induced leucopenia and gill alteration. Chemical and mechanical dispersion induced similar effects. After contamination, a principal component analysis showed two distinct areas: the first one included the control and dispersants groups, the second one dispersion of the oil. After the 15-day recovery period, it was not possible to differentiate the groups. This study shows that, in the experimental conditions tested, the dispersion, either chemical or mechanical, enhances the consequences of exposure to crude oil without long-lasting consequences.

The dynamic behavior of water quality and quantity in the Egyptian drains is often viewed as a disruption to the normal operation and performance of the process of water reuse in irrigation. The control of such behavior has been challenging and often elusive in practice. Therefore, this paper presents a framework to advance the understanding and opportunities for improving the reuse process by developing a multivariate process control model. The model starts with preliminary analysis for water quality data that are collected at the reuse site on the examined drain. This phase comprises investigating data distribution and dependency. Then, univariate control charts are used to investigate the state of control for the independent and normally distributed variables. For dependent variables, principal components analysis is used as a method of synthesizing the variables information. In this case, principal component scores are displayed using multivariate control charts. If in-control case existed, process capability index is used to provide a numerical measure of whether or not the reuse process is capable of producing water that satisfies the irrigation quality standards. Since the model will only detect assignable causes if out-of-control or in-capable case existed, management, operational, and/or engineering action will usually be necessary to sustain the reuse process. In these cases, an action plan in response to the model signals will be vital. The main function of the proposed model is to safely manage the reuse practice using statistical quality control techniques. The model was demonstrated using water quality data collected during the period from January 2006 to July 2011 from Hanut (EH02) and El-Salam 3 (ESL03) pump stations along Hadus drain, Eastern Nile Delta-Egypt. The recommended model is automatic, algorithmic, self-tuning, and computerizable.

A 3-year study was conducted to determine the effects of anaerobic digestion (AD), large particle solids, and manure additive (More Than Manure, MTM™) on ammonia (NH₃) and greenhouse gas (GHG; carbon dioxide, nitrous oxide, and methane) emissions when raw and treated manure were surface-applied. The presence of large particle solids resulted in greater NH₃ emissions, probably, due to reduced infiltration of liquid manure into soil (P < 0.05). Anaerobic digestion did not have a consistent effect on NH₃ emission. Manure with greater ammoniacal nitrogen (AN) concentrations had significantly greater NH₃ loss after manure application (P < 0.05). Anaerobic digestion of manure also did not have a significant effect on GHG flux (P > 0.05). Raw manure with large particle solids had significantly greater CO₂ flux than the other raw manure treatments on the day of manure application (P < 0.05). There was no significant manure treatment effects (P > 0.2) on methane flux over the 3-day period after manure application. The manure additive MTM™ did not have significant effects (P > 0.05) on NH₃ and GHG fluxes. The results of this study suggest that solids and AN concentrations in manure are the most important factors affecting NH₃ emissions after surface application.

To biocontrol algal bloom, a novel algicidal bacterium, Enterobacter sp. NP23, was isolated. This strain has an effective algicidal activity against Chlorella vulgari, Microcystis aeruginosa, Scenedesmus, and Chlorella pyrenoidosa. Meanwhile, the growth factors were assayed to obtain a high cell density of strain NP23. As a result, three growth factors (i.e., KNO₃0.6 %, MnSO₄·H₂O 0.001 %, and K₂HPO₄0.3 %) were determined as the critical roles in enhancing the cell density of 10¹³ CFU/mL. Moreover, algicidal activity assays revealed that strain NP23 exhibited high algicidal activities against M. aeruginosa and Scenedesmus. These results indicate that this wild-type strain would provide a new member for biocontrolling microalgal and cyanobacterial populations in eco-technology.

The aim of the present study was to evaluate the influence of the recirculation rate on the efficiency of a 1,000-L pilot anaerobic sequencing batch biofilm reactor (ASBBR) treating effluent from a small dairy plant over a long-term period (570 days). Three operational conditions were studied, in which recirculation rates were varied, resulting in upflow velocities of 0.2, 3.8, and 6.4 m h⁻¹and the cycle time of 48 h. The biomass was immobilized on plastic supports containing polyurethane foam. The organic loading rate varied according to the operations occurring in the dairy plant. After system stability had been verified, temporal profiles of the substrate and metabolite concentrations were obtained, allowing kinetic parameter inference. Sludge samples from the inoculum and from the reactor were analyzed through microscopic examination, molecular biology analyses, and specific methanogenic activity assays. The average efficiencies of organic matter removal were 82 ± 11, 84 ± 9, and 87 ± 9 % at velocities of 0.2, 3.8, and 6.4 m h⁻¹, respectively. Microscopic examinations indicated that the fluorescent microorganisms decreased throughout the experiment, and they were not detected in the last condition. Homoacetogenesis was inferred as a possible pathway for H₂removal and for maintenance of the methanogenic process. Specific methanogenic activity increased throughout the monitoring period. It was possible to conclude that the ASBBR was efficient, robust, and reliable in treating dairy effluents under the conditions used.

The potential use of the arsenic-tolerant woody leguminous species Anadenanthera peregrina (L) Spegazzini for rehabilitating arsenic (As)-contaminated areas was studied. In an As (539.33 mg/kg)-contaminated soil experiment, plants were able to accumulate arsenic in their roots with a low transfer index to the shoot. Inoculation with arbuscular mycorrhizal fungi (AMF) amplified this behavior and improved both biomass production and the phosphorus concentration in the shoot. AMF inoculation not only improved A. peregrina plant growth but also protected the shoot against As toxicity. Aside from the AMF inoculation, the addition of organic matter reduced the soil pH, thus improving the ability of the roots to accumulate arsenic. The majority (81 %) of the variations in As accumulation in A. peregrina roots were explained by the effects of the organic matter and soil pH as well as AMF treatments, as found by a principal component analysis. A. peregrina promoted phytostabilization through As root sequestration. Therefore, A. peregrina plants inoculated with AMF in the presence of organic matter are recommended to rehabilitate degraded areas of soil contaminated with arsenic.

Base cation weathering (BCw) rate is one of the most influential yet difficult to estimate parameters in the calculation of critical acid loads of nitrogen (N) and sulfur (S) deposition for terrestrial systems. Only the clay correlation–substrate method, a simple empirical model, has been used for estimating BCw rates for forest ecosystems in the conterminous USA and may not be suitable for application at all sites without calibration or revision. An alternate model, PROFILE, may offer an improved method to estimate BCw rates. It is a transferable, process-based model that simulates the weathering rates of groups of minerals. The objective of this study was to evaluate PROFILE using national datasets as a method to estimate BCw rates for forests in the USA, focusing on Pennsylvania (PA) as the first test state. The model paired with national datasets was successfully applied at 51 forested sites across PA. Weathering rates ranged from 119 to 9,245 eq ha⁻¹ year⁻¹ and were consistent with soil properties and regional geology. Comparisons of terrestrial critical acid loads with 2002 N and S deposition showed critical load exceedances at 53 % of the sites. This trial evaluation of PROFILE paired with national datasets in PA establishes that there are sufficient data to support the estimation of BCw rates and determination of critical acid loads for forests in the USA. However, the paired method should be applied in other locations to further evaluate the performance of the model in different regions of the country.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are pollutants of significant global concern, and China is one of the main dioxin-emitting countries in the world. Facing increasing dioxin concentrations in the environment, the Chinese government set a mandatory goal of 10 % reduction in the rate of emission intensity by 2015 in an attempt to reduce dioxin emissions. In the study presented here, we estimated the outputs (or waste disposal capacities) of the four key dioxin-emitting industries in China in 2015. We then estimated that the total amount of dioxins released from these four industries was approximately 8.0 kg toxic equivalent (TEQ)/year. These results indicate that dioxin emissions in China have not decreased under the current plan, and the plan needs to be adjusted. A goal for a decrease in the total dioxin emissions in China is proposed, and several policies and measures aimed at allowing the target dioxin emission decrease to be achieved are recommended.