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Urban sewage sludge (USS) is increasingly being used as an alternative organic amendment in agriculture. Because USS originates mostly from human excreta, partially metabolized pharmaceuticals have also been considered in risk assessment studies after reuse. In this regard, we investigated the cumulative effect of five annual USS applications on the spread of antibiotic-resistant bacteria (ARB) and their subsequent resistance to toxic metals in two unvegetated soils. Eventually, USS contained bacterial strains resistant to all addressed antibiotics with indices of resistance varying between 0.25 for gentamicin to 38% for ampicillin and azithromycin. Sludge-amended soils showed also the emergence of resistome for all tested antibiotics compared to non-treated controls. In this regard, the increase of sludge dose generally correlated with ARB counts, while soil texture had no influence. On the other hand, the multi-antibiotic resistance (MAR) of 52 isolates selected from USS and different soil treatments was investigated for 10 most prescribed antibiotics. Nine isolates showed significant MAR index (≥ 0.3) and co-resistance to Cd, As and Be as well. However, events including an extreme flash flood and the termination of USS applications significantly disrupted ARB communities in all soil treatments. In any case, this study highlighted the risks of ARB spread in sludge-amended soils and a greater concern with the recent exacerbation of antibiotic overuse following COVID-19 outbreak.

In this research work, raw poultry manure biochar (RPM-B) was post-modified by two metal salts and then evaluated for P recovery from aqueous solutions in batch mode. The modified biochar characterization showed that RPM-B impregnation with aluminum and manganese salts led to a significant improvement of their surface properties through the pH-zero charge reduction as well as the specific surface areas and the functional group contents increase. Phosphorus recovery tests indicated that the post-treated biochar with AlCl3 (RPM-B-Al) and with KMnO4 (RPM-B-Mn) exhibited relatively high recovery efficiencies with Langmuir’s adsorption capacities of 23.5 and 8.4 mg g−1, respectively. Kinetics and isothermal data modeling, as well as the in-depth analytical characterization of the post-modified biochars before and after adsorption, indicates that P recovery occurs homogeneously on monolayer surfaces through mainly anion exchange, precipitation, and electrostatic interactions. On the other hand, P desorption efficiency increases with the desorbing solution pH values. The best P desorption yields were observed for an initial pH of 9.0 to 78% and 80% for RPM-B-Al-P and RPM-B-Mn-P, respectively. All these results suggest that RPM-B-Al and RPM-B-Mn could be considered promising materials for phosphorus recovery from wastewaters with a possible reuse in agriculture as potential soil amendments.

Sludge generation as an organic by-product of wastewater treatment has seen a consistent increase worldwide due to population growth and industrial activities. This poses a chronic challenge regarding management options and environmental concerns. The agricultural valorization of unconventional organic materials has become inevitable, especially in semi-arid and arid countries that suffer from depleted soils and shortages in farm manure supply. High-income countries have also been interested in this recycling practice to mitigate landfilling or incineration issues. Sewage and some industrial sludges contain a complex mixture of beneficial and harmful substances, which varies with the origin of effluents. Therefore, sludge land application should be well managed in order to achieve sustainable agro-environmental goals. This review paper focuses on different aspects related to sludge reuse in agriculture, starting by investigating the diversity of sludge types and composition. In addition to the preponderant urban sewage sludge, the less-studied industrial sludges, such as those generated from pulp and paper mills or gas-to-liquid industries, are hereby addressed as well. Then, post-land application effects are discussed in relation to sludge quality, dose, and reuse conditions. The present paper also examines the disparities between guidelines that determine sludge conformity for land application in various countries or regions. Accordingly, special attention is given to increasing risks related to emerging pollutants in sludge such as pharmaceuticals, which have been overused since the outbreak of COVID-19 pandemic. This exhaustive investigation will assist the establishment of sustainable strategies for the safe agricultural reuse of biosolids.

Micronutrient deficiencies in global food chains are a significant cause of ill health around the world, particularly in developing countries. Agriculture is the primary source of nutrients required for sound health, and as the population has continued to grow, the agricultural sector has come under pressure to improve crop production, in terms of both quantity and quality, to meet the global demands for food security. The use of engineered nanomaterial (ENM) has emerged as a promising technology to sustainably improve the efficiency of current agricultural practices as well as overall crop productivity. One promising approach that has begun to receive attention is to use ENM as seed treatments to biofortify agricultural crop production and quality. This review highlights the current state of the science for this approach as well as critical knowledge gaps and research needs that must be overcome to optimize the sustainable application of nano-enabled seed fortification approaches.

Actinomycetales is an order of actinobacteria that have an important role in the decomposition of organic matter. Their abundance and distribution can reflect a good level of soil fertility as well as biological activity. In this research study, actinomycetal diversity in soil was investigated under various field treatments with biowastes. Initially, unvegetated agricultural soil plots of 4 m2 had been annually amended with increasing rates of municipal solid waste compost (MSWC at 40, 80 and 120 t ha−1 year−1) and farmyard manure (FM at 40 and 120 t ha−1 year−1) for eight consecutive years. Control consisted of unamended soil and all treatments were distributed in four randomized complete blocks. At the end of the experimental period, total DNA was extracted from fresh topsoil samples (0–20 cm) then nested PCR-DGGE sequencing method was applied to assess the long-term effect of treatments on the diversity of actinomycetes. Analytical outcomes revealed the presence of ten actinomycetal families with Streptomycetaceae, Pseudonocardiaceae and Nocardioidaceae being the most dominant regardless to changes in experimental conditions. Besides, the long-term accumulation of both biowastes in soil affected the diversity of actinomycetal communities in different ways including contribution, stimulation or inhibition. Interestingly, soil treated with MSWC at an equivalent rate of 40 t ha−1 year−1 was likely to provide optimal growth conditions for major identified genera because it showed the highest actinomycetal diversity as compared to the rest of the treatments.

Urban sewage sludge (USS) is increasingly applied to agricultural soils, but mixed results have been reported because of variations in reuse conditions. Most field trials have been conducted in cropping systems, which conceal intrinsic soil responses to sludge amendments due to the rhizosphere effect and farming practices. Therefore, the current field study highlights long-term changes in bare soil properties in strict relationship with soil texture and USS dose. Two agricultural soils (loamy sand [LS] and sandy [S]) were amended annually with increasing sludge rates up to 120 t ha-1 yr-1 for 5 yr under unvegetated conditions. Outcomes showed a USS dose-dependent variation of all studied parameters in topsoil samples. Soil salinization was the most significant risk related to excessive USS doses. Total dissolved salts (TDS) in saturated paste extracts reached the highest concentrations of 37.2 and 43.1 g L-1 in S soil and LS soil, respectively, treated with 120 t USS ha-1 yr-1 . This was also reflected by electrical conductivity of the saturated paste extract (ECe ) exceeding 4,000 µS cm-1 in both treatments. As observed for TDS, fertility indicators and bioavailable metals varied with soil texture due to the greater retention capacity of LS soil owing to higher fine fraction content. Soil phytotoxicity was estimated by the seed germination index (GI) calculated for lettuce, alfalfa, oat, and durum wheat. The GI was species dependent, indicating different degrees of sensitivity or tolerance to increasing USS rates. Lettuce germination was significantly affected by changes in soil conditions showing negative correlations with ECe and soluble metals. In contrast, treatment with USS enhanced the GI of wheat, reflecting higher salinity tolerance and a positive effect of sludge on abiotic conditions that control germination in soil. Therefore, the choice of adapted plant species is the key factor for successful cropping trials in sludge-amended soils.

The aim of this article is to investigate the dynamic relationship between corruption, investment, and economic growth in Tunisia within a multivariate framework. In the empirical section, we use a...

This study was carried out to investigate the impacts of cyanobacteria (

Demographic explosion, climate change, urbanization, change of life quality, and food demand have put extra pressure on Food, Energy, Water, and Waste (FEWW) resources.A special focus has been placed on university campuses as they are representative urban communities with a substantial need for food, energy, and water and they generate waste. Furthermore, universities can be models for the community as they can apply and disseminate new ideas. The case study of the Qatar University via the Doha Living Lab (DLL) generates ideas and gives solutions to the FEWW Nexus through urban agriculture practices adopted to the climatic conditions of Qatar. The DLL follows the M-NEX Design method consisting of three steps: Design Development, Design Evaluation, and Implementation by engaging stakeholders and the local community. The areas of the DLL increase food production on the campus while minimizing the use of energy and water, enhance biodiversity as well as soil quality by valorizing food waste. The carbon footprint of DLL is reduced by 2% when the same quantity of food is produced locally than imported. This applies when 75% of the energy needs come from renewable sources, 75% of the needed animal feed comes from bio waste, and finally, when novel greenhouse technologies are utilized with low energy consumption. According to the research results, the FEWW Nexus and food production on campus can be sustainable in terms of low carbon footprint with minimal resource use, use of renewable energy sources, and food waste valorization.

Cyanobacteria are found to be renewable and sustainable additives for growth improvement in crops. Extracts and biomass of three nitrogen-fixing cyanobacteria namely, Roholtiella sp. (QUCCCM97), Nostoc ellipsosporum (QUCCCM99), and Desmonostoc danxiaense (QUCCCM112) isolated from Qatar desert environment were tested for their ability to enhance the growth of bell pepper (Capsicum annuum L.) seedlings. Soilless cultivation experiments were carried out by applying the biomass and the aqueous extract of the three cyanobacteria separately. Seedlings were transplanted to Hoagland’s solution under regulated conditions. In total, 2, 4, and 6 mL L−1 of the three microalgae extract as well as 1 and 2 mg L−1 of the three microalgae biomasses (as biofertilizer) were added to the Hoagland solution. An assessment of seedling growth parameters such as shoot length, root length, fresh weight, dry weight, spad index, number of leaves per plant, and growth rate was performed. However, among the different doses and concentrations of investigated QUCCCM97, 99, and 112, our findings revealed that shoot length (cm), root length (cm), fresh weight (g), the number of leaves per plant, and growth rate were positively affected and significantly increased at maximum dose/concentration compared to control plants. With QUCCCM97, shoot length, root length, fresh weight, the number of leaves, and the growth rate increased by 17.5%, 40.3%, 26.0%, 21.6%, and 22.8%, respectively, compared to the control. Additionally, with QUCCCM99, the same parameters increased by 12.3%, 25.3%, 15.1%, 9.3%, 51.8%, respectively. While in presence of QUCCCM112, they increased by 8.7%, 30.1%, 15.6%, 5.4%, 48.6%, respectively. Our results demonstrated that extracts and biomass of cyanobacteria strains investigated here, and particularly Roholtiella sp. (Nostocales), have an enhancement potential of the seedling growth and could be used in modern agriculture to enhance productivity under the soilless system and ensure sustainability. This work was funded by the Graduate Student Grant (QUST-1-CAS-2020-10) provided by Qatar University. Additionally, all cyanobacteria cultures, biomass production and HVP extraction were covered by the grant NPRP8-1087-1-207 provided by Qatar National Research Fund (a member of The Qatar Foundation). Open Access provided by Qatar University IDC funds of R.B.-H. The statements made herein are solely the responsibility of the authors.

The purpose of this paper is to study the effect of trade openness on the environmental quality by taking into consideration the role of institutions. We used a panel of 143 countries observed duri...

The agricultural reuse of urban sewage sludge in degraded croplands has seen a wide acceptance for biowaste recycling and for the improvement of soil fertility. However, soil degradation and health issues may arise from the fact that sludge addition causes chemical and biological contamination if mismanaged. To closely monitor the long term soil-sludge interactions, a field study was conducted over a three-year period under a semi-arid climate. More precisely, changes in topsoil properties were assessed in 4-m2 uncropped plots amended with sludge rates equivalent to 0, 40, 80 and 120 t ha−1 year−1 for two soil textures: soil A (sandy loam) and soil S (sandy). Results showed that all studied parameters changed significantly in a dose-dependent manner for both soils as compared to untreated controls. As such, sludge addition improved consistently TOC, N, P and K content up to soils treated with 120 t ha−1 year−1. The enhancement of soil nutrient status impacted positively on biological properties, including microbial biomass and soil enzyme activities (dehydrogenase, protease and phosphatase). However, the variation of soil properties was more important in soil A characterized by a higher fine fraction thus stronger retention capacity. Accordingly, XRD analysis of soil A revealed several identifiable peaks representing kaolinite and illite clays in contrast to soil S. Unexpectedly, high to excessive sludge doses of 80 and 120 t ha−1 year−1 did not provoke soil degradation after three repeated annual amendments. In fact, pH values in both soils remained within neutral to alkaline range (7.76–8.63); total heavy metals (Cu, Zn, Ni and Pb), soil salinity and fecal coliforms were all below threshold values for contaminated soils.

Semi-arid agricultural soils have increasingly been subjected to urban sewage sludge (USS) applications due to accelerated soil depletion and shortages in manure supply. Research studies addressing USS reuse have mostly been conducted in cropping systems and focused on changes in topsoil properties of a given texture. Therefore, sludge-soil interactions could be largely influenced by the presence of plants, soil particle composition and depth. In this field study, two agricultural soils (sandy, S and sandy loam, SL) received simultaneously four annual USS applications of 40, 80, and 120 t ha−1 year−1 in absence of vegetation. Outcomes showed the increase of carbon and macronutrients in both soils proportionally to USS dose especially in the topsoil profile (0–20 cm). Subsoil (20–40 cm) was similarly influenced by sludge rates, showing comparable variations of fertility parameters though at significant lower levels. The depth-dependent improvement of soil fertility in both layers enhanced the microbiological properties accordingly, with significant variations in soil SL characterized by a higher clay content than soil S. Besides, positive correlations between increases in sludge dose, salinity, trace metals, and enzyme activities in both soils indicate that excessive sludge doses did not cause soil degradation or biotoxic effects under the described experimental conditions. In particular and despite high geoaccumulation indices of Ni in both soils and profiles, the global concentrations of Cu, Ni, Pb, and Zn were still below threshold levels for contaminated soils. In addition, the maintenance of pH values within neutral range and the increase of organic matter content with respect to control would have further reduced metal availability in amended soils. Therefore, we could closely investigate the effects of texture and depth on the intrinsic resilience of each soil to cope with repetitive USS applications.

In this study, nutrients release/adsorption from/by raw poultry manure-derived biochar produced at a pyrolysis temperature of 600 &deg, C (RPM-B) was assessed under static and dynamic conditions. Batch sequential leaching experiments of RPM-B for a total contact time of 10 days showed that both phosphorus and potassium were slowly released but with higher amounts compared to various other animal- and lignocellulosic-derived biochars. The cumulated released P and K amounts were assessed to 93.6 and 17.1 mg g&minus, 1, which represent about 95% and 43% of their original contents in the RPM-B, respectively. The column combined leaching/adsorption experiments showed that amending an alkaline sandy agricultural soil with two doses of RPM-B (at 5% and 8% w:w) resulted in an efficient retention of NO3-N and NH4-N, and on the contrary, important leached amounts of PO4-P, K+, Mg2+, and Ca2+ but with relatively slow kinetic release rates for a long period. Even after 40 days of dynamic leaching, these latter nutrients continued to be released with kinetic rates lower than 10 mg kg&minus, 1 d&minus, 1. Thus, compared to synthetic fertilizers, RPM-B valorization as organic amendment for poor semiarid soils could be considered as an attractive, eco-friendly, and sustainable waste recycling option.

This article analyzes whether trade openness and foreign direct investment are driving factors for human development in the Middle East and North African region. We used data of 13 MENA countries o...

Urban communities are affected by population growth, urbanization and climate change, thus being vulnerable to food, energy and water demand. According to the United Nations, the world’s population is expected to increase by 2 billion people in the next 30 years and 68% of them are projected to live in urban areas by then. At the same time, 1/3 of the food produced in the world for human consumption every year gets lost or wasted and still, 795 million people worldwide are malnourished. A sustainable Food, Energy, Water and Waste Nexus is urgent. The Moveable Nexus Project is aiming to give a solution to the FEW Nexus through urban design methods and agricultural practices by practicing the design method, the evaluation effect and the participation. The design method will be practiced through design charrettes and international workshops and the evaluation will be realized by a Food, Energy & Water consumption environmental footprint calculator. Finally, the participation phase will engage the stakeholders and the community at the Doha Living Lab. The Doha Living Lab will quantify the urban FEWW-fluxes through urban agriculture and will try to achieve sustainability in terms of food production, new crops and new production technology, water management, organic waste management, reuse and recycle. The Living Lab will also assess the needs of the community and the involved stakeholders, by engaging them in every process thus enhancing resilience among people and agri-food systems.

The aim of this paper is to define the optimal level of liquidity and to investigate its impact on the overall bank profitability. To achieve these goals, we use a large sample of 127 countries over the period 2005-2015. The whole sample is divided in two sub-samples. The first covers 46 high income countries and the second includes 81 low and middle income countries. We performed the Panel Smooth Transition Regression (PSTR) as econometric approach. Empirical results show that the optimal level of liquidity that affects bank profitability is 24.18% for high income countries and 40.45% for low and middle income countries. Findings also indicate that credit risk decreases significantly the level of profitability of the two groups of countries.

The main purpose of this study is to investigate the interaction between financial liberalization, banking crisis and economic growth by taking into consideration the role of institutions. Our sample covers 15 Middle East and North African observed during the period 2000–2013. Using a dynamic panel data framework, our findings reveal that financial liberalization contributed to improve economic growth in MENA countries while banking crisis had harmful effects on MENA economies. The quality of institutions did not have a clear impact except for rule and order and democratic institution. These results have important policy implications. To grow output and avoid the occurrence of banking crisis, MENA countries should reinforce their institutions quality by adopting good practice of governance and regulation.

The main purpose of this paper is to investigate the relationship between financial sector development and economic growth taking into consideration the role of institutions quality. Our sample is on a group of 143 countries observed during the period of 2006-2013. The sample is dived into 100 developing and 43 developed countries. Using structural GMM the paper shows that financial sector plays a crucial role in economic development and growth for the whole sample as well as for developed and developing countries. However, the results show that unlike developing countries, developed countries enjoyed the presence of proper institutions in their countries which in turn have contributed further to the development of their financial sector.

Pyrolysis is a thermochemical process that permits the conversion of biomasses into energy (bio-oil and biogas) and a solid residue called biochar. The generation of biochar from lignocellulosic materials has been, for longtime, the predominant research focus. Wastewater treatment plants produce huge amounts of sludge biomass and there exists an increasing evidence for their possible reuse as a promising pyrolysis feedstock in recent literature. Though the valorization of biochars generated from lignocellulosic biomasses has been the subject of many reviews, there exists a critical knowledge gap regarding the effect of synthesis conditions of the sludge-derived biochars (SDBs) on their efficiency in the treatment of wastewater. This review critically analyzes the available literature related to SDBs characteristics and application to adsorb inorganic and organic pollutants from effluents. The physico-chemical properties and adsorption efficiency of SDBs are mainly tuned by the nature of raw sludge, pyrolysis conditions, and pre/post-treatments. Indeed, biochars originating from digested sludge have better adsorption capacities towards nutrients and heavy metals compared to those obtained from the non-digested sludge. The nutrients recovery from urban wastewater could be significantly improved when the raw sludge is mixed with lignocellulosic biomass and Mg/Ca rich materials. On the other hand, the chemical activation of sludge at reagent/sludge ratios higher than 2:1 permits to generate SDBs with adsorption capacities comparable and even better than commercial activated carbons. Moreover, the embedment/coating of SDBs with specific nanomaterials and tailored functional groups could significantly improve the adsorption capacities of various organic toxic pollutants and at the same time enhance their chemical degradation. The effect of the nature of target pollutants (organic or inorganic) on the underlying adsorption mechanisms by SDBs was also deeply reviewed. Finally, this paper provides the main application challenges as well as insights regarding the promising future directions for SDBs research and development.

Resume Cette etude vise a tester empiriquement la relation entre la diversification des revenus et le pouvoir de marche ainsi que la relation entre le pouvoir de marche, la diversification des revenus et la stabilite financiere bancaire. En se basant sur une base de donnees de 10 banques commerciales Tunisiennes sur la periode allant de 1990 a 2013, on demontre qu'il existe une relation significative et positive entre le pouvoir de marche et la stabilite financiere. Ceci vient renforcer les resultats des recherches anterieures portant sur differents systemes bancaires dans plusieurs pays.

International audience; Effects of olive cake (OC) supplementation on carcass traits, contractile muscle properties and meat quality of lambs fed indoors or grazing in a Medicago arborea rangeland were studied. Twenty-four weaned male lambs (average body weight 24.3 ± 1.1 kg) were assigned into four treatment groups: indoor without OC, indoor with OC, pasture without OC and pasture with OC. The first two groups of lambs were fed indoor with oat hay ad libitum as based diet. The two others reared on natural rangeland improved by Medicago arborea. One of indoor and pasture groups were supplemented with 280 g/d of OC. All the groups received 400 g of concentrate. The experimental trial lasted about 3 months. Then, lambs were slaughtered at 33 kg. Rangeland lambs had higher ADG. Feeding system (FS) and OC supplementation did not affect (P > 0.05) hot and cold carcass weights and dressing percentage. Lambs fed indoor had the greater commercial dressing percentage (P 0.05). Lambs supplemented with OC had lower ultimate pH (P

The agricultural reuse of urban sewage sludge (USS) modifies soil properties depending on sludge quality, management, and pedo-environmental conditions. The aim of this microcosm study was to assess C mineralization and subsequent changes in soil properties after USS addition to two typical Mediterranean soils: sandy (Soil S) and sandy loam (Soil A) at equivalent field rates of 40 t ha-1 (USS-40) and 120 t ha-1 (USS-120). Outcomes proved the biodegradability of USS through immediate CO2 release inside incubation bottles in a dose-dependent manner. Accordingly, the highest rates of daily C emission were recorded with USS-120 (3.7 and 3.9 mg kg-1 d-1 for Soils S and A, respectively) after 84 d of incubation at 25 °C. The addition of USS also improved soil fertility by enhancing soil macronutrients, microbial proliferation, and protease activity. Protease showed significant correlation with N, total organic C, and heterotrophic bacteria, reflecting the biostimulation and bioaugmentation effects of sludge. Soil indices like C/N/P stoichiometry and metabolic quotient (qCO2 ) varied mostly with mineralization rates of C and P in both soils. Despite a significant increase of soil salinity and total heavy metal content (lead, nickel, zinc, and copper) with USS dose, wheat germination was not affected by these changes. Both experimental soils showed intrinsic (Soil A) and incubation-induced (Soil S) phytotoxicities that were alleviated by USS addition. This was likely due to the enhancement of biodegradation and/or retention of phytotoxicants originating from previous land uses. Urban sewage sludge amendments could have applications in soil remediation by reducing the negative effects of allelopathic and/or anthropogenic phytoinhibitors.