Sediments: sink,archive, and source of contaminants

Environmental Science and Pollution Research -     

Herbicide safeners: uses,limitations, metabolism,and mechanisms of action

Several methods were examined to minimize crops injury caused by herbicides. Thus increase their selectivity. A selective herbicide is one that controls weeds at rates that do not injure the crop. Herbicides are selective in a particular crop within certain limits imposed by the herbicide, the plant, the application rate, the method and time of application, and environment conditions. Herbicide safeners are compounds of diverse chemical families. They are applied with herbicides to protect crops against their injury. Using chemical safeners offer practical, efficient and simple method of improving herbicide selectivity. This method has been applied successfully in cereal crops such as maize, rice and sorghum, against pre-emergence thiocarbamate and chloroacetanilide herbicides. Some reports indicate promising results for the development of safeners for post-emergence herbicides in broadleaved crops. Various hypotheses were proposed explaining mechanisms of action of herbicide safeners: interference with uptake and translocation of the herbicide, alteration in herbicide metabolism, and competition at site of action of the herbicide. Even though progress was made in the development of herbicide safeners and in understanding their mechanisms of action, more research is needed to elucidate clearly how these chemicals act and why their activity is restricted to particular crops and herbicides.     

Nanoanalytics: history,concepts, and specificities

Environmental Science and Pollution Research - This article deals with analytical chemistry devoted to nano-objects. A short review presents nano-objects, their singularity in relation to their...     

Perchlorate: Problems,Detection, and Solutions

The perchlorate anion (ClO₄^–) is produced when the solid salts of ammonium, potassium, and sodium perchlorate, and perchloric acid dissolve in water. Ammonium perchlorate, used in solid rocket engine fuels, has a limited shelf life and must periodically be replaced. Before 1997, perchlorate could not be readily detected in groundwater at concentrations below 100 μg/L, until the California Department of Health Services developed an acceptable analytical method that lowered the detection limit to 4 μg/L. Subsequently, groundwater containing perchlorate were soon encountered in several western states, and contamination became apparent in Colorado River water. Most perchlorate salts have high water solubilities; concentrated solutions have densities greater than water. Once dissolved, perchlorate is extremely mobile, requiring decades to degrade. Health effects from ingesting low dosage perchlorate-contaminated water are not well known: it interferes with the body's iodine intake, causing an inhibition of human thyroid production. Contaminated surface and groundwater treatment may require bio- and/or phytoremediation technologies. Perchlorate in groundwater is relatively unretarded; it probably travels by advection. Therefore, it may be used as a tracer for hydrocarbon and metal contaminants that are significantly more retarded. Possible forensic techniques include chlorine isotopes for defining multiple or commingled perchlorate plumes.     

Perchlorate: Problems,Detection, and Solutions

The perchlorate anion (ClO 4 m ) is produced when the solid salts of ammonium, potassium, and sodium perchlorate, and perchloric acid dissolve in water. Ammonium perchlorate, used in solid rocket engine fuels, has a limited shelf life and must periodically be replaced. Before 1997, perchlorate could not be readily detected in groundwater at concentrations below 100 µg/L, until the California Department of Health Services developed an acceptable analytical method that lowered the detection limit to 4 µg/L. Subsequently, groundwater containing perchlorate were soon encountered in several western states, and contamination became apparent in Colorado River water. Most perchlorate salts have high water solubilities; concentrated solutions have densities greater than water. Once dissolved, perchlorate is extremely mobile, requiring decades to degrade. Health effects from ingesting low dosage perchlorate-contaminated water are not well known: it interferes with the body's iodine intake, causing an inhibition of human thyroid production. Contaminated surface and groundwater treatment may require bio- and/or phytoremediation technologies. Perchlorate in groundwater is relatively unretarded; it probably travels by advection. Therefore, it may be used as a tracer for hydrocarbon and metal contaminants that are significantly more retarded. Possible forensic techniques include chlorine isotopes for defining multiple or commingled perchlorate plumes.     

Persistence of phorate in soils: role of moisture, temperature, preexposure, and microorganisms

In laboratory incubation studies with three soils of varying physicochemical characteristics, phorate was more persistent in nonflooded (60% water holding capacity) soils than in flooded soils. Phorate sulphoxide was recovered as the only metabolite of phorate in nonflooded soils while three metabolites (diethyl dithiophosphate, triethyl dithiophosphate and an unidentified metabolite) were formed in flooded soils. Study indicates that in nonflooded soils phorate is degraded via oxidation while in flooded soils hydrolysis is the major degradation process. Degradation of phorate was accelerated by an increase in incubation temperature. Preexposure or repeated application of soils to phorate slightly decreased the persistence of phorate or its metabolites. Decreased persistence of phorate and its metabolites formed in nonsterile soils compared to sterile soils suggested the role of microorganisms in their transformation.     

Phenylheptatriyne: Occurrence, synthesis, biological properties, and environmental concerns

In addition to a complete bibliography on the occurrence, synthesis, photochemistry, biological activity, and mechanism of phototoxicity of phenylheptatriyne, new data on its phototoxicity in larvae of the mosquito , in and in fish ( ) are presented. The apparent lack of target specificity suggests that additional research will be necessary before considering using PHT in field applications.     

Goa: tourism,migrations, and ecosystem transformations

This article is based on a larger case study that investigated the role of tourist induced and other population movements in causing coastal ecosystem change in Goa, India. It focuses especially upon agro-ecosystems locally known as khazan lands, and sand dunes, and how they are transformed to accommodate the needs of tourists and tourism. The effects of different forms of tourism upon land cover and land-use change is assessed. The research findings suggest that it is not population movements alone that cause ecosystem changes, but the changes in relations between people and ecosystems. This means that in some cases land cover has not changed as much as land use, and in other cases land cover has changed dramatically. Intermediary influences upon land use and land-cover change are also legal, political, and economic factors, particularly changes in property rights.     

Issues of livelihood, sustainable development, and governance: Bay of Bengal

This article is based on the findings of the Global International Waters Assessment (GIWA) Subregion 53, Bay of Bengal. It introduces the Subregion. The wide disparity in development indicators in the Bay of Bengal Subregion (BOBSR) is presented. The large population of poor people living in South Asia is presented as a factor that needs special attention. The article focuses on the 3 geographic sites selected for detailed analysis: i) the Ganges-Brahmaputra-Meghna river systems; ii) the Merbok Estuary mangroves, Malaysia; and iii) the Sunderbans mangroves, Bangladesh. Integrated water management based upon regional cooperation among Bangladesh, India and Nepal holds opportunities for mutual benefit. Policy options are proposed. For mangrove ecosystems, the impacts of urbanization in Malaysia and the unmanaged expansion of shrimp farming in Bangladesh are analyzed. Improved governance was seen to hold promise for enhancing economic benefits from shrimp farming while safeguarding the natural ecological system. However, these measures need to be a part of national efforts to achieve the UN Millennium Development Goals.     

Environmental risk,toxicity, and biodegradation of polyethylene: a review

Environmental Science and Pollution Research - Polyethylene is the second-most-commonly-used commercial polymer. It is used in various industries, including agricultural mulches, composite...     

Mycoremediation of heavy metals: processes,mechanisms, and affecting factors

Environmental Science and Pollution Research - Industrial processes and mining of coal and metal ores are generating a number of threats by polluting natural water bodies. Contamination of heavy...     

Fibers,Electrostatics, and Filtration: A Review of New Technology

This symposium sponsored by the Fiber Society and the Filtration Society has provided a clear indication that the “black-art” era of filtration has passed or is on its way out. The R & D efforts reviewed here by investigators from diverse disciplines provide evidence that these high efficiency particulate control devices can be made to function not only more consistently at high levels but now with even better control of the fine, health damaging particles. The outstanding improvement in every filtration parameter, reliably attainable by aerosol charging and/or by imposing an electric field on the filter, indicates clearly that fabric filtration has now reached an even higher plateau in particulate control technology.     

Bacterial degradation of chlorophenols: pathways, biochemica, and genetic aspects

Chlorophenols belong to the group of toxic and persistent to microbial attack xenobiotics. Nevertheless, due to the adaptation microorganisms acquire the ability to use chlorophenols as the sole source of carbon and energy. The present review describes the diversity of aerobic pathways for the utilization of halogenated phenols by bacteria with the emphasis on the main reactions and intermediates formed, enzymes responsible for these reactions and their genetic basis. Taking into account (i) the fact that enzymes degrading chlorophenols are similar to the ones involved in the conversion of other (chloro)aromatic compounds and (ii) that present numerous publications describing the properties of separated enzymes or encoding their genes are published, this review was planned as the attempt to present both, the most general and specific aspects in chlorophenols degradation with the emphasis on the literature of the last ten years.     

Review of characterization,factors, impacts,and solutions of Lake eutrophication: lesson for lake Tana,Ethiopia

Environmental Science and Pollution Research - Lake eutrophication and water quality deterioration have become a major environmental problem in urban areas and fertilized basins in developing...     

Poverty, economic growth, deprivation, and water: the cases of Cambodia and Vietnam

Poverty reduction decorates all development agendas, but the complexity of the poverty issue is too often hidden behind simplistic indicators and development goals. Here, a closer look is taken at the concepts of "deprivation" and "vulnerability" as outcomes of poverty. Deprivation leads typically to social exclusion and marginalization; such groups are particularly weak in getting themselves out of poverty by "self-help," and economic growth does not trickle down to these people. When looking at the connections between poverty reduction and economic growth, special emphasis should be put on the differences between modern and more traditional sectors: development of the modern sector should not marginalize and exclude those dependent on more traditional livelihoods. Two case studies--The Tonle Sap area, Cambodia, and the Mekong Delta, Vietnam--reveal that investment in education, empowerment of small-scale entrepreneurship and other means of microeconomic environment, along with good governance, infrastructure, and income distribution can ensure that economic growth includes the poorer echelons of society.     

Types,sources, socioeconomic impacts,and control strategies of environmental noise: a review

Noise exposure has reached an alarming degree over the years because of rapid growth in the industry, transportation, and urbanization. Therefore, it is a dire need to provide awareness of the sources and mitigation strategies of noise, and to highlight the health, and socio-economic impacts of noise. A few research studies have documented this emerging issue; however, there is no comprehensive document describing all types of noise, their impacts on living organisms, and control strategies. This review article summarizes the sources of noise; their effects on industrial workers, citizens, and animals; and the value of property in noisy areas. The plethora of literature is showing an increased level of noise in various cities of the world, which have various health consequences such as high blood pressure, insomnia, nausea, heart attack, exhaustion, dizziness, headache, and triggered hearing loss. Apart from humans, noise also affects animal habitat, preying, and reproduction ability; increases heart rate and hearing loss to even death and loss in property value; and impairs the hospital environment. Finally, we have discussed the possible strategies to mitigate the noise problem, policy statements, and regulations to be followed, with future research directions based on the identified research gaps.

     

Planning nature-based solutions: Principles,steps, and insights

Nature-based solutions (NBS) find increasing attention as actions to address societal challenges through harnessing ecological processes, yet knowledge gaps exist regarding approaches to landscape planning with NBS. This paper aims to provide suggestions of how planning NBS can be conceptualized and applied in practice. We develop a framework for planning NBS by merging insights from literature and a case study in the Lahn river landscape, Germany. Our framework relates to three key criteria that define NBS, and consists of six steps of planning: Co-define setting, Understand challenges, Create visions and scenarios, Assess potential impacts, Develop solution strategies, and Realize and monitor. Its implementation is guided by five principles, namely Place-specificity, Evidence base, Integration, Equity, and Transdisciplinarity. Drawing on the empirical insights from the case study, we suggest suitable methods and a checklist of supportive procedures for applying the framework in practice. Taken together, our framework can facilitate planning NBS and provides further steps towards mainstreaming.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01365-1) contains supplementary material, which is available to authorized users.