Comparative algological and bacteriological examinations on biofilms developed on different substrata in a shallow soda lake

According to the European Water Framework Directives, benthic diatoms of lakes are a tool for ecological status assessment. In this study, we followed an integrative sample analysis approach, in order to find an appropriate substratum for the water qualification-oriented biomonitoring of a shallow soda lake, Lake Velencei. Six types of substrata (five artificial and one natural), i.e., andesite, granite, polycarbonate, old reed stems, Plexiglass discs and green reed, were sampled in May and in November. We analysed total alga and diatom composition, chlorophyll a content of the periphyton, surface tension and roughness of the substrata and carbon source utilisation of microbial communities. Water quality index was calculated based on diatom composition. Moreover, using a novel statistical tool, a self-organising map, we related algal composition to substratum types. Biofilms on plastic substrates deviated to a great extent from the stone and reed substrata, with regard to the parameters measured, whereas the biofilms developing on reed and stone substrata were quite similar. We conclude that for water quality monitoring purposes, sampling from green reed during springtime is not recommended, since this is the colonization time of periphyton on the newly growing reed, but it may be appropriate from the second half of the vegetation period. Stone and artificially placed old reed substrata may be appropriate for biomonitoring of shallow soda lakes in both spring and autumn since they showed in both seasons similar results regarding all measured features

Economic Aspects of Sanitation in Developing Countries

Improved sanitation has been shown to have great impacts on people's health and economy. However, the progress of achieving the Millennium Development Goals (MDGs) on halving the proportion of people without access to clean water and basic sanitation by 2015 has thus far been delayed. One of the reasons for the slow progress is that policy makers, as well as the general public, have not fully understood the importance of the improved sanitation solutions. This paper, by gathering relevant research findings, aims to report and discuss currently available evidence on the economic aspects of sanitation, including the economic impacts of unimproved sanitation and the costs and economic benefits of some common improved sanitation options in developing countries.; DATA USED IN THIS PAPER WERE OBTAINED FROM DIFFERENT INFORMATION SOURCES: international and national journal articles and reports, web-based statistics, and fact sheets. We used both online search and hand search methods to gather the information.; Scientific evidence has demonstrated that the economic cost associated with poor sanitation is substantial. At the global level, failure to meet the MDG water and sanitation target would have ramifications in the area of US$38 billion, and sanitation accounts for 92$142 billion (US$year 2005). This translates to a per capita spending of US$28 for sanitation. Annually, this translates to roughly US$14 million. The evidence complied in this paper demonstrates that investing in sanitation is socially and economically worthwhile. For every US$1 invested, achieving the sanitation MDG target and universal sanitation access in the non-OECD countries would result in a global return of US$9.1 and US$11.2, respectively.; Given the current state of knowledge, sanitation is undeniably a profitable investment. It is clear that achieving the MDG sanitation target not only saves lives but also provides a foundation for economic growth

Improved phosphorus use efficiency in agriculture: A key requirement for its sustainable use

Mineral phosphorus (P) fertilizers processed from fossil reserves have enhanced food production over the past 50. years and, hence, the welfare of billions of people. Fertilizer P has, however, not only been used to lift the fertility level of formerly poor soils, but also allowed people to neglect the reuse of P that humans ingest in the form of food and excrete again as faeces and urine and also in other organic wastes. Consequently, P mainly moves in a linear direction from mines to distant locations for crop production, processing and consumption, where a large fraction eventually may become either agronomically inactive due to over-application, unsuitable for recycling due to fixation, contamination or dilution, and harmful as a polluting agent of surface water. This type of P use is not sustainable because fossil phosphate rock reserves are finite. Once the high quality phosphate rock reserves become depleted, too little P will be available for the soils of food-producing regions that still require P supplements to facilitate efficient utilization of resources other than P, including other nutrients. The paper shows that the amounts of P applied in agriculture could be considerably smaller by optimizing land use, improvement of fertilizer recommendations and application techniques, modified livestock diets, and adjustment of livestock densities to available land. Such a concerted set of measures is expected to reduce the use of P in agriculture whilst maintaining crop yields and minimizing the environmental impact of P losses. The paper also argues that compensation of the P exported from farms should eventually be fully based on P recovered from 'wastes', the recycling of which should be stimulated by policy measures. © 2011 Elsevier Ltd

Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options

Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus recovery). However the emerging global challenge of phosphorus scarcity with serious implications for future food security, means phosphorus will also need to be recovered for productive reuse as a fertilizer in food production to replace increasingly scarce and more expensive phosphate rock. Through an integrated and systems framework, this paper examines the full spectrum of sustainable phosphorus recovery and reuse options (from small-scale low-cost to large-scale high-tech), facilitates integrated decision-making and identifies future opportunities and challenges for achieving global phosphorus security. Case studies are provided rather than focusing on a specific technology or process. There is no single solution to achieving a phosphorus-secure future: in addition to increasing phosphorus use efficiency, phosphorus will need to be recovered and reused from all current waste streams throughout the food production and consumption system (from human and animal excreta to food and crop wastes). There is a need for new sustainable policies, partnerships and strategic frameworks to develop renewable phosphorus fertilizer systems for farmers. Further research is also required to determine the most sustainable means in a given context for recovering phosphorus from waste streams and converting the final products into effective fertilizers, accounting for life cycle costs, resource and energy consumption, availability, farmer accessibility and pollution. © 2011 Elsevier Ltd

Sustainable use of phosphorus : EU tender ENV.B1/ETU/2009/0025

As sustainable phosphorus use will sooner or later become essential for global food security, action is needed. As far as the required actions are concerned, the report has identified short-term and long-term policy options which could improve the current level of phosphorus use efficiency in agriculture. The report emphasizes, however, that policies should not be developed in isolation, let alone for agriculture only, but that all parts of the chain, that is primary production, processing and consumption, should be addressed in an integrative way. The current reliance on imported rock-based phosphorus (‘3 kg P per European citizen per year’) can not be continued in the long run. To become truly sustainable, phosphorus use efficiency must approach a level close to 100% in each chain. Therefore, a full recycling of phosphorus will become a condition sine qua non for global and European food security. The urgency of policies and measures needed for that will be determined by the phosphate rock reserves considered exploitable (including geopolitically and legally accessible), the prevention of accumulation and losses, the size of the global population and its preferences in terms of food, feed, fibers and fuels, and its appreciation of biodiversity. This will require drastic adjustments to the way we manage agriculture, and it may also require adjustments to our society as a whole, including the processing of our ‘wastes’

Future supply of phosphorus in agriculture and the need to maximise efficiency of use and reuse

Commercially viable reserves of rock phosphate are limited and only a few countries are significant producers. China and the US will play a much smaller role within 50 years time and the bulk of the world's mined phosphorus will come from Morocco. A conservative estimate of longevity of the resource shows that at a 1% exponential increase for the next 50 years followed by zero increase, the global reserves would last 235 years. If one uses the UN global population growth rate to determine future demand, with a stabilisation by 2100, the current global reserves would last 172 years. This estimate can be further reduced to 126 years if Africa develops its agriculture and to just 48 years if in addition bio-energy crops are given higher priority. The phosphorus losses are significant in the mining/beneficiation/ /fertiliser production steps (35% of what is mined is not converted into usable product) and in agriculture (30% of what is added as fertiliser is not contained in agricultural output, with most being retained in the soil) but they are even higher within the areas of food processing, distribution and consumption (60% of the P in food is lost). To reduce phosphorus losses the questions of erosion from farm fields and more effective handling of manure from high density livestock feedlots need to be addressed. When it comes to food processing, improvements in crop storage, processing facilities and trade methods are needed. At present most of the excreted phosphorus from humans ends up lost in the environment. Phosphorus extraction from wastewater, sludge, manures and other organic sources is only starting and needs worldwide promotion. About one billion people are under-nourished and many are smallholder farmers that cannot afford chemical fertilisers. Food production in developing countries will probably have to double by 2050. More conservative policies and measures are required in the management of fertilisers to feed a world with 9 billion people. Countries need to further develop productive sanitation systems in order to safely reuse human and animal excreta. Guidelines now exist for the use of human urine as a substitute for chemical fertiliser in agriculture. There is a higher chance that food security can be achieved by maintaining soil fertility if all available sources of fertiliser resources are better managed – animal manure, crop and food residues, chemical fertilisers and human excreta. For these reasons a much more conservative approach is needed in the exploitation of fossil phosphate-rock and that reuse and more efficient systems should be promoted and developed

Assessment of environmental and farm business impacts of phosphorus policies in two European regions

This paper presents analyses of the economic and environmental impact of relevant phosphorus management policy scenarios, using representative pig and poultry farms in the Emilia-Romagna region (Po River basin, Italy) and Niedersachsen region (Ems River basin, Germany) as case studies. The analysis was done by using a farm-level linear programming bioeconomic model developed for different farm and animal types-sows, fattening pigs, laying hens and broilers. The baseline for the assessed scenarios involved farms situated within the Nitrate Vulnerable Zones (NVZs) and therefore, were subject to indirect phosphorus fertilization limitations via the Nitrates Directive (ND). The analyzed phosphorus management policy scenarios included the implementation of two different balances of 8.7 kg and 4.35 kg of P per ha per year, inspired by the German Fertilizer Ordinance for phosphorus fertilization implemented in 2007 and later updated from 2017 up to 2023, respectively. We also included a more rigorous zero P balance scenario. The results of the scenario simulations, based on model assumptions, reveal that the introduction of direct phosphorus management policies for pig and poultry farms situated in high livestock dense regions can be done without causing any significant impact on farm gross margin (around 2% of reduction) for both regions and all four animal types, except for sows and broiler production in the Ems River Basin (up to 12% of reduction). Selected technologies and methods, inspired by current practices, have been analyzed for their cost efficiency to achieve the target P balance of the individual scenarios, including export of slurry out of the farm or export of separation solids. Results also highlight that the Nitrates Directive alone is not enough to handle the P issue in monogastric livestock farms