Relation between solid phase speciation and oral/lung bioaccessibility of metal(loid)s polluted soils in inhabited area: Contribution of synchrotron-based experiment.

The presence of contaminated sites/soils in or near cities can pose significant risks to public health. The city of Viviez (France) was taken in reference site bears significant industrial responsibility, particularly in zinc metallurgy, with the presence of a now rehabilitated smelter. This has led to soil contamination by zinc (Zn), lead (Pb), arsenic (As), and cadmium (Cd), with concentrations reaching up to 4856 mg kg, 1739 mg kg, 195 mg kg, and 110 mg kg, respectively.

A review: Biological technologies for nitrogen monoxide abatement.

Nitrogen oxides (NO), including nitrogen monoxide (NO) and nitrogen dioxide (NO), are among the most important global atmospheric pollutants because they have a negative impact on human respiratory health, animals, and the environment through the greenhouse effect and ozone layer destruction. NO compounds are predominantly generated by anthropogenic activities, which involve combustion processes such as energy production, transportation, and industrial activities. The most widely used alternatives for NO abatement on an industrial scale are selective catalytic and non-catalytic reductions; however, these alternatives have high costs when treating large air flows with low pollutant concentrations, and most of these methods generate residues that require further treatment.

Chlorine Concentration Modelling and Supervision in Water Distribution Systems.

The quality of the drinking water distributed through the networks has become the main concern of most operators. This work focuses on one of the most important variables of the drinking water distribution networks (WDN) that use disinfection, chlorine. This powerful disinfectant must be dosed carefully in order to reduce disinfection byproducts (DBPs).

Hydrolysis and Methanogenesis in UASB-AnMBR Treating Municipal Wastewater Under Psychrophilic Conditions: Importance of Reactor Configuration and Inoculum.

Three upflow anaerobic sludge blanket (UASB) pilot scale reactors with different configurations and inocula: flocculent biomass (F-UASB), flocculent biomass and membrane solids separation (F-AnMBR) and granular biomass and membrane solids separation (G-AnMBR) were operated to compare start-up, solids hydrolysis and effluent quality. The parallel operation of UASBs with these different configurations at low temperatures (9.7 ± 2.

Investigating the relationship between speciation and oral/lung bioaccessibility of a highly contaminated tailing: contribution in health risk assessment.

Anthropogenic activities such as industrial, mining, or agricultural are the main sources of environmental contamination. One of the most problematic contaminations concerns metals and metalloids from mining activities. This contamination raises the question of the environmental risk induced and the spread of this pollution (geographical and trophic) and the associated health risk.

Decreasing environmental impact of landfill leachate treatment by MBR, RO and EDR hybrid treatment.

A prototype pilot plant testing for a novel complete treatment strategy for landfill leachate aimed to decrease its environmental impact was studied. Pre-treatment of leachate was performed by means of a membrane biore-actor (MBR) decreasing inorganic carbon concentration by 92 ± 8% and achieving N removals of 85%. Suspended solids removal in the MBR >99.

Coagulation-flocculation and moving bed biofilm reactor as pre-treatment for water recycling in the petrochemical industry.

Water recycling and reuse is of important value in water-using sectors like petrochemical industry. The aim of this research was to optimise the pre-treatment of petrochemical wastewater to undergo a further membrane treatment, with the final objective of water recycling within the same industry. Laboratory coagulation-flocculation tests prior to biological treatment were performed using Actiflo® Veolia commercial technology and an optimal coagulant dose of 30 mg/L ferric chloride was obtained.

Use of nitrogen and oxygen isotopes of dissolved nitrate to trace field-scale induced denitrification efficiency throughout an in-situ groundwater remediation strategy.

In the framework of the Life+ InSiTrate project, a pilot-plant was established to demonstrate the viability of inducing in-situ heterotrophic denitrification to remediate nitrate (NO)-polluted groundwater. Two injection wells supplied acetic acid by pulses to an alluvial aquifer for 22months. The monitoring was performed by regular sampling at three piezometers and two wells located downstream.

Life cycle and human health risk assessments as tools for decision making in the design and implementation of nanofiltration in drinking water treatment plants.

A combined methodology using life cycle assessment (LCA) and human health risk assessment (HHR) is proposed in order to select the percentage of water in drinking water treatment plants (DWTP) that should be nanofiltered (NF). The methodological approach presented here takes into account environmental and social benefit criteria evaluating the implementation of new processes into conventional ones. The inclusion of NF process improves drinking water quality, reduces HHR but, in turn, increases environmental impacts as a result of energy and material demand.

Ecological screening indicators of stress and risk for the Llobregat river water.

The objective of this article is to develop and apply several simple and rough indicators for river aquatic ecosystems assessment in order to screen potential chemical stressors. Several indicators, based on toxicity (PNEC) and on legislation levels (EQS) have been developed. All these indicators are ratios that were calculated by using public and private data of concentrations of a large list of compounds during a period of five years, including metals and organic compounds in the lower part of the Llobregat river basin at the intake of the drinking water treatment plant.

Model-based study of nitrite accumulation with OUR control in two continuous nitrifying activated sludge configurations.

Achievement of partial nitrification relies on the different characteristics of the microorganisms involved in the two steps of nitrification (AOB, ammonium oxidizing bacteria and NOB, nitrite oxidizing bacteria). Several configurations and conditions have been used to achieve partial nitrification taking into account their different responses in front of some environmental conditions like pH, temperature (T), dissolved oxygen (DO) and the inhibitory compounds free ammonia (FA) and free nitrous acid (FNA). This work is a theoretical study about the utilization of a control strategy based on controlling OUR by manipulating the influent flow-rate together with additional changes in T, pH or DO for achieving stable partial nitrification.

Expert control for a stable operation of a partial nitrification system to treat highly concentrated ammonium wastewater.

This work presents the application of expert control strategies for a successful and stable operation of partial nitrification. A high-strength ammonium wastewater was treated in a continuous pilot plant with a configuration of three reactors in series plus a settler. The system was operated at mild temperature (around 25 degrees C) and at high sludge retention time to obtain a significant nitrifying biomass concentration.

Total and stable washout of nitrite oxidizing bacteria from a nitrifying continuous activated sludge system using automatic control based on Oxygen Uptake Rate measurements.

Partial nitrification (ammonium oxidation to nitrite) has gained a lot of interest among researchers in the last years because of its advantages with respect to complete nitrification (ammonium oxidation to nitrate): decrease of oxygen requirements for nitrification, reduction of COD demand and CO(2) emissions during denitrification and higher denitrification rate and lower biomass production during anoxic growth. In this study, an extremely high-strength ammonium wastewater (3000-4000mg NL(-1)) was treated in a continuous pilot plant with a configuration of three reactors in series plus a settler. The system was operated under the maximum possible volumetric nitrogen loading rate, at mild temperature (around 25 degrees C), with high sludge retention time (around 30d) and significant nitrifying biomass concentration (average of 1800+/-600mg VSSL(-1)).

Model-based design of a control strategy for optimal start-up of a high-strength nitrification system.

The objective of this study was to define an automatic control loop for the start-up of a high-strength nitrification system to achieve a rich nitrifying biomass from a poor nitrifying sludge by means of simulation tools. The used model considered the nitrification as a two-step model with substrate and non-competitive inhibitions. Two control strategies (on-off controller and proportional-integral (PI) controller) were designed, simulated and compared.

Respirometric calibration and validation of a biological nitrite oxidation model including biomass growth and substrate inhibition.

The modelling of the nitrification process of high-strength ammonium wastewater must be designed to consider it as a two-step reaction with substrate inhibition. Consequently, kinetic and stoichiometric parameters of both steps are required. In this work, the second step in the nitrification process was studied: a biological nitrite oxidation model was formulated, calibrated and validated using only oxygen uptake rate (OUR) measurements.