Recent technologies for glyphosate removal from aqueous environment: A critical review.

The growing demand for food has led to an increase in the use of herbicides and pesticides over the years. One of the most widely used herbicides is glyphosate (GLY). It has been used extensively since 1974 for weed control and is currently classified by the World Health Organization (WHO) as a Group 2A substance, probably carcinogenic to humans. The industry and academia have some disagreements regarding GLY toxicity in humans and its effects on the environment. Even though this herbicide is not mentioned in the WHO water guidelines, some countries have decided to set maximum acceptable concentrations in tap water, while others have decided to ban its use in crop production completely. Researchers around the world have employed different technologies to remove or degrade GLY, mostly at the laboratory scale. Water treatment plants combine different technologies to remove it alongside other water pollutants, in some cases achieving acceptable removal efficiencies. Certainly, there are many challenges in upscaling purification technologies due to the costs and lack of factual information about their adverse effects. This review presents different technologies that have been used to remove GLY from water since 2012 to date, its detection and removal methods, challenges, and future perspectives.

Leaching of metals from red mud and toxicity in human cells in vitro.

Toxicity of red mud, a waste from alumina production, was studied using human breast cancer MCF-7 cells. Culture medium was prepared by mixing water for 3 days with the red mud and removing solid particles afterwards (red mud water). Culture for 48 h of the cells in this medium in neutral pH decreased the cell viability, as analyzed by the MTT-test, and increased the formation of reactive oxygen species. Thus, neutralization does not eliminate the toxicity of red mud. In preliminary experiments, a combined effect of five metals (Cr, Li, V, Al, As) increased the formation of ROS (reactive oxygen species) statistically significantly. Each element separately did not have a similar effect. In environmental applications, red mud is likely to be used after activation. In this work, the red mud was activated using hydrochloric acid to study the physical and chemical properties before and after the treatment. Activation increased the specific surface area of red mud from 16 m2 g-1 to 148 m2 g-1, which is beneficial in many environmental applications such as in the adsorptive removal of pollutants. After activation, leaching of some elements from the red mud decreased (e.g. Al from 38.0 to 0.56 mg L-1, As from 21.0 to 2.1 µg L-1, V from 172.0 to 29.8 µg L-1) while some increased (e.g. Li from 0.04 to 2.81 mg L-1, Cr from 0.35 to 3.23 mg L-1).

Vanadia-Zirconia and Vanadia-Hafnia Catalysts for Utilization of Volatile Organic Compound Emissions.

Utilization is a sustainable and interesting alternative for the destructive treatment of volatile organic compounds due to avoided CO2 emission. This work concentrates on the development of active and sulfur-tolerant catalysts for the utilization of contaminated methanol. Impregnated and sol-gel prepared vanadia-zirconia and vanadia-hafnia catalysts were thoroughly characterized by N2 sorption, analytical (S)TEM, elemental analysis, XRD and Raman spectroscopy, and their performances were evaluated in formaldehyde production from methanol and methanethiol mixture. The results showed higher activity of the sol-gel prepared catalysts due to formation of mono- and polymeric vanadia species. Unfortunately, the most active vanadia sites were deactivated more easily than the metal-mixed oxide HfV2O7 and ZrV2O7 phases, as well as crystalline V2O5 observed in the impregnated catalysts. Metal-mixed oxide phases were formed in impregnated catalysts through formation of defects in HfO2 and ZrO2 structure during calcination at 600 °C, which was evidenced by Raman spectroscopy. The sol-gel prepared vanadia-zirconia and vanadia-hafnia catalysts were able to produce formaldehyde from contaminated methanol with high selectivity at temperature around 400 °C, while impregnated catalysts required 50-100 °C higher temperatures.

Precarious work increases depression-based disability among male employees.

BACKGROUND: Precarious employment is a potent occupational health risk, but little is known about its association with work-related disability and its causes. This study analyzes whether employment precariousness is associated with receiving disability pension (DP) due to depression and whether this differs according to gender. METHODS: Statistics Finland's Quality of Work Life Surveys (1997, 2003, 2008 and 2013) were merged with register-based DP data obtained from the Finnish Centre for Pensions. The survey material was used to measure employment precariousness using five variables: fear of job loss, poor employability prospects, previous unemployment, low earnings and temporary contracts. We followed 20-60-year-old employees until 2016 and studied Cox proportional hazard ratios (HRs) for receiving DP among women and men, adjusting for sociodemographic covariates, working conditions and health at baseline. RESULTS: The overall risk of receiving DP tended to increase as precarious job features accumulated. Among men, a higher risk of receiving DP due to depression was associated with previous unemployment [HR 2.2, 95% confidence interval (CI) 1.1-4.2] and poor employability (HR 2.4, 95% CI 1.3-4.7), whereas no corresponding association was found among women. CONCLUSIONS: Employment precariousness may reflect a psychological stress mechanism that predisposes the individual to mental health problems, predicting future disability. Work disability risk shows gendered differences depending on the cause of DP. Promoting employability at workplace and policy levels could offset the health risks associated with precariousness.

Ceramic hydroxyapatite foam as a new material for Bisphenol A removal from contaminated water.

Ceramic hydroxyapatite foam (CF-HAP) was prepared by combining slip-casting and foaming methods. The prepared CF-HAP was characterized by scanning electron microscopy (SEM), physisorption of N2, Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results of the specific surface area and SEM analyses revealed that the used shaping method provides CF-HAP with a wide range of porosity including macro and mesopores. Based on FTIR and XRD analyses, the CF-HAP is similar to pure well-crystallized hydroxyapatite. The adsorption results revealed that 94% of the BPA with a concentration of (40 mg/L) was effectively removed from the water and that the maximum adsorption capacity was higher in acidic than in basic medium. The thermodynamic studies indicated that the adsorption reaction was spontaneous and endothermic in nature. The adsorption capacity increased with the temperature and the BPA is chemisorbed on the ceramic foam. The isotherm data fitted slightly better with the Liu than with the Freundlich and Langmuir models suggesting that the adsorption was homogeneous and occurred only in the monolayer. The adsorption process depends largely on the BPA concentration and the results fitted well with the pseudo-first-order model. This confirms that the interaction between the BPA and the CF-HAP was mainly chemical in nature. The FTIR analysis of the used and fresh CF-HAP showed that all the hydroxyl and phosphorus bands characteristic of the hydroxyapatite shifted after adsorption of Bisphenol A. This suggests that the adsorption of Bisphenol A occurred in the sites of the hydroxyapatite. Therefore, it can be concluded that the CF-HAP has the potential to be used as an adsorbent for wastewater treatment and purification processes.

Oxidation of Dichloromethane over Au, Pt, and Pt-Au Containing Catalysts Supported on γ-Al2O3 and CeO2-Al2O3.

Au, Pt, and Pt-Au catalysts supported on Al2O3 and CeO2-Al2O3 were studied in the oxidation of dichloromethane (DCM, CH2Cl2). High DCM oxidation activities and HCl selectivities were seen with all the catalysts. With the addition of Au, remarkably lower light-off temperatures were observed as they were reduced by 70 and 85 degrees with the Al2O3-supported and by 35 and 40 degrees with the CeO2-Al2O3-supported catalysts. Excellent HCl selectivities close to 100% were achieved with the Au/Al2O3 and Pt-Au/Al2O3 catalysts. The addition of ceria on alumina decreased the total acidity of these catalysts, resulting in lower performance. The 100-h stability test showed that the Pt-Au/Al2O3 catalyst was active and durable, but the selectivity towards the total oxidation products needs improvement. The results suggest that, with the Au-containing Al2O3-supported catalysts, DCM decomposition mainly occurs via direct DCM hydrolysis into formaldehyde and HCl followed by the oxidation of formaldehyde into CO and CO2.

Porous carbon materials derived from olive kernels: application in adsorption of organic pollutants.

Adsorption of organic pollutants (OPs), bisphenol A, and diuron, from aqueous solutions onto porous carbon materials (CMs) prepared from olive kernels, have been investigated. The effects of initial pH, initial OP concentration, temperature, and contact time on the adsorption capacity were studied. The adsorption of bisphenol A and diuron onto CMs was found to be optimal at pH 5.6 and 6.9, respectively. It was noticed that the adsorption of those organic pollutants from aqueous solution declined with increasing temperature and the process is exothermic. The rate of adsorption followed the second order kinetic equation. The equilibrium results showed that Langmuir model fits well with the data. The maximum adsorption capacities obtained using the best CM were 476 and 434 mg g-1 for BPA and diuron, respectively. The results showed that CMs made from olive kernels are an excellent and inexpensive biomass waste-derived sorbent. Graphical abstract.

Photocatalysis and catalytic wet air oxidation: Degradation and toxicity of bisphenol A containing wastewaters.

Bisphenol A (BPA) is a commonly used chemical in consumer products. It is an endocrine disrupter that has potentially significant negative effects on human health. The use and chemical stability of BPA have resulted in the appearance of the chemical in wastewaters. Since the current wastewater treatment technologies are not effective enough to remove BPA, new methods to degrade BPA are required. In this paper, we report the efforts made towards developing a bi-functional catalyst for consecutive catalytic wet air oxidation-photocatalytic water treatment. It was found that 2.5% Pt/Ti0.8Ce0.2O2 is a potential bi-functional catalyst for the consecutive treatment. Concentration and toxicity of BPA were successfully reduced by catalytic wet air oxidation. Although BPA was further reduced by photocatalysis, it was not reflected in further decrease of cell toxicity. Thus wet-air oxidation combined with photocatalysis is a promising approach for the reduction of BPA.

Perceived gender discrimination at work and subsequent long-term sickness absence among Finnish employed women.

BACKGROUND: Discrimination has many kinds of consequences for employees and their well-being. This is an important aspect when considering certain issues, such as the need to prolong working careers. The objective of this study is to investigate the association of perceived gender discrimination at work with subsequent long-term sickness absence among Finnish employed women. METHODS: We used a representative sample of Finnish employed women (n = 8000) merged with register-based follow-up data. We examined the relationships of control variables with gender discrimination using cross tabulation, and the relationships of the controls with subsequent sickness absences were examined using analyses of variance. The effects of gender discrimination on long-term sickness absence were analysed using a negative binomial model. RESULTS: Perceived gender discrimination increased long-term sickness absence among employed women after controlling for age discrimination, various background, work and health-related factors. Employed women reporting perceived gender discrimination had a 1.4-times higher incidence rate ratios (IRR) of long-term sickness absence than those not reporting perceived gender discrimination. The association was strongest among upper-level socioeconomic group (IRR 2.2) in the adjusted model. CONCLUSIONS: Our findings suggest that gender discrimination at work is a risk factor for long sickness absence among women. Therefore, it is essential to increase awareness and prevention of discrimination to reduce negative gender-based treatment at work.

Structured carbon foam derived from waste biomass: application to endocrine disruptor adsorption.

In this paper, a novel structured carbon foam has been prepared from argan nut shell (ANS) was developed and applied in bisphenol A (BPA) removal from water. The results showed that the prepared carbon foam remove 93% of BPA (60 mg/L). The BPA equilibrium data obeyed the Liu isotherm, displaying a maximum uptake capacity of 323.0 mg/g at 20 °C. The calculated free enthalpy change (∆H° = - 4.8 kJ/mol) indicated the existence of physical adsorption between BPA and carbon foam. Avrami kinetic model was able to explain the experimental results. From the regeneration tests, we conclude that the prepared carbon foam has a good potential to be used as an economic and efficient adsorbent for BPA removal from contaminated water. Based on these results and the fact that the developed structured carbon foam is very easy to separate from treated water, it can serve as an interesting material for real water treatment applications.

Activated carbon produced from waste coffee grounds for an effective removal of bisphenol-A in aqueous medium.

Bisphenol-A is widely used chemical in industry and unfortunately often detected in natural waters. Considered as an emerging pollutant, bisphenol-A represents an environmental problem due to its endocrine-disrupting behavior. The production of activated carbon from alternative precursors has shown to be attractive in the removal of emerging pollutants from the water. Activated carbon was produced from waste coffee by physical and chemical activation and applied in the removal of bisphenol-A. The samples were characterized by elemental analysis, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and analysis of textural properties. Bisphenol-A adsorption experiments showed that the chemically activated carbon was more efficient due to its high specific surface area (1039 m2/g) compared to the physically activated carbon (4.0 m2/g). The bisphenol-A adsorption data followed the pseudo-second-order model and Langmuir isotherm, which indicated a maximum adsorption capacity of 123.22 mg/g for chemically activated carbon. The results demonstrated a potential use of the coffee grounds as a sustainable raw material for the production of chemically activated carbon that could be used in water treatment.

Relational justice, economic fluctuations, and long-term sickness absence: a multi-cohort study.

Objectives Previous studies mainly based on the public sector show that organizational justice is associated with a lower risk of sickness absence (SA). The purpose of this study is to analyze this association with multi-cohort data from different employment sectors and to discover whether the association varies according to the general economic context or financial situation of the workplace. Methods Cross-sectional Finnish Quality of Work Life surveys from 1997, 2003, and 2008 were combined with data on long-term SA obtained from the Finnish Social Security Institution. The associations between SA periods in the three years following each survey and perceived relational justice, general economic context, and the perceived financial situation of the workplace were analyzed with negative binomial regression. Results Higher level of relational justice was statistically significantly associated with lower rate of SA after controlling for baseline health, but not after controlling for job control and job demands. An interaction was found with relational justice and the financial situation of the workplace. Higher level of relational justice was related to a lower risk of SA when the financial situation of the workplace was stable, but there was a higher risk of SA when the financial situation was insecure. Conclusions The association between relational justice and a lower risk of SA is in line with previous studies when the financial situation of the workplace is stable. In unstable economic conditions, employees may have the courage to take sick leave when they are ill if they are fairly treated by their supervisor.

Precarious work and the risk of receiving a disability pension.

AIMS: Precarious employment is an emerging determinant of occupational health, but its association with work-related disability remains little understood. We operationalised precarious work as a multidimensional construct and examined how the accumulation of precarious job features predicts the incidence of receiving a disability pension (DP). METHODS: The study comprised 13,228 employees aged 20-54 who had been interviewed for the Finnish Quality of Work Life Surveys in 1984, 1990, 1997, or 2003. We measured precarious work with five variables that reflect both subjective and objective job insecurity: the threat of dismissal/unemployment; poor employability; low earnings; previous unemployment; and temporary contract. An eight-year follow-up was merged with the pooled cross-sectional data, and Cox proportional hazard ratios (HR) for receiving a DP were compared between the insecurity measures, controlling for sociodemographic covariates, job characteristics and health at the baseline with a step-wise procedure. RESULTS: Precarious employees had an elevated risk of receiving a DP (all covariates adjusted for). The risk of receiving a DP was associated with subjective job insecurity, with the strongest indicator being poor employability. The association between the threat of unemployment and receiving a DP was weak before controlling for health. Among objective insecurity measures, low earnings and earlier unemployment were weakly connected to receiving a DP before controlling for sociodemographic covariates, job characteristics and health. CONCLUSIONS: We recommend the evaluation of several precarious job features in future studies. The risk of receiving a DP could potentially be offset by improving individuals' employability.

Mobile knowledge workers and traditional mobile workers: Assessing the prevalence of multi-locational work in Europe.

This article contributes to the discussion on flexible working by assessing empirically the prevalence of mobile, multi-locational work in Europe (EU-28, Norway and Switzerland). Drawing on data from the Sixth European Working Conditions Survey, the prevalence of multi-locational work across Europe is examined in terms of the knowledge intensity of the work. Knowledge-intensive occupations are characterised by a high level of individual skills, typically acquired through tertiary-level education, and a high degree of autonomy combined with frequent use of ICT. According to the results, working on mobile sites - a practice that augments working in the primary workplace - is most common in northern European countries, where the proportion of knowledge-intensive occupations is high. However, even in the Nordic region, knowledge workers predominantly work at their employers' premises. This finding is in marked contrast with the hyperbole and expectations which assume that ICT allows knowledge workers to work free from the constraints of time and space. Agriculture, construction and transport workers still represent the largest proportion of the mobile workforce. Knowledge-intensive job features, however, predict the adoption of working at home. The analysis adds to the literature on flexible working by taking into account both traditional and knowledge-intensive forms of multi-locational work as well as providing a cross-national comparison.

Steam activation of waste biomass: highly microporous carbon, optimization of bisphenol A, and diuron adsorption by response surface methodology.

Highly microporous carbons were prepared from argan nut shell (ANS) using steam activation method. The carbons prepared (ANS@H2O-30, ANS@H2O-90, and ANS@H2O-120) were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared, nitrogen adsorption, total X-ray fluorescence, and temperature-programmed desorption (TPD). The ANS@H2O-120 was found to have a high surface area of 2853 m2/g. The adsorption of bisphenol A and diuron on ANS@H2O-120 was investigated. The isotherm data were fitted using Langmuir and Freundlich models. Langmuir isotherm model presented the best fit to the experimental data suggesting micropore filling of ANS@H2O-120. The ANS@H2O-120 adsorbent demonstrated high monolayer adsorption capacity of 1408 and 1087 mg/g for bisphenol A and diuron, respectively. The efficiency of the adsorption was linked to the porous structure and to the availability of the surface adsorption sites on ANS@H2O-120. Response surface method was used to optimize the removal efficiency of bisphenol A and diuron on ANS@H2O-120 from aqueous solution. Graphical abstract ᅟ.

Toward new benchmark adsorbents: preparation and characterization of activated carbon from argan nut shell for bisphenol A removal.

The use of argan nut shell as a precursor for producing activated carbon was investigated in this work. Two activated carbons AC-HP and AC-Na were prepared from argan nut shell by chemical activation method using phosphoric acid (H3PO4) and sodium hydroxide (NaOH), respectively. Textural, morphological, and surface chemistry characteristics were studied by nitrogen physisorption, TGA, SEM, TXRF, FTIR, XRD, and by determining the pHPZC of the AC-HP. The adsorption experiments revealed that AC-HP was more efficient in adsorption of BPA due to high specific surface area (1372 m2/g) compared to AC-Na (798 m2/g). The obtained adsorption data of BPA on AC-HP correlated well with the pseudo-second-order model and the Langmuir isotherm (Qmax = 1250 mg/g at 293 K). The thermodynamic parameters (ΔG° < 0, ΔH° < 0, and ΔS° < 0) indicate that adsorption of BPA on AC-HP was spontaneous and exothermic in nature. The regeneration of AC-HP showed excellent results after 5 cycles (95-93%). This work does not only provide a potential way to use argan nut shell but also represents a sustainable approach to synthesize AC-HP, which might be an ideal material for various applications (energy storage, catalysis, and environmental remediation).

FT-IR-cPAS--new photoacoustic measurement technique for analysis of hot gases: a case study on VOCs.

This article describes a new photoacoustic FT-IR system capable of operating at elevated temperatures. The key hardware component is an optical-readout cantilever microphone that can work up to 200 °C. All parts in contact with the sample gas were put into a heated oven, incl. the photoacoustic cell. The sensitivity of the built photoacoustic system was tested by measuring 18 different VOCs. At 100 ppm gas concentration, the univariate signal to noise ratios (1σ, measurement time 25.5 min, at highest peak, optical resolution 8 cm(-1)) of the spectra varied from minimally 19 for o-xylene up to 329 for butyl acetate. The sensitivity can be improved by multivariate analyses over broad wavelength ranges, which effectively co-adds the univariate sensitivities achievable at individual wavelengths. The multivariate limit of detection (3σ, 8.5 min, full useful wavelength range), i.e., the best possible inverse analytical sensitivity achievable at optimum calibration, was calculated using the SBC method and varied from 2.60 ppm for dichloromethane to 0.33 ppm for butyl acetate. Depending on the shape of the spectra, which often only contain a few sharp peaks, the multivariate analysis improved the analytical sensitivity by 2.2 to 9.2 times compared to the univariate case. Selectivity and multi component ability were tested by a SBC calibration including 5 VOCs and water. The average cross selectivities turned out to be less than 2% and the resulting inverse analytical sensitivities of the 5 interfering VOCs was increased by maximum factor of 2.2 compared to the single component sensitivities. Water subtraction using SBC gave the true analyte concentration with a variation coefficient of 3%, although the sample spectra (methyl ethyl ketone, 200 ppm) contained water from 1,400 to 100k ppm and for subtraction only one water spectra (10k ppm) was used. The developed device shows significant improvement to the current state-of-the-art measurement methods used in industrial VOC measurements.

Fourier transform infrared photoacoustic multicomponent gas spectroscopy with optical cantilever detection.

The sensitivity of photoacoustic spectroscopy was improved with the invention of optical cantilever detection (PAS-OCD). However, the ability of present PAS-OCD devices to carry out multicomponent detection is poor. To overcome this, a Fourier transform infrared photoacoustic spectrometer with optical cantilever detection (FT-IR-PAS-OCD) prototype was assembled. In this article, the first evaluation and performance tests of the prototype are described. Selectivity, sensitivity, and the linearity of the signal response are evaluated. The linear response was studied for methane and carbon dioxide and confirmed in the whole analyzed concentration range from 500 to 3500 ppm and from 2500 to 17500 ppm, respectively. The calculated signal-to-noise ratio (SNR) and limit of detection were 2027 and 0.5 ppm for methane and 1362 and 4 ppm for carbon dioxide, with a measurement time of 100 seconds. Selectivity was studied with a multicomponent gas mixture of propene, methane, carbon dioxide, and methylmercaptane. The results indicate that a quantitative analysis of all components in the mixture is possible using the FT-IR-PAS-OCD.

Effect of process parameters on catalytic incineration of solvent emissions.

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al(2)O(3) catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.