Current Pollution Reports最新文献

Purpose of Review

Free-flowing rivers act as conduits for sediment and nutrient transport from the land to coastal oceans. In the past decades, many of global rivers have been dammed for water resource management. The associated ecological impacts have become a wide concern, and have been intensively studied. In this work, we aim to review the research progress of the topic on sediment and nutrient trapping by river dams using CiteSpace, summarize the findings of previous literatures, and propose perspectives for future studies.

Recent Findings

We found that (i) this topic has been continuously concerned and the publication number has been increasing annually. In 2006–2021, there are 1385 publications in total, including 1318 articles and 23 reviews; (ii) dams can interrupt river connectivity and trap sediment and nutrients in reservoirs, greatly deceasing sediment and nutrient loads to coastal oceans; (iii) sediment and nutrient trapping by dams has caused a series of ecological impacts, including reservoir capacity loss, river channel erosion, river delta land loss, reservoir eutrophication, and massive greenhouse gas emissions.

Summary

This review summarized the changes of riverine sediment and nutrient loads caused by dams, and their impacts on river ecosystems. The following aspects should be concerned in future studies: the impacts of biogeochemical cycling within reservoirs on the stoichiometry and bioavailability of nutrients in dam discharge, the net greenhouse gas emissions caused by dams, and the cumulative impacts of cascade dams. It adds our comprehensive understanding of sediment and nutrient trapping by river dams and will be beneficial to future studies in this field.

Purpose of Review

Advanced oxidation processes (AOPs) are proven effective in degrading recalcitrant pollutants in wastewater. Numerous researchers have been targeting advanced catalytic materials to further promote AOP efficiency. Recent studies indicated the great catalytic activity of FeOCl in AOP systems, inducing the prevailing research on the modification and application of the FeOCl-based layer-structure materials. This review summarizes the progress in existing works of FeOCl as AOP catalysts and provides challenging perspectives for future work.

Recent Findings

FeOCl shows outstanding catalytic performance in conventional Fenton and other AOP systems, such as Fenton-like, photo-activated and electro-activated processes. Nevertheless, FeOCl catalytic efficiency in AOPs still demands improvement owing to the relatively low effective surface area of bulk-phase FeOCl, slow regeneration of active Fe (II) from Fe (III), prone leaching of iron ions, and difficulty in recycling or long-term functioning. Consequently, various modification approaches, including intercalation, exfoliation, combination, and membrane-fabrication, have been adopted to effectively promote pollutant removal efficiency in different FeOCl-catalyzed AOP systems.

Summary

This review presents the promising application of FeOCl as catalysts in AOPs and multiple modification methods successfully applied to FeOCl for catalytic performance improvement. Moreover, some remaining gaps in FeOCl preparation, purity determination, stability control, complex water matrix effects, and mechanism illustration are summarized, hopefully providing viable viewpoints for future research on AOP water treatment practices.

Graphical Abstract

Schematic illustration of FeOCl and its modified products in AOPs for water treatment.

Purpose of Review

Extreme weather including heat waves, droughts, and extreme precipitation can impact the microbiological risks of drinking water in complex and comprehensive ways. These impacts are especially concerned with coastal cities due to the higher frequency and intensity of extreme weather. This review was aimed at summarizing these impacts from the view of different parts of drinking water systems including water sources, drinking water treatment plants (DWTPs), and drinking water distribution systems (DWDSs).

Recent Findings

All extreme weather will pose microbiological threats to drinking water quality. However, the threats are realized in direct or indirect ways. In the former, the extreme weather itself can alter the microbial biomass, growth rate, activity, and tolerance. In the latter, it will first change the physicochemical water parameters and/or the performance of the water treatment processes and then impact microbes. Meantime, extreme weather can result in the induction, occurrence, and removal of emerging microbiological contaminants, thus making the situation more complicated.

Summary

This review summarized the potential impacts of extreme weather on microbiological risks of drinking water in coastal cities. It also analyzed the interactive relationship between extreme weather and microbes. However, many knowledge gaps remained for this issue. The occurrence, transportation, control, and removal mechanism/methods of microbial contaminants under the background of climate change should be further investigated.

Graphical Abstract

Purpose of Review

Microalgae-mediated resource recovery and recycling of wastewater might be useful in producing biomass, biofertilizers, and environmentally acceptable bioproducts. This review aims to provide a comprehensive understanding of the challenges and opportunities of wastewater valorization to valuable algal biomass by opting a self-sustainable carbon-neutral approach.

Recent Findings

Various challenges and opportunities of using unsterilized urban wastewater are explored to provide insights into addressing the processing issues. Major wastewater challenges include turbidity with blackish appearance, emerging contaminants, pathogenic microbial community, and higher nutrient load. A brief comparison of sterilization techniques has been made, mainly focusing on principles, advantages, and limitations. Despite the challenges, it is found that microalgae-based resource recovery could be a viable and promising opportunity in a wastewater-driven integrated biorefinery paradigm.

Summary

Despite the availability of various wastewater treatment methods, microalgae-based wastewater treatment is promising, and carbon neutral approach which transforms the nutrients to valuable biomass, thereby reducing the nutrient load of the water. However, microalgal cultivation in wastewater encounters physical and biological challenges. In this article, challenges, opportunities, and sterilization methods of wastewater are critically reviewed concerning microalgae-based resource recovery from the urban wastewater. The processing of wastewater-produced algal biomass could be valorized into multiple products in minimal waste and carbon-neutral paradigm.

Graphical Abstract

The textile, paper and pulp, distillery, and pharmaceutical industries are only a few of the many sectors that contribute significantly to the contamination of water bodies and their unsuitability for human use. Pharmaceuticals, which are credited with saving millions of lives in recent decades, have emerged as a new category of environmental hazard. Their prolonged presence in the environment has a number of negative effects, including gene toxicity, hormone interference, antibiotic resistance, the imposition of sex organs, and many others. To ensure that everyone in the world can access to uncontaminated and safe drinking water, it is important to treat pharmaceutical laden wastewater before discharge in fresh water body. Nanotechnology is getting significant attention due to enormous properties such as the high surface area to volume ratio, new optical properties, and desired shape. Nanomaterials might be a strong option for purifying water of a variety of environmental pollutants. This review also touches on several environmental aspects of pharmaceuticals, including (i) the current status of pharmaceuticals production and their use pattern, (ii) sources, occurrence, and transport behaviour of pharmaceuticals, (iii) analysis techniques and potential toxicity of pharmaceuticals and (iv) various conventional and advanced nanotechnology for water remediation. The present review is predominately designed to highlight the progress and major update in advantaged nanotechnology for remediation of pharmaceutical contaminated wastewater. The literature study (2015–2022) critically illustrated the recent pharmaceutical contaminations concerns and remediation efforts emphasizing nanotechnology like nanoadsorption, AOPs, nano-catalyst, electrochemical degradation and nanomembrane/nanofiltration technology.

Purpose of Review

Noise is penetrating urban life pervasively and is imperative for demonstrating the factors behind it regarding built environment, aka buildings and urban form. So, this review aims to provide a better understanding of the association between building acoustics and urban form characteristics.

Recent Findings

There is a growing attention for building acoustics, including materials and simulation aspects with various increasing urban form attributes, i.e., the built and natural environment and transportation.

Summary

Building acoustics is a key aspect of urban life and falls within the interface of various urban form characteristics. While these two main attributes are not sufficiently addressed, they may adversely affect individuals; thus, all the more reason to explore this nexus. This study has evaluated 67 peer-reviewed journal articles after systematically reviewing the triple resources in assessing building acoustics and urban form between 2016 and 2022. This review separates the indoor and outdoor categories within the simulation, theory, building materials, facade, and the built environment sub-categories. The study does not only review the overall scope of present studies but also direct future directions of their associations.

In the present study, a systematic review along with a meta-analysis was conducted based on relevant studies from 11 Asian countries (1999–2022, Scopus, PubMed, MEDLINE, ScienceDirect, and Google Scholar) to evaluate the crop-wise differences in the accumulation of trace element (TE) in the edible part of different crops (vegetables: leafy (LV), root (RV), fruit (FV); cereal crops: rice (RIC), wheat (WHE), maize (MAZ)). Based on the median concentration of the compiled data, the TE accumulation in different vegetable crops was ranked in the decreasing order of Fe > Zn > Mn > Cu > Ni > Cr > Pb > Co > Se > Cd > As, and in cereal crops, this is followed as Fe > Zn > Cu > Ni > Cr > Co > Pb > As > Se > Cd > Hg. A clear difference was found between vegetable categories, with a higher accumulation of most of the elements in LV, especially spinach, coriander, radish leaves, mustard, amaranthus, and pakchoi than other vegetable types. Root vegetables displayed higher bioconcentration factors (BCF) than the other two vegetable types. For cereal crops, higher metal contents were found in WHE followed by RIC and MAZ, but RIC had relatively higher BCF for certain metals (As, Cd, Cu, Cr, Ni) and WHE dominated for the remaining metals. When compared with the prescribed safe limits of the non-essential metals (As, Cd, and Pb), this study revealed that the majority of the vegetable and cereal crop contaminations were from Bangladesh, China, India, Iran, and Pakistan.

Membrane distillation (MD) is a sustainable approach for the treatment of challenging saline water by effective removal of non-volatile compounds at high water recovery, offering near-to-zero liquid discharge to environment. Progressive efforts have been made in recent literature to mitigate membrane fouling and enhance the wetting resistance of MD for long-term stable operation; however, extensive energy consumption is the key constraint that hinders MD to become an economically sustainable solution for industrialization. This review represents the evaluation of energy consumption in MD in comparison with other existing advanced water treatment technologies (e.g., reverse osmosis). An up-to-date review of low-energy MD utilization to minimize energy consumption is provided in this work. High energy consumption in MD can be compensated by the effective utilization of renewable energy sources such as solar energy, geothermal energy, or waste heat. However, due to the sporadically unequal distribution and unstable availability of these low-grade sources, the dependence on the abundance of these energy sources may limit the flexibility in commercial MD applications. A recent approach to reduce specific thermal energy through direct heating of the membrane or spacer is also discussed in this review. The development of the membrane materials/configurations was highlighted for mitigating the effects of temperature polarization and improving energy efficiency by localized heating at/near the membrane surface by using photothermal, electrothermal, or induction materials.

Purpose of Review

In the context of COVID-19 sweeping the world, the development of microbial disinfection methods in gas, liquid, and solid media has received widespread attention from researchers. As a disinfection technology that can adapt to different environmental media, microwave-assisted disinfection has the advantages of strong permeability, no secondary pollution, etc. The purpose of this review is to put forward new development requirements for future microwave disinfection strategies by summarizing current microwave disinfection methods and effects. From the perspective of the interaction mechanism of microwave and microorganisms, this review provides a development direction for more accurate and microscopic disinfection mechanism research.

Recent Findings

Compared to other traditional environmental disinfection techniques, microwave-assisted disinfection means have the advantages of being more destructive, free of secondary contamination, and thorough. Currently, researchers generally agree that the efficiency of microwave disinfection is the result of a combination of thermal and non-thermal effects. However, the performance of microwave disinfection shows the differences in the face of different environmental media as well as different types of microorganisms.

Summary

This review highlights the inactivation mechanism of microwave-assisted disinfection techniques used in different scenarios. Suggestions for promoting the efficiency and overcoming the limitations of low energy utilization, complex reactor design, and inaccurate monitoring methods are proposed.