The transport and retention of nanoplastics (NP, 200 nm nanopolystyrene) functionalized with surface carboxyl (NPC), sulfonic (NPS), low-density amino (negatively charged, NPA−), and high-density amino (positively charged, NPA+) groups in seawater-saturated sand with/without humic acid were examined to explore the role of NP surface functionalities. The mass percentages of NP recovered from the effluent (Meff) with a salinity of 35 practical salinity units (PSU) were ranked as follows: NPC (19.69%) > NPS (16.37%) > NPA+ (13.33%) > NPA− (9.78%). The homoaggregation of NPS and NPA− was observed in seawater. The transport of NPA− exhibited a ripening phenomenon (i.e., a decrease in the transport rate with time) due to the high attraction of NP with previously deposited NP, whereas monodispersed NPA+ presented a low Meff value because of the electrostatic attraction between NPA+ and negatively charged sand. Retention experiments showed that the majority of NPC, NPS and NPA+ accumulated in a monolayer on the sand surface, whereas NPA− accumulated in multiple layers. Suwannee River humic acid (SRHA) could remarkably improve the transportability of NPC, NPS, and NPA− by increasing steric repulsion. The strong attraction between NPA+ and the deposited NPA+ in the presence of SRHA triggered the weak ripening phenomenon. As seawater salinity decreased from 35 PSU to 3.5 PSU, the increase in electrostatic repulsion of NP-NP and NP-sand enhanced the transport of NPC, NPS, and NPA−, and the ripening of NPA− breakthrough curves disappeared. In deionized water, NPC, NPS, and NPA− achieved complete column breakthrough because the electrostatic repulsion between NP and sand intensified. However, the Meff values of NPA+ in 3.5 PSU seawater and deionized water presented limited increments of 15.49% and 23.67%, respectively. These results indicated that the fate of NP in sandy marine environments were strongly affected by NP surface functionalities, seawater salinity, and coexisting SRHA.

The papaya is a commercially important fruit commodity worldwide. Being a climacteric fruit, it is highly perishable. Thus, for the transportation of papaya fruit for long distances without loss of quality, it is necessary to avoid the autocatalytic effect of ethylene in accelerating the ripening of the fruit. This work addresses the application of heterogeneous photocatalysis to the degradation of ethylene. A TiO₂ sol-gel supported on polypropylene (PP) and on glass was used as the catalytic material, and a UV-A lamp was employed as the radiation source. Initially, a concentration of 500 ppbv ethylene was exposed to the catalyst material irradiated by UV-A radiation. A sensitive photoacoustic spectrometer was used to monitor the photocatalytic activity. The TiO₂ sol-gel supported on the glass substrate was more efficient than on the PP in degrading the ethylene. Under direct UV-A exposure, the skin appearance of ‘Golden’ papaya was damaged, depreciating the fruit quality and thus preventing its commercialization. However, the feasibility of the heterogeneous photocatalysis to preserve the fruit quality was achieved when ethylene was removed from the storage ambient using fans, and then, this plant hormone was degraded by a reactor set apart in a ventilation closed system.

Di-n-butyl phthalate (DBP) is a typical endocrine-disrupting chemical with higher detection frequency and concentration in agricultural soil (particularly in paddy-field soil of Guangdong Province) of China. In this study, a greenhouse experiment was conducted to investigate variation in uptake and accumulation of DBP by 20 rice cultivars and to screen low DBP-accumulating cultivars. DBP concentrations in plants varied greatly with rice cultivars, growth stages, and tissues. The highest DBP concentrations in both roots and shoots were observed at the ripening stage, with concentrations 2–100-fold higher than those at tillering, jointing, and flowering stages. At the ripening stage, DBP concentrations decreased in the order of leaf > root > stem > grain, and significant differences of DBP concentrations were observed among various rice cultivars. Moreover, the magnitude of variation in DBP concentrations among various cultivars was greater in stems and grains than in roots and leaves. The translocation factors of DBP from roots to stems and from shoots to grains were <1.0, and those from stems to leaves were almost >1.0. Overall, cultivars Yuxiangyouzhan, Jinnongsimiao, Tianyou 122, and Wuyou 380 accumulated relatively lower DBP in grains, resulting in lower DBP exposure. The DBP uptake and translocation pathways in rice require further investigation. Graphical abstract ᅟ

The authors analyzed certain species and varieties of fruit tree in which applied crop technology is used and also undergoes the effects of climate change. The aim is to extend productive crop varieties, resistant to disease and pests, in order to obtain superior yields. The research was conducted in orchards located in northwestern Romania (on 8.59 ha), intensively cultivated with apple, plum, and almond species. The blooming period of the species and fruit production was studied in 2009, the first year of the farm’s commercial production, and then compared to figures from 2016 to see the changes that occurred. Climatic conditions were studied throughout the period of existence of the farm (2002–2016). To determine the influence of the climatic factor on the blooming and production periods, respectively, every year is considered having pre-blooming, blooming, and ripening periods. It was found that climate change influences the annual biological cycle of the trees: the vegetative rest period of the trees shortens, the tree vegetation begins earlier in the spring, and the blooming period is advanced by as much as 10 days compared to normal cultivated varieties. All these factors have direct repercussions on the quantity of production.

The extensive use of plasticizers containing di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) results in high residual concentrations in agricultural soils and poses potential risks to human health through the food chain. Here, two rice cultivars with low (Fengyousimiao) and high (Peizataifeng) phthalic acid ester (PAE) accumulation were grown in leaching columns packed with DBP- and DEHP-contaminated soils to investigate their transport, fraction distribution, and accumulation in soil-rice-water system. Significant differences in soil vertical distribution of DBP and DEHP were observed among the two cultivars, sterilization and non-sterilization treatments. Both DBP and DEHP could leach to the bottom layer even though their concentrations in both soil and pore water decreased along with soil depth. DBP and DEHP concentrations in pore water were significantly correlated with those in corresponding soil layer at ripening stage. The available fractions including desorbing and non-desorbing fractions were predominant in the total concentrations of DBP and DEHP of soils. DBP and DEHP storages in coarse soil fractions (i.e., coarse and fine sands) with higher bioavailability displayed higher bioconcentration factors compared to finer soil fractions (i.e., silt and clay), and bioconcentration factors of Peizataifeng were higher than those of Fengyousimiao. The variations in vertical migration and accumulation of DBP and DEHP by the two cultivars implied different adverse effects on the security of groundwater and food.