In this study, a novel wastewater sampling method based on biofilm collection on a multi-armed polyethylene strips (so called “Octopus”) is proposed. The implementation of this method is a step forward to prevent illegal industrial discharges into sewerage systems and receiving water bodies. Prior applications of biofilm collection were performed in Bielefeld, Germany, in 1994. The success of the method encouraged other municipalities to apply this method for monitoring indirect discharges into sewerage systems. Municipality of Konya, Turkey, started to use the method in 2013. Continuous monitoring has been performed for the determination of regulated heavy metals: chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), mercury (Hg) and cadmium (Cd). Unauthorized discharges of Cr, Zn and Ni were identified in Konya by performing sewerage slime tests through biofilm analyses. 2686 mg/kg d.m. Cr, 3949 mg/kg d.m. Zn and 3300 mg/kg d.m. Ni were highest values determined for biofilm samples taken from monitoring sites. In this paper, the principles of the method will be introduced, and findings from the wastewater of Konya City will be given in comparison with findings from Bielefeld, Germany. Conducted results reveal high (and likely illegal) heavy metal discharges into the sewerage system in Konya. The continuous monitoring of sewerage systems with biofilm collectors is an effective and efficient method for point source control of wastewater pollutants.

In recent years, climate change and carbon sinks have been widely studied by the academic community, and relevant research results have emerged in abundance. In this paper, a scientometric analysis of 747 academic works published between 1991 and 2018 related to climate change and carbon sinks is presented to characterize the intellectual landscape by identifying and revealing the basic characteristics, research power, intellectual base, research topic evolution, and research hotspots in this field. The results show that ① the number of publications in this field has increased rapidly and the field has become increasingly interdisciplinary; ② the most productive authors and institutions in this subject area are in the USA, China, Canada, Australia, and European countries, and the cooperation between these researchers is closer than other researchers in the field; ③ 11 of the 747 papers analyzed in this study have played a key role in the evolution of the field; and ④ in this paper, we divide research hotspots into three decade-long phases (1991–1999, 2000–2010, and 2011–present). Drought problems have attracted more and more attention from scholars. In the end, given the current trend of the studies, we conclude a list of research potentials of climate change and carbon sinks in the future. This paper presents an in-depth analysis of climate change and carbon sink research to better understand the global trends and directions that have emerged in this field over the past 28 years, which can also provide reference for future research in this field.

Proteins of extracellular polymeric substances (EPS) in sewage sludge play a key role in the sludge dewatering. Ethanol can denature proteins and improve sludge dewaterability. In this study, ethanol was used to precondition and combined with Fe³⁺ and rice husk (RH) for dewatering enhancement. The experimental results of the capillary suction time (CST) reduction efficiency indicated that the sewage sludge pretreated with ethanol and Fe³⁺-RH revealed well cooperative formation mechanism with regard to dewatering performance. Using the response surface methodology (RSM) determined that CST reduction efficiency of sewage sludge reached 78.5% under optimal conditions of ethanol 25.21 g/g dry solid (DS), Fe³⁺ 185.70 mg/g DS, and RH 406.02 mg/g DS, respectively. Moreover, the results showed that the composite conditioner is effective for the specific resistance to filtration decreased from initial 1.66E + 13 m/kg to 2.44E + 11 m/kg. The analysis of EPS showed that extractable proteins in EPS increased to maximum when the sludge was pretreated by Fe³⁺-RH because EPS were destroyed and proteins in EPS were released. After the addition of ethanol, extractable protein content was reduced because of protein precipitation and released interstitial water and bound water. The sludge morphology analysis indicated that the RH as a skeleton builder provided the outflow passages, which enhanced the dewatering performance of sludge. From these results, the combination treatment of ethanol and Fe³⁺-RH is a promising synergetic strategy to enhance the dewaterability of sewage sludge.

As the whole world is witnessing what novel coronavirus (COVID-19) can do to the mankind, it presents several unique features also. In the absence of specific vaccine for COVID-19, it is essential to detect the disease at an early stage and isolate an infected patient. Till today there is a global shortage of testing labs and testing kits for COVID-19. This paper discusses about the role of machine learning techniques for getting important insights like whether lung computed tomography (CT) scan should be the first screening/alternative test for real-time reverse transcriptase-polymerase chain reaction (RT-PCR), is COVID-19 pneumonia different from other viral pneumonia and if yes how to distinguish it using lung CT scan images from the carefully selected data of lung CT scan COVID-19-infected patients from the hospitals of Italy, China, Moscow and India? For training and testing the proposed system, custom vision software of Microsoft azure based on machine learning techniques is used. An overall accuracy of almost 91% is achieved for COVID-19 classification using the proposed methodology.

Siegesbeckia orientalis L. was identified as a novel Cd-hyperaccumulator and valuable phytoremediation material. However, the molecular mechanisms underlying Cd accumulation in S. orientalis are largely unknown. In this study, RNA-Seq analysis was performed to study the Cd-accumulating mechanisms in its roots with or without Cd treatment. The RNA-seq analysis generated 312 million pairs of clean reads and 78G sequencing data. De novo transcriptome assembly produced 355,070 transcripts with an average length of 823.59 bp and 194,207 unigenes with an average length of 605.68 bp. Comparative transcriptome analyses identified a large number of differentially expressed genes in roots under Cd stress, and functional annotation suggested that S. orientalis utilizes various biological pathways involving many gene networks working simultaneously to cope with the stress. This study revealed that four biological pathways were mainly involved in S. orientalis tolerance to Cd stress, including reactive oxygen species scavenging, phenylpropanoid biosynthesis pathway, Cd absorption and transport, and ABA signaling pathway. The genes related to photosynthesis and heavy metal transport are likely the potential candidates and could be further investigated to determine their roles in Cd tolerance in S. orientalis roots. These findings will be useful to understand the Cd accumulation mechanisms in S. orientalis and facilitate the study of phytoremediation at the molecular level in plants.

Magnetic nanoparticles (MNPs) are used in a wide range of sectors ranging from electronics to biomedicine, as well as in eutrophicated lake restoration due to their high P, N, and heavy metal adsorption capacity. This study assessed the effects of MNPs on mortality and morphometric changes of D. magna. According to the SEM, the synthesised MNPs were found to have spherical nanoparticles, be uniformly distributed, and have a homolithic size distribution of 50–110 nm. The EDX spectra confirmed the elemental structure and purities of these MNPs. A total of 396 neonates were used for short-term bioassays (96 h) through the MNPs in the laboratory (16:8 photoperiod). Experiments were applied in triplicate for each concentration of CuFe₂O₄, CoFe₂O₄, and NiFe₂O₄ MNPs and their respective control groups. Mortality and morphological measurements of each individual were recorded every 24 h. In the probit analysis, the 96-h LC₅₀ (p < 0.05) for CuFe₂O₄, CoFe₂O₄, and NiFe₂O₄ MNPs was calculated to be 1.455 mg L⁻¹, 39.834 mg L⁻¹, and 21.730 mg L⁻¹, respectively. CuFe₂O₄ MNPs were found to be more toxic than the other two MNPs. The concentrations of CuFe₂O₄, CoFe₂O₄, and NiFe₂O₄ MNPs drastically affected life span and morphologic growth of D. magna as a result of a short time exposure. The results of this study are useful for assessing what risks they pose to freshwater ecosystems.

In order to make hydropower station’s development and operation harmonious with ecological protection, the optimal operation of hydropower stations to meet the needs of ecological protection is studied. Firstly, the ecological protection function of river course is defined according to the minimum ecological runoff and suitable ecological runoff. Then, a multi-objective optimal running model of reservoir which can maximize the capacity of ecological protection and generation is proposed. Finally, an improved multi-objective particle swarm optimization algorithm (MOPSO), which can construct a neighborhood for each particle and choose the neighborhood optimal solution by adopting self-organizing mapping (SOM) method, is proposed to solve the model. The model is applied to the Shui-Kou Hydropower Station in Minjiang, China. The results show that the model can get the optimal schedule with balanced consideration of ecological benefits and power generation benefits, which has not a great impact on the economic benefits of reservoirs while achieving the goal of ecological environment. The research results can provide theoretical basis and concrete scheme reference for reservoir operation.

Exploring fiscal reform’s pollution effect draws increasing attention. Our paper brings a new perspective, i.e., the vertical fiscal imbalance (VFI) perspective, to study such issue. With the panel data of China’s provincial level from 1999 to 2016, we reveal whether and how VFI affects environmental pollution. We find that VFI significantly enhances the environmental pollution level of China. As the VFI increases, environmental pollution effect caused by VFI appears to be aggravated. According to the transmission path check, we confirm in our paper that VFI can indirectly lead to environmental degradation by affecting the two channels environmental regulation and industrial transformation. Further, through the sub-sample regressions, we find that the impacts of VFI on environmental pollution as well as the transmission paths are regionally heterogeneous. Finally, we believe that using the VFI as a variable to explore fiscal reform’s effect on environment is of rationality, and for a better environmental quality, VFI should be avoided.

This study aimed to investigate the effect of honeybee pollen as an antioxidant source in a maturation medium of sheep oocytes on the in vitro maturation rate, glutathione concentration, and gene expression. To our knowledge, this study might be the first of its kind in this field. Sheep oocytes were cultured in vitro with honeybee pollen at four different concentrations (0.0, 1.0, 10.0, and 50.0 μg/ml). The results indicated that the ratio of oocytes that reached metaphase II stage was higher in the honeybee pollen-treated groups than in the control group (p ≤ 0.05). The reduced glutathione (GSH) mean content of matured oocytes was 9.85 nmol/25 oocytes, when honeybee pollen was added to the in vitro maturation (IVM) medium at a concentration of 1.0 μg/ml, compared with 5.84 and 4.44 nmol when using 10.0 and 50.0 μg/ml honeybee pollen, respectively. On the other hand, there was no significant difference in glutathione concentration between the control and 1.0 μg/ml honeybee pollen groups. Expression of candidate genes (GDF-9, BAX, Cyclin B, C-MOS, and IGF1) was upregulated in oocytes cultured with honeybee pollen when compared with oocytes cultured without honeybee pollen. In conclusion, the addition of honeybee pollen at a concentration of 1.0 μg/ml to IVM medium improved the in vitro maturation rate of sheep oocytes, increased the glutathione concentration, and improved gene expression.

Heavy metal contamination of river water has become a major issue affecting environmental and human health worldwide. This study makes an effort to observe the heavy metal incidence of River Brahmaputra, India, and its river restoration assessment for 2 years, 2017–2018 and 2018–2019. River Brahmaputra is the second longest and a major transboundary river of the South Asian region, which transcends the political boundaries of China, India and Bangladesh. The Pearson correlation analysis was used to analyse the interrelationships between physico-chemical parameters (which was also analysed during our study) and heavy metals. Heavy metal pollution index and multivariate analyses such as hierarchical cluster analysis and principal component analysis were used to establish our scientific observations. An assessment involving people’s willingness to pay for river restoration was also done. Arsenic (As), lead (Pb), antimony (Sb), nickel (Ni), chromium (Cr), mercury (Hg) and cadmium (Cd) were monitored in three stations, namely, Dibrugarh Town (Tinkunia Ghat), Guwahati City (Bharalumukh) and Dhubri Town (Jahajghat), for the periods 2017–2018 and 2018–2019. The overall mean concentration was in the order Hg > Ni > Cr > Pb > Cd > As > Sb. Heavy metal pollution index was found in the order station 2 (344) > station 3 (320) > station 1 (317). Results clearly indicate the presence of heavy metal pollution in the Brahmaputra river, with very high levels in Guwahati City. Concentrations of Ni, Cr, Hg and Cd were found to be very high while As presence was marginally high. Concentration of Pb and Sb were nearly the prescribed World Health Organization and Bureau of Indian Standards limits. Multivariate analyses suggest that the heavy metal pollution is linked to similar sources in all the sampled sites. Further, the river restoration assessment revealed that citizens are willing to pay an average of INR 22.6 (USD 0.30) for restoring the water quality. Therefore, given the high levels of heavy metal contamination witnessed in the Brahmaputra river and citizens willingness to contribute towards restoring its water quality, the need for an appropriate river restoration strategy and water policy is strongly felt as an outcome of this study.