Impact of nanoplastics on the biodegradation, ecotoxicity, and key genes involved in imidacloprid metabolic pathways in papyrus (Cyperus papyrus L.).

Both nanoplastics (NPs) and imidacloprid (IMI) are widely distributed in the environment and have attracted significant attention due to their adverse effects on ecosystems. Constructed wetlands have the potential to remove IMI, but there is still limited understanding of how wetland plants interact with IMI, especially when influenced by different charged NPs. This study assessed their ecotoxicological effects, as well as the fate and transformation of IMI in papyrus (Cyperus papyrus L.) under the influence of different charged NPs and identified key driving genes in the plant. Results show that simultaneous exposure to positively charged PS-NH2 and IMI inhibited plant growth. The combined action of NPs and IMI intensified their toxicity, enhancing lipid peroxidation and altering antioxidant enzyme activities. The IMI removal efficiency, which was primarily driven by biodegradation, was 80.61%, 88.91%, and 74.71% in the IMI-alone, co-IMI/PS_COOH, and co-IMI/PS_NH2 systems, respectively. PS-NH2 restricted the roots-to-shoots translocation ability of IMI. PS-COOH enhanced IMI oxidation and nitro reduction, while PS-NH2 inhibited 2-OH-IMI dehydrogenation to IMI-olefin in papyrus. Transcriptomics and gene network analysis identified the genes encoding CYP450 enzymes, reductases, hydrolases, dehydrogenases, and peroxidases as those influencing IMI biodegradation. These enzymes play a crucial role in the hydroxylation, dehydrogenation, reduction, and oxidation processes during biodegradation of IMI in the presence of NPs. This study expands the understanding of the impact of differently charged NPs on the IMI remediation efficacy of papyrus, thus providing new insights into the phytoremediation of organic contaminants in constructed wetlands.

Do differentially charged nanoplastics affect imidacloprid uptake, translocation, and metabolism in Chinese flowering cabbage?

Micro(nano)plastics are ubiquitous in the environment. Among the microplastics, imidacloprid (IMI) concentration has been increasing in some intensive agricultural regions, thus receiving increased attention. However, only a few studies have investigated the interaction of nanoplastics (polystyrene (PS)) and IMI in vegetable crops. We studied the effects of positively (PS-NH2) and negatively (PS-COOH) charged nanoplastics on the uptake, translocation, and degradation of IMI in Chinese flowering cabbage grown in Hoagland solution for 28 days. PS-NH2 co-exposure with IMI inhibited plant growth, resulting in decreased plant weight, height, and root length. Translocation of IMI from the roots to the shoots was significantly lower in the presence of PS-NH2, whereas PS-COOH accelerated the accumulation and translocation of IMI in plants, thus potentially affecting IMI metabolism in plants. Notably, IMI-NTG and 5-OH-IMI were the two dominant metabolites. PS-NH2 co-exposure with IMI induced significant oxidation stress and considerably affected the activities of superoxide dismutase (SOD) and peroxidase (POD), indicating that the antioxidant defense system was the main mechanism for reducing oxidative damage. Notably, both positively and negatively charged nanoplastics can accumulate in Chinese flowering cabbage. Plants in the PS-COOH alone treatment group had the highest concentration of nanoplastics in both roots and shoots. The accumulation of nanoplastics, IMI, and its metabolites in plants raises concerns about their combined potential toxicity because it compromises food safety.

Potential for phytoremediation of neonicotinoids by nine wetland plants.

Broad-spectrum insecticides such as neonicotinoids tend to accumulate and detrimentally impact natural ecosystems. Accordingly, we aimed to assess the neonicotinoid phytoremediation abilities of nine wetland plant species commonly used in constructed wetland systems: Acorus calamus, Typha orientalis, Arundo donax, Thalia dealbata, Canna indica, Iris pseudacorus, Cyperus alternifolius, Cyperus papyrus and Juncus effusus. We assessed their removal of six neonicotinoids and explored the mechanisms responsible for the observed removal in a 28-day experiment. The planted systems effectively removed the neonicotinoids, with removal efficiencies of 9.5-99.9%. Compared with the other neonicotinoids, imidacloprid, thiacloprid and acetamiprid were most readily removed in the planted systems. C. alternifolius and C. papyrus exhibited the best removal performance for all six neonicotinoids. Based on our assessment of mass balance, the main removal processes were biodegradation and plant accumulation. Plants can enhance neonicotinoid removal through enhancing biodegradation. The differences in transport and accumulation behaviors may be related to plant species and physicochemical properties of neonicotinoids. Further research is merited on the toxicity of neonicotinoids to plants and microorganisms and the metabolic pathways by which neonicotinoids are broken down in wetland systems.

Irrigation using hybrid constructed wetland treated domestic sewage: Uptake of phthalic acid esters and antibiotics by Ipomoea aquatica forssk.

Irrigation with treated wastewater (WW) has been promoted to meet global water demands. This study investigates the occurrence and accumulation of targeted phthalic acid esters (PAEs) and antibiotics in soil and Ipomoea aquatica Forssk. irrigated with WW discharged from six hybrid constructed wetlands (HCWs), with evaluation of the associated human health risks. Results revealed that HCWs can effectively reduce the transfer of PAEs and antibiotics to soil and I. aquatica. HCW2 (VF-SF-HF) was found to be most efficient for the removal of PAEs (68.4%-95.3%) and antibiotics (28.5%-99.4%). Among the targeted PAEs, the concentration of bis (2-ethyl) hexylphthalate (DEHP) was the highest in irrigation water, soil and I. aquatica, while benzylphthalate (BBP) exhibited the highest bioconcentration factor (BCFF). Among the targeted antibiotics, the concentration of sulfapyridine (SPD) was highest in various environmental media, while norfloxacin (NFX) exhibited the highest BCFF. The properties of PAEs and antibiotics were found to be responsible for the differential uptake patterns. The estimation of the threshold of toxicological concern and hazard quotient showed that I. aquatica irrigated with HCWs treated wastewater presented a minor risk to human health. However, comprehensive safety evaluation is required for the widespread use of HCWs treated wastewater for irrigation purposes.

An optimization solution of a laser plane in vision measurement with the distance object between global origin and calibration points.

Equation construction of a laser plane demonstrates a remarkable importance for vision measurement systems based on the structured light. Here we create a simple 1D target with a cone at the bottom and a checkered pattern on the top to calibrate the equation of the laser plane in the view field of a camera. A group of 2D coordinates of the intersection points are extracted from the images with the 1D target at different positions. The objective function is constructed to optimize the coefficients of the laser plane by minimizing the difference between the distance from the feature point to the the origin point and the length of the 1D target. The projective lines of the optimized laser plane on the 3D calibration board overlap the real intersection lines in the experimental images. Finally, the comparison work about the influences of the non-Gaussian noise and point number is investigated experimentally. The experiments show that the method of the distance optimal object from the feature point to the origin point provides an accurate and robust calibration for the laser plane in structured light measurement.