In this study, the iron ore slag as the photocatalyst was introduced into the constructed wetland simulation system. The comparative experiment of the constructed wetland method and photocatalysis-constructed wetland combination method that treats the high-salt chromium-containing wastewater was carried out. The best HRT of the photocatalysis-constructed wetland combination system was studied. The effects of these two methods on biochemical oxygen demand (BOD₅), chemical oxygen demand (COD) removal and Cr (VI) reduction rate of the high-salt chromium-containing wastewater were analyzed after 14 cycles. The results showed that when optimal HRT was 4 h; the COD and BOD₅ of the wastewater reduced by 47% and 31%, and the reduction rate of Cr (VI) was 83% separately in the constructed wetland system. The COD and BOD₅ of the wastewater reduced by 83% and 42%, and the reduction rate of Cr (VI) was 96% separately in the photocatalysis-constructed wetland combination method system. At the same time, the changes of plant parameters under these two systems were studied, and the results showed that the addition of photocatalyst and hydrogen peroxide to constructed wetlands did not affect the normal indicators of plant growth. The results showed that the photocatalysis-constructed wetland combination method not only reduced the treatment time greatly, but also improved the quality of the treated wastewater significantly.

Tundra is one of the most sensitive biomes to climate warming. Understanding plant eco-physiological responses to warming is critical because these traits can give feedback on the effects of climate-warming on tundra ecosystem. We used open-top chambers following the criteria of the International Tundra Experiment to passively warm air and soil temperatures year round in alpine tundra. Leaf size, photosynthesis and anatomy of three dominant species were investigated during the growing seasons after 7 years of continuous warming. Warming increased the maximal light-saturated photosynthetic rate (P_max) by 43.6% for Dryas. octopetala var. asiatica and by 26.7% for Rhododendron confertissimum across the whole growing season, while warming did not significantly affect the P_max of V. uliginosum. The leaf size of Dr. octopetala var. asiatica and Rh. confertissimum was increased by warming. No marked effects of warming on anatomical traits of Dr. octopetala var. asiatica were observed. Warming decreased the leaf thickness of Rh. confertissimum and Vaccinium uliginosum. This study highlights the species-specific responses to climate warming. Our results imply that Dr. octopetala var. asiatica could be more dominant because it, mainly in terms of leaf photosynthetic capacity and size, seems to have advantages over the other two species in a warming world.

Hexavalent chromium Cr(VI) is a well-known environmental toxic metal that causes reprotoxicity in pregnant females. There are currently no appropriate interventions or treatments for Cr(VI) exposure during pregnancy. Herein, the protective effect of melatonin (MLT) against Cr(VI)-induced reprotoxicity is investigated by administrating MLT to pregnant mice exposed to Cr(VI). The results indicate that MLT effectively alleviates Cr(VI)-induced adverse pregnancy outcomes, restoring the decreased fetal weight and increased fetal resorption and malformation caused by Cr(VI) exposure to normal levels. MLT reduces the negative effects of Cr(VI) on follicular atresia and the development of primordial follicle in the maternal ovarian, thereby mitigating the decline in the reserve of primordial follicles. MLT alleviates Cr(VI)-induced oxidative stress, hence reducing the excessive accumulation of malondialdehyde in the maternal ovary. MLT inhibits Cr(VI)-induced apoptosis of ovarian granulosa cells and the expression of cleaved caspase-3 in the ovary. MLT reduces the increase in serum follicle-stimulating hormone caused by Cr(VI) exposure, while elevating anti-Mullerian hormone levels. We demonstrate that MLT reverses Cr(VI)-induced reprotoxicity in pregnant mice, opening up a new avenue for treating reproductive defects caused by environmental stress.

Cancers have always been the most difficult to fight, the treatment of cancer is still not considered. Thus, exploring new anticancer drugs is still imminent. Traditional Chinese medicine has played an important role in the treatment of cancer. Polyphenol oxidase (PPO) extracted from Edible mushroom has many related reports on its characteristics, but its role in cancer treatment is still unclear. This study aims to investigate the effects of PPO extracted from Edible mushroom on the proliferation, migration, invasion, and apoptosis of cancer cells in vitro and explore the therapeutic effects of PPO on tumors in vivo. A cell counting kit-8 (CCK8) assay was used to detect the effect of PPO on the proliferation of cancer cells. The effect of PPO on cancer cell migration ability was detected by scratch test. The effect of PPO on the invasion ability of cancer cells was detected by a transwell assay. The effect of PPO on the apoptosis of cancer cells was detected by flow cytometry. Female BALB/c mice (18–25 g, 6–8 weeks) were used for in vivo experiments. The experiments were divided into control group, model group, low-dose group (25 mg/kg), and high-dose group (50 mg/kg). In vitro, PPO extracted from Edible mushroom significantly inhibited the proliferation, migration, and invasion capability of breast cancer cell 4T1, lung cancer cell A549, and prostate cancer cell C4-2, and significantly promoted the apoptosis of 4T1, A549, and C4-2. In vivo experiments showed PPO inhibitory effect on tumor growth. Collectively, the edible fungus extract PPO could play an effective role in treating various cancers, and it may potentially be a promising agent for treating cancers.

When constructed wetlands are used to treat high-Pb wastewater, Pb may become a stress to wetland plants, which subsequently reduces treatment performance and the other ecosystem services. To facilitate the design and operation of constructed wetlands for treatment of Pb-rich wastewater, we investigated the irreversible inhibitory level of Pb for Typha latifolia through experiments in microcosm wetlands. Seven horizontal subsurface flow constructed wetlands were built with rectangular plastic tanks and packed with marble chips and sand. All wetlands were transplanted with nine stems of Typha latifolia each. The wetlands were batch operated in a greenhouse with artificial wastewater (10 L each) for 12 days. Influent to the seven wetlands had different concentrations of Pb: 0 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, and 500 mg/L, respectively. The results suggested that leaf chlorophyll relative content, relative growth rate, photosynthetic characteristics, activities of superoxide dismutase, peroxidase, and content of malondialdehyde were not affected when initial Pb concentration was at 100 mg/L and below. But when initial Pb concentration was above 100 mg/L, all of them were seriously affected. We conclude that high Pb concentrations wastewater could inhibit the growth of Typha latifolia and decrease the removal rate of wetlands.

The reductive removal of hexavalent chromium Cr6+ by iron slag from aqueous solutions was investigated. Iron slag was treated with a grinding miller and washed thoroughly. The redox reaction of iron slag onto the chromium Cr6+ was initiated by Fenton’s reagent (Fe2+/H2O2). The optimum conditions for adsorption of Cr6+ were found to be as follows: pH 3; photocatalyst dose 0.13 g/L; COD 400 mg/L; Cl- concentration 5 mg/L; matrix was gravel and construction waste and contact; reaction time was 270 min. In addition, the action mechanism of each factor in the wastewater was analyzed. In the reaction system, pH was the main influencing factor. When the pH was 3, the reduced rate of Cr6+ could reach 99%. High salinity had a certain effect on Cr6+ reduction. When the Cl- concentration was more than 6 mg/L, Cr6+ reduction rate was below 90%. Owing to high efficiency and low cost, iron slag could be used as an effective catalyst for Cr6+ removal from wastewater.