Matrix effect in case of purification of oily waters by membrane separation combined with pre-ozonation

In the present study, oil in water emulsions (c_oil?=?100 ppm; d_{oil droplets}?<?2 μm) was purified with ozonation followed by microfiltration using polyethersulfone (PES) membrane (d_pore?=?0.2 μm). The effects of pre-ozonation on membrane microfiltration were investigated in detail both in case of ultrapure and model groundwater matrices, applying different durations (0, 5, 10, and 20 min) of pre-ozonation. Simultaneously, the effects of added inorganic water components on the combined method were investigated. Size distribution of oil droplets, zeta potentials, fluxes, and purification efficiencies were measured and fouling mechanisms were described in all cases. It was found that the matrix significantly affected the size distribution and adherence ability of oil droplets onto the membrane surface, therefore fouling mechanisms also were strongly dependent on the matrix. In case of low salt concentration, the total resistance was caused mainly by reversible resistance, which could be significantly reduced (eliminated) by pre-ozonation. In case of model groundwater matrix, nearly twice higher total resistance was measured, and irreversible resistance was dominant, because of the higher adhesion ability of the oil droplets onto the membrane surface. In this case, pre-ozonation resulted in much lower irreversible, but higher reversible resistance. Increased duration of pre-ozonation raised the total resistance and reduced the elimination efficiency (due to fragmented oil droplets and water soluble oxidation by-products) in both cases, therefore short pre-ozonation can be recommended both from economic and performance aspects.     

Changes of the phytoplankton community as symptoms of deterioration of water quality in a shallow lake

Covering more than 60% of the lake surface, macrophytes determined the taxonomic composition of phytoplankton. We have found numerous indications of ecological deterioration and an increased trophic level year to year: an increased total number of taxa; a significantly increased number of species of Chlorophyta, Bacillariophyceae and Cyanoprokaryota; a decreased number of Chrysophyceae; increased Nygaard index, and high diversity and variability of phytoplankton functional groups. Within 2 years (2002 and 2003) algal biomass doubled: from 3.616 to 7.968 mg l^?1. An increased contribution of Chlorococcales and Cyanoprokaryota indicates progressive eutrophication of the lake. The average size of planktonic algae increased, particularly Cyanoprokaryota, where small-celled decreased dramatically and were replaced by large colonies. Cyanoprokaryota remained the dominant group of phytoplankton after 10 years, and the ecosystem of the lake remained in the turbid state. This group of algae had the average biomass 9.734 mg l^?1, which constituted almost 92% of the total biomass.     

Perceptions of American and Russian environmental scientists of today’s key environmental issues: a comparative analysis

Modern science is global. This is particularly true of environmental science, which has been guided to a considerable extent by international environmental policy. Accordingly, one might expect the standards of scientific research around the globe to have unified over the last 30 years. Yet environmental scientists from different nations and scientific schools have demonstrably dissimilar views on key environmental issues. This is the conclusion we reached after a series of in-depth interviews with prominent American and Russian environmental scientists. The greatest difference was found in the perception of two global issues—stratospheric ozone depletion and climate change.     

Laboratory study on sustainable use of cement–fly ash–polypropylene fiber-stabilized dredged material

The major problem associated with gravity dam was siltation of reservoir which reduced its effective water storage capacity. In order to maintain effective storage capacity of reservoir, dredging of deposits was required and dredged material was disposed of haphazardly causing damage to the sensitive environment. A better alternative could be the possibility of utilization of dredged deposits in construction works involving large quantities of material. The dredged material consisted of very fine sandy silt possessing poor geotechnical characteristics and was required to be stabilized with suitable additives before use as construction material. This laboratory investigation evaluated geotechnical properties of dredged reservoir material stabilized with cement, fly ash and fiber for its probable use as subbase in lightly trafficked roads. Compaction, unconfined compressive strength and tensile strength tests were performed on appropriate combinations of the constituent materials. The results of study revealed significant improvement in unconfined compressive strength and split tensile strength after stabilization with cement and fly ash. The unconfined compressive strength and split tensile strength of cement–fly ash-stabilized dredged reservoir material improved further upon addition of polypropylene fiber. The composite possessed the potential to be utilized as sustainable material in subbase of roads subject to further validation before application in the field. The dredging of sediments improved effective storage capacity of reservoir and increased its sustainable life period. The utilization of fly ash could diminish the environmental and economic concerns arising out of its haphazard disposal.     

Identifying land suitable for agricultural land reform using GIS-MCDA in South Africa

Land reform is identified as a key tool in fostering development in South Africa. Twenty years after the advent of democracy in South Africa, the land question remains a critical issue for policy makers. Several frameworks have been put in place by the government to identify land that is strategically located for land reform. However, many of these frameworks are not well aligned and not objective in defining strategically located land for land reform and often lead to unsustainable land use management practices. This has hampered the government’s land reform initiative in promoting agricultural land reform and food security. Accordingly, there is a need to develop a decision support tool that facilitates the identification of strategically located land for land reform. This study proposes the use of geographic information systems (GIS) and multi-criteria decision analysis (MCDA) to develop a strategically located land index (SLLI) to identify land suitable for agricultural land reform. Participatory workshops and the group analytical hierarchy process were utilised to identify and weigh criteria used in computing the SLLI. The results indicate that land that is suitable for agricultural land reform is scarce, and there are also competing needs on the highly suitable land for agriculture. The study demonstrates that GIS and MCDA are invaluable tools in facilitating evidence-based decision-making for land reform and sustainable land use management practices. The SLLI is not the panacea to land identification; there is also need to appreciate the contested nature of land in South Africa.     

Abandonment landscapes: user attitudes,alternative futures and land management in Castro Laboreiro,Portugal

Land abandonment is an important process for the European Union, which primarily occurs in less productive, remote and mountainous areas with unfavourable conditions for agriculture. Future management directions of these abandonment areas are under debate, with increasing calls to adjust policies to the local characteristics, including the promotion of rewilding and the management of succession of larger areas of less-productive land. While there is an increase in studies focusing on the environmental impacts of land abandonment, there are few studies that focus on the perceptions of abandonment by different user groups, even though an understanding of local perceptions, opportunities and trade-offs associated with changing land management is crucial for landscape-related policies and planning measures. In a case study in Northern Portugal, we used a combination of statements, photograph rating exercises and open questions to assess the perceptions of local inhabitants, visitors and experts regarding land abandonment and their preferences of different possible trajectories after abandonment. The results show that all user groups have a negative response towards abandonment and associate it mainly with negative emotions and the loss of heritage and traditions. The assessment of the different abandonment stages and outcomes clearly yielded different preferences and explanations, which can be used as input for finding a common ground for landscape management, reducing conflict and as a starting point for a more spatially targeted and nuanced management approach.

     

No net loss of what,for whom?: stakeholder perspectives to Biodiversity Offsetting in England

Market-based instruments (MBIs) have emerged as a popular approach to balance development and conservation objectives. However, their ability to accomplish this is often beset by poor implementation in practice. This is testament to a widening gap between the rate of policy development and implementation of MBIs and the maturity of research and evaluation on their design, and impact on affected stakeholders. Within this context, this paper examines multi-stakeholder perspectives to the adoption of Biodiversity Offsetting in England, an instrument designed to enable biodiversity losses in one place to be compensated through conservation improvements elsewhere. Analysis reveals issues associated with social and ecological compensation of biodiversity loss. Findings suggest that there is a need for a broader consideration of issues surrounding distributive justice, access to nature and the status of ownership over sites of common heritage when accounting for biodiversity loss and its compensation. This message is salient to both the study context as well as the burgeoning international practice of Biodiversity Offsetting.     

Land cover effects on water balance partitioning in the Colombian Andes: improved water availability in early stages of natural vegetation recovery

Regional Environmental Change - Vegetation actively affects different components of the water budget in multiple spatial and temporal scales. Changes in vegetation cover and structure—such as...     

Trends in social metabolism and environmental conflicts in four Andean countries from 1970 to 2013

In the global map of environmental injustices (http://www.ejatlas.com), the Andean countries (AC) report many ecological distribution conflicts. Our hypothesis is that the patterns of such conflicts are explained by the structural shifts of the economies and the concomitant changes in their metabolic profiles. Since the 1990s, these countries went through a strong reprimarization process, which changed their social metabolism as well as intensified environmental pressures and conflicts. In monetary terms, in the AC group of countries (Colombia, Ecuador, Peru and Bolivia), the primary sector increased its importance both in exports as well as in GDP. In the metabolic dynamics, the Domestic Extraction of materials (measured in tons) increased by a factor of 3.4 after jumping from 336 to 1145 MT between 1970 and 2012. This was driven by the fossil fuel and mining sectors. This reality was reflected in the environmental conflicts. Mining, fossil fuels, biomass and hydropower plants are the most conflictive sectors. The research in this article relies on a study of material flow analysis for the four AC carried out by the authors as well as 244 environmental conflicts reported in the EJAtlas until August 2016. The shifts in the metabolic–economic patterns help explain the dynamics and characteristics of the environmental conflicts in the AC. Such conflicts produce social mobilizations, which if successful, might help move society towards sustainability and environmental equity.     

Keeping pace with forestry: Multi-scale conservation in a changing production forest matrix

The multi-scale approach to conserving forest biodiversity has been used in Sweden since the 1980s, a period defined by increased reserve area and conservation actions within production forests. However, two thousand forest-associated species remain on Sweden’s red-list, and Sweden’s 2020 goals for sustainable forests are not being met. We argue that ongoing changes in the production forest matrix require more consideration, and that multi-scale conservation must be adapted to, and integrated with, production forest development. To make this case, we summarize trends in habitat provision by Sweden’s protected and production forests, and the variety of ways silviculture can affect biodiversity. We discuss how different forestry trajectories affect the type and extent of conservation approaches needed to secure biodiversity, and suggest leverage points for aiding the adoption of diversified silviculture. Sweden’s long-term experience with multi-scale conservation and intensive forestry provides insights for other countries trying to conserve species within production landscapes.