Phytoremediation potential of duckweeds (Lemna minuta, Lemna minor) to remove nutrients from simulated wastewater was analyzed. In two separate experiments, the two species were grown for 28 days in waters enriched with nitrate and phosphate to simulate nutrient concentrations of domestic wastewater. Water physical and chemical measurements (temperature, pH, conductivity, oxygen) and plant physiological and biochemical analysis (biomass, relative growth rate–RGR, nutrient and chlorophyll contents, peroxidative damage, bioconcentration factor–BCF) were made to test and compare the phytoremediation capacity of the two Lemna species. L. minuta biomass increased almost tenfold during the time-course of the treatment resulting in a doubling of the mat thickness and a RGR of 0.083 ± 0.001 g/g day. Maximum frond content of phosphate was reached by day 21 (increase over 165%) and nitrate by day 7 (10%). According to the BCF results (BCF > 1000), L. minuta was a hyperaccumulator for both nutrients. On the other hand, L. minor biomass and mat thickness decreased continuously during incubation (RGR = − 0.039 ± 0.004 g/g day). In L. minor fronds, phosphate content increased until day 14, after which there was a decrease until the end of the incubation. Frond nitrate content significantly decreased by day 7, but then remained relatively constant until the end of the experiment. L. minor proved to be hyperaccumulator for phosphates, but not for nitrates. Results indicated L. minuta has a greater potential than L. minor to remove both nutrients by bioaccumulation, especially phosphates, demonstrated also by better physiological and biochemical responses. However, during the incubation, the chlorophyll content of L. minuta mat did continuously decrease and peroxidative damage had increased until day 14, indicating that the system was under some kind of stress. Strategies to avoid this stress were discussed.

At a building or dwelling scale, accurate evaluation of the water savings potential from rainwater harvesting (RWH) can be achieved by simulating the performance of the RWH system using a balance equations model. At an urban scale, water savings potential is usually estimated from the balance between the annual rainfall and annual water consumption. This approach has limited accuracy since it assumes an infinite storage capacity and it disregards the variability of the ratio between the water collected and water consumed in each building. This paper presents a methodology to evaluate rainwater harvesting potential at an urban level taking into consideration buildings’ characteristics and consumption pattern. The complexity of the model is balanced with the format and detail of the information available to allow fast and easy implementation with few resources. The proposed methodology is applied to the city of Lisbon, Portugal, located on the Atlantic coast of the Mediterranean climate region. The results demonstrate water savings potential ranging from 16 to 86% depending on the buildings and occupancy characteristics. The spatial variability of the rainfall in the city of Lisbon was found to be negligible for rainwater harvesting potential evaluation.

Phosphorus (P) is responsible for algal growth and the structural changes in algal communities. Therefore, it is essential to know whether the different phosphorus availability to different algae can change the community structure. In this study, the interspecific competition was investigated at two bloom-forming cyanobacterium, Cylindrospermopsis raciborskii and Microcystis aeruginosa, when both were treated with five different phosphate compounds, including K₂HPO₄, β-glycerol phosphate, (2-aminoethyl)-phosphinic acid, glyphosate, and P-free. The results of mono-culture experiments showed that the two species could utilize the dissolved organic phosphorus (DOP) and K₂HPO₄ (DIP) as the sole P resource. Moreover, the specific growth rates and the endogenous alkaline phosphatase activity in M. aeruginosa cells were much lower than those in C. raciborskii under DOP and DIP treatments. In the co-cultured experiments, however, a significant biomass increase in C. raciborskii was observed in all experimental P treatments, except for glyphosate, regardless of its initial cell density proportion. A 31.8–63.4% increase in cell number of C. raciborskii was found after incubated into K₂HPO₄, while the highest biomass of mixed samples, 17.72 × 10⁶ cell mL⁻¹, was observed in the (2-aminoethyl)-phosphinic acid treatment (50C50M). Additionally, higher specific growth rate was also found in C. raciborskii when compared with M. aeruginosa under P-free; the increasing proportion of C. raciborskii were 29.1% (50C50M), 16.4% (75C25M), and 36.7% (25C75M), respectively. When the mixed samples were co-cultivated under glyphosate, C. raciborskii cells appeared to be depressed, whereas the cell density of M. aeruginosa increased rapidly. The findings indicated that an excellent P competition might give some advantages for C. raciborskii dominance in natural waters with DIP limitation or DOP abundance.

The distribution of arsenic (As) in environmental compartments is investigated in the Nalaikh Depression of N-Mongolia. In Nalaikh, lignite coal is mined by artisanal small-scale mining (ASM) approaches. Because As is often associated with sulfuric minerals in coal, it was hypothesized that enrichment of As is related to coal ASM. A second hypothesis considered coal combustion in power plants, and stoves are a key source of As in the local environment. Three mobilization and distribution scenarios were developed for potential As pathways in this semiarid environment. About 43 soil and 14 water sites were analyzed for As concentrations and meaningful parameters in soil and water. About 28 topsoil samples were analyzed in surface-subsurface pairs in order to identify potential eolian surface enrichment. Additionally, fluvial-alluvial sediments and geogenic and anthropogenic deposits were sampled. Water was sampled as surface water, groundwater, precipitation, and industrial water. Results show that As does not pose a ubiquitous risk in the Nalaikh Depression. However, locally and specifically in water, As concentrations may exceed the WHO guideline value for drinking water by up to a factor of 10. A carefully selected sampling strategy allows the evaluation of the distribution scenarios, which reveals a combination of (a) geogenic As in groundwater and distribution via surface water with (b) anthropogenic As redistribution via eolian pathways. An immediate linkage between As redistribution and coal mining is not evident. However, As distribution in fly ash from coal combustion in the local power plant and yurt settlements is the most likely As pathway. Hence, the results indicate the potential influence of diffuse, low-altitude sources on As emission to the environment. As such, this study provides a good example for As distribution under semiarid climate conditions influenced by geogenic and anthropogenic factors.

Empirical studies pertaining to the effects of fiscal policy instruments on environmental quality have provided mixed evidence. We consider the asymmetric effects of fiscal policy instruments on environmental quality for the top ten Asian carbon emitters over the period 1981–2018. We go beyond the literature and claim that the effects could be asymmetric. More specifically, we found that a positive shock in government expenditure will worsen environmental quality in Malaysia, UAE, Thailand, Indonesia, Turkey, Iran, India, and China, and improve it in Japan. On the other hand, we found that cutting government expenditure will improve environmental quality in these economies and will worsen only in Japan. Moreover, a higher government income tax revenue uniquely increases the government’s spending that increases the carbon emissions in Malaysia, UAE, Thailand, Indonesia, Turkey, Iran, India, and China, and decrease in Japan. The negative shock of government revenue has adverse results on carbon emissions in these economies. However, short-run asymmetric effects translate to long-run effects in most Asian economies.

Counterpart cooperation is a major innovative measure in China’s strategy for revitalizing north-eastern China. While promoting economic progress, regional counterpart cooperation should also focus on low-carbon economy and sustainable development. Under the background of China’s proposed innovative cooperation strategy, using a multi-regional input-output (MRIO) model and structural decomposition analysis (SDA), this study takes Jilin province and its counterpart Zhejiang province as an example and decomposes the change in carbon emission intensity (CEI), which is a widely used indicator to measure regional carbon emission performance. The decomposition spans the years 2007 to 2012, at the level of two provinces and departments. By comparing the factors that drive and inhibit CEI in the two provinces, it was found that the production technology effect in Jilin province primarily drove the growth in CEI, while in Zhejiang province, the opposite occurred. Second, the structural effects of agriculture and heavy industry in Jilin province accounted for the largest proportion of this change, and the pulling effect on the increase in CEI in Jilin was significantly higher than that in Zhejiang province. Third, the scale effect of agricultural demand in Zhejiang province was much higher than that in Jilin province, and the same trend was observed for the scale effect of heavy industrial exports.

Metal pollution has been a serious problem facing river systems worldwide, which can adversely affect human health through food chain. The goal of this study was to determine the distribution, sources, and health risk of dissolved metals (Cr, Mn, Ni, Cu, Zn, As, Cd, Pb, Al, Sb, V, Co, Mo) in major rivers located in the hilly area of southeastern China (namely, Jiulongjiang River (JL), Minjiang River (MJ), Oujiang River (OJ), Qiantangjiang River (QT), Raohe River (RR), Fuhe River (FR), Xinjiang River (XR), Ganjiang River (GR), Xiushui River (XS), Xiangjiang River (XJ), Zishui River (ZR), Yuanjiang River (YR), Lishui River (LR)) during dry and wet seasons. Results indicated that metal concentrations were spatially and temporally distinct. Metals of Mn, Ni, Cu, Cd, Sb were significantly higher in specific rivers than other metals. And metals of Cr, Ni, As, and Al concentrations were obviously higher in dry season than in wet season. The comparison with drinking water guidelines of China and other countries indicated that waterbodies were polluted higher by Al than other metals at most sites. Metals in JL and XJ may have health risk to local adults with hazard index (HI) > 1. While special attention should be paid to As, which had a potential carcinogenic risk to adults in study area with CR higher than the critical value. Source analysis with statistical method indicated that point and non-point pollutants from anthropogenic activities are the main sources of metals, with the exception of Al, Ni, V, Cr, and Mo that were mainly from natural processes. This study could be useful for the management and protection of the China’s Southern hilly area river systems.

In the last decades, nanotechnology-based tools started to draw the attention of research worldwide. They offer economic, rapid, effective, and highly specific solutions for most medical issues. As a result, the international demand of nanomaterials is expanding very rapidly. It was estimated that the market of nanomaterials was about $2.6 trillion in 2015. In medicine, various applications of nanotechnology proved their potential to revolutionize medical diagnosis, immunization, treatment, and even health care products. The loading substances can be coupled with a large set of nanoparticles (NPs) by many means: chemically (conjugation), physically (encapsulation), or via adsorption. The use of the suitable loading nanosubstance depends on the application purpose. They can be used to deliver various chemicals (drugs, chemotherapeutic agents, or imaging substances), or biological substances (antigens, antibodies, RNA, or DNA) through endocytosis. They can even be used to deliver light and heat to their target cells when needed. The present review provides a brief overview about the structure and shape of available NPs and discusses their applications in the medical sciences.

In this study, we aim to determine the median lethal dose (LD₅₀) of glyphosate isopropylamine salt (GI), which is commonly used in the world and especially in Turkey against to weeds, in male and female rats by using the probit or logit analysis method. A total of 140 Wistar rats were used, including 70 females and 70 males. To determine LD₅₀, the male and female rats were randomized into 7 groups made up of 10 animals in each group. At doses of 6000, 6500, 7000, 7500, 8000, 8500, and 9000 mg / kg, GI was administered to the male and female rats by oral gavage. After dosing, the animals were periodically monitored for 14 days. No deaths were observed after 48 h of herbicide application. In this study, only logit analysis was used for the LD₅₀ value to be calculated in the male rats within 24 h, while other analyses were carried out with the probit method. In the female and male rats, the LD₅₀ levels of GI between 24 and 48 h were determined as 7444.26–7878.50 mg/kg and 7203.58–7397.25 mg/kg, respectively. According to these results, it was concluded that female rats are more sensitive to GI than male rats. We believe that the findings that were obtained will guide researchers, clinicians, and toxicologists through preventive and curative studies against acute poisoning that may occur with GI.

In this research, several biochemical variations in plant of Lemna minor L. were investigated to reflect Ag⁺ toxicity. Lemna minor L. changed colorless AgNO₃ to colloidal brown at doses equal to and greater than 1 mg L⁻¹. Optical and fluorescence microscopy revealed the presence of bright spots in roots of tested plant related to Ag/Ag₂O-NPs. Photosynthetic pigment contents of Lemna minor L. declined upon exposure to Ag⁺ with an evidently higher decrease in chlorophyll a than in chlorophyll b. Similarly, Ag⁺ treatment caused an evident reduction in the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). The reduction in antioxidase activity was significantly higher in POD than in SOD and CAT. Ag⁺ treatment resulted in a significant increment in the level of malondialdehyde (MDA) content as the judging criteria of cellular injury which showed sign of dose-related. The alterations occurred in RAPD profiles of treated samples following Ag⁺ toxicity containing loss of normal bands, appearance of new bands, and variation in band intensities compared with the normal plants. In addition, morphological character and biomass of Lemna minor L. subjected to increasing Ag⁺ concentrations were evaluated to reveal Ag⁺ toxicity. Our study demonstrated that Lemna minor L. have a high sensitivity to indicate fluctuation of water quality. It would be beneficial that modulating the genotype of Lemna minor L. to bear high proportion of contaminates.