This study aimed to develop a visible and near-infrared (Vis/NIR) chemical imaging (400–1000 nm) technique to provide rapid prediction of the contents of sodium humate dissolved in aquaculture environment. Gray reference image with 5% reflectance value was first used to correct the obtained raw images in order to promote the reflectance values as compared to that with 99% reflectance for further spectral analysis. Successive projection algorithm (SPA) was introduced to extract four optimal wavelengths, which were then used for the establishment of back-propagation artificial neural network (BP-ANN) models. The results revealed that the BP-ANN model based on the selected four optimal wavelengths better performed ([Formula: see text] = 0.986, [Formula: see text] = 0.985, [Formula: see text] = 0.993, RMSEC = 0.329 mg/L, RMSECV = 0.433, RMSEP = 0.734 mg/L) than that based on the whole 381 wavelengths ([Formula: see text] = 0.978, [Formula: see text] = 0.996, [Formula: see text] = 0.977, RMSEC = 0.388 mg/L, RMSECV = 0.625, RMSEP = 0.734 mg/L). Finally, a series of chemical images were developed to clearly display the concentration distribution of the sodium humate dissolved in water, demonstrating that Vis/NIR chemical imaging technique was feasible to quantify the contents of sodium humate in the aquatic environment and could be further used for real-time monitoring the quality of aquaculture water.

The goal of this research was the electrooxidation (EO) of a nonionic surfactant nonylphenol decaethoxylate (NP-10) in aqueous solution and denim wastewater. Three different configuration systems were evaluated in batch cells using a boron-doped diamond (BDD) anode; copper, iron, and BDD were used as cathodes. The EO process was carried out in a batch process, in a glass cell with a capacity of 1000 mL. The anode surface area was 0.0307 m² and 1–3 A of current intensity were applied (3, 6, 10 mA/cm²) with an electrolysis time of 240 min for aqueous solution and 780 min for denim wastewater in order to investigate the degradation of the surfactant. The processes were analyzed in terms of chemical oxygen demand (COD) and total organic carbon (TOC). The maximum mineralization efficiency in aqueous solution for the BDD-Cu electrooxidation system was 92.2% for COD and 45.6% for TOC at pH 2 and 3 mA/cm² of current intensity. For denim wastewater, the removal efficiency was 44.1% for COD and 26.5% for TOC at pH 4.5 and 6 mA/cm² of current intensity, using a BDD-BDD system. The raw and treated (aqueous solution and denim) wastewater were characterized by UV-Vis and infrared spectroscopy.

Several studies have demonstrated that the most effective way to control eutrophication is to reduce phosphorus input at the scale. Water quality monitoring programs need to separately evaluate the different polluting sources to provide a suitable estimate of their relative contributions and thus accurately prioritize possible restoration actions. Urban area cases, where a portion of untreated wastewater is often discharged directly into receiving surface waters by combined sewer overflows (CSOs) during rain events, remain unsolved. In this context, an urban watershed located in Northern Italy with 60 CSOs has been chosen as a case study, and four rainy events have been hourly monitored. The proposed monitoring program consists of the combined use of caffeine and turbidity to estimate the volume and phosphorus load spilled into the river from the CSOs, respectively. Caffeine proved to be a suitable molecule to quantify the volume of wastewater discharged into water bodies, based on a per capita caffeine load of 10.8 mg inhab⁻¹ d⁻¹, estimated in the present work. This research showed that, on average, more than half of the total phosphorus loads transported by the river is due to the CSO discharges (56.5%). The knowledge of the prevailing responsibility of the CSO discharges for the Lambro River quality allows prioritizing effective restoration actions.

The pollution of the air and the monitoring of indoor air quality are receiving increasing attention worldwide, and many methodologies are now available to identify sources of pollution. However, there has been less work concerning the development of techniques to mitigate the effects of indoor air pollution. The aim of this study was to modify cotton fabrics with silver nanoparticles in order to use them in air conditioner filters. To achieve this goal, common fabrics purchased from commercial sources were evaluated in terms of their filtration properties (permeability, pressure drop, and collection efficiency) and were subsequently modified by impregnation with nanoparticles. This modification was achieved by immersion of the filters in nanoparticle suspensions. After drying the filter, collection of particulate matter was made in a toilet. The results showed that the filters impregnated with silver nanoparticles were able to significantly reduce the activity of microorganisms present in the airborne particulate matter, resulting in growth inhibition to the microorganisms which were retained (76.70%) and passed through (96.34%) the cotton filters.

Copper/zinc bioaccumulation and the effect of phytotoxicity on the growth of lettuce (Lactuca sativa L.) were studied in plastic vessels containing (i) non-contaminated soil, (ii) copper-contaminated soils at concentrations of 75.0 and 125.0 mg kg⁻¹, (iii) zinc-contaminated soils at concentrations of 1200 and 2400 mg kg⁻¹, and (iv) soil enriched with swine manure. Copper and zinc concentrations in lettuce leaves were determined by flame atomic absorption spectrometry during 42 days of growth. Copper concentrations from 0.92 to 13.06 mg kg⁻¹ were found in lettuce leaves grown in copper-contaminated soils and zinc concentrations from 58.13 to 177.85 mg kg⁻¹ were found in lettuce leaves grown in zinc-contaminated soils. Copper and zinc concentrations in lettuce leaves grown in swine manure-enriched soils ranged from 0.82 to 8.33 and 0.68 to 13.27 mg kg⁻¹, respectively. Copper and zinc bioaccumulation caused a decrease in lettuce growth in metal-contaminated soils and an increase in phytotoxicity effects when compared to growth in non-contaminated and manure-enriched soils. These findings were confirmed by measuring leaf areas and biomasses. Copper was less toxic to lettuce than zinc due to the different concentrations in the soil. Lettuce growth and development was better in the swine manure-enriched soil than non-contaminated soil, which indicates that swine manure is a safe agricultural biofertilizer when used in appropriate amounts to avoid metal bioaccumulation in soil and plants.

Fumigation is an important crop protection practice employed to control soil pathogens and diseases. Metham sodium and cadusafos are two commonly used soil fumigants for this purpose. However, little information is available on their effects on non-target soil organisms. The aim of the study was to determine the ecotoxicity of these chemical fumigants on earthworms (organismal responses and DNA damage) and soil microbial communities. Changes in soil microbial community function and structure were evaluated by means of Biolog™ Ecoplates and phospholipid fatty acid (PLFA) analyses, respectively. Both fumigants had a significant (p < 0.05) negative impact on all earthworm endpoints. Earthworms did not reproduce; biomass was affected negatively and manifested significant DNA damage with metham sodium causing more pronounced effects in comparison to cadusafos. The fumigants had an inhibitory effect on microbial growth. No lasting effects were observed in the community structure but cadusafos had a pronounced effect on the microbial community functional diversity. Metham sodium and cadusafos had varying effects on earthworm and microbial endpoints. This illustrates the importance of using different bioindicators to get a better understanding of the overall effects on the soil ecosystem.

Zeolite and limestone were tested for their capability of removing As and Fe from acidic water in batch and column experiments. Synthetic acidic water with 3 mg/L As and 50 or 100 mg/L Fe at pH = 2 was used in the column experiments. In the batch experiments, the As concentration, the mass of media, and the contact time were varied between 0.2 and 5 mg As/L, 0.5 and 50 g, and 0.25 and 42 h, respectively. Maximum As sorption capacity as indicated by the Langmuir model was 0.17 mg/g for zeolite and 1.3 mg/g for limestone, at 18-h contact time and 6.3 g/L medium concentration. Energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analyses revealed that As and Fe were retained in zeolite at the end of the batch experiments. The main factors affecting As and Fe removal efficiency and pH raising capacity were the contact time and the media concentration. This was confirmed in the column experiments, since zeolite and limestone columns presented 99% As removal, under a hydraulic loading rate of 21.8 mm/day. However, limestone columns presented a higher Fe removal: 99 versus 73% for zeolite. The results indicate that limestone could be more appropriate than zeolite when As and Fe are present under acidic conditions, given its higher capacity to remove both As and Fe and to raise pH.

Prometryn has been used in crop (e.g., corn and sorghum) field to prevent growth of annual grasses and broadleaf weeds for many years. As a moderately persistent herbicide in soil, prometryn may exert detrimental effects on environmental safety and crop production. The present study assessed the photodegradation of prometryn residues in soil by exploring a variety of factors such as soil moisture, temperature, and light exposure that potentially affect prometryn photodegradation. The dissipation rate of prometryn during a 14-day period of study was more than 90% under 15 (low pressure), 100, and 300 W (medium pressure) UV light exposure. The half-life of prometryn decay under UV light (53.5–116.4 h) was far less than that under xenon light (1131.6 h) and dark (3138.7 h) conditions. When the soil moisture (clay loam) was 60% of the field moisture capacity, it was most effective for prometryn photodegradation. The prometryn photodegradation on soil with 60% moisture level was increased with temperature and prometryn concentrations. The theoretical optimization scheme for eliminating prometryn in soil was recommended. The degraded products of prometryn under UV light and darkness were characterized using ultra high-performance liquid chromatography coupled to a linear ion trap-orbitrap hybrid mass spectrometer (UPLC-LTQ-orbitrap-MS/MS) and showed that prometryn decay in soil was through hydroxylation, dealkylation, and dethiomethylation pathways.

In developing countries, it is uncommon to find watersheds that have been the object of detailed environmental studies. It makes the assessment of the magnitude of environmental impacts and pollution of these sites difficult. This research demonstrated ways to understand the dynamics of river bottom sediments contamination, even for watersheds with a lack of environmental data. Based on geochemical affinity, we conducted a comprehensive study on the concentration of metals and metalloids. Then, we discussed the probable origin of the concentration of these elements at the bottom sediment along the Matipó River. The Matipó River is an important tributary of the Doce River, which stood out in international headlines because of the mining tailing dam disaster in Mariana, Minas Gerais, in 2015. The bottom sediment samples were taken in 25 stations located along the basin in different seasonal periods. The results showed that copper ([Formula: see text] = 464.7 mg kg⁻¹) and zinc ([Formula: see text] = 287.7 mg kg⁻¹) probably have natural origin, despite of the high concentrations. Lead ([Formula: see text] = 28.0 mg kg⁻¹), chromium ([Formula: see text] = 153.2 mg kg⁻¹), and nickel ([Formula: see text] = 41.8 mg kg⁻¹) also had high concentrations at some collecting stations, and this probably reflected the local natural conditions. The bedrock of the studying basin is dominantly composed of metabasalts and metatonalites interlayered with calcitic and dolomitic metalimestone. On the other hand, the concentration was worrisome in stations near human activities, possibly due to impacts caused by unsustainably agriculture and livestock.

The growing demand for and production of commercial silver nanoparticles (AgNPs) inevitably increases the risk for their environmental release and soil accumulation, which could have deleterious effects on plant growth and soil microorganism communities. However, to date, little is known about how AgNPs impact plant growth, seed quality, and soil microbial communities. We therefore evaluated wheat growth and seed quality after exposure to low concentration of AgNPs while characterizing the composition of the associated soil microbial community by high-throughput sequencing of 16S rRNA genes. Our results showed that low concentration of AgNPs (1 mg/kg in fresh soil) neither inhibited wheat seedling growth nor changed the amino acid content in wheat seeds. Interestingly, the soil microorganisms in the wheat-planted group had more diversity and richness than those in the bulk-soil group. The structure of the bacterial community was affected by AgNP exposure, most significantly during the transition from the seedling to the vegetative stage of the wheat, but recovered to normal level after 49 days of treatment. In conclusion, the results from this study highlight that the environmental risks associated with low concentration of AgNPs, which have clear bioeffects on soil microorganisms, warrant further investigation.