Perfluorooctanoic acid (PFOA) is extremely persistent and bioaccumulative in the environment; thus, it is very urgent to investigate an effective and moderate technology to treat the pollution of PFOA. In this study, a process combined iron and granular activated carbon (Fe⁰/GAC) micro-electrolysis with VUV-Fenton system is employed for the remediation of PFOA. Approximately 50 % PFOA (10 mg L⁻¹) could be efficiently defluorinated under the following conditions: pH 3.0, dosage of Fe 7.5 g L⁻¹, dosage of GAC 12.5 g L⁻¹, and concentration of H₂O₂ 22.8 mmol L⁻¹. Meanwhile, during the process, evident defluorination was observed and the concentration of fluoride ion was eventually 3.23 mg L⁻¹. The intermediates including five shorter-chain perfluorinated carboxylic acids (PFCAs), i.e., C7, C6, C5, C4, and C3, were also analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) and defluorination mechanisms of PFOA was proposed, which involved photochemical of OH·, direct photolysis (185-nm VUV), and photocatalytic degradation of PFOA in the presence of Fe³⁺ (254-nm UV).

Landfills represent a severe environmental problem mainly due to the generation of leachates, and this study aimed to evaluate sublethal effects of a domestic landfill leachate in the freshwater bivalve Corbicula fluminea. Clams were submitted to in situ tests along a stream, at three sites, representing increasing distances from the leachate discharge (Pq1, Pq2, and Pq3), for 1, 5, and 15 days. The following biomarkers were analyzed in the gills and digestive glands: 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities, multixenobiotic resistance mechanism (MXR), total antioxidant capacity (TAC), reactive oxygen species (ROS), and lipid peroxidation (LPO). Metallothionein (MT) content was determined in the gills and DNA damage in hemocytes. The mortality rate of animals during in situ tests was reduced as the distance from the leachate discharge source increased. On the other hand, biomarker results showed sublethal effects on C. fluminea confined at all sites of PqS. GST, TAC, ROS, and DNA damage were the most significant biomarkers for this species and should be considered for future monitoring and assessment of freshwater environments located in landfill areas.

Glomalin is a specific fungal glycoprotein produced by arbuscular mycorrhizal (AM) fungi belonging to the Glomerales which could efficiently sequestrate heavy metals. The glomalin has been introduced as a heat shock protein and there are evidences that increasing levels of heavy metals could enhance its production. We examined the influence of Cd concentrations on glomalin production by AM fungus, as well as its contribution to the sequestration of Cd in both pot and in vitro culture conditions. Pot experiment was carried out using pure sand with Trifolium repens L. as host plant, mycorrhized by Rhizophagus irregularis and treated with Cd levels of 0, 15, 30, and 45 μM. In vitro experiment was performed in two-compartment plates containing the transformed carrot roots mycorrhized with the same fungus and treated with Cd levels of 0, 0.001, 0.01, and 0.1 mM. The immunoreactive and Bradford reactive glomalin contents in both experiments increased as so raising Cd concentration. Total Cd sequestrated by hyphal glomalin in both cultures was significantly increased as the levels of Cd increased. The highest contents of Cd sequestration in pot (75.78 μg Cd/mg glomalin) and in vitro (11.44 μg Cd/mg glomalin) cultures were recorded at the uppermost levels of Cd, which significantly differed with other levels. Our results suggested that under Cd-induced stress, stimulated production of glomalin by AM fungus may be a protective mechanism against the toxic effect of Cd.

The present study on organophosphate deals with the reports on pollution and toxicity cases throughout India. The use of pesticides was introduced in India during the 1960s which are now being used on a large scale and represents the common feature of Indian agriculture. Use of organophosphates as a pesticide came as an alternative to chlorinated hydrocarbons due to their easy degradability. Although these xenobiotics degrade under natural condition, their residues have been detected in soil, sediments, and water due to their non-regulated usage practice. The over-reliance on pesticides has not only threatened our environment but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits throughout India. This paper highlights many of the cases where different organophosphates have been detected exceeding their respective MRL values. Some organophosphates detected are so hazardous that even WHO has listed them in class 1a and class 1b hazardous group. Presence of their residues in blood, milk, honey, and tissues of human and animals revealed their excessive use and bioaccumulating capabilities. Their intentional or unintentional uptake is causing thousands of deaths and severity each year. Most of the toxicity cases presented here are due to their uptake during a suicidal attempt. This shows how easily these harmful substances are available in the market.

Analytical methods using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of metabolites or contaminants (or both) in various tissues of aquatic organisms and in the aquatic environment have received increasing attention in the last few years. This review discusses the findings relevant to such procedures published between 2005 and 2015. The aim is to evaluate the advantages, restrictions, and performances of the procedures from sample preparation to mass spectrometry measurement. To support these discussions, a general knowledge on LC-MS/MS is also provided.

Nitrogen (N) is considered as a key element that triggers algal boom in the Indian River Lagoon (IRL), South Florida. Intensive agriculture may have contributed to increased N input into the IRL. Runoff and storm water samples were collected in representative agricultural fields and along waterways that connect lands to the IRL from April 2013 to December 2014. Concentrations of different N species (particulate N, dissolved organic N, dissolved NH₄ ⁺-N, and NO₃ ⁻-N) and related water physical–chemical properties were measured. Total N (TN) concentrations generally decreased from agricultural field furrows to discharging point of the waterways but were generally above the US EPA critical level (0.59 mg L⁻¹) for surface water. Organic N was the dominant form of dissolved N, followed by NO₃ ⁻-N, and dissolved NH₄ ⁺-N. Concentrations and speciation of N in water varied with sites and sampling times but were generally higher in summer and fall and lower in spring and winter, as affected by the seasonality of regional hydrology and agricultural practices. Correlations occurred between N concentration, water physical properties, and rainfall. This information has important implications in the development of best management practices to minimize the impacts of agricultural practice on N loading in the Indian River Lagoon.

Phenanthrene (Phe) with carcinogenicity is ubiquitous in the environment, especially in aquatic environment; its toxicity is greater. To help determine toxicity risk and remediation strategies, this study predicted seasonal fate of Phe in aquatic environment. Candidate mechanisms including biodegradation, sorption, desorption, photodegradation, hydrolysis and volatility were studied; the results for experiments under simulated conditions for normal, wet and dry seasons in the Yinma River Basin indicated that biodegradation in sediment, sorption, desorption, and volatility were important pathways for elimination of Phe from aquatic environment and showed seasonal variations. A microcosm which was used to mimic sediment/water system was set up to illustrate seasonal distribution and transport of Phe. A Markov chain was applied to predict seasonal fate of Phe in air/water/sediment environment, the predicted results were perfectly agreed with results of microcosm experiments. Predicted results with a Markov chain suggested that volatility and biodegradation in sediment were main elimination pathways, and contributions of elimination pathways showed seasonal variations; Phe was eliminated from water and sediment to negligible levels over around 250 h in August and over 1000 h in May; in November, Phe was eliminated from water to a negligible level while about 31 % of Phe amount still remained in sediment over 1000 h.

The reaction of zero-valent iron and aluminum with oxygen produced reactive oxidants that can oxidize 4-chlorophenol (4-CP). However, oxidant yield without metal surface cleaning to dissolve the native oxide layer or in the absence of ligands was too low for practical applications. The addition of oxalate (ox) to dissolved oxygen-saturated solution of Fe⁰–Al⁰ significantly increased oxidant yield because of the dissolution, pH buffer, and complexing characteristics of ox. Ox-enhanced reactive oxidant generation was affected by ox concentration and solution pH. The critical effect of ox dosing was confirmed with the reactive species of [Feᴵᴵ(ox)₀] and [Feᴵᴵ(ox)₂ ²⁻]. Systematic studies on the effect of the initial and in situ solution pH revealed that 4-CP oxidation was controlled by the continuous release of dissolved Fe²⁺ and Al³⁺, their fate, and the activation mechanisms of O₂ reduction. The degradation pathway of 4-CP in ox-enhanced Fe⁰–Al⁰/O₂ may follow the 4-chlorocatechol pathway. The robustness of the ox-enhanced Al⁰–Fe⁰–O₂ process was determined with one-time dosing of ox. Therefore, ox is an ideal additive to enhancing the Fe⁰–Al⁰/O₂ system for the oxidative degradation of aqueous organic pollutants.

The aims of the present study were to obtain the seafood dietary patterns of coastal residents, to determine the concentrations of heavy metals, and to evaluate the possible health risks caused by seafood intake. The daily food intakes of 24 types of seafood were collected from 738 participants from Xiamen, a southern Chinese coastal city, using food frequency questionnaire (FFQ) and dietary history method. One hundred and fifty-six samples of 14 types of highest intake seafood were collected from local markets for lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), and arsenic (As) determination. Health risks via seafood consumption were evaluated by calculating the target hazard quotient (THQ) and the total hazard index (HI) for carcinogenic and non-carcinogenic effects recommended by the US Environmental Protection Agency. The results showed that the seafood daily intake of Xiamen residents was 61.5 (2.14, 115) g/day. The concentrations of Pb, Cd, Cr, Hg, and As in seafood were ND–0.45 mg/kg, ND–0.19 mg/kg, ND–0.80 mg/kg, ND–0.70 mg/kg, and 0.32–16.9 mg/kg, respectively. Concentrations of Cd and As in some samples were higher than national limitation standards. Consumption of 14 common types of seafood would not pose non-carcinogenic risk. However, some types, such as sparuslatus, oyster, and porphyra tenera, would form a carcinogenic risk. Regardless of a carcinogenic or non-carcinogenic risk, As posed the highest risk on humans. The observed HI value for non-carcinogenic effect of all metals in all seafood reached 0.69–2.20, and the metal orders of risk can be listed as As > Hg > Cr > Cd > Pb, reiterating the risk of As is a matter of concern in seafood from Xiamen markets.

The aim of this study was to assess the potential of newly isolated yeast strains Schwanniomyces etchellsii M2 and Candida pararugosa BM24 to produce yeast biomass on olive mill wastewater (OMW). Maximum biomass yield was obtained at 75 % (v/v) OMW, after 96 h of incubation at 30 °C and 5 % (v/v) inoculum size. The optimal carbon/nitrogen (C/N) ratio was in the range of 8:1 to10:1, and ammonium chloride was selected as the most suitable nitrogen source. Under these conditions, a maximum biomass production of 15.11 and 21.68 g L⁻¹ was achieved for Schwanniomyces etchellsii M2 and Candida pararugosa BM24, respectively. Proteins were the major constituents of yeast cells (35.9–39.4 % dry weight), lipids were 2.8–5 % dry weight, and ash ranged from 4.8 to 9.5 % dry weight. Besides biomass production, yeast strains were also able to reduce toxicity and polluting parameter levels of the spent OMW-based medium. The practical results presented show that pH rose from initial value of 5.5 to 7.24–7.45 after fermentation. Approximately 23.1–41.4 % of the chemical oxygen demand (COD) and 15.4–19.2 % of the phenolic compounds were removed. The removal of phenolic compounds was associated with their biodegradation and their partial adsorption on yeast cells.