Agricultural Reuse Research Articles

Conversion of Leather Industry Solid Waste to Organic Fertilizer by Vermicomposting: Use for Plant Growth

The generation of leather industry solid waste is a matter of concern for its potential polluting ability. This study assessed vermicomposting of leather industry-generated lime flesh and shaving waste through a mix with cattle dung using Eisenia fetida earthworm, aiming at sustainable reuse in agriculture. The chromium content of shaving waste was optimized to under 2 mg/kg using hydrogen peroxide with potassium carbonate treatment. The lime flesh was treated with hydrochloric acid treatment. Treated shaving waste and lime flesh were mixed with cattle dung in a proportion of 1:1 and 2:1 in different vermicompost fields. After 30 days 40 Eisenia fetida were introduced in each field and vermicomposted for 90 days within a moisture of 50%. The number of earthworms increased in the 1:1 portion of vermicompost. The number of earthworms, pH, total organic carbon (TOC), total Kjeldahl nitrogen (TKN), carbon and nitrogen ratio (C: N), total potassium (TK) and total phosphorus (TP) readings was taken at 0, 30, 60 and 90 days respectively. Composting resulted in a significant reduction of pH, and TOC. A reduction in C: N ratio by approximately nine-fold and an increase in TKN and TP was observed. A slight reduction of TK was also observed. The results indicated that the earthworm Eisenia fetida has been able to convert the lime flesh and shaving waste into nutrient-enriched fertilizer products in the same proportion of waste and cow dung. The vermicompost was applied on the Napier grass plantation and the accumulation of heavy metal effect on plants was investigated for eco-friendly plant growth. The composts and plants’ different parts were analysed for heavy metals. It was found to be under the permissible limits recommended by WHO. The vermicompost enhanced the organic matter significantly and nutrients were improved for better crop yield.

Analysis of wastewater reuse options using a multicriteria decision tool for Phuket, Thailand

The act of balancing between water demand and water supply in Phuket Island is facing challenges, suggesting water reuse options in various activities on the island should be properly promoted considering the potential benefits in a variety of dimensions. This research presented options to reuse effluent water from wastewater treatment plants for Phuket Municipality in 3 main activity groups, namely, domestic reuse, agricultural reuse, and raw water for water treatment plants (WTP). Water demand, additional water treatment trains, and the length of the major water distribution pipeline for each water reuse option were designed, and its cost and expenses were calculated. Multi-criteria decision analysis (MCDA) was used by 1000Minds internet-based software to prioritize the suitability of each water reuse option based on a four-dimensional scorecard, including economic, social, health, and environmental aspects. The decision algorithm for the trade-off scenario based on the government's budget allocation was proposed to obtain weighing without subjective expert opinions. The results revealed that recycling effluent water as raw water for the existing WTP was the first priority, followed by agriculture reuse for planting coconut, Phuket's economic crops, and domestic reuse. There was a significant difference in the total scores of economic and health indicators between the first- and second-priority options because of the difference in the additional treatment system in which the first-priority option applied the microfiltration and reverse osmosis system, which could effectively eliminate viruses and chemical micropollutants. In addition, the first priority option required a much smaller piping system than other water reuse options because it relied on the existing plumbing system of WTP, lowering the investment cost, which was a very important indicator for decision-making.

Maximizing agricultural reuse of recycled nutrients: A spatially explicit assessment of environmental consequences and costs

Recovering nutrients from organic materials to reduce artificial fertilizer inputs requires the implementation of processing technologies and can involve considerable logistics and transportation costs. Reducing such costs by directly applying organic materials to agricultural land can contribute to pollution due to potential contaminants and unbalanced nutrient ratios. Assessing the cost of increased recycling requires a spatially explicit approach because availability of organic materials, nutrient demand and agro-ecosystem properties vary spatially. A multi-objective model was developed to estimate the trade-offs between costs of nutrient recovery and improvements in nutrient distribution for a case study area in The Netherlands. The evaluated recovery processes included solid-liquid separation followed by reverse osmosis to recover nutrients from pig manure which was compared to a conventional process via hygienisation and export. Results indicate that, even in a nutrient saturated area, replacement potential of artificial nitrogen (N) and phosphorus (P) fertilizers through locally reclaimed nutrients is limited to about 17% N and 55% P. A cost optimum was found when about 48% of the initial pig manure quantities were processed via nutrient recovery and directed to land. Increasing manure processing for nutrient recovery led to a redistribution of nutrients and trace metals (zinc (Zn) and copper (Cu)), resulting in more localized concentration. Zn and Cu were enriched by about 8% and 2%, respectively, when maximizing nutrient recovery. Our generic model offers a methodology to assess the trade-offs between increased recycling and associated spatial effects to facilitate sustainable recycling infrastructures for achieving more circular agriculture.

Metatranscriptome Revealed the Efficacy and Safety of a Prospective Approach for Agricultural Wastewater Reuse: Achieving Ammonia Retention during Biological Treatment by a Novel Natural Inhibitor Epsilon-Poly-l-Lysine.

Appropriate inhibitors might play important roles in achieving ammonia retention in biological wastewater treatment and its reuse in agriculture. In this study, the feasibility of epsilon-poly-l-lysine (ε-PL) as a novel natural ammonia oxidation inhibitor was investigated. Significant inhibition (ammonia oxidation inhibition rate was up to 96.83%) was achieved by treating the sludge with ε-PL (400 mg/L, 12 h soaking) only once and maintaining for six cycles. Meanwhile, the organic matter and nitrite removal was not affected. This method was effective under the common environmental conditions of biological wastewater treatment. Metatranscriptome uncovered the possible action mechanisms of ε-PL. The ammonia oxidation inhibition was due to the co-decrease of Nitrosomonas abundance, ammonia oxidation genes, and the cellular responses of Nitrosomonas. Thauera and Dechloromonas could adapt to ε-PL by stimulating stress responses, which maintained the organic matter and nitrite removal. Importantly, ε-PL did not cause the enhancement of antibiotic resistance genes and virulent factors. Therefore, ε-PL showed a great potential of ammonia retention, which could be applied in the biological treatment of wastewater for agricultural reuse.

A combined bio-system to improve effluent water quality from sewage wastewater plants for agricultural reuse

A continuous lab-scale integrated bio-system was conducted to treat sewage wastewater from Abu-Rawash wastewater treatment plant (WWTP). The bio-system showed high efficiency in removing chemical oxygen demand (COD), biological oxygen demand (BOD5), and total suspended solids (TSS). The experimental analysis results indicated that the maximum COD removal and methane yields were 97.6 and 13.74 mmol CH4/Kg COD at a hydraulic retention time (HRT) of 6 h, respectively. Zn, Mn, and Fe were removed at a high rate of up to 96.6%. The sponge bio-carriers have improved overall treatment performance and substantially improved mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS) ratio at an appreciated range, and the total pathogenic organisms were removed up to 99.8% in the second stage. Because the innovative bio-system enables a rapid startup process, is simple to use, and is inexpensive, it can provide an economically feasible alternative for wastewater management and could be extended to full-scale applications for agricultural purposes.

Quantitative study for the effect of water velocity on water quality change

Atmospheric reaeration process plays a key role in degradation of organic matter and self-purification processes affecting dissolved oxygen (DO) concentrations in rivers and streams. Moreover, water quality (WQ) processes can be highly dependent on flow velocity conditions. Where, highly reaeration rates are positively correlated with high flow velocity. Therefore, the present work reports deep insights on the role of flow velocity with reaeration process in the concentration of DO and biochemical oxygen demand (BOD5). This study was applied along the largest agricultural drainage water reuse project, El-Salam Canal in Egypt. The hydrodynamic (HD) characteristics and WQ parameters (DO and BOD5) along the canal were simulated using a one-dimensional HD and WQ model (MIKE 11). The simulated results indicated that the canal was deteriorated towards El-Salam Canal after mixing with El-Serw and Bahr Hadous drains. Statistical regression fitted line and Pearson correlation analysis, were performed on the simulation results of the reaeration rates with flow velocity and WQ values, indicating a significant correlation. Accordingly, water velocity should be taken into account as a key factor for describing the WQ change.

Is the recycling of purified water from the Ain El Arbaa region for agricultural purposes possible?

The region of Ain El Arbaa, like all Algerian municipalities, suffers from a water shortage crisis. The main objective of this work is to investigate the possibility of reusing treated water from the region. 
 For this purpose, we have examined the quality of the water treated by the D'Ain El Arbaa treatment plant. 
 The analyzes carried out on the incoming sewage and outgoing waste water from the lagoon focused on the following parameters: (pH, total suspended solids (TSS), biological oxygen demand (BOD5), chemical oxygen demand (COD), NH4, electrical conductivity). This during the period from January 2021 to May 2021 with a sampling frequency of twice a month. 
 The results obtained show that this purification process using two sectors (pre-treatment, secondary treatment) is insufficient and does not meet the quality standards required for agricultural use for the parameters: TSS, COD, and electrical conductivity. For the preservation of the receiving environment, the results did not comply with the standards for the parameters TSS, DOC, NH4.
 The abatement yields of the lagoon treatment plant studied were average for all the parameters studied.
 So according to this work we can conclude that natural lagooning alone is not sufficient to have purified water that complies neither with the quality required for agricultural reuse, nor with the quality required for discharge into the natural environment.
 Then the addition of a complementary tertiary treatment, such as filter basins planted with macrophytes is necessary.

Multivariate Analysis of Physical and Chemical Soil Attributes Under Forage Palm Cultivation and Agriculture Reuse in the Semiarid Region

The use of treated effluents (UTE) for irrigation has grown considerably in recent years, especially in arid and semi-arid regions. The objective of this research was to evaluate the effect of soil fertility under cultivation with forage cactus intercropped with different legumes. The experiment was conducted over a period of two years in a research unit that uses irrigation with reuse water (RW) in consortia of cactus species with wood and forage legumes. The soil layers were analyzed in the layers of 0-10 and 10-20 cm in three seasons: T0: without reuse water (RW); T1: dry season + reuse water (RW); T2: wet season + reuse water (RW) under cultivation of three palm varieties or cochineal cactus (mexican elephant ear palm, small palm and baiana). The soil attributes evaluated were granulometry, soil density, pH, salinity, sodicity, macronutrients, organic matter, Mineral N and total organic carbon stock (O.C.S). The plants were periodically irrigated with domestic effluent treated with constant irrigation 2 L h-1. The data were subjected to multivariate statistical analysis, using correlation matrix, cluster analysis, and factorial analysis considering the factors as principal components. According to the factorial analysis, Factor 1 (F1) and Factor 2 (F2)—F1 consisting of Sand, Ca2+, pHs, stock of. K and base saturation (V), and F2 consisting of Soil Organic Matter (SOM), stock of. Mg, CEC, stock of Ca2+, clay and soil density—were essential to differentiate the environments. The cluster analysis formed four groups. The structural groups showed greater similarity, denoting the relationship between source material and land use, followed by the chemical groups pHs, Ac. Pot., V+, CEC, Na+, stock of Na+, PST, and Ds; the structural weighted total porosity, stock of P.; Ksoil, stock of K, and Mg, SB, Te, stock of . Mg, and finally stock of Total, stock of Nitrog, Nit. Inorg.; SOM, TOC, Ca2+ and Tp of soil. This is a local peculiarity due to the climatic pattern of the Brazilian semiarid region in use of domestic sewage treated in agriculture as a forage index and as a social factor. The multivariate statistical analysis through principal component analysis and clustering made it possible to form groups according to soil attributes, which can help in decision making regarding soil fertility and fertilization management in this region with agricultural reuse application mainly in semiarid regions of Brazil.

Full-Scale O3/Micro-Nano Bubbles System Based Advanced Oxidation as Alternative Tertiary Treatment in WWTP Effluents

Wastewater treatment plant effluents can be an important source of contamination in agricultural reuse practices, as pharmaceuticals are poorly degraded by conventional treatments and can enter crops, thereby becoming a toxicological risk. Therefore, advanced tertiary treatments are required. Ozone (O3) is a promising alternative due to its capacity to degrade pharmaceutical compounds, together with its disinfecting power. However, mass transfer from the gas to the liquid phase can be a limiting step. A novel alternative for increased ozone efficiency is the combination of micro-nano bubbles (MNBs). However, this is still a fairly unknown method, and there are also many uncertainties regarding their implementation in large-scale systems. In this work, a combined O3/MNBs full-scale system was installed in a WWTP to evaluate the removal efficiency of 12 pharmaceuticals, including COVID-19-related compounds. The results clearly showed that the use of MNBs had a significantly positive contribution to the effects of ozone, reducing energy costs with respect to conventional O3 processes. Workflow and ozone production were key factors for optimizing the system, with the highest efficiencies achieved at 2000 L/h and 15.9 gO3/h, resulting in high agronomic water quality effluents. A first estimation of the transformation products generated was described, jointly with the energy costs required.

Effect of Irrigation Management and Water Quality on Soil and Sorghum bicolor Payenne Yield in Cape Verde

Treated water use for agriculture will promote sustainable irrigation development and food sovereignty. The aim of this study is to assess the feasibility of subsurface drip irrigation (SDI) compared to drip irrigation (DI) and of reclaimed water (RW) versus conventional groundwater (CW), to produce forage sustainably in a warm arid region. A sorghum experiment was conducted in a field on Santiago Island (Cape Verde). A forage yield of 200 t fresh matter·ha−1·year−1, irrigated by RW, was obtained. Considering Cape Verde regulations, it is possible to irrigate sorghum using a drip system and RW without adding fertilizers. Soil fertility (OM and Ntot) increased, while risk parameters (EC, nitrate, and Na) returned to their initial values after the rainy season. The best irrigation water use efficiency was obtained by RWSDI (200 L·kg−1 DM) compared to RWDI, which needed 34% more water. According to the results, a high nitrate elimination rate in treatment plants might not be desirable if agricultural reuse is planned to irrigate high-N-demanding species. Establishing new salinity tolerance levels under reuse conditions with SDI, and irrigating in rainy months to promote the lixiviation of salts in arid regions are also necessary.

Distribution Characteristics of Typical Heavy Metals in Sludge from Wastewater Plants in Jiangsu Province (China) and Their Potential Risks

Recently, increasing attention has been paid to heavy metals in sludge. However, limited literature could be found on the distribution characteristics of heavy metals in sludge and their potential risks. In this study, sludges from wastewater plants in Jiangsu Province (China) were selected for the investigation of heavy metal loadings, showing that typical heavy metal levels were in the order of Zn > Cu > Cr > Ni > Pb > As > Hg > Cd, ranging from 154 to 2970 mg/kg, 28 to 1150 mg/kg, 10 to 136 mg/kg, 9 to 262 mg/kg, 0 to 79 mg/kg, 12.1 to 41.6 mg/kg, 0.67 to 19.50 mg/kg and 0.21 to 2.77 mg/kg, respectively. Analysis of the typical heavy metal distribution in sludge indicated that Hg, Zn and Cu were obviously influenced by the degree of industrial intensity and exploitation of human activities, while Ni, Cd, Pb, As and Cr were more evenly distributed. Effects of sewage sources and wastewater-treatment processes on heavy metal levels implied that different industrial wastewaters resulted in different metal contents, but the distribution of Ni, Cd, Pb, As and Cr in different treatment processes was similar. Furthermore, Hg and Cd had the strongest ecological risk, with their levels reaching severe, suggesting that sludge was not recommended for agricultural reuse in this study.

Opportunities for Water Reuse Implementation in Metropolitan Areas in a Complex Approach with an LCA Analysis, Taking Warsaw, Poland as an Example

Water shortages are currently becoming a more global than local issue. This paper aims to demonstrate a complex, universal urban water reuse system, allowing for a reduction of freshwater withdrawal. Opportunities for improvement were analyzed in the categories of municipal services: power and heat production, greenery irrigation, landscaping, street and public transport fleet cleaning. Technical possibilities were coupled with current international legislative requirements. Two scenarios for universal, complex water reuse systems in the municipal area were evaluated, including all essential city services. Results of the case study show that ozonation and filtration of treated wastewater should be sufficient to obtain the desired water quality for urban purposes. Current legislation mainly addresses agricultural water reuse, so their requirements should be adjusted to assess the water quality needed for other applications. When water is used in public spaces, constant monitoring for the presence of pathogens should be maintained due to the risk of human exposure. A life cycle assessment was conducted to evaluate the environmental impacts associated with the topic of water transportation in urban areas, which is infrequently considered in such studies. Two scenarios including different means of transport were compared. It was shown that with constant daily operation, it is necessary to build an independent water network, since the environmental impact of water delivery by tank lorries increases substantially.

Transforming Agriculture: Innovations in Sustainable Wastewater Reuse – A review

This scientific review delves into the crucial role of wastewater reuse in agriculture for sustainable water resource management, especially in the context of water scarcity. The paper examines innovative wastewater treatment methods like biofiltration, membrane bioreactors, and electrocoagulation, exploring their effectiveness and limitations. It emphasizes the significance of proper wastewater treatment in mitigating risks and maximizing benefits. Key considerations such as economic viability and social acceptance are highlighted, urging comprehensive cost-benefit analyses and active engagement with stakeholders. Drawing from case studies in Tshwane, Egypt, Valencia, and Sde Warburg, successful wastewater reuse practices underscore the importance of stringent water quality standards, public education, regulatory frameworks, and stakeholder involvement in achieving sustainable wastewater management. Despite global advancements, challenges persist in the adoption of these technologies in many African countries, necessitating collaborative efforts and targeted capacity-building for widespread implementation. Historical insights reveal the evolution of wastewater irrigation from European and American cities to its current global prevalence, impacting around 10% of the world’s irrigated land with untreated or partially treated wastewater. Technological advancements, such as biofiltration relying on microbial activities, membrane bioreactors integrating biological treatment with filtration, and electrocoagulation as an electrochemical process, offer sustainable solutions. Case studies highlight the economic, environmental, and social benefits of successful wastewater reuse programs. However, the review acknowledges the risks associated with wastewater reuse, including environmental contamination and public health hazards. To strike a balance between risks and benefits, the paper advocates for proper wastewater treatment, robust regulatory frameworks, and responsible farming practices. It concludes by stressing the need for collaborative efforts, international partnerships, and targeted capacity-building initiatives to overcome barriers to the adoption of advanced wastewater treatment technologies in African countries, fostering water management, ensuring food security, and contributing to social and economic development amid global challenges.

Modeling slow sand filtration for sustainable safe wastewater reuse in agriculture in Draa Sfar mine region (Marrakech, Morocco)

Modeling slow sand filtration for sustainable safe wastewater reuse in agriculture in Draa Sfar mine region (Marrakech, Morocco)

Decoration of polystyrene with nanoparticles of cobalt hydroxide as new composites for the removal of Fe(iii) and methylene blue from industrial wastewater.

Effluent water from different industries is considered one of the most serious environmental pollutants due to its non-safe disposal. Therefore, proper treatment methods for such wastewater are strongly stimulated for its potential reuse in industries or agriculture. This study introduces a composite fabricated via doping of polystyrene with nanoparticles of cobalt hydroxide as a novel adsorbent for dye and heavy metal decontamination from wastewater. The adsorbent fabrication involves the preparation of polystyrene via high-internal phase emulation (HIPE) polymerization followed by its intercalation with particles of alkali cobalt. The chemical composition and structural properties of the synthesized composite were confirmed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). Moreover, scanning electron microscopy (SEM) and N2 adsorption-desorption surface area analysis were performed to identify the surface and morphological characteristics of the composite. Then, the ability of this structure toward the removal of methylene blue dye (MB) and heavy metal (iron iii) species from waste aqueous solutions was investigated. Successful elimination for both MB and Fe(iii) was achieved by the presented composite. Elevated adsorption capacities of 75.2 and 112.3 mg g-1, toward MB and Fe(iii) respectively, were detected for the presented polymer-metal hydroxide composite. The increased values of the composite are attributed to the presence of both organic and inorganic functional groups within its structure. Kinetic and isotherm studies for the removal of both cationic species revealed that adsorption processes fit the pseudo-second-order kinetic model and Langmuir isotherm model. Additionally, thermodynamics measurements indicated that the adsorption process of methylene blue and Fe ions is feasible, spontaneous, physisorption, and endothermic.

Reuse of effluents from cattle slaughterhouses: multicriteria evaluation

Cattle slaughterhouses generate a large amount of effluent with a high concentration of organic and inorganic compounds. However, the choice of appropriate technologies can produce effluents with sufficient quality for the practice of reuse as a strategy for saving water. This study aimed to determine the efficiency of effluent treatment systems from cattle slaughterhouses to promote the reuse of effluents, specifically for fertigation. The multicriteria analysis was employed, adopting the ELECTRE I method. The effluent treatment alternatives, the definition of the degree of importance, and the weights of each established criterion were considered. The estimated volume of effluents generated in slaughterhouses in Brazil was 85.374 million m³/year, with a high concentration of biochemical/chemical oxygen demand, nutrients, oils, and greases, solids, and E. coli. The treatment technologies that showed the best performance were UASB reactor + ultrafiltration and activated sludge + ultrafiltration, producing effluents with compatible quality for agricultural reuse under Brazilian legislation.

Effect of Treated Wastewater from Anaerobic Digester Coupled with Anaerobic Baffled Reactor as Fertigation on Soil Nutrient Residues, Growth and Yield of Maize Plants

Water scarcity, wastewater management and growing food demand associated with global population increase, are among the drivers cited for water reuse in agriculture. The current study intends to contribute on the influence of treated wastewater from the anaerobic digester coupled with anaerobic baffled reactor (ABR) as a fertigation on soil nutrient residues, growth and yield attributes of maize plants by using surface drip irrigation system to apply the treated wastewater. The experiment consisted of experimental plots irrigated with treated wastewater and control plots irrigated with tap water; all with three replications. The treated wastewater was lightly alkaline with pH of 7.8±0.2 and high concentration of nutrients than tap water, but were within the acceptable levels. Fertigation with treated wastewater improved soil fertility evidenced by significant improvement (P≤0.05) in plant height, leaf area Index (LAI) and maize yield. Plant height was 1.5 times taller and LAI was about 2.5 times more in treatment than in control plots. Yield attributes in experimental plots including number of grains per cob, (97±11.3); weight of grains per cob, (80.7±7.9 g); mass of 100 grains, (35.0±3.5 g), and grain yield, (745.8±62.9 Kg/ha) were significantly higher (P≤0.05) compared to their counterpart control plots. The grain yield in experimental plots was about 37% higher than the yield in control plots. Therefore, fertigation with treated wastewater from the anaerobic digester coupled with ABR improves maize yield and is advisable in areas with water scarcity.

Implication of sewage sludge increased application rates on soil fertility and heavy metals contamination risk

This paper aims to assess soil fertility and risk contamination parameters in response to increased amendment rates of sewage sludge application, under semi-arid climatic conditions of Morocco, using two soil textures: soil A (clay-silty) and soil B (sandy-clay) over two years. To this end, sewage sludge and soils treatments physicochemical parameters, heavy metals content, degree of pollution and associated risks were evaluated and compared to controlled soils. The results showed that all studied parameters changed significantly (p < 0.05) in a dose-dependent manner for both soils compared to the untreated control soils. Indeed, there were significant increase in organic matter (OM), total organic carbon (TOC) and nutrients content (N, P and K) of both sols as a response to increased sewage sludge amendment rates. Overall, sewage sludge application showed a positive agronomic potential for both soil and plant. However, there were concern about some heavy metals contamination risks, the results showed a gradual increase of heavy metals concentration in this order: Cu > Pb > Zn > Ni > Cd > Cr. Nevertheless, their concentrations were below the critical values established by the European Union for the agronomic use of soil. The obtained results of assessed parameters indicating SS degree of pollution and associated risks showed a low to a moderate contamination risks of heavy metals. Accordingly, environmental risks of sewage sludge application will be related to increase of heavy metals mainly in a long-term agricultural reuse. Thus, optimal management of sewage sludge application is recommended to ensure sustainability and benefits at the same time to master the contamination risks.

Preference and paradox: Local residents’ perspectives on the reuse of post‐agricultural brownfield sites

AbstractStructural change in the agricultural economy may result in the abandonment of agricultural buildings, creating rural brownfield sites. Since the fall of the Iron Curtain in 1989, post‐agricultural brownfields have become very common in Central and Eastern Europe. Our aim is to uncover and understand the reuse preferences for 16 reuse options, among 1275 survey respondents (local residents) from 272 rural communities with post‐agricultural brownfields in the Czech Republic. The influence of respondent status, the socioeconomic characteristics of those communities and environmental characteristics of communities were tested using redundancy analysis and variation partitioning. Three types of reuse were identified as most preferred among respondents: agricultural reuse, industrial reuse and reuse for housing, services and leisure time activities. We found strong and significant ties between the pattern of preferences for potential reuse options and demographic, community socioeconomic and environmental context variables. It can therefore be concluded that preferences for rural renewal tend to be constructed comprehensively and encompass social, economic and environmental dimensions of sustainability. In order to implement a vision that promotes sustainable rural development, we need to recognise that the preferences of rural residents are fundamentally shaped by the local environment and are therefore highly dependent on the place‐based circumstances.

Recovery of Energy and Nutrients from Mycotoxin-Contaminated Food Products through Biological Treatments in a Circular Economy Perspective: A Review

Mycotoxins’ contamination of food products is a well-known issue that is gaining interest nowadays due to increasing contaminations that are also related to climate change. In this context, and considering the principles of Circular Economy, finding robust and reliable strategies for the decontamination and valorisation of mycotoxin-contaminated products becomes mandatory. Anaerobic digestion (AD) and composting appear as promising biological treatments to degrade mycotoxins and allow for recovering energy (i.e., biogas production) and materials (i.e., nutrients from digestate and/or compost). The aim of the present paper was to carry out an organic revision of the state of the art of energy and materials recovery from mycotoxin-contaminated food products through biological treatments, highlighting results and research gaps. Both processes considered were not generally affected by the contamination of the feedstocks, proving that these compounds do not affect process stability. Mycotoxins were highly removed due to the concurrence of microbiological and physical agents in AD and composting. From the literature review, emerged the points that still need to be addressed before considering large scale application of these processes, which are (i) to deepen the knowledge of biochemical transformations of mycotoxins during the processes, (ii) to assess the fate of mycotoxins’ residues and metabolites in soil once digestate/compost are applied, (iii) to evaluate and optimize the integration of AD and composting in order to increase the environmental and economical sustainability of the processes, and (iv) to update legislation and regulations to allow the agricultural reuse of organic fertilizers obtained from contaminated feedstocks.