The goal of this research was to develop a new approach for tertiary water treatment, particularly disinfection and removal of refractory organic compounds, without adding any chemical. Hydrogen peroxide can indeed be produced from dissolved oxygen owing to electrochemical processes. Using various current intensities (1.0 to 4.0 A), it was possible to in situ produce relatively high concentration of H₂O₂with a specific production rate of 0.05 × 10⁻⁵ M/min/A. Likewise, by using ultraviolet-visible absorption spectroscopy method, it was shown that other reactive oxygen species (ROS) including HO*radical and O₃could be simultaneously formed during electrolysis. The ROS concentration passed from 0.45 × 10⁻⁵ M after 20 min of electrolysis to a concentration of 2.87 × 10⁻⁵ M after 100 min of electrolysis. The disinfection and the organic matter removal were relatively high during the tertiary treatment of municipal and domestic wastewaters. More than 90 % of organic compounds (chemical oxygen demand) can be removed, whereas 99 % of faecal coliform abatement can be reached. Likewise, the process was also effective in removing turbidity (more than 90 % of turbidity was removed) so that the effluent became more and more transparent.

Alum water treatment sludge is composed of amorphous hydroxyl-Al, which has variable charge surfaces with a large Brunauer-Emmett-Teller (BET) surface area (103 m⁻² g⁻¹) capable of specific adsorption of organic matter molecules, phosphate, and heavy metals. The effects of adding dried, ground, alum water treatment sludge (10 % w/w) to the feedstock for composting municipal green waste alone, green waste plus poultry manure, or green waste plus biosolids were determined. Addition of water treatment sludge reduced water soluble C, microbial biomass C, CO₂ evolution, extractable P, and extractable heavy metals during composting. The decrease in CO₂ evolution (i.e., C sequestration) was greatest for poultry manure and least for biosolid composts. The effects of addition of water treatment sludge to mature green waste-based poultry manure and biosolid composts were also determined in a 24-week incubation experiment. The composts were either incubated alone or after addition to a soil. Extractable P and heavy metal concentrations were decreased by additions of water treatment sludge in all treatments, and CO₂ evolution was also reduced from the poultry manure compost over the first 16–18 weeks. However, for biosolid compost, addition of water treatment sludge increased microbial biomass C and CO₂ evolution rate over the entire 24-week incubation period. This was attributed to the greatly reduced extractable heavy metal concentrations (As, Cr, Cu, Pb, and Zn) present following addition of water treatment sludge, and thus increased microbial activity. It was concluded that addition of water treatment sludge reduces concentrations of extractable P and heavy metals in composts and that its effect on organic matter stabilization is much greater during the composting process than for mature compost because levels of easily decomposable organic matter are initially much higher in the feedstock than those in matured composts.

Industrial effluent treatment plants (ETPs) are very important in protecting the environment and different life forms from harmful industrial waste. Hence, the efficiency of ETPs must be regularly monitored, particularly after major repair or replacement work. Present study evaluated the performance of an ETP over a period of 4 months, during which aeration tank (T1) of the activated sludge unit was replaced with a new one (T2). System had to be maintained operational during this transition, which warranted close monitoring of the system performance due to the daily load of hazardous industrial wastewater. Analysis showed that the raw wastewater was highly variable in composition and contained many hazardous organic and inorganic pollutants, such as heavy metals, bisphenol A and cyanoacetylurea. It showed significant toxicity against HepG2 cells in vitro. However, the ETP was found to successfully treat and detoxify the wastewater. Denaturing gradient gel electrophoresis (DGGE) analysis showed large temporal fluctuations in the ETP microbial community, which is consistent with the variable composition of wastewater. It indicated that functional stability of the ETP was not associated with stability of the microbial community, probably due to high microbial biodiversity and consequently high functional redundancy. In conclusion, the CETP showed consistent level of detoxification and microbial community dynamics after switching to T2, indicating successful development, acclimatization and commissioning of T2.

An approach consisting in combining in situ and laboratory experiments is often favoured for investigating the mechanisms involved in the weathering of the materials of the cultural heritage. However, the realistic simulation in the laboratory of the environmental conditions ruling the interactions of atmospheric compounds with materials is a very complex task. The aim of this work is to characterise CIME, a new chamber specially built to simulate the interactions between materials of the cultural heritage and the environment. The originality of this instrument is that beside the usual climatic parameters (temperature, relative humidity, solar radiation) and gaseous pollutants, it also allows the controlled injection of different types of particulate matter such as terrigenous, marine and anthropogenic. Therefore, varied realistic atmospheric environments (marine or urban) can be easily simulated within CIME. In addition to the technical description of CIME, this paper shows the first results obtained by the impact of gaseous pollutants on non-durable glass, bronze and limestone. The first experiments for the deposition of different particles (calcite, clays, soot and halite) are also presented.

The tools developed for acid mine drainage (AMD) prediction were proven unsuccessful to predict the geochemical behavior of mine waste rocks having a significant chemical sorption capacity, which delays the onset of contaminated neutral drainage (CND). The present work was performed in order to test a new approach of water quality prediction, by using a chelating agent solution (0.03 M EDTA, or ethylenediaminetetraacetic acid) in kinetic testing used for the prediction of the geochemical behavior of geologic material. The hypothesis underlying the proposed approach is that the EDTA solution should chelate the metals as soon as they are released by sulfide oxidation, inhibiting their sorption or secondary precipitation, and therefore reproduce a worst-case scenario where very low metal attenuation mechanisms are present in the drainage waters. Fresh and weathered waste rocks from the Lac Tio mine (Rio tinto, Iron and Titanium), which are known to generate Ni-CND at the field scale, were submitted to small-scale humidity cells in control tests (using deionized water) and using an EDTA solution. Results show that EDTA effectively prevents the metals to be sorbed or to precipitate as secondary minerals, therefore enabling to bypass the delay associated with metal sorption in the prediction of water quality from these materials. This work shows that the use of a chelating agent solution is a promising novel approach of water quality prediction and provides general guidelines to be used in further studies, which will help both practitioners and regulators to plan more efficient management and disposal strategies of mine wastes.

Higher uptake and translocation of copper (Cu) into plant tissues can cause serious physiological and biochemical alterations in root and leaf tissues of plants. The present study investigates the ameliorative role of salicylic acid (SA) and ascorbic acid (AsA) against Cu-induced toxicity changes in cotton genotypes (two parental lines (J208, Z905) and their hybrid line (ZD14)). To study the tolerance potential against Cu (100 μM) stress, 2-week-old cotton seedlings were pretreated with 100 μM either SA or AsA for three days. Elevated Cu concentration in nutrient media increased Cu accumulation in roots and shoots of all the three cotton genotypes studied. Roots were the main Cu storage site, followed by leaves and stems. Increased cellular Cu concentration significantly inhibited the root and shoot development, although leaf growth was more sensitive toward Cu toxicity. Cu-induced oxidative stress to cotton leaves was evident from significantly increased hydrogen peroxide (H₂O₂) contents and lipid membrane damage. Increasing Cu translocation toward cotton leaves strongly influenced the malondialdehyde (MDA) contents, which, in turn, inhibited biomass production. SA and AsA pretreated cotton seedlings showed better growth under Cu stress. Despite increase in overall Cu uptake, the SA-pretreated seedlings could defy Cu toxicity through inhibited Cu translocation and modification in the activities of antioxidative enzymes. Whereas, tolerance to Cu-induced toxicity in AsA pretreated plants was associated with Cu exclusion from tissues and reduction of the overall Cu uptake. The present study revealed that the alleviatory role of AsA was significantly higher than SA regarding Cu stress in our experimental cotton genotypes. Furthermore, the hybrid cotton genotype (ZD14) performed well followed by J208 and Z905 in the present experimental setup.

Human activities generate a great amount of sewage daily, which is dumped into the sewer system. After sewage-treatment processes, sewage sludge is generated. Such byproduct can be treated by different methods; the result of treatment is a stabilized compost of reduced pathogenicity that has a similar inorganic chemical composition to the raw sewage sludge. After such pretreatment, sewage sludge is called a biosolids, and it can be used in agriculture. In this contest, the present study evaluated the effects of a sample of biosolids on the perivisceral fat body of a diplopod. These invertebrates are soil organisms that play an important role in the dynamics of terrestrial ecosystems, and as a consequence, they are in contact with xenobiotics present in this environmental compartment. Special emphasis is given on the interpretation of the effects of complex mixtures in target organs of diplopods. A semiquantitative analysis for the evaluation of histopathological changes in the perivisceral fat body was proposed. The sample-induced histopathological and ultrastructural changes in individuals exposed to it, and the severity of the effects was positively related to the exposure time, resulting in the deaths of exposed individuals after 90 days. Thus, the results indicate the need for caution in the use of biosolids as well as the need for improving waste management techniques, so they will produce environmentally innocuous final products.

Elucidating the role of cyanobacteria in the biotransformation of arsenic (As) oxyanions is crucial to understand the biogeochemical cycle of this element and indicate species with potential for its bioremediation. In this study, we determined the EC₅₀ for As(III) and As(V) and evaluated the biotransformation of As by Synechococcus sp. through high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption fine structure spectroscopy (XAFS). Synechococcus sp. exhibited higher sensitivity to As(III) with an EC₅₀, ₉₆ ₕ of 6.64 mg L⁻¹ that was approximately 400-fold lower than that for As(V). Even though the cells were exposed to concentrations of As(III) (6 mg L⁻¹) approximately 67-fold lower than those of As(V) (400 mg L⁻¹), similar intracellular concentrations of As (60.0 μg g⁻¹) were observed after 30 days. As(V) was the predominant intracellular As species followed by As(III). Furthermore, organic As species such as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) were observed in higher proportions after exposure to As(III). The differential toxicity among As oxyanions indicates that determining the redox state of As in the environment is fundamental to estimate toxicity risks to aquatic organisms. Synechococcus sp. demonstrated potential for its application in bioremediation due to the high accumulation of As and production of As organic compounds notably after exposure to As(III).

This paper aims to report the assessment of trends in deaths and disability-adjusted life years (DALYs) attributed to ambient particulate matter (PM) pollution from 1990 to 2010 by sex and age in Iran. We used the data of the Global Burden of Disease (GBD) 2010 Study, and then we extracted its data on Iran for the years 1990, 2005, and 2010. The proportion of deaths and the DALYs caused by specific risk factors were assessed by using the comparative risk assessment and calculating the attributed burden of exposure level to each risk factor compared with the theoretical minimum level of risk exposure. Uncertainties in distribution of exposure, relative risks, and relevant outcomes calculation were disseminated into the estimates of the attributable deaths and DALYs. We found that the age-standardized death rate attributed to ambient PM pollution decreased to 27.90 cases per 100,000 populations from 1990 to 2010 [86, 95 % uncertainty interval (UI) 76–97 to 62; 95 % UI 54–71 per 100,000 populations, respectively]. This was mainly because of greater decrease in cardiovascular diseases (CVDs) than in the other diseases attributed to PM pollution. Despite a decrease in the total DALYs and mortality rate attributed to PM pollution, the death percent increased by 6.94 %, 95 % UI 6.06–7.90 % from 1990 to 2010. The number of the DALYs and death in age groups of more than 70 years increased in 2010 compared to that in 1990. The median percent change of the DALYs and death for all age groups shows that the DALYs and death increased by 6 % (95 % UI 8–19 %) and 45 % (95 % UI 30–60 %), respectively, in 2010 in comparison to that in 1990. The increase in the DALYs and mortality attributable to PM pollution emphasizes the necessity of the effective interventions for improving air quality, as well as for increasing the public awareness to reduce the exposure of vulnerable age groups to PM pollution.

The aim of this paper was to estimate the potential leakage of acrylamide monomer, used for flocculation in a settling basin, towards the groundwaters. Surface–groundwater interactions were conceptualized with a groundwater transport model, using a transfer rate to describe the clogged properties of the interface. The change in the transfer rate as a function of the spreading of the clogged layer in the settling basin was characterized with respect to time. It is shown that the water and the Acrylamide transfer rate are not controlled by the spreading of the clogged layer until this layer fully covers the interface. When the clogged layer spreads out, the transfer rate remains in the same order of magnitude until the area covered reaches 80 %. The main flux takes place through bank seepage. In these early stage conditions of a working settling basin, the acrylamide flux towards groundwaters remains constant, at close to 10 g/year (±5).