Search Results (291)

Determining the amount of biowaste generated, separated, and recycled at source in households (BHrecycled) is crucial for assessing its potential inclusion in the total mass of waste prepared for reuse and recycling on the country level. Although the EU has introduced standardized rules for BHrecycled measurement, it is still a major challenge. This study, the first to be conducted on a large scale in Poland and the EU countries, aimed to determine the actual mass of BHrecycled (kitchen waste (B_K) per capita per year (kg/(capita·year)) and garden waste (B_G) per square meter of green area (kg/(m²·year)) in 1150 households that use an active composting unit located in more than 400 municipalities in all the voivodeships in Poland. Each municipality is characterized by individual MSW generation (MSW_G) values (the amount of waste generated per capita per year). The MSW_G values of the municipality where the household was located were used to group the data of B_K and B_G. In Poland, the average masses of B_K and B_G remained within the ranges of 81.02–107.49 kg/(capita·year) and 1.02–2.87 kg/(m²·year), respectively, across the MSW_G value. However, there was no clear statistical relationship between the MSW_G value and B_K or B_G. The average masses of B_K and B_G were ca. 97 kg/(capita·year) and ca. 2 kg/(m²·year). These results enable the determination of the total amount of BHrecycled in Poland. By incorporating these findings into waste management, strategies, monitoring, and reporting practices can be improved. Moreover, it promotes compliance with the EU recycling targets. Full article

Biodrying and composting are aerobic processes to treat and stabilize organic solid waste, but biodrying involves a shorter process time and does not require the addition of water. The resulting biodried material (BM) is mainly used as an energy source in cement production or in municipal solid waste incineration with energy recovery, but when obtained from agricultural or agroindustrial organic waste, it could also be used as a soil amendment, such as compost (CO). In this study, the phytotoxicity of BM compared to CO, both made from organic wastes (orange peel, mulch and grass), was evaluated on seed germination and growth (for 90 days) of lettuce (Lactuca sativa L.) seedlings on treatments prepared from mixtures of BM and soil, soil (100%) and a mixture of CO and soil. The germination index (GI%) was higher for BM extracts (200 g/L) than for CO extracts (68% vs. 53%, respectively). According to their dry weight, lettuce grew more on the CO mixture (16.5 g) than on the BM (5.4–7.4 g), but both materials far exceeded the soil values (0.15 g). The absence of phytotoxicity suggests that BM acts as a soil amendment, improving soil structure and providing nutrients to the soil. Therefore, biodrying is a quick and low-cost bioprocess to obtain a soil improver. Full article

The modern world has brought extensive socioeconomic and ecological changes. Urbanization in developing nations has significantly increased municipal solid waste, necessitating in-depth understanding of waste composition particularly in developing nations for sustainable management practices. This study aimed to classify and characterize waste while evaluating potential waste management methods. Mixed methods were used to examine landfilled waste from Soshanguve and Hatherley sites in Tshwane Metropolitan, South Africa, using techniques such as Fourier transform infrared spectroscopy, X-ray fluorescence, proximate, and ultimate analysis. Seasonal variations in waste components were analysed over two seasons. The study identified that both sites are predominantly composed of organic waste, accounting for over 42 wt.%, with moisture content of ~50 wt.%, and minimal recyclables (<5 wt.%). Seasonal variations in MSW were significant for glass (<4% increase), organic waste (<5% increase), while plastic decreased by ~7% during spring. The biodegradable waste showed high carbon (>50%) and oxygen (>40%) levels, low ash content (<18%), and calorific values of 15–19 MJ/kg. Biodegradables mainly contained oxides of calcium, silicon, iron (III), and potassium with chemical composition indicating functional groups that emphasize composting and energy recovery benefits. The research provides insights into sustainable waste management, revealing waste composition at Tshwane landfills, aiding informed decision-making for resource usage and environmental conservation. Full article

The integration of different agroecological practices could significantly mitigate the impact of climate change. Therefore, a 2-year field experiment on organic zucchini was carried out to study the effects of clover (Trifolium alexandrinum L.) cover crop management (green manure, GM vs. flattening using a roller crimper, RC), compared to a control without cover (CT). This agroecological practice was tested in combination with the following different fertilizer treatments: T1. compost produced by co-composting coal mining wastes with municipal organic wastes compost plus urea; T2. compost produced with the same matrices as T1, replacing urea with lawn mowing residues; T3. non-composted mixture of the industrial matrices; T4. on-farm compost obtained from crop residues. The GM management showed the highest marketable yield and aboveground biomass of zucchini, with both values higher by approximately 38% than those recorded in CT. The T1, T2, and T3 treatments showed higher SOC values compared to T4 in both years, with a gradual increase in SOC over time. The residual effect of fertilization on SOC showed a smaller reduction in T3 and T4 than in T1 and T2, in comparison with the levels recorded during the fertilization years, indicating a higher persistence of the applied organic matter in these treatments. The findings of this study pointed out that combining organic fertilization and cover cropping is an effective agroecological practice to maintain adequate zucchini yields and enhance SOC levels in the Mediterranean environment. Full article

The treatment of wastewater and the utilization of the by-products of these processes are an important part of the circular economy. The sewage sludge, a result of wastewater treatment, could be used as a material for plant nutrient supply and/or soil-improving products. The city of Nyíregyháza, Hungary, with 120,000 citizens, has a well-planned water treatment plant operated by Nyírségvíz Ltd., which, in cooperation with the Research Institute of Nyíregyháza, developed a municipal sewage sludge compost (SSC). The closed loop of sewage water treatment and the agricultural utilization of its by-product has been developed and managed. The compost product called Nyírkomposzt was planned for acidic sandy soils. Beyond the agronomic benefits, the sustainable and environmentally sound utilization of SSC reduces sewage sludge disposal. This active involvement of a water utility company demonstrates the potential of cross-sectoral cooperation in solving environmental problems. The quality of the compost fits the Hungarian legislation. To study the effects of 0, 9, 18, and 27 t ha⁻¹ doses of compost on acidic sandy soil, a long-term small plot experiment was started in 2003. The cumulative effects of the regular (every third year, last treatment before sampling in 2021) application of the SSC showed positive changes in basic soil properties, depending on the doses used. Increasing values were found in the case of pH from 4.5 to 6, plant available P₂O₅ from 240 to 690 ppm, and plant available K₂O from 180 to 200 ppm. The plant-available zinc and copper content also increased. Soil organic matter and total N content stabilized at around 0.9% and 0.08%, respectively. The grain yields of winter rye also increased in both investigated years. The yields of 18 t ha⁻¹ treatment were about two times higher compared to the control, but only in 2022 was the difference significant. Our findings underscore the potential of well-planned SSC applications to improve the fertility of ploughed, acidic sandy soil, taking into account the theory of the circular economy by utilizing wastes and decreasing landfilling. Full article

The use of trees to revegetate urban areas contaminated by mining activity is a low-cost, low-maintenance technique, of which the success will depend on the plant species, planting methods, and geochemical processes at the soil-plant interface. This study analyzed the evolution of mineral composition in the rooting soil, tree, and herbaceous vegetation on soils contaminated by As, Cd, Cu, Co, Pb, and Zn. An in-situ experiment was carried out in Lubumbashi (South-eastern DR Congo) with six tree species (Acacia auriculiformis, Albizia lebbeck, Delonix regia, Leucaena leucocephala, Mangifera indica, and Syzygium guineense), in 0.187 m³ pits amended with municipal compost and limestone. After planting in the amended and unamended (control) pits, soil samples were taken for chemical analysis. Eighteen months after planting, a floristic inventory was carried out to assess the spontaneous colonization of herbaceous species. The results show an increase in metal concentrations in the rooting soil between 2019 and 2023 (Cu: 725 ± 136 to 6141 ± 1853 mg kg⁻¹; As: 16.2 ± 1.4 to 95 ± 28.5 mg kg⁻¹; Cd: 2.7 ± 1.3 to 8.7 ± 2.0 mg kg⁻¹; Co: 151 ± 36.3 to 182 ± 113 mg kg⁻¹; Zn: 558 ± 418 to 1098 ± 1037 mg kg⁻¹), with a stable pH and a decrease in nutrients (P, K, Ca, and Fe). The trees planted in the amended pits showed better height and diameter growth and greater survival than the controls, reaching average heights of 8 m and a DBH of up to 22 cm four years after planting. A total of 13 spontaneous herbaceous species were recorded, with an increased abundance during the second inventory. These results confirm the effectiveness of pit amendment for the rapid revegetation of urban soils polluted by trace metals. Full article

Circular economy in the context of municipal organic waste management has boosted the emergence of novel composting scenarios, such as community composting and decentralized urban composting in small installations, which favors localized management and valorization of organic waste streams. However, there is little information about the agronomic use of the composts obtained from these new organic waste management systems as an alternative for inorganic fertilization in crop production. In this work, municipal solid waste-derived composts from two decentralized composting scenarios (CM1 and CM2 from community composting, and CM3 and CM4 from decentralized urban small-scale composting plants) were applied and mixed in the top layer of a calcareous clayey-loam soil to assess their effects as alternative substitutes for conventional soil inorganic fertilization (IN) during two successive cultivation cycles of lettuce (Lactuca sativa L.) grown in pots with the amended soils. These treatments were also compared with an organic waste (goat–rabbit manure, E) and a control treatment without fertilization (B). The effects of the fertilizing treatments on the crop yield and quality, as well as on the properties of the soil considered were studied. In general, the application of the different composts did not produce negative effects on lettuce yield and quality. The compost-derived fertilization showed similar lettuce yields compared to the inorganic and manure-derived fertilizations (IN and E, respectively), and higher yields than the soil without amendment (B), with increases in the initial yield values of B, for the first cycle from 34.2% for CM1 to 53.8% for CM3, and from 20.3% for CM3 to 92.4% for CM1 in the second cycle. Furthermore, the organically amended soils showed a better crop development, obtaining higher values than the control treatment in the parameters studied. In addition, the incorporation of the organic treatments improved the soil characteristics, leading to 1.3 and 1.2 times higher organic matter contents in the soils with CM2 and in the soils with CM1, CM3, and E, respectively, compared to the control soil without fertilizing treatment (B), and 2.0 and 1.8 times greater organic matter contents, respectively, compared to soil with inorganic fertilization (IN). Therefore, the use of municipal solid waste-derived composts from these new organic waste management systems, such as the decentralized composting scenarios studied (community composting and urban decentralized small-scale composting plants), is presented, not only as a sustainable valorization method, but also as an alternative for the use of inorganic fertilizers in lettuce cultivation, while enhancing soil properties, contributing to increasing the circularity of agriculture. Full article

Soil management in vineyards is a crucial component of sustainable viticulture. Weed control under the row has traditionally been addressed using mechanical, physical, and chemical techniques, but herbicides pose environmental and health risks. The circular economy offers an alternative approach by converting organic waste into a resource, such as compost. This study explores the effectiveness of compost derived from the organic fraction of municipal solid waste (MSW) not only as a mulching technique but also as a potential biological agent for weed control through allelopathic mechanisms in vineyards. Experiments were conducted both in the field and under controlled conditions. In the field, compost was applied under the vine row as mulch and incorporated into the soil. Under controlled conditions, germination tests were performed to assess weed inhibition at different compost concentrations. Field results demonstrated that compost applications, both as mulch and incorporated into the soil, significantly inhibited weed growth during the first period after application compared to the tilled control without compost. Thus, this inhibition is not limited to physical mulching; it also applies to the release of allelopathic compounds from compost. Controlled condition experiments showed strong inhibition of germination in Cichorium intybus and Foeniculum vulgare seeds, confirming the anti-germinative effects of compost, particularly on small-seeded weed species. Compost is a promising tool for sustainable vineyard management, offering fertilization and weed-suppression benefits while reducing herbicide use. Full article

Soil degradation is caused by climate change and some agricultural practices. The use of compost from organic waste can be a sustainable solution, but poses risks to soil, crops and fruit. This article examined vineyard yield, vine and wine composition when compost from sewage sludge and urban waste was applied to two soils. One rainfed plot received 80 UFN kg/ha, while two irrigated plots received 40 and 80 UFN kg/ha. Compared to mineral fertilizer, compost increased crop yield (+60% in rainfed conditions) and above-ground biomass (+15% in rainfed conditions). Aromatic series were obtained by grouping the aroma compounds according to their aroma descriptor. In both rainfed and irrigated trials, higher values were observed in the fruity, green, waxy and floral series in wines from vines fertilized with compost compared to the control and chemical fertilization. The compounds with a higher influence in such series were ethyl butanoate, ethyl hexanoate, ethyl octanoate, hexanal, phenylacetaldehyde and 2-phenylethanol. Organoleptically, wines from compost were preferred to those from mineral fertilizer, with ratings close to the control wine, particularly in aroma, flavor and overall impression. Although further studies are needed, compost fertilization appears on the one hand to improve wine quality and, on the other hand, is a suitable alternative that reduces municipal waste. Full article

Within the Life-NADAPTA project (LIFE16 IPC/ES/000001), and in the framework of sustainable waste management, a study was carried out on the microbiological evolution during the composting process of the organic fraction of municipal solid waste (FORSU) using aerated static piles and their agricultural application on a pilot scale. This is necessary to ensure effective sanitization of the compost and that its application does not pose any risk. The microbiological parameters considered were as follows: Salmonella sp., Escherichia coli, total coliforms, and Enterococcus sp. The physicochemical parameters moisture, total solids, organic matter, nitrogen, phosphorus, and heavy metals were also evaluated. Salmonella sp. was not detected throughout the process, and the concentration of the three microbiological indicators decreased to the sanitary conditions recommended by legislation. As a result, the compost obtained complied with the requirements set out in the regulations on fertilizer products and was highly stabilized and mature for application on agricultural land. Tests were carried out on the soil before, during and after the vegetative cycle of the crop and on the irrigation water. The soil results showed that the addition of the organic amendment did not alter the populations of the tested micro-organisms at the end of the crop growing cycle. Thus, an adequate treatment of the residues allows them to be used in a sustainable way, but an adequate monitoring of the operational parameters is necessary to ensure this. Full article

Acid mine drainage (AMD) is a major environmental issue due to its high heavy metal concentrations and low pH, posing risks to ecosystems and human health. In Hualgayoc, Cajamarca, Peru, AMD contamination from mining activities necessitates effective remediation strategies. This study evaluated the removal efficiency of organic amendments, municipal waste compost (MWC), cattle manure compost (CMC), vermicompost (HMS), corn stalk biochar (CSB), sludge biochar (SLB), pine biochar (PBC), and native macrophytes Carex pichinchensis (CAX), Juncus ecuadoriensis (JSP), and Myriophyllum aquaticum (MYA) in removing As, Cd, Cu, Fe, and Zn. A physicochemical characterization of AMD, amendments, and plants was conducted, and sorption capacity was determined through triplicate analyses. The results showed that SLB achieved a 100% Zn removal, while CSB removed over 90% of Cu and Fe. Among the organic amendments, CMC demonstrated the highest As and Cd removal (~100%). Regarding macrophytes, CAX achieved a ~97% Fe removal, and MYA exhibited Cd affinity. CSB had the highest sorption capacity for Cu (0.139 mg/g), Fe (1.942 mg/g), and Zn (0.149 mg/g), highlighting its potential for metal remediation. Organic amendments enhanced metal adsorption and stabilization, outperforming macrophytes in heavy metal removal. Combining organic amendments with native plants is recommended to assess their synergistic potential for AMD remediation. Full article

The Separately Collected Organic Fraction of Municipal Solid Waste (SC-OFMSW) is the biodegradable kitchen and canteen waste fraction that is separately collected at source and classified by the European Waste Catalogue under code 20 01 08. The utilization of SC-OFMSW Compost has emerged as a sustainable approach to enhancing agricultural soil quality and supporting soil biodiversity and productivity, while also serving as a viable option for disposing of treated urban waste. This study investigates the dose effect of SC-OFMSWC through phytotoxicity and growth assays in Arabidopsis thaliana and Lactuca sativa seeds and seedlings, as well as the impact of the same compost on the chemical and microbiological properties of soil under open field conditions. During the field trial in an agricultural orchard, soil pH, nutrient content, organic matter, and microbial activity following SC-OFMSWC and chemical fertilizer application were evaluated. In the greenhouse trial, a significant increase in germination rate and biomass production was found for L. sativa at a compost concentration of 2.5%, while neutral to negative effects were observed for A. thaliana. In the open field, results indicated significantly increased levels of organic carbon and enhanced microbial biomass and activity, accompanied by a general increase in nutrients, promoting soil health and resilience, with only limited increases in EC values and heavy metal content. These findings underscore the potential of SC-OFMSWC as an effective agricultural soil improver and a promising component in sustainable nursery management practices. Full article

This paper reviews methods of municipal sewage sludge (MSS) disposal in the Republic of Poland. The MSS amount produced in 2022 in sewage treatment plants is 580.7 thousand tons of total solids. This is related to the increase in the amount of treated sewage and the use of the co-digestion of sewage sludge with waste. MSS generated in municipal sewage treatment plants constitutes waste with code 19 08 05—stabilized MSS. It is subjected to the rules of conduct specified in the Act on Waste. According to data from the Central Statistical Office, in 2022, the most popular disposal method was its use in agriculture (27.1%). Approximately 18% of the MSS from treatment plants was thermally treated. A significant part of MSS is also used for crops, compost production, and reclamation. MSS management requires an individual approach from sewage treatment plant operators and the use of effective disposal methods. Considering the assumption of the circular economy, it is necessary to consider the possibility of recovering valuable raw materials from MSS and producing products for reuse. One of the possibilities of reusing MSS is to generate porous materials. Moreover, MSS can be transformed into multiple types of soil improvers and fertilizers. Full article

Municipal solid waste management (MSWM) is an advantageous subject for implementing circular economy (CE) strategies. In this context, the waste generation and waste collection steps of MSWM in the third largest Greek city (Patras), in western Greece, were evaluated according to the proposed CE indicators. Public opinion and knowledge on CE in MSWM were also evaluated in a small sample of citizens from the Municipality of Patras (207 individuals) through a questionnaire survey. Results showed that (a) the CE performance indicators objectively assessed circularity in MSWM; (b) Patras fared better than Greece and EU in some indicators [waste generation (kg per capita × year), food waste generation (kg per capita × year)] and worse in others [food waste composting (% w/w), WEEE recycling (kg per capita × year)]; (c) citizens have not adopted CE practices in their waste management; and (d) there is a clear reluctance to change practices in older individuals. Based on these results, some recommendations for improvement were made. These results may aid in delineating existing conditions in MSWM in large eastern Mediterranean cities and contribute to the transition toward a reduction in waste disposal and an increase in material reuse. Full article

Phytostabilization of metals involves the inactivation of metals in the soil through the use of various materials as soil amendments, which reduces the bioavailability of metals, and then the introduction of vegetation. There are limited data comparing the effectiveness of different phytostabilization amendments under the same soil and environmental conditions. Therefore, the aim of this research was to compare the effectiveness of a range of soil amendments on reducing the extractability of metals, metal uptake by plants, microbial activity in soil and nutrient availability to plants. Eight materials potentially limiting metal availability were used in a pot experiment: two composts (CG, CM), municipal biosolids (SB), bentonite (BEN), phosphorus fertilizer (PF), amorphous iron oxide (FE), waste rock material (WR), calcium carbonate (LM); and these materials were compared with typical fertilization (NPK) and an untreated soil as the control (CTL). The following trace metal-contaminated soils were used in the pot experiment: soil taken from the area of strong dust fall from the zinc and lead smelter (soil P); soil taken from an outcrop of ore-bearing rocks near a smelter waste heap (soil H); soil artificially polluted through smelter dust spill in the 1990s (soil S). In general, the greatest yields of plants (oat and white mustard) were recorded for compost-treated soils. Changes in the solubility of zinc (Zn) and cadmium (Cd) after the application of various amendments largely reflected changes in soil pH. Biosolids caused a significant increase in extractable Zn and Cd, which was related to the decrease in soil pH, while a significant reduction in Cd extractability was observed across soils after the application of both composts, especially the compost characterized by alkaline pH. Interestingly, low extractability of Cd in the soil with the addition of another compost was observed, despite the pH decrease, as compared to the control pots. This fact proves the high sorption capacity of the compost towards Cd. The microbiological analyses revealed the highly beneficial effect of composts for dehydrogenases and nitrification activities, and for soil respiration, whereas soil amendment with iron oxide caused an increase in respiration activity across soils. Full article