NaCl Improves Suaeda salsa Aniline Tolerance in Wastewater

Cigarette: an unsung anthropogenic evil in the environment

The world's population is growing steadily, and this trend is mirrored by a sharp rise in the number of people who smoke cigarettes. Instead of properly disposing of their cigarette waste, most people simply toss them aside, leading to serious environmental consequences. According to previous statistics, in 2012 alone, 6.25 trillion cigarettes were consumed by 967 million chain smokers. Past studies have shown that up to 30% of global litter is made up of cigarette waste. These discarded cigarette butts are non-biodegradable and contain over 7000 toxicants such as benzene, 1,3-butadiene, nitrosamine ketone, N-Nitrosonornicotine, nicotine, formaldehyde, acrolein, ammonia, aniline, polycyclic aromatic hydrocarbons, and various heavy metals. These toxicants have a negative impact on the habitats of wildlife and can cause serious health problems such as cancer, respiratory disorders, cardiac issues, and sexual dysfunction. Although it is still unclear how littered cigarettes affect plant growth, germination, and development, it is clear that they have the potential to harm plant health. Just like single-use plastic, trashed cigarette butts are a critical new rising form of pollution that requires scientific attention for effective recycling and disposal management. It is important to properly dispose of cigarette waste to protect the environment and wildlife, as well as to prevent harm to human health.

A Core-Shell Amino-Functionalized Magnetic Molecularly Imprinted Polymer Based on Glycidyl Methacrylate for Dispersive Solid-Phase Microextraction of Aniline

A core-shell amino-functionalized glycidyl methacrylate magnetic molecularly imprinted polymer (MIP) was synthesized by the suspension polymerization/surface imprinting method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mercury porosimetry, nitrogen gas adsorption–desorption, and elemental analysis. This MIP was used as the sorbent in dispersive solid-phase microextraction (DSPME) of aniline from textile wastewater prior to high-performance liquid chromatography-mass spectrometry (HPLC-MS) measurements. Since aniline is toxic and a probable human carcinogen, its determination in water is of great significance. This is a challenging task because aniline is usually present at trace levels. The effects of different DSPME variables on the preconcentration efficiency have been studied by using the Plackett–Burman screening design of experiments (DoE) followed by response surface methodology optimization using the Box-Behnken design. Thus, DoE enabled the investigation of several variables simultaneously. Under optimized conditions, aniline was effectively and selectively separated by a small amount of the DSPME sorbent and detected in real textile wastewater samples. The method detection limit of 1 ng mL−1 was attained, with good method linearity and acceptable recovery and precision. The results showed that the studied MIP could be a reliable DSPME sorbent for efficiently analyzing trace aniline in real wastewater samples.

Plant Volatiles of Lettuce and Chicory Cultivated in Aquaponics Are Associated to Their Microbial Community

In this work, an aquaponic cultivation system for Lactuca sativa (L.) and Chicorium intybus (L.) was compared to a hydroponic one, focusing on the main microbial populations related to food safety and their volatile compounds (VOCs), concluding with Spearman correlations among the microbes and VOCs. Different sections of both systems were sampled at the end of the commercial development of the plants. Plants cultivated in aquaponics were in general more contaminated than those from hydroponics, while for the cultivation waters a higher contamination of the hydroponics than aquaponics system was unexpectedly observed. Furthermore, the chicory exhibited higher levels of all microbial groups compared to lettuce grown under the same cultivation system. The results obtained also showed correlations between the distribution of some VOCs and microbial groups in the phyllosphere, while some examples of positive correlations between 2-nonanone (a positive phytostimulant compound) and anaerobic bacilli of the rhizosphere in lettuce were reported. So far, multivariate analysis of VOCs was able to discriminate on the basis of varieties but not on the cultivation systems. In conclusion, the microbial characteristics of the two ecosystems depended both on plant variety and cultivation method but further studies will need to deeply investigate the variables influencing the microbial quality of vegetable foods obtained by aquaponics. On the other hand, the analysis of the VOCs was more related to the microbial community of each plant variety considered, whatever the cultivation system. In precision agriculture, metabolomics may represent an opportunity to study the holobiome and through it the interactions between plants and their microbial populations, to possibly provide for a tool to assess the microbiological quality of vegetable foods obtained by aquaponic systems.

Desalination of Municipal Wastewater Using Forward Osmosis

Membrane technology has gained much ground in water and wastewater treatment over the past couple of decades. This is timely, as the world explores smart, eco-friendly, and cheap water and wastewater treatment technologies in its quest to make potable water and sanitation commonplace in all parts of the world. Against this background, this study investigated forward osmosis (FO) in the removal of salts (chlorides, sulphates, and carbonates) and organics (chemical oxygen demand (COD), turbidity, total suspended solids (TSS), and color) from a synthetic municipal wastewater (MWW), mimicking secondary-treated industrial wastewater, at very low feed and draw solution flow rates (0.16 and 0.14 L/min respectively), using 70 g/L NaCl solution as the draw solution. The results obtained showed an average of 97.67% rejection of SO₄²⁻ and CO₃²⁻ while Cl⁻ was found to enrich the feed solution (FS). An average removal of 88.92% was achieved for the organics. A permeation flux of 5.06 L/m².h was obtained. The kinetics of the ions transport was studied, and was found to fit the second-order kinetic model, with Pearson’s R-values of 0.998 and 0.974 for Cl⁻ and CO₃²⁻ respectively. The study proves FO as a potential technology to desalinate saline MWW.

Characterizing Humic Substances from Native Halophyte Soils by Fluorescence Spectroscopy Combined with Parallel Factor Analysis and Canonical Correlation Analysis

Soil is one of the principal substrates of human life and can serve as a reservoir of water and nutrients. Humic substances, indicators of soil fertility, are dominant in soil organic matter. However, soil degradation has been occurring all over the world, usually by soil salinization. Sustainable soil productivity has become an urgent problem to be solved. In this study, fluorescence excitation-emission matrices integrated with parallel factor analysis (PARAFAC) and canonical correlation analysis (CCA) were applied to characterize the components of fulvic acid (FA) and humic acid (HA) substances extracted from soils from the Liaohe River Delta, China. Along the saline gradient, soil samples with four disparate depths were gathered from four aboriginal halophyte communities, i.e., the Suaeda salsa Community (SSC), Chenopodium album Community (CAC), Phragmites australis Community (PAC), and Artemisia selengensis Community (ASC). Six components (C1 to C6) were identified in the FA and HA substances. The FA dominant fractions accounted for an average of 45.81% of the samples, whereas the HA dominant fractions accounted for an average of 42.72%. Mature levels of the HA fractions were higher than those of the FA fractions, so was the condensation degree, microbial activity, and humification degree of the FA fractions. C1 was associated with the ultraviolet FA, C2 was referred to as visible FA, C3 and C4 were relative to ultraviolet HA, C5 represented microbial humic-like substances (MH), and C6 referred to visible HA. C1, C2, C5 and C6 were latent factors of the FA fractions, determined using the CCA method and could possibly be used to differentiate among the SSC, CAC, PAC and ASC samples. C3, C4, C6 and C5 were latent factors of the HA fractions, which might be able to distinguish the ASC samples from the SSC, CAC and PAC samples. Fluorescence spectroscopy combined with the PARAFAC and CCA is a practical technique that is applied to assess the humic substance content of salinized soils.