Saline areas are progressively increasing in irrigated lands of the Aral Sea Basin and this obstructs intensive agricultural development and food security in this region. Such circumstances, leading to the expansion of salt-affected areas, are assumed to become climate change, rising of groundwater levels and its mineralizations, poor functioning of the collector-drainage system, and insufficient compliance with agro-technical requirements. These drivers, in turn, lead to the withdrawal of arable land for agricultural purposes and a significant drop in crop yields. Regarding Uzbekistan, this research on soil salinity assessment was conducted in the irrigated areas of the Sirdarya province by analyzing raw data derived from traditional methods from 2000 to 2015, as well as from 2016 to 2019, using the integrated traditional and geographic information systems (GIS)–based methods. Soil salinity maps of the Sirdarya province were created to investigate spatial and temporal changes in soil salinity using the inverse distance weighting (IDW) interpolation method based on the results of field survey and laboratory studies. The results of this research revealed that the IDW interpolation method had a great potential and accuracy to map longitudinal changes in salt-affected irrigated areas. Moreover, it was determined that soil salinity highly depends on local terrain conditions and there is a weak dependence on climatic factors. The main findings of this research advocate agricultural specialists and local farmers to get distinctly encouraged to take the following measures to address the actual soil salinity state in the irrigated areas of the province: targeted and economic use of irrigation water; existing drainage networks are in perfect working condition and monitoring their full effective operation; and, lastly, accelerating the integration of innovative GIS technologies into traditional methods.

Globally benthic invertebrate biotic indices are widely used to assess stream health. In New Zealand, the response of biotic indices to high nitrate-nitrogen (hereafter nitrate) concentrations has not been rigorously tested. We conducted a field survey of benthic invertebrates in 41 lowland intensively farmed Canterbury streams representing a wide nitrate gradient (0.4–11.3 mg/l) to determine if biotic indices respond in a predictable manner to increasing nitrate (e.g. show a subsidy stress response). Our results show commonly used biotic indices were not able to detect any effects of high nitrate. We found homogenous and tolerant benthic invertebrate communities dominated and suggest the lack of any detected effects may be because taxa sensitive to nutrients have already been lost from these systems. Therefore, we recommend caution is needed when using biotic indices in lowland agricultural streams where nutrients may be high.

Carbon nanotubes (CNTs) are widely used and may pose potential environmental risks to soil and groundwater systems. Therefore, it is important to improve current understanding of the fate and transport of CNTs in porous media. In this study, the transport behavior of multi-walled carbon nanotubes (MWCNTs) with different surface modifications were examined in water-saturated sand columns under different pH (5 and 7) and ionic strength (0.1, 1, and 5 mM) conditions. COOH-MWCNTs have the strongest mobility among the five types of MWCNTs, followed by pristine MWCNTs. NH₂-MWCNTs, Cu-MWCNTs, and Fe-MWCNTs have the weaker mobility. The transport of five types of MWCNTs decreased with the increase of ionic strength, while increased with the increase of pH value. The results suggested that the transport of MWCNTs can be affected by the electrostatic attraction between the functional groups on the surface of MWCNTs and quartz sand. Moreover, the pH and ionic strength of the solution also played an important role in enhancing the transport of MWCNTs, which have great significance for evaluating the transport and fate of MWCNTs in natural environment.

Once a wastewater treatment plant (WWTP) exceeds its capacity, it is necessary to discharge a proportion of the flow to watercourses through combined sewer overflow (CSO) structures. In coastal urban areas, CSO spills may occur in seawaters. The present study analyses the effects of these spills into urban coastal bathing areas, through a qualitative survey-based analysis in Badalona and Barcelona, focusing on stakeholders' reputation and image involved in the sewer system and beaches management (i.e. intangible damages) and the consequences for the economy (i.e. tangible damages). The direct relation between CSO spills and impacts on restaurants’ revenues is not observed since business owners in Badalona and Barcelona do not perceive any economic impact due to these events. Their main concern is the municipality’s image, which might affect the citizens’ view of the management of the responsible agents and indirectly, the tourist sector, especially in Barcelona. Residents perception in this matter is remarkably different in both cities. In Badalona, residents know the problem and even the body responsible for setting the red flag and the beaches closure (i.e. the municipality). In Barcelona, though, residents are quite confused about this. The complexity in terms of competencies in sewer systems management requires a better communication campaign for the citizens to avoid misunderstandings and unnecessary loss of trust in the City Council. Decision-makers and stakeholders should be interested in understanding the perception of affected users upon these events to take appropriate measures to enhance awareness programs or measures to reduce overflows.

The instant endeavor was undertaken for determination of lead (Pb) in water, soil, forage, and cow’s blood domesticated in contaminated area of heavy automobiles’ exhaust in Sahiwal town of District Sargodha, Pakistan. Water samples showed that the concentration of Pb ranged from 1.14 to 0.44 mg kg⁻¹ at all sites. It was maximum at site 5 and minimum at site 2. Soil samples showed the concentration of Pb at all sites ranged from 1.58 to 0.279 mg kg⁻¹. It was maximum in soil where Avena sativa was grown at site 5 and was found minimum in soil where Zea mays was grown at site 2. While among samples of forage, the concentration of Pb ranges from 0.048 to 2.002 mg kg⁻¹. The highest Pb amount was found in Brassica campestris at site 1 and the minimum was recorded in Trifolium alexandrinum at site 2. Finally, the blood samples of cow depicted that concentration of Pb ranged from 4.468 to 0.217 mg kg⁻¹. It was the maximum at site 1 and the minimum at site 3. It is recommended that such study should be conducted in other districts for public awareness.

The Bhagirathi–Hooghly estuary represents one of the most populated estuaries in the Indian subcontinent with dense settlements along its course. The concomitant high anthropogenic influences and enhancement of nutrient load due to uncontrolled discharges from non-point source in monsoon play important role in habitat variability and consequential changes in the water quality of the estuary. Even though such nutrient loadings are expected to cause significant changes in the ecosystem functioning, a documentation of the habitat heterogeneity has largely remained unavailable from this important yet unmonitored estuary. Thus, the present work aims at assessment of water quality and trophic status of the habitat by application of a combination of abiotic and phytoplankton-specific indices as recommended by different international and national authorities. Results suggest that water quality deteriorated during periods of seasonal precipitation due to enhanced nutrient loadings that culminated in altering the trophic status of habitat. Comparisons with regard to international standards further corroborated the influence of seasonal precipitation on water quality and trophic status of the habitat. Phytoplankton functional groups largely reflected the changing nature of the habitat well, with dominance of those taxa that are more persistent under warm, nutrient replete shallow euphotic depths of the habitat. These findings further suggest that it is essential to regularly monitor the health of this estuarine ecosystem to as to sustain the different life forms that will be essential for the livelihood of people in this area.

No effective strategy has been found so far to control the emission of microplastics. The purpose of this article is to review the available control strategies, as well as barriers to developing them. Based on the estimations in the available literature, decomposition of larger plastics, clothes washing and tire abrasion play an essential part in the total emission rate of microplastics into the ocean. Nonetheless, there is no corresponding information regarding the soil, and more information is needed to prioritize the emission sources of microplastics more preciously. Generally, there have been two approaches for the management of the microplastic issues, including the substitution of non-plastic materials for plastic ones in products such as personal care products, and microplastic removal from wastewater. The former is in its infancy and has commenced only in a few developed countries. Existing wastewater treatment plants (WWTPs) as the other approach can transfer a significant portion of the microplastics into the sludge. The result is that the final destination of these microplastics can be the soil. Since there is little information on how serious the impact of microplastics is on the soil as compared with water, the currently used WWTPs cannot be considered as a final remedy. Furthermore, there has been not been any specifically designed techniques to remove microplastics from wastewater efficiently and economically.

Recent infrastructure development in China and other developing countries has attracted global attention. As a control project of traffic engineering, tunnels also have rapidly increased. However, fire accidents induced by traffic accident or gas explosion frequently occur in tunnels, causing irreversible damage to the tunnel rocks. Moreover, the corrosive effects of acid rain or polluted groundwater have a long-term effect on the tunnel and surrounding rocks. In this paper, physical and thermophysical properties tests as well as Brazilian splitting test were conducted on red sandstone specimens after heating at a variety of different temperature and acidic solution erosion. The responses of surface features, mass, P wave velocity, porosity and thermal conductivity, and the tensile strength of the red sandstone were compared and analyzed. In addition, the effects of high temperature (25–1000 °C) and acidic solution on microscopic structures, defect morphology, and mineral reaction of the red sandstone were observed and analyzed. The experimental results show that high temperature and acidic chemical solution significantly affects the physical and mechanical properties of the rock mass. The typical parameters, such as surface features, mass and P wave velocity, porosity, thermal conductivity, and tensile strength, are closely affected by acidity. In addition, we observed that the physical properties of red sandstones change with temperature and can be divided into three stages, and at 300–800 °C stage, they significantly declined. The results provide a basis for rock damage and failure induced by fire and acidic groundwater seepage in tunnels.

High dust concentration produced in the fully mechanized longwall mining face is a significant threat to the front-line workers. It is critical to discover the potential safety zone to ensure routine personnel operation. Fluent 2020 R1 is employed to reappear the spatial dust distribution based on the gas-solid coupling theory. The dust migration behavior and safety regional division are illuminated in the spatial longwall mining face. The formation of dust concentration trigonum is introduced with the particle diffusion force analyzed. The YZ plane safety zone area shows an increasing trend at X = 70–95 m. The respirable dust concentration decreases from the peak value to the safe value at sidewalk 4.0–4.6 m. The safety zone area and length both pose a linear growth with the increasing wind velocity. In the XY plane, the safety zone area and length extend by 1.26 times and 1.33 times, respectively. The horizontal plane creates a greater growth rate of safety zone than the vertical plane. The drum rotation creates a wind circumfluence that exerts an obvious effect on the dust distribution around the coal cutter. The sidewalk region mainly situates in the safety zone for the personal squat down, while it is gradually exposed to the dangerous dust pollution situation as the breathing height rises.