Use Of Composted Sewage Sludge Research Articles

Sustainable use of composted sewage sludge: Metal(loid) leaching behaviour and material suitability for application on degraded soils

Composted sewage sludge was investigated as a promising material for the reclamation or remediation of degraded sites. Using sewage sludge as soil amendment provides environmental benefits and risks while supporting circularity and waste minimisation. This study aims to comprehensively assess the suitability of locally available low-cost sludge treatment for sustainable and environmentally safe topsoil disposal in a brownfield area affected by coal mining. A nine-month composting was conducted before field application to the soil environment. The objectives were to assess: (i) composting time-dependent and pH-dependent metal(loid) leachability from composted sludges, (ii) the effect of sludges on metal(loid) leachability from soil over the first six months, and (iii) metal(loid) plant uptake during the first vegetation season as well as the bioaccumulation and translocation factors. The set of standardised leaching experiments confirmed the positive effect of compost maturity, i.e. despite some fluctuations over time, metal(loid) availability from the final composts was very low. Some metals showed unusual pH-dependent behaviour with the highest leachability at pH 8 due to excessive release of dissolved organic matter from the not-yet-stabilised matrix. Ecotoxicity testing confirmed the safety of the final composts for further soil application. The sludge-amended plots displayed similar metal(loid) leaching and pH evolution in time compared to the control biomass-amended plot. However, plant species (Artemisia vulgaris L.) that formed the natural vegetation cover of the experimental plots showed cumulative metal(loid) uptake. Cadmium and zinc were identified as the critical metals possibly related to the applied sludges, yielding high bioaccumulation and translocation factors. Yet, the quality of the compost feedstock, heterogeneity, and background values of the brownfield site need to be considered. Nevertheless, soil respiration indicated no adverse effects on soil health six months after sludge application. Overall, the composted material demonstrated potential suitability for remediation application in the studied area.

Unlocking fertilization potential of anaerobically digested sewage sludge centrate for protein-rich rice cultivation with composted sludge amendment

The use of composted sewage sludge (CSS) and centrate as alternatives to synthetic fertilizers in rice cultivation holds great promise. This study aims to determine the effects of varying doses and timings of centrate derived from anaerobically digested sewage sludge on rice yield, nutrient quality, and soil fertility when applied as a topdressing to rice fields fertilized with CSS. At the panicle initiation (PI) stage, 100, 300, and 500 kg N ha−1 of centrate topdressing (CT100, CT300, and CT500, respectively) was applied. In addition, different topdressing timings at a total dose of 500 kg N ha−1 were evaluated, including a two-split application (40% at active tillering (AT) and 60% at PI; CT500S2) and a three-split application (40% at AT + 40% at PI + 20% at heading; CT500S3). At a rate of 160 kg N ha−1, CSS was used as a base fertilizer in all treatments. A control treatment received synthetic fertilizers at a rate of 160 kg N ha−1 as a base application and 100 kg N ha−1 as a topdressing. Results showed that CSS-treated rice plants exhibited a lower N status and leaf chlorophyll content during the vegetative growth stage; however, the split application of centrate topdressing improved plant N status, resulting in an increase in biomass and grain yield. Centrate and CSS tended to increase the mineral content of rice; nevertheless, a significant accumulation of As in grains raised concerns about food safety. Combining CSS and centrate has the potential to increase rice production, improve grain nutritional value, and decrease reliance on synthetic fertilizers. However, it is essential to optimize this fertilization, mitigate environmental risks, and ensure food safety by employing appropriate fertilization dosing and timing as well as appropriate field management strategies.

Sewage sludge composted in the coloring and development of Bermuda grass

Abstract ‘Barazur’ or DiscoveryTM (Cynodon dactylon) is a new variety of Bermuda grass that has slow vertical growth and a bluish-green colour, and the use of sewage sludge in implantation of this species may be an alternative for its sustainable cultivation, without need for chemical fertilizers. Thus, the objective was to evaluate the influence of sewage sludge compound on colour and development of Bermuda grass DiscoveryTM. The experiment was conducted in the field with sod implanted in black plastic containers (volume 8.46 L) filled with soil + sand (1:1) and added different dosages of sludge compost, being: 0 g L -1 (control), 30 g L-1, 60 g L-1 and 120 g L-1. Digital image analysis, fresh and dry leaf mass, Nitrogen leaf and Nitrogen leaf accumulation were evaluated. It was observed that the sewage sludge influenced on turfgrass colouring and development, where 30 g L-1 showed excellent results for colouring with less mass production and N accumulation than the highest dose, showing that this treatment is sufficient for lawn development, without the need of using higher concentrations of compound. It is concluded that the use of composted sewage sludge at a dose of 30 g L-1 is recommended for use in implantation of Bermuda grass DiscoveryTM.

Composted sewage sludge with sugarcane bagasse as a commercial substrate for Eucalyptus urograndis seedling production

Sewage sludge can be used as a source of organic matter and nutrients, whereas sugarcane bagasse can be used as a decompaction material; by composting a mixture of the two, a low-cost substrate for forest nurseries can be obtained. This research investigated the use of composted sewage sludge with sugarcane bagasse (CSB) as a commercial substrate in nurseries to grow seedlings of the hybrid clone Eucalyptus urograndis. Several CSB treatments were evaluated in comparison with a control (no P addition) and a commercial substrate (CS). Before composting, CSB was conditioned with P to increase its final concentration: CSB+1.5, 3.0, and 4.5% triple superphosphate (TP) or reactive phosphate (RP). After 120 d, the Eucalyptus response to all eight substrates was assessed by: i) plant morphological traits (H, height; D, diameter; SB, shoot biomass; RB, root biomass; TB, total dry biomass; GCI, green color intensity; and root system quality) and ii) chemical parameters of shoots and roots. Significant differences among treatments were ascertained using an ANOVA, and variability was interpreted using principal factor analysis (PFA). The treatment with CSB+3% TP (TP3.0) exhibited statistically (p < 0.05) higher performance in regards to morphological parameters (H, D, SB, TB) and the nutrient contents of shoots and roots (N, P, Ca, Na, Mn, Zn, and Cu) than the other treatments and control. The results suggest that B and K could play a fundamental role in both the observed variability and the improved plant performance in the TP3.0 substrate. PFA also showed i) the key role of OM as the primary source/sink of some pivotal macronutrients/heavy metals and ii) the existence of important antagonistic/synergistic effects between elements as a primary driver affecting the concentration/behavior of elements in the shoot/root system. Overall, the research demonstrated that with an addition of only 3.0% TP, the CSB performance was better than the most commonly used and widespread commercial substrate in industrial forest nurseries.

Oxygen demand of waters associated with the use of sewage sludge compost and limestone outcrop as a filtration system

The use of composted sewage sludge (SW) and limestone outcrop residue (LR) as water filter systems has been tested. An experimental design based on the use of columns (0–30 cm) was used with both wastes under a heavy irrigation regime (2000 mL/week) for 12 weeks. Half of them were irrigated with nonsaline water (NS) and the others with saline water (S). Four treatments combining the quality of the irrigation water and wastes were obtained: SW-NS, SW-S, LR-NS, and LR-S. The chemical oxygen demand (COD), biochemical oxygen demand (BOD 5 ), and suspended solids were measured. The results indicated that COD and BOD 5 were higher in the treatments with SW than LR, whereas saline irrigation did not modify BOD 5 compared with nonsaline irrigation, but COD increased in both wastes. The environmental concern due to organic matter displacement in waters should be taken into account when using these wastes, especially SW. Moreover, the use of S may increase the COD with the consequent risk for natural water. When designing a filter system considering inert and organic matter, SW and LR can be effective materials and should be taken into consideration.

Sewage sludge compost in zoysia grass sod production

This study evaluated whether the use of composted sewage sludge in zoysia grass sod production can partially or completely substitute fertilization based on urea. The experiment was conducted on a sod farm located in Itapetininga, São Paulo State, Brazil. The experimental design was a complete randomized block design with five replications and experimental plots of 5 m2 in a 2x6 factorial scheme. The first factor was the method of application (single or split), and the second factor was composted sewage sludge fertilization and two controls (no fertilization and a standard dose of conventional fertilizer). The conventional fertilizer (urea) dose corresponds to 300 kg N ha-1 and the sewage compost doses correspond to 100, 200, 300, and 400 kg N ha-1 . The experiment began with the liming of the total area at 60 days after the previous harvest of zoysia grass sod. Three methods were used to evaluate sod production: soil cover rate, green color intensity, and leaf analysis. At 212 days after the beginning of the experiment, the compost treatment of 30 Mg ha-1 (300 kg ha-1 of N), applied in a single dose, allowed for complete sod formation (100% soil cover rate).

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.

Nitrogen compound pollution associated with the use of sewage sludge compost and limestone outcrop residue under saline irrigation

The use of composted sewage sludge and limestone outcrop residue in land rehabilitation, soil improvement, and technosol making can influence the mobility of nitrogen compounds in groundwater. This experiment analyzed this source of possible pollution under an experimental design based on the use of columns (0–30 cm) formed by both wastes and a heavy irrigation regime. Two waters of different quality (saline and non-saline) were used for irrigation. The presence of nitrate, nitrite, and ammonium in the leachates was checked. The environmental risk due to the presence of nitrogen species associated with the use of these materials was very low in general, although nitrate was the most important compound affected by the use of sewage sludge compost and saline water. The combination of saline water for irrigation with the compost has to be seriously considered as a source of pollution for surface and ground waters, and the use of both resources may be a key factor to be studied (low-quality water and sewage sludge compost).

Doses de lodo de esgoto compostado em produção de tapete de grama esmeralda imperial

A eficiência da adubação nitrogenada para gramados pode ser aumentada com a utilização de fontes de liberação lenta, como composto de lodo de esgoto, que, em razão das suas características, pode ser um substituto de parte ou do total da adubação inorgânica para as gramas. Não foram encontrados resultados referentes à utilização de lodo compostado na cultura da grama, no Brasil. Objetivou-se com este trabalho avaliar o efeito de doses de composto de lodo de esgoto na produção da grama esmeralda Imperial. Os tratamentos foram constituídos de cinco doses de composto de lodo de esgoto (0, 12, 24, 36 e 48 Mg ha-1, base seca), mais um tratamento com adubação inorgânica (300 kg ha-1 N, 80 kg ha-1 P2O5 e 200 kg ha-1 K2O). Os compostos orgânicos presentes no composto têm diferentes taxas de mineralização, liberando aos 120 dias após a aplicação do lodo mais Mg (100 %), K (90 %) e N (67 %) do que S (57 %), P (40 %) e Ca (31 %). A utilização do composto de lodo na cultura da grama Imperial proporcionou adequado fornecimento de nutrientes, quando aplicado superficialmente, em doses maiores que 36 Mg ha-1. As doses de composto proporcionaram, após a colheita do tapete, aumento linear da acidez potencial e do teor de matéria orgânica, P, S, Fe, Cu, Mn, Zn, As, Cu e Ni e redução linear do pH, do teor de Ca e Mg e da saturação por bases do solo. O aumento das doses do composto de 0 a 48 Mg ha-1 reduziu a massa dos tapetes de grama, atingindo valores de 4,0 kg/tapete, quando a maior dose foi aplicada. Altas doses também proporcionaram os maiores valores de resistência dos tapetes na ordem de 35 e 33 kgf, com as doses de 36 e 48 Mg ha-1, respectivamente.

Ameliorating Topsoil Conditions by Biosolid Application for a waste Landfill landscape

Sanitary landfills, created for the disposal of solid waste, usually are developed into parks afterthey are closed. However, soil amelioration with organic matter is usually needed to restore fertility andpromote revegetation. Sewage sludge creates a massive waste disposal problem. The use of composted sewage sludge (biosolid) as a soil conditioner might restore the soil fertility at landfill sites and simultaneously alleviate the need for sewage sludge disposal. We applied biosolid to waste landfill soil and evaluated its effects on soil properties and tree growth in a field experiment. Biosolid improved soil characteristics including moisture, organic matter, and nitrogen content and also increased tree height and diameter at breast height. Physiological measures, such as chlorophyll content and photosynthetic rate, showed positive responses in trees grown in biosolid treatments. Heavy metal concentrations in soil and tree leaves after applying compost did not differ from concentrations measured at control sites. Therefore, we conclude that the use of biosolid in waste landfills would be an efficient, environmentally beneficial, and cost-effective method to restore the conditions of landfill soil for plants.

The Impact of Waste Compost-Based Soil Amendments on the Leaching Behavior of a Heavy Metal Contaminated Soil

The application of waste compost-based soil amendments to remediate contaminated land for soft-end use is an emerging technology that is cost-effective, simple to implement, and sustainable. This concept is tested in this paper in which a heavy metal contaminated soil is amended with two waste-based composts, with and without a zeolite additive fraction. The effect of the amendments is assessed in terms of the leachability of the amended soil. Fresh soil and soil that had been used in pot experiments were tested and compared. The results from batch and column leaching tests are presented and compared in terms of the leachability of Zn2+, Cd2+, Cl−, NO3−, and SO42− . The results show that green waste compost reduced the leachate concentrations of both Cd2+ and Zn2+ from 0.15 mg dm−3 and 4.7 mg dm−3 to 0.07 mg dm−3 and 2.3 mg dm−3 respectively, but only for Zn2+ did these concentrations fall below its World Health Organization (WHO) drinking water standard of 3 mg dm−3. The use of composted sewage sludge had the opposite effect and increased the leachate concentration of Zn2+ to 9.8 mg dm−3, which was to up to 3.3 times its WHO standard, and increased the leaching concentration of NO3− to 395.4 mg dm−3 (10 times its WHO standard). Batch leaching tests leached a larger quantity of metals than column leaching tests, while the leaching of anions was similar. The column test also showed that initial leaching concentrations of metals and anions can be much higher than those obtained with the batch test but these decline quickly as leaching continues.

Effects of composted sewage sludge on microbial biomass, activity and pine seedlings in nursery forest

The investigation was carried out in a 2 year experiment to evaluate the benefits and hazards of the use of composted sewage sludge as a restoration agent for the soil of the nursery forest intended for growing Pinus sylvestris seedlings. The grey forest soil (Haplic Greyzem) was amended with compost at the 25, 50, 75, 100, 150 and 175 t ha −1 application rates on a dry matter basis. The organic matter content increased with the increase in sludge amendment as well as the metal content. However, the concentrations of individual metals were below the current limits established for Russia and European countries. Sludge amendments enhanced the germination and decreased the mortality of the seedlings. The effects were more obvious for the soil with the highest sludge treatment. The beneficial effects on the biomass of seedlings and the height of the shoots as well as on the length of the roots of the pine seedlings were greater in plots with the highest rates of composted sludge. The application of composted sludge to soil was followed by an increase in microbial biomass and to a lesser extent in basal respiration. In the absence of any detrimental effect on microorganisms, this study lends support to using composted sewage sludge as the organo-mineral fertilizer for the soil of nursery forest.

Use of composted sewage sludge in growth media for broccoli

In this study, the use of composted sewage sludge (CSS) as a binary component with peat (P) in growth media for a horticultural crop, broccoli ( Brassica oleracea var. Botryti cv. Marathon), was evaluated. Four treatments were established, based on the addition of increasing quantities of composted sewage sludge to peat (0%, 15%, 30% and 50%, v/v). Physical, physico-chemical and chemical analyses of the different mixtures of CSS and P were made. Plant growth, biomass production and macronutrient (N, P, K, Ca, Mg), micronutrient (Fe, Cu, Mn, Zn) and heavy metal (Pb, Ni, Cd, Cr) contents of plants were determined. The addition of CSS to P increased plant nutrient and heavy metal contents of plants and electrical conductivity (EC) and bulk density values of the substrates. The use of CSS did not affect the germination rate, even at 50% compost. For broccoli growth, the highest yield was obtained with the medium prepared by mixing the peat with 30% of compost; however, the mixture with the most sewage sludge compost (50%) had the greatest contents of macro and micronutrients.