Water Scarcity Scenarios Research Articles

Incorporation of graphene oxide on thin film composite polysulfone/polyamide membranes

Potable water has become a valuable, and sometimes, scarce resource due to population growth and industrial activities. Therefore, technologies that can process and generate this product are necessaries to avoid a global scenario of water scarcity in the following years. Reverse osmosis desalination using membranes is one of the most used strategies to produce potable water. However, polymeric membranes are susceptible to fouling and chlorine attack, which reduce their lifespan. Different approaches have been used to solve these problems such as the incorporation of nanocharges on the polymeric matrix of the membranes. In this work, the incorporation of graphene oxide on the polyamide membranes using different insertion routes was reviewed. The main results show that using graphene oxide as an additive for the thin film composite membranes, highly improves their performance in desalination systems as shown with the increase in 80% of the permeate flux while retaining salt rejection, besides, the addition of this nanocharge potentially increased chlorine resistance in 25%.

Analysis of the response of the Epitácio Pessoa reservoir (Brazilian semiarid region) to potential future drought, water transfer and LULC scenarios

The Brazilian semiarid region (BSAR) is affected by the high precipitation variability and severe drought events over time, promoting recurrent water scarcity. The water supply in the BSAR has suffered since 2012 from severe incidents of rainfall reduction, creating a complex scenario of water scarcity, for instance, in Campina Grande city, which is supplied by the Epitacio Pessoa reservoir (EPR). This study analyzed the future impacts on the volume of the EPR based on potential future droughts, water transfer from the Sao Francisco River, population growth and recent changes in land use and land cover (LULC). Several procedures were performed, including (a) simulation of LULC scenarios with the LCM algorithm, (b) simulation of future rainfall scenarios for the period from 2020 to 2030, (c) streamflow simulation using the Soil Water and Assessment Tool (SWAT) model and (d) prediction of water storage in the EPR for the period from 2020 to 2030 using three rainfall scenarios (− 40%, − 45% and − 50%). The results indicated that the SWAT calibration and validation results were considered satisfactory based on the R2, Nash, and PBIAS values. The results were assumed from the rainfall scenarios for the period from 2020 to 2030 together with the LULC scenario for 2030, including the estimated outflow of water transfer from the Sao Francisco River. The results showed, based on the three adopted rainfall scenarios, that the reservoir would reach its critical volume in the first two years of the analyzed period, and the reservoir volume would then increase until 2024 and subsequently return to decrease, reaching the critical volume in 2030.

Automatic surface water distribution systems: A reliable alternative for energy conservation in agricultural section

The poor performance of surface water distribution systems in reliable, sufficient, and timely agricultural water distribution has significantly increased groundwater extraction. This has posed severe environmental challenges such as the significant decline in groundwater levels and increases in energy consumption. This study investigated the potential for automation of the surface water distribution systems to decrease groundwater extraction and energy conservation. The proposed approach was implemented in Nekoo-Abad Irrigation District, located in the arid region in Iran. The undesirable surface system’s performance results in the annual extraction of 82 Mm3 water from nearly 4181 active tubewells and the annual consumption of 236 MkWh to pump the groundwater for agricultural purposes merely. The automation improved the system performance so that annual groundwater extraction decreased by 16%. Reducing groundwater extraction decreased energy consumption by nearly 26%, 18%, and 14% in the normal and water scarcity scenarios. Moreover, the spatial analysis of research results indicated that groundwater extraction declined by 61–88% in shallow wells (<30 m deep), by 48–75% in wells 30–60 m, and by 5–10% in >120 m. It is expected that the entire system's automation will help achieve more of the research objectives, something which requires additional socioeconomic studies.

Non-structural modification of agricultural water distribution systems in large scale irrigation districts

The present study's primary objective is to investigate non-structural alternatives' effectiveness in providing a reliable agricultural water distribution in large scale irrigation districts. Accordingly, the following activities were conducted to accomplish the objective: i) developing an operation model of non-structural alternatives in MATLAB; ii) developing a simplified hydraulic flow simulation model in MATLAB, capable of being integrated the operation model. iii) operational performance appraisal of the developed model under the normal and water shortages scenarios, iv) spatial analysis of the obtained results with GIS to determine each alternatives' effectiveness. The developed model was tested on a real test case, extensive irrigation districts located in central Iran. Analysis of the obtained results reveals that employing the first to third non-structural alternative improved the mean value of the daily water distribution adequacy index by 6–8%, 10–11%, and 5–7% in the normal scenario, 4–5%, 8–7%, and 3–4% in the water scarcity scenario, compared to the water distribution process in the status quo. Besides, the alternatives lead to improving water distribution equity even under the water scarcity scenarios, where the equity improved by 10, 12, and 8% for the first through third alternatives compared to the status quo. Besides the technical assessment, a comprehensive evaluation concerning the non-structural alternatives' effectiveness was conducted, based on the environmental, agricultural, and social effects of these alternatives, to provide practical results. The latter assessment reveals that the second alternative's implementation is expected to lead to a remarkable 12% annual water extraction reduction from the aquifer, decommissioning about 1694 of the 14,440 authorized tube-wells within the district, and a 14.3% reduction in energy consumption. The results showed acceptable improvement in irrigation water distribution by employing non-structural alternatives under normal operating conditions and little improvement under water scarcity scenarios. It was shown that, given the limited infrastructure available in the irrigation districts in developing countries, improving operation management does not necessarily need massive investments in renovating and modernizing these districts.

Deficit Irrigation as a Suitable Strategy to Enhance the Nutritional Composition of HydroSOS Almonds

The Mediterranean region is one of the most water-scarce areas worldwide and is considered a climate-change hotspot. To assure the viability and competitiveness of irrigated agriculture, it is vital to implement strategies that can maximize water saving without compromising yield. Deficit irrigation (DI) for cultivating drought-tolerant species such as almond (Prunus dulcis (Mill.) D.A. Webb) can help in achieving this goal, while at the same time improving fruit chemical composition. This work evaluated the effect of DI techniques and cultivars on the chemical composition of almonds (cvs. Marta, Guara, and Lauranne) in order to elucidate the most suitable irrigation dose under water-scarcity scenarios. Three irrigation regimes were imposed: a control treatment (FI), which was fully irrigated, receiving 100% of the irrigation requirement (IR), and two sustained-deficit irrigation (SDI) strategies that received 75% (SDI75) and 65% (SDI65) of IR. Significant differences among cultivars and irrigation treatments were observed for antioxidant activity and organic acid, sugar, and fatty acid content, which were increased by the SDI strategies. In addition, highly significant correlations were found between leaf-water potential and components such as fumaric acid, sugars, and fatty acids. In terms of the cultivars, cv. Marta showed the highest antioxidant activity, cv. Guara was the richest in organic acids, and cv. Lauranne had the highest fatty acid content. Consequently, SDI strategies improved almond quality parameters related to their nutritional and sensory composition, with significant water savings (reductions of 25–35%) and without important yield loss.

Optimal and Fair Distribution of Water Under Water Scarcity Scenarios at a Macroscopic Level

This paper presents an optimization approach for designing water allocation systems at macroscopic level under water scarcity conditions. The proposed approach accounts for the proper water distribution of the available sources (dams, deep wells, lakes, rivers, etc.) and the incorporation of artificial sources (rainwater harvesting systems, and recycled water) to satisfy domestic and agricultural demands in a specific region at the maximum revenue. The proposed mathematical model incorporates fair distribution schemes (Social Welfare, Rawls and Nash Schemes), which allow determining fair water distribution options under water scarcity conditions. A case study for the city of Morelia in Mexico is presented to show the applicability of the proposed optimization approach. Results show that it is possible to obtain fair solutions for the water allocation for all the users under different water scarcity conditions.

Tensión de humedad del suelo, crecimiento, eficiencia en el uso del agua y rendimiento de maíz cultivado en el noroeste de México

En escenarios de escasez de agua, el manejo del riego en cultivos es de gran importancia. El objetivo de este trabajo fue identificar la tensión de humedad (T) óptima en suelo para producir el mayor crecimiento y rendimiento de maíz (Zea mays L.) cultivado en el valle de Mexicali, Baja California, México. El cultivo fue establecido durante el ciclo primavera-verano de 2017. Los tratamientos evaluados fueron cuatro tensiones de humedad [(T); (10, 20, 30 y 40 kPa)] y seis genotipos de maíz (G). Los tratamientos se distribuyeron bajo un diseño de bloques al azar con cuatro repeticiones (arreglo factorial doble). El primer factor fue tensión de humedad del suelo y el segundo factor la variedad de maíz. Se midió el crecimiento del cultivo expresado como altura, número de hojas, días a floración masculina (antesis), y área foliar. Al final del experimento se cosecharon las mazorcas de cada tratamiento y se calculó el peso de grano, rendimiento y eficiencia en el uso del agua de riego. No se encontró una interacción significativa entre las variables de respuesta evaluadas (T × G) (P &gt; 0.05). Durante los primeros 50 días después de la siembra, el factor que más afectó al crecimiento y desarrollo fue T. Con una menor T, menor fue el número de días para alcanzar la etapa de floración masculina (P &lt; 0.05). El rendimiento y la eficiencia en el uso del agua de riego fueron afectados por T y G (P &lt; 0.05). La variedad Asgrow RX 717 presentó la floración masculina en un menor tiempo que el resto de los genotipos, el más alto rendimiento (10.63 Mg ha-1) y la mayor eficiencia en el uso del agua de riego (48.79 kg ha-1 mm-1) que el resto de los genotipos evaluadas (P &lt; 0.05).

Response of residential water demand to dynamic pricing: Evidence from an online experiment

Abstract Urban water demand management is key to water supply sustainability in high-density, water-stressed areas throughout the world, and emerging technologies could transform it. In particular, smart metering could allow for conserving water by dynamically changing prices to reflect water scarcity and supply cost variability. Yet, little is known on end-users’ reaction to short-term price changes, an essential determinant of the effectiveness and acceptability of dynamic water pricing. This paper reports on the design and results of an online experiment that measures end-users’ water consumption decisions when confronted with time-varying prices, and investigates the interaction between pricing and water scarcity awareness. We design a series of treatments where players must indicate their shower length given different water prices, price variations, and scarcity scenarios. Beyond corroborating the theory that higher prices lower usage, the experiment finds evidence of a dynamic pricing effect: users respond more strongly to a given price if they have been exposed to a lower price before. This suggests short-term residential price increases could be effective at boosting water conservation.

A satellite-based ex post analysis of water management in a blueberry orchard

In the scenario of current water scarcity caused by climate change and increasing water demand for food production, farmers must adapt their water management practices by shifting from supply-driven water management to demand-driven water management, considering trade-offs among quality, quantity and costs. Thus, agricultural practices must take full advantage of technology, research and development and adapt to local requirements. Nowadays, remote sensing is a useful tool for estimating crop water demand (evapotranspiration) as well as mapping their spatial and temporal variability. In this work, we present a new methodology that allows the user to audit (ex post) the irrigation strategies of a blueberry field in central Chile using a decision support system for irrigation decision called AquaSat® as the main tool. This tool combines satellite information with field data and provides spatially distributed information on crop water use for managing irrigation at a farm scale. The main contribution of this work is to detail a new approach for irrigation management through the comparison of volume of applied water, against evapotranspiration and potential demand. This procedure allows the user to audit current irrigation management and to determine the impacts on productivity.From our results, we can conclude that the applied water levels used at the farm during both seasons throughout of the irrigation sector were insufficient to reach the potential blueberries yield.

Evaluation of the AquaCrop model for winter wheat under different irrigation optimization strategies at the downstream Kabul River Basin of Afghanistan

Afghanistan has an arid to semi-arid climate where irrigated agriculture largely depends on scarce irrigation water supplies from snowmelt from the high raised mountains. Under growing water scarcity, farmers not only need to use the available water more wisely but have to develop alternative options for coping water scarcity. Deficit irrigation schedule can be one of the options to mitigate the adverse impacts of water scarcity on crop production. In the current study, FAO’s crop water productivity model (AquaCrop) was calibrated and validated with field data in Kabul River Basin (KRB) for wheat crop to simulate four different water scarcity scenarios (S-A: business-as-usual scenario, S-B: refilling the soil profile to field capacity upon 50 % water depletion, S-C: refilling the soil profile upon 100 % depletion and S-D: refilling the soil profile upon 130 % depletion occurrence) for resultant yield, water productivity (WP) and biomass production. Two wheat fields, namely A and B were monitored intensively for soil moisture content, meteorological situation, irrigation application and post-harvest data. Results show that the measured WP was 1.4 kg m−3 ETa and 1.5 kg m−3 ETa whereas, the actual (measured) water use efficiency (WUE) was 0.58 kg m−3 and 0.66 kg m−3 for Field A and Field B, respectively. The WP of the scenarios S-A, S-B, S-C and S-D was 2.0-2.1 kg m−3 ETa (for plot B and A), 2.5 kg m−3 ETa, 2.74 kg m−3 ETa and 2.8 kg m−3 ETa respectively. Similarly, yield under these scenarios was 6.4 ton ha−1, 8.7 ton ha−1, 7.4 ton ha−1and 6.7 ton ha−1 respectively while the above ground biomass was 21.3 ton ha−1, 21.8 ton ha−1, 19 ton ha−1 and 18.3 ton ha−1 respectively. As a consequence, WP could increase by 92.8 %, 78 % and 95 % in S-B, S-C and S-D, respectively with reference to the measured WP. The optimized scenarios developed in this study can provide guidelines for policy makers and farming communities to mitigate the adverse impact of water scarcity through such innovative interventions.

Abastecimento rural de água: uso e demanda em comunidades do Semiárido e a disponibilidade hídrica das aluviões

Offering water in quantity and quality needed in the Brazilian semiarid is a challenge far from being overcome, especially when it comes to diffuse rural communities. Knowing uses, demands and sources of water is vital for better management in a scenario of water scarcity. The alluviums are a considerable alternative in the perspective of better coexistence with this reality. For the stretch on the Upper Capibaribe River, the most relevant usage characteristics, demands and types of water sources in rural communities in the semiarid were identified. The water availability of the alluvium in the area was also evaluated. The granulometry, the parameters of hydraulic conductivity and porosity and the estimation of the exploitable resources were obtained. The population uses water from different sources in a combined way. Water from cisterns is used almost exclusively for the most noble domestic activities, while the water stored in the alluvium is used primarily for the less noble and for family farming and animal husbandry. In general, the limitation of access to water determines which productive activities can be carried out. The sediments that make up the alluvium were classified as medium to coarse sands. The estimated potential for exploitable water volume of the alluviums has accredited them as the main source of supply for these communities.

Water productivity with localized irrigation using groundwater and reuse water in the cultivation of plant species

ABSTRACT This study aimed to analyze the water saving potential of replacing the traditional, furrow-irrigated banana crop in the Curu-Pentecoste Irrigated Perimeter with localized systems by inserting new cropping plans and sources of groundwater and reuse water. An analysis of the support capacity in shallow tube wells for irrigation was also performed, considering the scenario of full recharge and water scarcity. The economic analysis was performed using the profitability indicators of the investment analysis: benefit/cost ratio, net present value, internal rate of return and payback period. Water productivity data reveal that cropping plans associated with alternative sources of water from shallow tube wells and reuse of the excess surface irrigation water in localized systems are economically more attractive than traditional, furrow-irrigated banana crop. The support capacity of shallow tube wells reveals that the exploitation of this underground water resource in the region is a viable alternative for irrigation of small areas. With the exception of banana, the other scenarios analyzed showed positive cash flows from the second year.

Organic fertilizer as a chelating agent in photo-Fenton at neutral pH with LEDs for agricultural wastewater reuse: Micropollutant abatement and bacterial inactivation

In a water scarcity scenario, the reused wastewater could be an essential source for agricultural irrigation considering that 60% of fresh water is destined to this area. In this study, an organic fertilizer (Diethylene triamine pentaacetic acid, DTPA) was used as a new chelating agent of iron for photo-Fenton’s application at neutral pH using LEDs. Secondary effluents with different characteristics were tested for propranolol removal and bacterial inactivation. With DTPA, the best results were achieved with MBR matrix: 94.0% of propranolol removal and total bacterial inactivation after 120 min. IFAS matrix showed the worst results: 63.2% of propranolol removal and only 2-log reduction for Total Coliforms. The performance of DTPA as chelating agent was compared with EDTA and EDDS with two matrices. In MBR matrix, propranolol removal with EDTA was 100% in 15 min, while DTPA and EDDS reached similar results at 120 min (94.0 and 91.3%), respectively. The iron precipitation was evaluated, and DTPA showed high stability with Fe2+ (only 10.4% of iron reduction instead 97.3% for EDDS). In addition, it looks like that the stability of iron chelates plays an important role in bacterial inactivation. Thus, the experiments with DTPA showed the lowest bacterial growth-on-the-plate after 72 h of the end of the experiment. Biodegradability and phytotoxicity were also evaluated and the experiments with DTPA had the lowest toxicity. The results of the experiments performed with DTPA were compared with the values in Proposal for agricultural water reuse suggesting that treated effluent accomplish the requirements for agriculture.

Estabelecimento das curvas-chave, geração das séries de vazões e estimativa das vazões máximas outorgáveis nos postos da sub-bacia Guapi-Macacu, RJ

A crescente demanda dos usos da água, o aumento populacional e a ocorrência de eventos climáticos extremos colocam a disponibilidade hídrica em foco. Em diferentes lugares do mundo, a água já não se encontra de forma tão abundante quanto há décadas. O abastecimento humano continua sendo a maior preocupação e a prioridade em políticas voltadas aos usos dos recursos hídricos, no entanto, setores como indústria, agricultura e energia demandam quantidades significativas de água, além da manutenção de sistemas ambientais dependentes desse recurso natural. Todas essas questões evidenciam o conflito vivido atualmente quanto ao uso e aproveitamento hídrico. Uma gestão integrada e sustentável são alicerces fundamentais para a manutenção qualitativa e quantitativa dos recursos hídricos. A outorga é um instrumento legal para a garantia do uso da água por tempo e volume determinado, seja para fins de captação ou lançamento de efluentes, e para sua aprovação, são necessários estudos hidrológicos para a estimativa da vazão a ser outorgada, também denominada de vazão máxima outorgável. O presente estudo definiu as curvas-chave e as séries de vazões diárias das estações fluviométricas inseridas na bacia hidrográfica do rio Guapi-Macacu, localizada na porção leste da Baía de Guanabara. Com base nos resultados, propõe-se a adoção de uma nova vazão máxima outorgável,visando um cenário de escassez hídrica que garanta o uso integrado e sustentável da água na bacia.

Rejuvenating Yamuna River by Wastewater Treatment and Management

Yamuna is the most important tributary of Ganga River originating from the Yamunotri glacier of Himalaya, the ‘Asian Water Tower’. Since Yamuna is fed by the above glacier, the Ganga River supplies water perennially. The catchment area of Yamuna River is 3, 45,848km2 which is the largest among the other tributaries of Ganga. Surface water resource of the Yamuna River is 61.22km3 and the net groundwater availability is 45.43km3. Total sewage generation per annum from domestic and industrial sources in Yamuna River basin is about 9.63km3. Due to the mixing of the above human influenced sewage, the waterways of this basin are stinking in many reaches and almost dead near Delhi. The pollution loads of the stinking and dead reaches of this river pollute the groundwater of the Yamuna River basin in many reaches. To treat and recycle the above sewage load about 1,320 sewage treatment plants are necessary. The capital and annual maintenance cost of these plants are Rs. 22, 440 million/$320.57million, Rs. 10,070million/$143.86million respectively (at one US dollar equal to Rs. 70). Benefits of the Yamuna River basin sewage treatment and recycling are 1. About 1,156.32million m3 of biogas can be produced per annum 2. Or from the biogas about 2,312.64million kwh electricity can be produced and the value of the electricity is Rs. 8,044.24million/$144.92 million 3. The biogas can be used for running the sewage treatment plants and for cooking directly through pipes 4. About 433.62million tons of bio-sludge can be obtained per annum and used of agriculture with suitable amendments 5. About 45.43km3 of groundwater of this basin can be protected from the sewage loads 6. About 9.63km3 of the treated sewage per annum can be used for nondomestic uses and this much quantity of fresh water can be conserved from this basin for future use 7. The foul smell and the stinking environment of this basin can be completely stopped 8. The waterborne diseases and other water miseries will be arrested and 9. Above all the waterways can be made living rivers once again. The value of the 9.63km3 of conserved freshwater per annum is Rs. 14, 45,185.33million/$20,645.50million. In the present scenario of water stress and scarcity in the 21st century in many nations, using freshwater for all uses including for toilet is the outdated hypothesis.

GROWTH ANDYIELDOFSEMI-HYDROPONIC BELL PEPPER UNDERDESALINATION WASTE-WATER AND ORGANIC AND MINERALFERTILIZATION

ABSTRACT In a scenario of water scarcity in semiarid regions, it is imperative to design food production systems that use different sources of water. The waste of desaltersis a potential source, especially when combined with the hydroponics technique that includes the supply of nutrient solution as a source of water and nutrients. In addition, other techniques such as enhanced organic matter with biofertilizer can complement this low-quality water use strategy. Thus, the aim of this study was to analyze the possible dampening effect of biofertilizers in the open system of hydroponic culture of pepper owing to the increase in water salinity. The study was conducted at the Teaching Unit, Research and Extension, Federal Institute of Education, Science and Technology of Ceará, Limoeiro do Norte Campus. The experimental design was a factorial 5 × 4 randomized block for five saline water concentration sand three doses of biofertilizers and one control with mineral fertilizer, and four replicates totaling 80 experimental units with 3 plants per plot. The variables analyzed were number of fruits per plant, production, and length and width of the fruit. All production variables declined linearly with increasing salinity. In addition, the biofertilizer did not attenuate the deleterious effects of salinity as shown by the productivity data. The fertilization with mineral fertilizers produced greater yields, followed by application of 50%, 100%, and 150% of the biofertilizer dose.

Self-financed water bank for resource reallocation to the environment and within the agricultural sector

In closed river basins, economic activities commonly threaten instream flows, especially during drought episodes. In such situations, a suitable policy option is to recover water for the environment by purchasing water allocations from farmers through a water bank. However, the purchase of temporary water rights strongly depends on the public budget available for this purpose. We propose a self-financed water bank with the twofold objective of reallocating water within the agricultural sector and recovering a share of the purchased water for the environment. The main feature of this water bank is that it will operate in a monopsony-monopoly setting, using its market power to recover water for environmental purposes, and working with a balanced budget (expenditure on purchases will equal revenues from sales). A mathematical programming model is developed to simulate the potential performance of the proposed water bank in the Guadalquivir River Basin (southern Spain), considering society’s demand for environmental water and different water scarcity scenarios. Results show that a maximum of between 5.8% and 10.4% of total water availability can be recovered for the environment, depending on the severity of the drought, while total economic efficiency is increased, yielding a beneficial result for farmers and society.

Scenario Modeling of Urbanization Development and Water Scarcity Based on System Dynamics: A Case Study of Beijing-Tianjin-Hebei Urban Agglomeration, China.

Due to the accelerated process of urbanization in China, urban agglomerations have become the core areas for human settlement and economic development. High population and economic density has brought great pressure on water supply. Water scarcity is increasingly becoming one of the most important issues for the sustainable and healthy development of China’s urban agglomerations. In this paper, a system dynamics model was constructed to simulate the current conditions and future scenarios of urbanization development and water scarcity in the Beijing–Tianjin–Hebei (BTH) urban agglomeration in 2000–2030, by examining the interaction and feedback between the six major subsystems: water supply, water demand, water pollution, population urbanization, economic urbanization, and land urbanization. It is found that the South-to-North Water Diversion Project and the improved Reclaimed Water Reuse System may greatly increase the water supply. However, the speed of population urbanization and economic growth, the spatial structure of urban agglomeration and the water consumption pattern may determine the water demand. Although all scenarios may risk water scarcity in the future at some point, we could detect a comprehensive and relatively rational scenario to balance water scarcity, regional equity, and efficiency. It might help to synthetically understand the coordinated development mode between urbanization and water resources in Beijing–Tianjin–Hebei (BTH) urban agglomeration, and provide a useful analytical and decision support tool for scientists and policy-makers to achieve the sustainable urbanization development and water resource management.

Incentives to water conservation under scarcity: Comparing price and reward effects through stated preferences

Abstract Focusing on two different European institutional contexts, a stated preference approach is adopted to elicit the willingness to save water under three alternative incentive policies: a water price increase, monetary reward, and symbolic prize. In addition, two water scarcity scenarios, a ‘critical’ and a ‘regular’ scenario, are devised to analyze how information on water scarcity moderates the effect of incentives. Empirical results show that users become sensitive to monetary incentives (while they remain insensitive to non-monetary ones) when water is scarce. Batteries of pre-tests on the sample and robustness checks on the results strengthen the reliability of our findings and partially circumvent concerns related to the use of a stated preference approach. The study adds to the literature on the efficacy of economic incentives in the water sector and the role of local factors in explaining water users’ response.

Remediation of Eutrophic Aquatic Ecosystems: Evaluation of Phosphorus Adsorption by Sawdust.

A wide range of anthropogenic activities have caused various problems to the aquatic environment, leading to economic, social, and environmental losses. The use of materials for the recovery of water quality is very important due to the water scarcity scenario present in different parts of the world. The use of sawdust as an organic adsorbent for P removal in eutrophic environments attempts to address both water quality preservation and possible application of the organic adsorbent as fertilizer for agricultural practices. This use will result in important contributions to the water and food security. In this work, we performed laboratory experiments to study P adsorption and to evaluate possible adsorption of metals and emerging contaminants by sawdust. The experiments were carried out in 36 microcosms (glass jars), using 50% of the flasks as treatments (containing bags with sawdust) and the rest of the flasks as control (water and sediment without sawdust). For future application of sawdust as a fertilizer it is important to be aware of the presence of possible pathogenic microorganisms, thus the presence of helminth eggs was determined in the sawdust. The results showed the tendency of P adsorption by the biosorbent; maximum adsorption occurred at 214 d (41 μg P g-1 ), after the P desorption occurred. No helminth eggs or emerging contaminants and toxic metal were detected in the sawdust after its use as biosorbent, providing an important subsidy regarding the use of the biosorbent as soil fertilizer. Integr Environ Assess Manag 2019;00:1-12. © 2019 SETAC.