Explore the vast range of titles available.

Quantifying water implications of energy transitions is important for assessing long-term freshwater sustainability since large volumes of water are currently used throughout the energy sector. In this paper, we assess direct global energy sector water use and thermal water pollution across a broad range of energy system transformation pathways to assess water impacts of a 2 °C climate policy. A global integrated assessment model is equipped with the capabilities to account for the water impacts of technologies located throughout the energy supply chain. The model framework is applied across a broad range of 2 °C scenarios to highlight long-term water impact uncertainties over the 21st century. We find that water implications vary significantly across scenarios, and that adaptation in power plant cooling technology can considerably reduce global freshwater withdrawals and thermal pollution. Global freshwater consumption increases across all of the investigated 2 °C scenarios as a result of rapidly expanding electricity demand in developing regions and the prevalence of freshwater-cooled thermal power generation. Reducing energy demand emerges as a robust strategy for water conservation, and enables increased technological flexibility on the supply side to fulfill ambitious climate objectives. The results underscore the importance of an integrated approach when developing water, energy, and climate policy, especially in regions where rapid growth in both energy and water demands is anticipated.

Thermal pollution of rivers degrades water quality and ecosystem health, and cities can protect rivers by decreasing warmer impervious surface stormwater inflows and increasing cooler subsurface inflows and shading from riparian vegetation. This study develops the mechanistic i-Tree Cool River Model and tests if it can be used to identify likely causes and mitigation of thermal pollution. The model represents the impacts of external loads including solar radiation in the absence of riparian shade, multiple lateral storm sewer inflows, tributaries draining reservoirs, groundwater flow, and hyporheic exchange flow in dry weather steady flows and wet weather unsteady flows. The i-Tree Cool River Model estimates the shading effects of the riparian vegetation and other features as a function of heights and distances as well as solar geometry. The model was tested along 1500 m of a New York mountain river with a riparian forest and urban areas during 30 h with two summer storm events in 2007. The simulations were sensitive to the inflows of storm sewers, subsurface inflows, as well as riparian shading, and upstream boundary temperature inflows for steady and unsteady conditions. The model simulated hourly river temperature with an R2 of 0.98; when shading was removed from the simulation the R2 decreased 0.88, indicating the importance of riparian shading in river thermal modeling. When stormwater inflows were removed from the simulation, the R2 decreased from 0.98 to 0.92, and when subsurface inflows were removed, the R2 decreased to 0.94. The simulation of thermal loading is important to manage against pollution of rivers.

The article presents the results of numerical hydrothermal simulation of changes in the temperature regimes of the Don River under the effect of heat discharges of the Novocherkasskaya State Regional Power Station, taking into account the future Bagaevskoe Reservoir. The study utilizes STREAM_2D software complex for calculating two-dimensional fields off flow and temperature. Variants of optimization of thermal regimes are proposed to reduce the temperature at water intakes and in nearby areas to the levels meeting the standards. As the result, it was shown that the thermal discharges of the Novocherkasskaya SDPP into the Don River meet the ecological and fishery standards.

Water is probably the most inevitable substance for the survival of life on Earth. Though Earth has an infinite source of water, most of it is of no use since it is saline ocean water. Ignoring the water stored in continental glaciers, the only source of freshwater is groundwater. This resource is now under huge stress due to unplanned and over-use. Now the time has come to take groundwater management as a serious concern. Here, an attempt has been made to capture different issues of groundwater management, its applicability, and limitation in terms of the present state of research. This article discusses the feasibility of groundwater management in terms of groundwater quantity, artificial recharge to aquifer and groundwater quality both chemical and bacteriological. A holistic approach has been adopted to discuss technological advancements to address the groundwater management issues like desalination and membrane filtration, its limitations, and future scope of improvement. Thermal pollution of groundwater and its impact on saline water intrusion to coastal aquifers have been addressed in the discussion. The effect of global climate change on the hydrosphere and its impact on groundwater management have also been incorporated. One of the mitigations to global warming is exploring different sources of green energy. One of them and the most explored options is geothermal energy. The use of geothermal heat for electricity generation and space heating has also been included in the discussion with technological limitations which is always an open area of research.

While working on practical problems related to the spread of thermal pollution in rivers, we face difficulties related to the collection of necessary data. However, we would like to predict the increase in water temperature at the best accuracy to forecast possible threats to the environment. What level of accuracy is necessary and which processes that influence the water temperature change have to be taken into account are usually problematic. Those problems, with special stress on water–air heat exchange in practical applications in the so-called mid-field region in rivers, which is very important for the environmental impact assessment, constitute the main subject of the present article. The article also summarises the existing knowledge and practice on water–air heat exchange calculations in practical applications.

Economic and social development of urban and rural areas continues in parallel with the increase of the human population, especially in developing countries, which leads to sustained expansion of impervious surface areas, particularly paved surfaces. The conversion of pervious surfaces to impervious surfaces significantly modifies local energy balance in urban areas and contributes to urban heat island (UHI) formation, mainly in densely developed cities. This paper represents a literature review on the causes and consequences of the UHI and potential measures that could be adopted to improve the urban microclimate. The primary focus is to discuss and summarise significant findings on the UHI phenomenon and its consequences, such as the impact on human thermal comfort and health, energy consumption, air pollution, and surface water quality deterioration. Regarding the measures to mitigate UHI, particular emphasis is given to the reflective and permeable pavements.

Water quality depends on its physicochemical and biological parameters. Changes in parameters such as pH, temperature, and essential and non-essential trace metals in water can render it unfit for human use. Moreover, the characteristics of the local environment, geological processes, geochemistry, and hydrological properties of water sources also affect water quality. Generally, groundwater is utilized for drinking purposes all over the globe. The surface is also utilized for human use and industrial purposes. There are several natural and anthropogenic activities responsible for the heavy metal contamination of water. Industrial sources, including coal washery, steel industry, food processing industry, plastic processing, metallic work, leather tanning, etc., are responsible for heavy metal contamination in water. Domestic and agricultural waste is also responsible for hazardous metallic contamination in water. Contaminated water with heavy metal ions like Cr (VI), Cd (II), Pb (II), As (V and III), Hg (II), Ni (II), and Cu (II) is responsible for several health issues in humans, like liver failure, kidney damage, gastric and skin cancer, mental disorders and harmful effects on the reproductive system. Hence, the evaluation of heavy metal contamination in water and its removal is needed. There are several physicochemical methods that are available for the removal of heavy metals from water, but these methods are expensive and generate large amounts of secondary pollutants. Biological methods are considered cost-effective and eco-friendly methods for the remediation of metallic contaminants from water. In this review, we focused on water contamination with toxic heavy metals and their toxicity and eco-friendly bioremediation approaches.

With rapid urbanization and industrialization, rural rivers in China are facing deterioration in water quality and ecosystem health. Microorganisms living in river sediments are involved in biogeochemical processes, mineralization, and degradation of pollutants. Understanding bacterial community distribution in rural rivers could help evaluate the response of river ecosystems to environmental pollution and understand the river self-purification mechanism. In this study, the relationship between characteristics of sediment microbial communities and the surrounding environmental factors in a typical rural river was analyzed using 16S rRNA gene sequencing technology. The results showed that the dominant bacterial groups in the river sediment were Proteobacteria , Actinobacteria , Chloroflexi , Acidobacteria , Bacteroidetes , and Firmicutes , accounting for 83.61% of the total microbial load. Different areas have different sources of pollution which give rise to specific dominant bacteria. The upstream part of the river flows through an agricultural cultivation area where the dominant bacteria were norank_f_Gemmatimonadaceae , Haliangium , and Pseudolabrys , possessing obvious nitrogen- and phosphorus-metabolizing activities. The midstream section flows through an urban area where the dominant bacteria were Marmoricola , Nocardioides , Gaiella , Sphingomonas , norank_f_67-14 , Subgroup_10 , Agromyces , and Lysobacter , with strong metabolizing activity for toxic pollutants. The dominant bacteria in the downstream part were Clostridium_sensu_stricto_1 , norank_f__Bacteroidetes_vadinHA17 , Candidatus_Competibacter , and Methylocystis . Redundancy analysis and correlation heatmap analysis showed that environmental factors: ammonia nitrogen (NH 4 + –N) and total nitrogen (TN) in the sediment, and pH, temperature, TN, electrical conductivity (EC), and total dissolved solids (TDS) in the water, significantly affected the bacterial community in the sediment. The PICRUSt2 functional prediction analysis identified that the main function of bacteria in the sediment was metabolism (77.3%), specifically carbohydrate, amino acid, and energy metabolism. These activities are important for degrading organic matter and removing pollutants from the sediments. The study revealed the influence of organic pollutants derived from human activities on the bacterial community composition in the river sediments. It gave a new insight into the relationship between environmental factors and bacterial community distribution in rural watershed ecosystems, providing a theoretical basis for self-purification and bioremediation of rural rivers.

Context Cities have elevated temperatures compared to rural areas, a phenomenon known as the “urban heat island”. Higher temperatures increase the risk of heat-related mortality, which will be exacerbated by climate change. Objectives To examine the impact of climate change and urban growth on future urban temperatures and the potential for increased heat stress on urban residents. Methods We conducted a systematic review of scientific articles from Jan 2000 to May 2016. Results The majority (n = 49, = 86%) of studies examined climate change and the urban heat island in isolation, with few (8) considering their combined effect. Urban growth was found to have a large impact on local temperatures, in some cases by up to 5 °C in North-east USA. In some locations climate change increased the heat island, such as Chicago and Beijing, and in others decreased it, such as Paris and Brussels. When the relative impact of both factors was considered, the temperature increase associated with the urban heat island was always higher. Few studies (9) considered heat stress and its consequences for urban populations. Important contributors to urban temperatures, such as variation in urban density and anthropogenic heat release, were often excluded from studies. Conclusions We identify a need for an increased research focus on (1) urban growth impact on the urban heat island in climate change studies; (2) heat stress; and, (3) variation in urban density and its impacts on anthropogenic heat. Focussing on only one factor, climate change or urban growth, risks underestimating future urban temperatures and hampering adaptation.

Numerous human thermal climate indices have been proposed. It is a manifestation of the perceived importance of the thermal environment within the scientific community and a desire to quantify it. Schemes used differ in approach according to the number of variables taken into account, the rationale employed, and the particular design for application. They also vary considerably in type and quality, method used to express output, as well as in several other aspects. In light of this, a three-stage project was undertaken to deliver a comprehensive documentation, classification, and overall evaluation of the full range of existing human thermal climate indices. The first stage of the project produced a comprehensive register of as many thermal indices as could be found, 165 in all. The second stage devised a sorting scheme of these human thermal climate indices that grouped them according to eight primary classification categories. This, the third stage of the project, evaluates the indices. Six evaluation criteria, namely validity, usability, transparency, sophistication, completeness, and scope, are used collectively as evaluation criteria to rate each index scheme. The evaluation criteria are used to assign a score that varies between 1 and 5, 5 being the highest. The indices with the highest in each of the eight primary classification categories are discussed. The work is the final stage of a study of the all human thermal climatic indices that could be found in literature. Others have considered the topic, but this study is the first detailed, genuinely comprehensive, and systematic comparison. The results make it simpler to locate and compare indices. It is now easier for users to reflect on the merits of all available thermal indices and decide which is most suitable for a particular application or investigation.