The efficiency and mechanism of anion exchange resin Nanda Magnetic Polymer (NDMP) for removal of fluorescent dissolved organic matter in biologically treated textile effluents were studied. The bench-scale experiments showed that as well as activated carbon, anion exchange resin could efficiently remove both aniline-like and humic-like fluorescent components, which can be up to 40 % of dissolved organic matter. The humic-like fluorescent component HS-Em460-Ex3 was more hydrophilic than HS-Em430-Ex2 and contained fewer alkyl chains but more acid groups. As a result, HS-Em460-Ex3 was eliminated more preferentially by NDMP anion exchange. However, compared with adsorption resins, the polarity of fluorescent components had a relatively small effect on the performance of anion exchange resin. The long-term pilot-scale experiments showed that the NDMP anion exchange process could remove approximately 30 % of the chemical oxygen demand and about 90 % of color from the biologically treated textile effluents. Once the issue of waste brine from resin desorption is solved, the NDMP anion exchange process could be a promising alternative for the advanced treatment of textile effluents.

In this study, batch experiments have been carried out to investigate the mechanism of fluoride uptake by layered double hydroxide (LDH) and calcined layered double hydroxide (CLDH). Furthermore, practical use of these synthetic minerals was studied in continuous mini-column experiments. In these column studies, groundwater from Ethiopia was tested. LDH and CLDH were synthesized with Mg/Al mole ratio of 2. From batch experimental study, LDH and CLDH have shown maximum removal capacity of 84 and 222 mg F⁻/g from aqueous solution, respectively. It was observed that fluoride removal was pH dependent with favorable pH range of 5–7 (max. at pH 6). The mechanism of removal is suggested to be ion exchange for LDH and a memory effect followed by surface precipitation reaction for CLDH. The presence of other anions lowered defluoridation capacity of LDH in the order of PO₄ ³⁻ > SO₄ ²⁻ > NO₃ ⁻ ≈ Cl⁻. From continuous experiments at 1 mM NaHCO₃, LDH showed maximum defluoridation capacity of 1.3 mg/g and CLDH up to 20 mg/g. It was also observed that increase of bicarbonate concentration to 10 mM lowered the fluoride uptake capacity of CLDH to 4 mg/g. The presence of 1 mM H₄SiO₄ further reduced fluoride uptake capacity to 3 mg/g. CLDH column tested with groundwater from the Rift Valley with 10.5 mg F⁻/L has shown maximum removal capacity of 2.2 mg F⁻/g. Regeneration of this column indicated that CLDH has a good potential to be re-used.

This work investigates the sorption behaviour of six hydrophobic organic compounds (HOCs) from the trichlorobenzenes (TCBs) and polycyclic aromatic hydrocarbons (PAHs) on Danube sediment using batch and column experiments, either in the presence or absence of carbon nanotubes (CNTs). For all HOCs investigated, nonlinear isotherms were obtained. Based on logKoc, it can be concluded that the Danube sediment has a higher sorption affinity for PAHs than TCBs. A positive correlation between HOC molecular hydrophobicity and sorption affinity was obtained, meaning that hydrophobic interactions play a significant role. There was a negative correlation between molecular hydrophobicity and the percentage of eluted HOCs, indicating that more hydrophobic molecules show less mobility in the sediment column. In the presence of CNTs in the sediment column, HOC concentrations in the column eluate decreased by factors of 2–3. Metal oxides and hydroxides on the surface of the sediment under the given experimental conditions had positively charged centres that caused the deposition of CNTs, leading to simultaneous sorption of organic compounds on both sediment organic matter (SOM) and CNTs. The increased retention of HOCs in the presence of CNTs on the sediment column reduces their mobility, which might also suggest that CNTs may be used for remediation of contaminated soils and sediments.

Myocardial infarction is the acute condition of myocardial necrosis that occurs as a result of imbalance between coronary blood supply and myocardial demand. Air pollution increases the risk of death from cardiovascular diseases (CVDs). The aim of this study was to investigate the effects of particulate matter (PM) on oxidative stress, the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) messenger RNA (mRNA) level induced by ischemia–reperfusion injury, and the protective effects of vanillic acid (VA) in the isolated rat heart. Male Wistar rats were randomly divided into eight groups (n = 10), namely control, VAc, sham, VA, PMa (0.5 mg/kg), PMb (2.5 mg/kg), PMc (5 mg/kg), and PMc + VA groups. Particles with an aerodynamic diameter <10 μm (PM₁₀) was instilled into the trachea through a fine intubation tube. Two days following the PM₁₀ instillation, the animal’s hearts were isolated and transferred to a Langendorff apparatus. The hearts were subjected to 30 min of global ischemia followed by 60 min of reperfusion. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), xanthine oxidase (XOX), and lactate dehydrogenase (LDH) were measured using special kits. Reverse transcription polymerase chain reaction (RT-PCR) was used to determine levels of iNOS and eNOS mRNA. An increase in left ventricular end-diastolic pressure (LVEDP), S–T elevation, and oxidative stress in PM₁₀ groups was observed. Ischemia–reperfusion (I/R) induction showed a significant augment in the expression of iNOS mRNA level and a significant decrease in the expression eNOS mRNA level. This effect was more pronounced in the PM groups than in the control and sham groups. Vanillic acid caused a significant decrease in LVEDP, S–T elevation, and also a significant difference in eNOS mRNA expression level, antioxidant enzymes, iNOS mRNA expression level, and oxidative stress occurred on myocardial dysfunction after I/R in isolated rat hearts. This study showed that PM₁₀ exposure had devastating effects on the myocardial heart, oxidative stress, and eNOS and iNOS mRNA expression levels. Vanillic acid was able to improve these parameters. Vanillic acid as a potent antioxidant could also provide protection against particulate matter-induced toxicity.

The influence of groundwater on the degradation of 1,4-dioxane (dioxane) by siderite-activated hydrogen peroxide coupled with persulfate was investigated through a series of batch experiments. The degradation of dioxane was considerably slower in groundwater compared to the tests conducted with ultrapure water. Additional tests were conducted to examine potential inhibitory effects of selected ions in isolation. The inhibition effect of anions on dioxane degradation, from strongest inhibition to weakest, was bicarbonate (HCO₃⁻) > sulfate (SO₄²⁻) > chloride (Cl⁻). The inhibition effect of cations on dioxane degradation, from strongest inhibition to weakest, was calcium (Ca²⁺) > potassium (K⁺) > magnesium (Mg²⁺). Bicarbonate and calcium ions, which are the most abundant ions in the groundwater used herein, resulted in the greatest decrease in dioxane degradation rate compared to the other constituents. The results of experiments conducted to evaluate their impact over a range of concentrations showed that dioxane degradation was reduced asymptotically with the increase in their concentrations. The results of this study reveal a potential inhibitory effect caused by groundwater constituents during the application of activated binary H₂O₂-persulfate for in situ treatment of organic contaminants in groundwater. This effect is attributed to radical scavenging, and its impact should be considered during the evaluation of total oxidant demand (TOD) prior to application.

In this paper, a method using liquid-liquid microextraction in a dynamic system combined with spectrophotometry was developed for preconcentration and determination of lead in samples of shrimp and oyster. In the procedure, a system is proposed in which the organic drop is maintained at the bottom of a glass tube, with the passage of a stream of aqueous solution, avoiding the use of a microsyringe. The method is based on the transfer of metal species present in the aqueous phase in the form of complexes with the ligand 2-(5-bromo-2-pyridylazo)-5-dimethylaminophenol (5-Br-PADAP) to the organic phase trichloroethylene. Experimental conditions, such as sample flow rate, concentration of the complexing reagent, extraction solvent, time of extraction, and pH, were optimized. Under optimized conditions, the limit of detection and quantification obtained were 0.48 and 1.60 μg L⁻¹, respectively. The accuracy was evaluated by the determination of lead in the certified reference material BCR-414, Plankton. The procedure was applied to the determination of lead in samples of shellfish, with recoveries ranging from 92 to 103 %. The method enabled a fast, accurate, and simple alternative for the determination of lead in seafood samples.

Synthesis parameters of nano manganese oxide (NMO) were tuned in order to maximize Cs and Co sorption efficiencies. The prepared oxide was characterized using various techniques including x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), SEM, and surface area analyzer. The sorption characteristics with respect to uptake of Cs, Co, and Pb were evaluated. An α − phase nano manganese oxide with a surface area of 165 m² g⁻¹ was synthesized. Maximum adsorption capacities were 230 mg g⁻¹ for Pb²⁺, 73 mg g⁻¹ for Cs⁺, and 26 mg g⁻¹ for Co²⁺. The intra-particle diffusion was the rate-limiting step in the case of Pb²⁺, whereas both intra-particle diffusion and film diffusion contribute to the rate-determining step in the adsorption process in the case of Cs⁺ and Co²⁺. FT-IR analyses reveled that Cs⁺ and Co²⁺ coordinated to vacancy sites of NMO as inner-sphere complexes, while Pb²⁺ formed bidentate corner-sharing complexes. NMO had high affinity for Pb²⁺ but was also effective for sorption of Cs⁺ and Co²⁺ over a wide pH range, even in the presence of Na⁺. HCl (0.5 mol L⁻¹) solution could regenerate the adsorbent successfully, and the NMO could be efficiently reused with lower production of residues. Thus, the prepared NMO can be efficiently used in wastewater treatment in terms of high adsorption capacity, easy availability, and low cost.

In this study, the effects of exposure to engineered nickel oxide (NiO 40–60 nm) and cobalt oxide (CoO <100 nm) nanoparticles (NP) were investigated on Artemia salina. Aggregation and stability of the aqueous NP suspensions were characterized by DLS and TEM. Acute exposure was conducted on nauplii (larvae) in seawater in a concentration range from 0.2 to 50 mg/L NPs for 24 h (short term) and 96 h (long term). The hydrodynamic diameters of NiO and CoO NPs in exposure medium were larger than those estimated by TEM. Accumulation rate of NiO NPs were found to be four times higher than that of CoO NPs under the same experimental conditions. Examinations under phase contrast microscope showed that the nanoparticles accumulated in the intestine of Artemia, which increased with increasing exposure concentration. Differences were observed in the extent of dissolution of the NPs in the seawater. The CoO NPs dissolved significantly while NiO NPs were relatively more stable. Oxidative stress induced by the NP suspensions was measured by malondialdehyde assay. Suspensions of NiO NPs caused higher oxidative stress on nauplii than those of CoO NPs. The results imply that CoO and NiO NPs exhibit toxicity on Artemia (e.g., zooplankton) that is an important source of food in aquatic food chain.

Agricultural practices are usually supported by several chemical substances, such as herbicides. Linuron and chlorbromuron are phenylurea herbicides largely used to protect crops from weeds, blocking photosynthesis by inhibition of the photosystem II complex. The former, also commercially known as lorox or afalon, is selectively used to protect bean and French bean plants, fennels, and celeriacs; the second, commercially known as maloran, is selectively used for carrots, peas, potatoes, soy sprouts, and sunflowers. Considering the widespread use of herbicides and, more generally, pesticides, it is important to clarify their involvement on human health, one of them concerning the possible direct or indirect effect on the genome of exposed populations. Here, we show that these herbicides are endowed by mutagenic properties, as demonstrated by an increased number of chromosomal aberrations (CAs) in two exposed Chinese hamster cell lines derived from ovary and epithelial liver, respectively. This was also confirmed by sister chromatid exchange (SCE) and micronucleus (MN) assays. Our present and previously obtained data clearly indicate that phenylurea herbicides must be used with great caution, especially for agricultural workers who use large amounts of herbicides during their work, and particular attention should be given to residues of these herbicides and their involvement in environmental pollution.

The National Environment Council (CONAMA Resolution 375/06) defined to achieve sanitation quality parameters, for the use of sewage sludge in agriculture, the adoption of additional pathogen reduction processes is necessary. Sludge that is stored for longer periods generally shows higher levels of sanitation, particularly on the helminth egg inactivations which are among the most resistant pathogens. The objective of this study was to monitor the Ascaris egg removal and inactivation efficiency of long-term storage of sludge from septic tanks and up-flow anaerobic sludge blanket (UASB) reactors, besides evaluating the influence of covering and manually revolving or stirring the sludge over a 2-year period. The study was undertaken in the cities of Fazenda Rio Grande and Apucarana, Southern Brazil. In total, 18 experimental treatments were installed and nine samples were assessed at weeks 0, 4, 9, 13, 17, 30, 47, 61, and 104. The standard defined in the CONAMA for class A sludge (one viable egg per 4 g TS) was reached for all treatments at 9 weeks of storage. Two years of storage were necessary in order for the covered, UASB-centrifuge sludge to reach CONAMA standards. Of the six treatments using septic sludge, only one achieved the established standard. This treatment was realized in Apucarana and involved a revolving/stirring process. The period of 104 weeks of storage of the septic sludge was not sufficient to completely inactivate Ascaris eggs for the other treatments. Between study locations, Apucarana performed better than Curitiba which is likely due to greater levels of insolation and temperature.