Degradation of 2,4-D in soils by Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles combined with stimulating indigenous microbes

Purpose  

Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe₃O₄ nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also studied.     

Effect of Pb toxicity on leaf growth, antioxidant enzyme activities, and photosynthesis in cuttings and seedlings of Jatropha curcas L

Background  

Cuttings and seedlings of Jatropha curcas L. were exposed to different regimes of lead (Pb) stress as Pb(NO₃)₂ at 0 (CK), 0.5, 1, 2, 3, and 4 mM kg⁻¹ soil.     

Photochemical transformation of the thyroid hormone levothyroxine in aqueous solution

Purpose  

The direct aqueous photolysis of the thyroid hormone levothyroxine (T₄) has been studied.     

Wavelet transform-based artificial neural networks (WT-ANN) in PM10 pollution level estimation, based on circular variables

Introduction  

In this paper, a novel method in the estimation and prediction of PM₁₀ is introduced using wavelet transform-based artificial neural networks (WT-ANN).     

Interaction of Cr(VI) species with thermally treated brick clay

Purpose  

The purpose this research is to investigate the interaction of Cr(VI) species, present as Cr₂O₇²⁻, at ambient temperature with brick clay pre-fired at different temperatures.     

Effects of sulfur dioxide pollution on the translocation and accumulation of heavy metals in soybean grain

Background  

Open-top chambers were used to study the impact of simultaneous exposure to atmospheric SO₂ pollution and heavy metal contamination in soils on the metal contents and productivity of soybean plant.     

On the relationship between ozone and its precursors in the Pearl River Delta: application of an observation-based model (OBM)

Background, aim, and scope  

Photochemical smog, characterized by high concentrations of O₃ and fine particles, is of great concern in the urban areas, in particular megacities and city clusters like the Pearl River Delta.     

Study of the uncertainty in NO<Subscript>2</Subscript> chemiluminescence measurements due to the NO–O<Subscript>3</Subscript> reaction in sampling lines

Introduction  

The change in light intensity that takes place when an ambient air sample is drawn into the detection chamber of a chemiluminescence monitor generates changes in the concentrations of several species, such as NO₂, NO and O₃. Although this phenomenon has been known for several decades, there is still no commonly accepted approach on when or how to correct for it in NO₂ and O₃ readings.     

Adsorption of Pb,Cd, Cu,Zn, and Ni to titanium dioxide nanoparticles: effect of particle size,solid concentration,and exhaustion

Purpose  

Adsorption of metals (Pb, Cd, Cu, Ni, Zn) to TiO₂ nanoparticles and bulk particles was examined for use as a contaminant removal substrate as a function of particle size, sorbent concentration, and exhaustion.     

Assessing the potential exposure risk and control for airborne titanium dioxide and carbon black nanoparticles in the workplace

Purpose  

This study assessed the potential exposure risks for workers in the workplace exposed to airborne titanium dioxide nanoparticles (TiO₂-NPs) and carbon black nanoparticles (CB-NPs). The risk management control strategies were also developed for the NP engineering workplace.     

PM<Subscript>10</Subscript> source apportionment in the surroundings of the San Vicente del Raspeig cement plant complex in southeastern Spain

Introduction  

The concentrations of trace metals, ionic species, and carbonaceous components in PM₁₀ (particulate matter with aerodynamic diameters smaller than 10 μm) were measured from samples collected near an industrial complex, primarily composed of cement plants, in southeastern Spain, from September 2005 to August 2006.     

Transformation of atmospheric ammonia and acid gases into components of PM<Subscript>2.5</Subscript>: an environmental chamber study

Introduction  

The kinetics of the transformation of ammonia and acid gases into components of PM_2.5 has been examined. The interactions of existing aerosols and meteorology with the transformation mechanism have also been investigated. The specific objective was to discern the kinetics for the gas-to-particle conversion processes where the reactions of NH₃ with H₂SO₄, HNO₃, and HCl take place to form (NH₄)₂SO₄, NH₄NO₃, and NH₄Cl, respectively, in PM_2.5.     

Photocatalytic degradation of dichlorvos in aqueous TiO<Subscript>2</Subscript> suspensions

Introduction  

In the present work, we explored the kinetics of dichlorvos (2,2-dichlorvinyl dimethyl phosphate, DDVP) decay through UV-A light-induced TiO₂ photocatalysis at pH 4 and 9, and the formation of degradation intermediates and final products under specific experimental conditions. Experimental observations and theoretical considerations allowed us to suggest the degradation mechanism of DDVP by the UV/TiO₂ process in aqueous solution.     

Removal of alkylphenols from polluted sites using surfactant-assisted soil washing and photocatalysis

Background and purpose  

Surfactant-assisted soil washing and photocatalysis are well-known remediation processes of environmental concern. The application of photocatalysis to treat soil washing extracts containing 4-methylphenol, 4-ethylphenol and 4–tert-butylphenol in the presence of nonionic (C₁₂E₈ and C₁₂E₂₃) and anionic (SDS) surfactants and some of their binary mixtures was investigated in this work by studying the pollutants degradation in the presence of TiO₂ dispersions irradiated with simulated solar light.     

Response of denitrification genes <Emphasis Type="Italic">nirS</Emphasis>, <Emphasis Type="Italic">nirK</Emphasis>, and <Emphasis Type="Italic">nosZ</Emphasis> to irrigation water quality in a Chinese agricultural soil

Purpose  

Denitrification is an important biochemical process in global nitrogen cycle, with a potent greenhouse gas product N₂O. Wastewater irrigation can result in the changes of soil properties and microbial communities of agricultural soils. The purpose of this study was to examine how the soil denitrification genes responded to different irrigation regimes.     

Increases of dissolved organic carbon in temperate and boreal lakes in Quebec, Canada

Purpose  

Increases in dissolved organic carbon (DOC) concentrations have been reported in surface waters worldwide in the last 10 to 20 years. The causes behind these increases have been attributed to many factors, including climate change and decreasing depositions of atmospheric sulphate ( \textSO₄^{2 -} {\text{SO}}_4^{{{2} - }} ). Trends in DOC concentrations and their potential causal factors were examined in a network of 30 lakes lying in undisturbed temperate and boreal catchments in the province of Quebec, Canada.     

Gas phase reactions of unsaturated esters with Cl atoms

Background, aim, and scope  

Acrylate and methacrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon (CH₂=CHCOO– and CH₂=CCH₃COO–, respectively) and are widely used in the polymer plastic and resin production. Rate coefficients for Cl reactions for most of the unsaturated esters have not been previously determined, and a good understanding is needed of all the atmospheric oxidation processes of these compounds in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of photo-oxidants and therefore on health and environment.     

Night-time atmospheric chemistry of methacrylates

Background, aim, and scope  

Methacrylates are α, β-unsaturated esters that are widely used in the polymer plastics and resins production. Kinetic information of NO₃ radical reactions is especially scarce and a good understanding of all the atmospheric oxidation processes of these compounds is necessary in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of ozone and other photooxidants.     

Factors that have an effect on degradation of diclofenac in aqueous solution by gamma ray irradiation

Purpose  

Gamma ray irradiation is considered as an effective way to degrade diclofenac. However, due to the extensive coexisting substances in natural waters, the use of gamma ray irradiation for degradation is often influenced by multiple factors. The various factors that affect degradation efficiency, such as initial diclofenac concentration, initial pH, and the concentration of the additives including H₂O₂ (·OH radical promoter), CH₃OH (·OH radical scavenger), thiourea (·OH, H·, and e_aq⁻ scavenger), humic acid, and NO₃⁻ (coexisting substances in natural waters), are investigated. Furthermore, possible intermediate products are identified and corresponding transformation pathways are proposed.     

Water-soluble main ions in precipitation over the southeastern Adriatic region: chemical composition and long-range transport

Background, aim and scope  

Precipitation samples collected from 1995 to 2000 at meteorological station in the eastern outskirts of Herceg Novi (Montenegro) were analysed on Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^–, SO₄ ^2–, NO₃ ^– and NH₄ ⁺. Four-day backward trajectory simulations were conducted during the precipitation period to investigate the regional transport of main ions and their deposition in the region of the southeastern Adriatic Sea. The air mass trajectories were classified into six trajectory categories by the origin and direction of their approach to Herceg Novi.