A major inland alkalinity lake in Northeast China, the Chagan Lake, was studied for the changes of its water qualities over the past three decades. Water quality data, including total nitrogen (TN), total phosphorus (TP), pH, dissolved oxygen (DO), and fluoride (F⁻), were analyzed to derive key indices for guiding water quality management. Our study found that the Chagan Lake had an average trophic state index (TSI) ranging 50 to 70; the average TSI for TP ranging between 70 and 80, and the average TSI for TN being 50. Over the past three decades, the TSI values generally trended lower, but there was a slight uptrend from 2012 onwards. Seasonal variations in the concentrations of TN and TP were identified. The TSI values in September were higher than those in May, while the values of un-ionized ammonia (UIA) during rainy seasons were higher than those during dry seasons. The average values of alkalinity and F⁻ in the lake water exceeded the upper limits set in the Chinese water quality standards, i.e., 20 mg/L and 1 mg/L, respectively. It was defined that the evolution of lake water quality proceeded in four consecutive periods, namely natural, deterioration, improvement, and risk period; the improvement period benefitted from a historical water conservation project. Our study concluded that the amount of irrigation discharge into the Chagan must be monitored, and controlled, in order to sustain the critical ecological functions currently provided by the Chagan Lake.

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Within this study, we were interested in the effects of wastewater on the development of antimicrobial resistance. Microorganisms can relatively promptly adapt to evolutionary pressures of the environment, including antibiotics. Therefore, we tested how the adaptability of the model microorganism Salmonella enterica is affected by wastewater full of pharmaceuticals, illicit drugs, and other micropollutants. Wastewater samples had been taken from effluent of hospitals and from wastewater treatment plant (WWTP) Petržalka influent and effluent. In these samples, presence of 38 substances was monitored. The highest concentration was observed in case of tramadol, citalopram, venlafaxine, cotinine, atenolol, valsartan, carbamazepine, azithromycin, and ciprofloxacin. According to this data, we focused also on individual pharmaceutical compounds presented in wastewater samples in elevated concentrations. Effect on resistance development of two pain relief medications (carbamazepine, tramadol), hypotensive medications (atenolol, valsartan), and the nicotine metabolite (cotinine) was also investigated. For this study, we employed concentrations presented in wastewater as well as in urine of patients and/or users. To determine the frequency of mutations leading to ciprofloxacin resistance, we applied the modified Ames test employing the strain Salmonella Typhimurium. Resistance index increased in the case of all wastewater samples from conventional hospitals where we observed a 1.22–1.69-fold increase of mutations leading to ciprofloxacin resistance. Tested compounds caused rise of resistance index in lower concentrations found in wastewater. The most significant increase of resistance index was detected after carbamazepine treatment.

It is necessary to study the contamination of antibiotics in natural water bodies and assess its impact on ecological and human risks because of the large-scale use in the world. The occurrence and distribution characteristics of 45 antibiotics in reservoirs in Dongguan were investigated. Approximately, 77.8% of the detectable concentration of 35 antibiotics were found in the evaluation samples with concentration ranged from not detected (ND) to 729.59 ng/L, and dehydrated erythromycin was the highest one that appeared in Tongsha Reservoir. Fluoroquinolones and tetracyclines were the most abundant antibiotics with the detection frequency of 100% at sum concentration of 7.23–212.43 ng/L and 13.46–72.66 ng/L, respectively. Macrolides had a lower detected frequency but with highest concentration level at five kinds of antibiotics. Sulfamethoxazole, lincomycin, dehydrated erythromycin, pefloxacin, and panofloxacin were selected as important evaluation indicators. Sulfaguanidine, sulfamethoxazole, sulfisoxazole, dehydrated erythromycin, and clarithromycin that showed a significant correlation with Cl⁻ and SO₄²⁻ indicated that the pollution source of these antibiotics may be related to wastewater treatment plants. Among detected antibiotics, trimethoprim, norfloxacin, sarafloxacin, lincomycin, oxytetracycline, novobiocin, dehydrated erythromycin, and clarithromycin presented high risk to aquatic ecosystem in the reservoirs. There was no risk to humans at different ages of detected antibiotics, but it should attract attention because of the cumulative effects of antibiotics, which may cause potential risks to the human body.

Study’s objective was to evaluate spatial variability of herbaceous cover species community in vineyards cultivated in soil with increasing Cu levels in Pampa biome. Three vineyards, with increasing soil Cu available contents and a natural field area (NF), were selected. In each experimental area, soil Cu content, botanical composition, cumulative aerial biomass, and aerial part Cu concentration, in most frequent species, were evaluated. In total, 39 vascular plant species were identified, including four exotic species. Biodiversity indicators did not significantly correlate with soil Cu. However, botanical composition variation could be observed. In NF, Poaceae and Asteraceae families presented greater dry mass contribution, while this contribution decreased in higher soil Cu concentration areas. The Cu concentration and accumulation in plant aerial part were higher in older vineyards, as plant aerial part accumulated, in average, 13.8 mg Cu m⁻². Among species found in experimental fields, Ageratum conyzoides, a species known to form Cu-tolerant populations, occurred in most areas, especially in vineyards, presenting higher aerial Cu concentrations, with a mean of 126.47 mg kg⁻¹. Soil enrichment with Cu did not alter the vegetation’s biodiversity, but may have contributed to the botanical composition modification. The native species, P. plicatulum and A. conyzoides, presented a high bio-accumulation factor and are potential candidates for phytoremediation techniques.

This paper selects energy consumption data of 11 provinces in YRB and 19 provinces and cities in non-YRB from 2014 to 2016 and constructs a shared border Metafrontier non-radial directional short model, adding CO₂ and AQI indicators as undesirable factors, in order to evaluate the total efficiency and the input and output efficiencies of these two regions. The results are as follows. (1) From the changes in the score and ranking of the two regions’ total environmental efficiency, only two provinces in YRB show a slight decrease, while most of them show a stable or rising trend; seven provinces in non-YRB have a low rising rate. This means during the study period that YRB made more progress at energy conservation, emission reduction, and pollution control than other provinces and cities in non-YRB. (2) The efficiency scores of energy consumption, GDP, CO₂, and AQI emissions are different in each province. Overall, the situation of YRB is better than that of non-YRB. Not only is the efficiency score of each index higher, but the efficiency difference between provinces and cities within the region is small, which is conducive to the linkage effect of the region and the realization of green coordinated development.

Due to eutrophication and water quality deterioration in clear reservoirs, it is necessary to monitor and manage the main water parameters: concentration of total phosphorus (CTP), chemical oxygen demand (CCOD), chlorophyll-a (CCₕₗₐ), total suspended matter (CTSM), and Secchi disk depth (SDD). Five random forest (RF) models are developed to estimate these parameters in Xin’anjiang Reservoir, which is a clear drinking water resource in Zhejiang, China. Then, the spatio-temporal distributions of the parameters over 7 years (2013–2019) are mapped using GaoFen-1 (GF-1) images and the relationships with driving factors are analyzed. Our study demonstrates that the parameters’ distributions exhibited a significant spatio-temporal difference in Xin’anjiang Reservoir. Spatially, relatively high CTP, CCOD, CCₕₗₐ, and CTSM but low SDD appear in riverine areas, showing strong evidence of impact from the incoming rivers. Temporally, CCₕₗₐ and CTSM reached high values in summer and winter, whereas SDD and CTP were higher in the summer and autumn, respectively. In contrast, no significant seasonal variations of CCOD could be observed. This may be why CCOD is not sensitive to hydrological or meteorological factors. However, precipitation had a significant impact on CCₕₗₐ, CTP, SDD, and CTSM in riverine areas, though these parameters were less sensitive to meteorological factors. Moreover, the geomorphology of the reservoir and anthropogenic interference (e.g., tourism activities) also have a significant impact on the water quality parameters. This study demonstrates that coupling long-term GF-1 images and RF models could provide strong evidence and new insights to understand long-term dynamics in water quality and therefore support the development of corresponding management strategies for freshwater reservoirs.

As wastewater treatment systems that strengthen natural processes, constructed wetlands provide both ecosystem services and disservices. Manipulating both the physical and ecological structures of constructed wetlands has been the key to improve ecosystem services while reducing disservices. Herein, an experiment using simulated constructed wetlands was conducted to explore the effect of two different substrate sizes (fine sand or coarse sand), plant richness (1, 3, or 4 species), and plant species identity on ecosystem services. Results indicated that (1) only in microcosms with coarse sand, species richness enhanced nitrogen removal efficiency while reduced nitrous oxide emissions and that (2) the presence of Phalaris arundinacea increased nitrogen removal rate, and the presence of Rumex japonicus or Oenanthe javanica decreased nitrous oxide emissions; (3) however, the net ecosystem services (nitrogen removal, greenhouse gas emissions, biofuel production) of microcosms with fine sand were higher than those of microcosms with coarse sand, and (4) interestingly, there was no difference in net ecosystem services between microcosms with coarse sand (1033 yuan ha⁻¹ day⁻¹; 1 yuan ≈ 0.14 USD) and those with fine sand (1071 yuan ha⁻¹ day⁻¹) for the four-species mixtures. Hence, in practice, ensuring plant species richness with appropriate species in microcosms with coarse sand can improve ecosystem services to a level equal to that of microcosms with fine sand and help to prevent constructed wetlands from clogging.

Using the 2000–2018 MODIS Land Surface Temperature (LST) data and taking 11 cities (counties) in the northern slope of the central Tianshan Mountains in northwestern China as the study area, the spatial-temporal characteristics, landscape indices, centroid, and geo-information Tupu (carto-methodology in geo-information, CMGI) of surface thermal landscape (STL) were analyzed, and the paper draws the following results: (1) There are great differences in the diurnal and seasonal STL. The higher thermal levels are distributed more northerly in spring, summer, and autumn, and more southerly in winter. (2) In terms of class type level and landscape level, different landscape indices show different characteristics in diurnal and seasonal thermal landscapes. (3) Centroids at different thermal levels during the daytime are more dispersed than at nighttime in spring and summer, while the opposite is found in autumn. In winter, centroids of different thermal levels are concentrated in the southern and central-southern regions. During the period of 2000–2018, centroids of different thermal levels tend to move with the varying of STL. (4) The whole STL in same seasons changed little, transition usually happens between adjacent thermal levels. Overall, compared with the eastern monsoon area, there are similarities and differences in the characteristics of the STL.

It is important to provide a more comprehensive understanding of cadmium (Cd) input and output in different contamination zones. In this study, we choose 15 sampling areas in three types of contamination zones (industrial and mining, suburb, and rural) to systematically study the inventory of soil Cd input and output in Changzhutan (CZT) urban agglomerations, Hunan Province, China. The results showed that the value of total Cd input in industrial and mining (34.58 g/ha/year) was respectively about 2 and 3 times of that in suburb and in rural. Meanwhile, the total output flux in industrial and mining also presented highest value (38.67 g/ha/year) among the zones. As for the contributions, atmospheric deposition was responsible for 85–89% of the total input fluxes, which was significantly higher than those of irrigation water and fertilizer. Crop harvesting, especially straw removal, was the dominant output pathway, contributing 66–78%. Moreover, Cd annual balance illustrated that the net input fluxes under straw removal scenario were negative in all zones, and it was opposite under straw returning scenario. Further, the changes of soil Cd concentrations under straw returning and straw removal scenario were compared by a dynamic mathematical model. The modeling results presented that the soil Cd content continued to increase under straw returning in 100 years, while it was declining under straw removal scenario. This prediction indicated straw removal was an important remediation for Cd-polluted paddy soil, especially in Hunan. Nevertheless, more treatment measures need to conduct to reach the safety limits in paddy soil.