Sewage Sludge Compost Research Articles

Yielding and Heavy Metals Accumulation in the Biomass of Grass Cultivated in Substrata with the Participation of Municipal Sewage Sludge and Green Waste Compost

Yielding and Heavy Metals Accumulation in the Biomass of Grass Cultivated in Substrata with the Participation of Municipal Sewage Sludge and Green Waste Compost

Effects of Composted Sewage Sludge on Soil Properties and Vegetable Quality from Abandoned Quarries

Effects of Composted Sewage Sludge on Soil Properties and Vegetable Quality from Abandoned Quarries

Effects of Composted Sewage Sludge on Soil Properties and Vegetable Quality from Abandoned Quarries

The effects of composted sewage sludge on soil properties and vegetable quality were investigated in a field experiment for two years. The soil was amended with 3, 15 or 30 t/ha of compost. The results indicated that the vegetable net production increased with the amendment dosage of 3 and 15 t/ha, while the net production decreased in the application amount of 30 t/ha. However, the Vitamin C (Vc) content of the three vegetables was reverse. The heavy metals concentrations in vegetables and soils could meet the national food and soil environmental quality standards of China (II). The accumulation concentrations of Cd, As and Hg in the three vegetables increased with the increasing amendment dosage, while the concentrations of Cr and Pb changed significantly with different types of vegetable. Heavy metal accumulation ability was in the order of celery > lettuce > cabbage, except for Cr. The accumulation of different heavy metals in soil was related to the migration characteristic of heavy metals, plant absorption capacities and the amendment dosage. The concentration of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the soils increased with addition of 15 t/ha and 30 t/ha, while the change was not statistically significant between the amendment of 3 t/ha and the control. The concentration of PCBs and PAHs in vegetables was positively correlated with compost addition amounts. The dissipation rate of PCBs and PAHs followed the principle of first-order kinetics, and vegetables could improve the dissipation rate. Therefore, the application of compost as soil amendment to abandoned quarries is a feasible strategy for sludge disposal because appropriate amount of compost could enhance the soil fertility, while the long-term application should be considered seriously.

English

English

Natural Organic Amendments for Improved Phytoremediation of Polluted Soils: A Review of Recent Progress

Environmental pollution caused by metals, radionuclides and organic pollutants affects quality of the biosphere: soil, water and air. Currently, great efforts have been made to reduce, remove or stabilize contaminants in polluted sites. There has been increasing interest in phytoremediation—the use of plants to reduce concentration of pollutants or to render them harmless. This paper provides a brief review of recent progress in the research and practical application of phytoremediation techniques. Improvements in phytoremediation due to utilization of organic amendments, namely, agro- and industrial wastes (such as sugar beet residue, composted sewage sludge or molasses), biochar, humic substances, plant extracts and exudates are discussed, as well as their influences on soil structure and characteristics, plants growth and bioavailability of pollutants. Both plant-assisted phytoremediation and the use of natural materials in the absence of remediating plant are believed to be cost-effective and environmentally friendly approaches for soil cleanup. However, the characterization and quantification of a range of natural materials used in phytoremediation are essential in order to implement these approaches to practice.

DECOMPOSIÇÃO DE LODO DE ESGOTO E COMPOSTO DE LODO DE ESGOTO EM NITOSSOLO HÁPLICO

RESUMO O uso agrícola de lodo de esgoto e derivados no Estado de São Paulo é regulamentado por norma federal e por norma paulista, que recomendam que esses materiais quando incorporados a solos agrícolas devem apresentar no mínimo 30 % de degradação do carbono total. Para observar as frações de degradação de um lodo de esgoto e de um composto, produzido a partir do mesmo lodo juntamente com poda de árvore urbana triturada, realizaram-se dois ensaios de biodegradação de C. As doses dos resíduos foram adicionadas em frascos contendo 500 g de solo coletado na profundidade de 0,00-0,20 m de um Nitossolo Háplico Álico textura argilosa. No ensaio I, as doses de lodo (L) e composto (C) utilizadas consideraram percentuais da necessidade em N para a cultura da cana-de-açúcar, e expressas em Mg ha-1 de resíduo (base úmida): L1 21,2 (100 %); L2 42,4 (200 %); C1 69,4 (50 %); C2 138,9 (100 %); e C3 277,8 (200 %). O ensaio II foi realizado apenas com o lodo de esgoto, utilizando-se doses 5, 10, 15 e 20 vezes maiores que aquelas recomendadas no ensaio I: L3 120; L4 240; L5 360; e L6 480, simulando sucessivas aplicações do resíduo no solo. O C-CO2liberado foi quantificado por meio da medida de condutividade elétrica. O lodo de esgoto no ensaio I apresentou menores frações de degradação quando comparado ao composto orgânico, mas a taxa de decomposição do composto foi menor, provavelmente pela presença de substâncias recalcitrantes resultantes do processo de humificação. A fração de degradação dos resíduos no solo atingiu valor próximo a 30 % apenas para a dose de lodo de esgoto 20 vezes superior à dose exigida pela cultura, e assim não poderiam ser utilizados em solos agrícolas argilosos. Observou-se a necessidade de revisão desse valor adotado pela legislação paulista de uso de resíduos orgânicos em solos.

Attributes of the soil fertilized with sewage sludge and calcium and magnesium silicate

ABSTRACTThis study aimed to evaluate the chemical attributes of an Inceptisol cultivated with castor bean (Ricinus communis L.), variety ‘BRS Energia’, fertilized with sewage sludge compost and calcium (Ca) and magnesium (Mg) silicate. The experiment was conducted at the ICA/UFMG, in a randomized block design, using a 2 x 4 factorial scheme with three replicates, and the treatments consisted of two doses of Ca-Mg silicate (0 and 1 t ha-1) and four doses of sewage sludge compost (0, 23.81, 47.62 and 71.43 t ha-1, on dry basis). Soil organic matter (OM), pH, sum of bases (SB), effective cation exchange capacity (CEC(t)), total cation exchange capacity (CEC(T)), base saturation (V%) and potential acidity (H + Al) were evaluated. There were no significant interactions between doses of sewage sludge compost and doses of Ca-Mg silicate on soil attributes, and no effect of silicate fertilization on these attributes. However, fertilization with sewage sludge compost promoted reduction in pH and increase in H + Al, OM and CEC. The dose of 71.43 t ha-1 of sewage sludge compost promoted the best soil chemical conditions.

Environmental consequences of the use of sewage sludge compost and limestone outcrop residue for soil restoration: salinity and trace elements pollution

Purpose This article analyzed the use of composted sewage sludge and limestone outcrop residue as a source of saline pollution to groundwater due to their use in soil rehabilitation and land restoration.

Changes in microbial dynamics during vermicomposting of fresh and composted sewage sludge

Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques to reduce its risk to the environment. This research studies vermicomposting and vermicomposting after composting of sewage sludge with the earthworm specie Eisenia andrei. In order to determine the effect that earthworms cause on the microbial dynamics depending on the treatment, the structure and activity of the microbial community was assessed using phospholipid fatty acid analysis and enzyme activities, during 112days of vermicomposting of fresh and composted sewage sludge, with and without earthworms. The presence of earthworms significantly reduced microbial biomass and all microbial groups (Gram+ bacteria, Gram− bacteria and fungi), as well as cellulase and alkaline phosphatase activities. Combined composting–vermicomposting treatment showed a lesser development of earthworms, higher bacterial and fungal biomass than vermicomposting treatment and greater differences, compared with the control without earthworms, in cellulase, β-glucosidase, alkaline and acid phosphatase. Both treatments were suitable for the stabilization of municipal sewage sludge and the combined composting–vermicomposting treatment can be a viable process for maturation of fresh compost.

Combination between Acidity Amendments and Sewage Sludge with Phosphorus on Soil Chemical Characteristics and on Development of Castor Bean

The addition of urban and industrial waste products to agriculture not only provides them with an adequate environmental destination but also increases the nutrient content and negative charges in the soil, especially in naturally acidic tropical soils with high phosphorus-fixing capacity, just as liming does in relation to the dependent charges of pH. Both cases make it possible to favor the availability of phosphate fertilization. The aim of this study was to assess the interactions between application of composted sewage sludge (SSS) and soluble phosphorus (P) in combination with different rates of limestone (LS) and steel slag (SS) on the characteristics of dwarf castor bean and soil chemical properties. The experiment was conducted in a greenhouse in Botucatu, SP, Brazil. The Oxisol soil used was incubated with the combinations—based on chemical analyses of the soil, the waste product and slag, considering the needs of castor bean—in the 45 days prior to sowing, undertaking analysis of castor bean growth and dry-matter weight after physiological maturity, the time at which soil analysis was performed. SSS as an amendment of soil acidity provided better results in the properties of soil acidity, sum of bases (SB), cation exchange capacity (CEC), and base saturation (BS%). The combinations of the amendments were similar in regard to the increase of P availability in the soil. Although SSS alone resulted in an increase in organic matter (OM), nitrogen (N), magnesium (Mg), potassium (K), boron (B), cupper (Cu), zinc (Zn), and iron (Fe) contents in the soil, the low P content in the waste product extended the castor bean cycle, requiring P supplementation in combination.

Composting sewage sludge with green waste from tree pruning

Sewage sludge (SS) has been widely used as organic fertilizer. However, its continuous use can cause imbalances in soil fertility as well as soil-water-plant system contamination. The study aimed to evaluate possible improvements in the chemical and microbiological characteristics of domestic SS, with low heavy metal contents and pathogens, through the composting process. Two composting piles were set up, based on an initial C/N ratio of 30:1, with successive layers of tree pruning waste and SS. The aeration of piles was performed by mechanical turnover when the temperature rose above 65 ºC. The piles were irrigated when the water content was less than 50 %. Composting was conducted for 120 days. Temperature, moisture content, pH, electrical conductivity (EC), carbon and nitrogen contents, and fecal coliforms were monitored during the composting. A reduction of 58 % in the EC of the compost (SSC) compared with SS was observed and the pH reduced from 7.8 to 6.6. There was an increase in the value of cation exchange capacity/carbon content (CEC/C) and carbon content. Total nitrogen remained constant and N-NO3- + N-NH4+ were immobilised in organic forms. The C/N ratio decreased from 25:1 to 12:1. Temperatures above 55 ºC were observed for 20 days. After 60 days of composting, fecal coliforms were reduced from 107 Most Probable Number per gram of total solids (MPN g−1) to 104 MPN g−1. I one pile the 103 MPN g−1 reached after 90 days in one pile; in another, there was recontamination from 105 to 106 MPN g−1. In SSC, helminth eggs were eliminated, making application sustainable for agriculture purposes.

Evaluation of morphological and chemical composition of seed geranium ‘Florever Deep Red’ F1grown in substrate containing municipal sewage sludge and potato pulp

Development of various types of agronomic, industrial or municipal waste as components of horticultural substrates can be an alternative to other commonly used substrates in the production of ornamental plants. These studies were conducted to provide data on the possible usage of municipal sewage sludge (MSS) compost for the cultivation of 'Florever Deep Red' geranium (Pelargonium ×hortorum) propagated from seeds. Substrates were prepared from sphagnum peat (SP) and four composts containing MSS, potato pulp (PP), rye straw (RS) or sawdust of coniferous trees (SD). The composts RSQUO (C) composition was as follows: CI - MSS 70%, RS 30%; CII - MSS 70%, SD 30%; CIII - MSS 35%, PP 35%, RS 30%; CIV - MSS 35%, PP 35%, SD 30%. Composts were amended to peat at 25, 50 and 75% (by volume). Geranium seedlings were planted in pots and grown on tables in a plastic tunnel without top dressing. The results of the study indicate that it is possible to grow seed geranium in peat-based substrates amended with the different composts without the use of top fertilization. The quality and abundance of geranium flowering varied according to the substrate, which largely depended on the composition of the compost and compost rate in the mixture. The substrate containing MSS and RS compost at the highest rate had a positive impact on the abundance of flowering, inflorescence size and decorative value of the plants. The content of macro nutrients and heavy metals in the leaves of geranium depended on the composition of the substrate and increased with the rate of compost.

FAVOUR STREET TREE ROOT GROWTH WITH HIGH SUPPLIES OF ORGANIC MATTER INDUCES CHANGES IN URBAN SOIL PROPERTIES

Physical properties of urban soils often limit tree development. Urban soils are compacted resulting in reduced water infiltration and air. The available soil volume for root colonisation is usually limited by the underground infrastructures. Exogenous organic matter has been shown to have a positive impact on the physical properties of agricultural soils. In some urban situations, the wide-scale availability of organic matter and the need for important soil restructuring have led to the addition of very large quantities of organic matter. Our objectives were to measure in soil reconstituted with high levels of organic matter: (1) the effects of organic matter decomposition on the evolution of physical properties, and on street tree root and shoot development; (2) the changes induced by tree root development on the physical properties of bulk soil. We monitored over a 60-month period, physical properties – dry bulk density, structural stability and permeability – of reconstituted soils placed in 600-L containers under natural conditions. The top layer was a sandy loam amended with 40% by volume of sphagnum peat or organic compost – a sewage sludge and wood chip compost or a green waste compost – lying on a layer of sandy loam. The control container was composed of two layers of sandy loam. Bare root, Ostrya carpinifolia Scop were planted into half of the containers and we monitored root biomass and distribution and, shoot development. Organic matter had significant effects on the soil physical properties compared to the control with a significant decrease of the soil bulk density and a significant increase of structural stability and infiltration rate. Root system significantly responded to organic matter content which increased the root mass and density. Root system development followed the vertical gradient of soil bulk density and, the underlying layer presented a small root number and was unsuitable for root growth. Similarly to the roots, branching number and order were favoured by organic matter compared to the control. After 2 years, the root development in the containers was assessed but did not affect the bulk soil physical properties which were similar for all treatments. After 5 years, statistical analysis showed that tree root density had significant effects on structural stability and infiltration rates comparing containers with and without tree. Great level of compost in a constructed soil increased physical properties and tree above and below ground development. We assessed that, five years after planting, the tree root system improved urban soil structure.

Influence of compost of sewage sludge and low-quality water on pesticide uptake by tomato plants grown in an iron mine soil

In mine soils, especially from arid or semiarid areas, the use of low-quality water for irrigation is a usual practice. Therefore to fill this gap, different experiments have been carried out to evaluate the effect of compost, pesticide and wastewater on the growth of tomato plants in a mine soil located at an iron extraction area. Soils proceeded from Alquife mine wastes whose most outstanding characteristics are alkaline conditions, low organic matter and electrical conductivity and high As concentration. The compost of sewage sludge (CSL) used to amend this soil had a slightly acid pH (6.8), EC 3.0 ± 0.07 dS m-1 (1/10 ratio, m/V) and 10 % organic carbon (OC) content. Irrigation was performed with distilled water (DW) or wastewater (WW) and two pesticides, the insecticide thiacloprid and the fungicide fenarimol, were applied to the soil. Tomato was grown directly from seeds on each pot. Four treatments with addition of pesticides were considered. For comparison purposes, two additional treatments without pesticides were also included. Addition of compost of sewage sludge led to a significant and sustained increase of soil OC content and dehydrogenase activity, while irrigation with wastewater had a slight or negligible effect on both properties. The plant species responded negatively to wastewater irrigation when this practice was undertaken with the application of both pesticides. No detectable amounts of thiacloprid, a relatively unstable and polar insecticide, were found in soil. The concentration of fenarimol in soil was higher after amendment with compost, but was not modified by irrigation with wastewater. In tomato shoots, the amounts of both pesticides were inversely correlated with final soil organic carbon, indicating that this soil property is relevant for their plant uptake. Besides, fenarimol concentrations in the soil and the tomato shoots were inversely related (r = −0.836). Tomato was not able to grow healthy in Alquife mine soil without compost addition. The irrigation with wastewater only reduced plant growth when used in combination with pesticides. Uptake of both pesticides by tomato plants was negligible according to the low bioaccumulation factor values, but was almost doubled for wastewater irrigation. Caution should be taken with the use of treated wastewater, because it may reduce plant growth in tomato that is a species sensitive to salinity.

Effect of soil moisture and sewage-sludge compost on some soil chemical properties and alfalfa forage macronutrients concentrations in greenhouse conditions

Improvement of plant nutrition is one of the approaches for augmenting the drought stress tolerance in plants. Due to low organic-matter content in most soils in arid and semi-arid regions of Iran, application of organic-wastes’ compost can increase water-holding capacity of the soil and improve plant nutrition. So, in this study, the interactive effects of soil moisture and municipal sewage-sludge compost were investigated on some soil chemical properties and concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in alfalfa (Medicago sativa cv. Garehyounjeh) forage in greenhouse conditions. A factorial experiment, based on randomized complete blocks design with three replications, was conducted with two factors of soil moisture at three levels (0.81FC-FC, 0.56FC-0.75FC and 0.35FC-0.50FC) and sewage sludge compost at four levels (0, 15, 30 and 60 g/kg of soil). The results showed that the main and interactive effects of sewage sludge compost and soil moisture on the concentration of N, P, K, Ca and Mg in alfalfa forage and electrical conductivity (EC), pH and K concentration in soil solution were significant. As soil moisture content decreased, the concentration of N, K, Ca and Mg in alfalfa forage and the EC and K concentration of soil solution significantly increased; while the concentration of P in alfalfa forage and pH of soil solution were significantly decreased. In all the studied soil water contents in this experiment, application of 60 g sewage-sludge compost per kg of soil as compared to the 30 g/kg level, significantly decreased alfalfa growth by increasing the salinity of soil solution. Under well-watered and water-deficit stress conditions, application of 30 g sewage-sludge compost per kg of soil improved alfalfa nutrition and its forage quality.

Soil quality improvement by the establishment of a vegetative cover in a mine soil added with composted municipal sewage sludge

The effect of two different composts of urban sewage sludge was investigated for the establishment of three different plant species (ryegrass, tomato and ahipa) on a mine soil (Alquife, SE Spain). The treatments consisted in a non-amended mine soil, and mine soils amended with composted sewage sludge (CSL) or composted sewage sludge with olive prune wastes (CLV) at 2, 5 and 10% (w/w). Different soil and plant parameters were measured. Soil pH was slightly modified but soil conductivity and soil organic C increased with compost addition and remained constant along incubation. Soil respiration and dehydrogenase activity increased more when amended with CSL than with CLV. At the end of the incubation period a decrease in enzyme activities was measured with increasing CSL doses suggesting a possible toxic effect of CSL above 5%. The plant species responded differently to both composts. In ahipa, the treatments did neither affect the leaf photosynthetic pigments nor the plant growth. In tomato and ryegrass, the 2% dose improved biomass but at 10% increased plant mortality and inhibited plant growth. Composted sewage sludge (≤5%) appeared to be the best solution when used as soil conditioner for improving plant establishment in this mine soil.

Antibiotic resistome and its association with bacterial communities during sewage sludge composting.

Composting is widely used for recycling of urban sewage sludge to improve soil properties, which represents a potential pathway of spreading antibiotic resistant bacteria and genes to soils. However, the dynamics of antibiotic resistance genes (ARGs) and the underlying mechanisms during sewage sludge composting were not fully explored. Here, we used high-throughput quantitative PCR and 16S rRNA gene based illumina sequencing to investigate the dynamics of ARGs and bacterial communities during a lab-scale in-vessel composting of sewage sludge. A total of 156 unique ARGs and mobile genetic elements (MGEs) were detected encoding resistance to almost all major classes of antibiotics. ARGs were detected with significantly increased abundance and diversity, and distinct patterns, and were enriched during composting. Marked shifts in bacterial community structures and compositions were observed during composting, with Actinobacteria being the dominant phylum at the late phase of composting. The large proportion of Actinobacteria may partially explain the increase of ARGs during composting. ARGs patterns were significantly correlated with bacterial community structures, suggesting that the dynamic of ARGs was strongly affected by bacterial phylogenetic compositions during composting. These results imply that direct application of sewage sludge compost on field may lead to the spread of abundant ARGs in soils.

Influence of sludge-ash composts on some properties of reclaimed land / Wpływ kompostów osadowo-popiołowych na niektóre właściwości rekultywowanego gruntu

Abstract The study was conducted in the area of the impact of sulfur mine in Jeziórko. The aim of the study was to assess changes in pH, cation exchange capacity and content of available phosphorus, potassium and magnesium after 6 years of conducting remediation. In the experiment (plots with an area of 15 m2) degraded soil was rehabilitating by post-floating lime and compost from sewage sludge, sewage sludge and ash from combined heat and power (CHP). Composts at a dose of dry matter 180 t · ha-1 (6%), were determined in accordance with Minister of the Environment Regulation from 2001, applied the following options: control (only native soil limed), compost from municipal sewage sludge, sewage sludge compost (80%) and ash (20%), compost from sewage sludge (70%) and ash (30%). The reclaimed plots were sown with mixture of rehabilitation grass. Single de-acidification, land fertilization and a further 6-year extensive (without fertilization) use had a different influence on the properties of the native soilless substratum. Irrespective of the reclamation manner, after six years land use in the upper layers, observed increase in the average content of available phosphorus, available potassium content does not changed significantly but recorded a tenfold decrease in the content of available magnesium.

Effect of Integrated nutrient management (INM) on growth attributes, biomass yield, secondary nutrient uptake and quality parameters of bhendi (Abelmoschus esculentus L.)

Organic manure from different sources could be an effective substitute of chemical fertilizers. Therefore, a field experiment was conducted to study the impact of various sources of organic manures viz., sole application of composted pressmud, vermicompost, sewage sludge and farmyard manure and its combination with various levels of inorganic fertilizers on growth attributes, biomass yield, yield attributes, secondary nutrient uptake and its available status and quality parameters of bhendi (A. esculentus (L.) Moench). The results indicated that application of pressmud @ 5 t ha-1 with 50 per cent recommended dose of fertilizer had recorded the highest calcium and magnesium uptake of 30.9 and 15.4 kg ha-1 respectively and biomass yield of 2233.2 kg ha-1, In comparison to control, the increases in biomass yield and calcium and magnesium uptake were 20 and 51 and 136% higher under the same set of treatment combinations . The results revealed that treatment received with pressmud application @ 5 t ha-1 along with 50 per cent recommended dose of fertilizers registered highest available calcium and magnesium content of 0.14 and 0.28% respectively. In addition to that, there was an improvement in growth parameters such as plant height and number of branches plant-1 at all the growth stages of crop and also quality attributes viz., crude fibre (10.2%) and mucilage content (1.56%) were recorded significantly highest by same treatment compared to control (15.0 and 1.2% respectively). Among the organics, pressmud based inorganic fertilizers application was suitable for higher biomass yield, improvement in quality parameters and also maintaining the fertility status of the secondary nutrients in soil.

Effect of fresh and mature organic amendments on the phytoremediation of technosols contaminated with high concentrations of trace elements

Organic compounds resulting from the decomposition of organic amendments are used in the remediation of trace element (TE) contaminated soils. The mobility, phytoavailability and soil exposure intensity of molybdenum (Mo), chromium (Cr), zinc (Zn), copper (Cu), Cobalt (Co) and Arsenic (As) were evaluated in the phytoremediation of contaminated technosols after the addition of two organic matter types, fresh ramial chipped wood (RCW) and composted sewage sludge (CSS). The experiment consisted of nine main treatment blocks: (A) 3X unamended soil (NE), (B) 3X soil amended with RCW and (C) 3X soil amended with mature CSS. Total dissolved TE concentrations were determined in soil pore water (SPW) sampled by Rhizon samplers. The soil exposure intensity was assessed by standard Chelex 100 DGT (diffusive gradient in thin films) probes. TE phytoavailability was characterized by growing dwarf beans on potted soils and analyzing their foliar TE concentrations. The results of the present study indicate that the addition of fresh RCW and CSS has a positive effect on contaminated technosols. RCW decreased the mobility of all the studied TE in the SPW, whereas CSS reduced the mobility of Mo, Cr and Co, while it increased the mobility of Zn, Cu and As compared with the NE soil.The Zn soil exposure intensity assessed by DGT was not significantly changed by the addition of RCW and CSS, while the Cr soil exposure intensity was significantly decreased after RCW addition compared with the soil treated with CSS and the NE soil. In contrast Cu and Co were non labile in the three soils. Both RCW and CSS decreased the foliar concentration and the mineral mass of Mo, Zn, Cr, As and Co in the bean leaves but increased the foliar Cu concentration.