scholarly journals Alternativas en la estabilización de lodos provenientes de plantas de tratamiento de aguas residuales

Author(s):  
Jonathan Gustavo Castillo Sánchez ◽  
Luis David Balarezo Saltos ◽  
María Belén Vinces Obando ◽  
Héctor Andrés Zambrano Rizo

La contaminación de los lodos que provienen de plantas de tratamiento de aguas residuales, afecta al medio ambiente y  a  la salud, por su contenido  de materia  orgánica, microorganismos y metales pesados. La presente investigación se realizó una caracterización físico-química y microbiológica en cuanto a humedad, proteínas, acidez, análisis del total de nitrógeno básico volátil (TVB-N), materia orgánica, metales pesados y parámetros microbiológicos con la finalidad de establecer la clase de lodo en base a las normativas ambientales internacionales, tales como USEPA, norma de la directiva europea y norma oficial mexicana, debido a la usencia de estas en el Ecuador. La concentración de metales se encuentra entre límite máximo de concentraciones estipulados por las tres normativas analizadas. En cuanto a los resultados de coliformes fecales se obtuvo 2,4x104 UFC/g, correspondiendo a un lodo de clase B según la USEPA; y a un lodo de clase C de acuerdo a la Norma Oficial Mexicana. En el presente se da un panorama general de los diferentes métodos de estabilización de lodos, en el cual se sugiere la utilización de cal debido a evidencias experimentales por diferentes investigaciones, siendo esta una de las más accesibles y eficientes.   Palabras claves— lodo residual, caracterización, estabilización, cal.   Abstract— Contamination of sludge from wastewater treatment plants affects the environment and health, because of their organic matter content, microorganisms and heavy metals. This research carried out a physical- chemical and microbiological characterization in terms of moisture, proteins, acidity, analysis of total volatile basic nitrogen (TVB-N), organic matter, heavy metals and microbiological parameters with the to establish the sludge class based on international environmental regulations, such as USEPA, the standard of the European directive and the official Mexican standard, due to the use of these in Ecuador. The concentration of metals is between the maximum limit of concentrations stipulated by the three regulations analyzed. As for the results of faecal coliforms, 2.4x104  CFUs/g was obtained, corresponding to a Class B sludge according to USEPA; and a Class C sludge according to the official Mexican standard. The present gives an overview of the different methods of sludge stabilization, in which  the use of lime is suggested  due to  experimental evidence by different research, this being one of the most accessible and efficient.   Index Terms— residual sludge, characterization, stabilization, lime.

2011 ◽  
Vol 64 (7) ◽  
pp. 1558-1565 ◽  
Author(s):  
E. Peruzzi ◽  
G. Masciandaro ◽  
C. Macci ◽  
S. Doni ◽  
B. Ceccanti

Phragmites australis for sludge dewatering and stabilization processes have been widely proved. The presence of reeds, indeed, efficiently allows solids dewatering and organic matter stabilization in order to obtain a stabilised product that can be suitable for land application, even if its environmental impact has to be considered. The actual revision of the European Union's Working Document on Sludge (2000), in fact, seems to be addressed to detect two principal categories of pollutants in sludge for agricultural use: heavy metals and toxic organic compounds. In this study are presented results about sludge stabilization and monitoring of heavy metal fractionation and organic compounds in four urban wastewater treatment plants managed by Acque S.p.A., (Tuscany, Italy). To evaluate the process of sludge stabilization parameters were determined that highlight the biochemical and chemico-structural properties of sludge organic matter. The results showed that stabilization of the sludge over time occurred as shown by the low content of water soluble carbon and dehydrogenase activity, and by the re-synthesis of humic-like matter highlighted by the pyrolytic indices of mineralization and humification. Results about fractionation showed that heavy metals were retained in fractions related to the stabilized organic matter. Moreover, toxic organic compounds showed a drastic reduction at the end of the monitoring period.


2013 ◽  
Vol 409-410 ◽  
pp. 160-163 ◽  
Author(s):  
Da Rong Li ◽  
Ying Hui Wang ◽  
Jian Hua Chen ◽  
Qiu Jun Li ◽  
Wei Sheng Wang ◽  
...  

The effects of hydrated lime, potassium dihydrogen phosphate, straw ash and silkworm excrement on the extractability of heavy metals, pH and organic matter content in soil were studied. The results showed that the application of the four organic-inorganic complex treatments decreased the concentration of available Pb by 22.2 to 48.9 percent, and reduced the concentration of available Cd by 29.1 to 58.4 percent, which was obviously superior to the single organic or inorganic treatments. The addition of hydrated lime had the greatest effects on soil pH, while the application of silkworm excrement significantly increased the organic matter content in soil.


2013 ◽  
Vol 64 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Jolanta Kwiatkowska-Malina ◽  
Alina Maciejewska

Abstract Organic matter takes part in all soil processes and influences the physical, chemical and biological properties of soil. The paper presents the analysis of heavy metal contents (Zn, Pb, Cd) in soil and biomass of darnel multifloral (Lolium multiflorum Lam.) cultivated at diverse conditions of soil reaction and organic matter content. A brown coal preparation (Rekulter) was applied as the source of organic matter in autumn 1999 to the studied soil, which was contaminated with cadmium, lead and zinc. The limiting influence of Rekulter on the uptake of heavy metals by darnel multifloral (two cuts of the test plant) was the highest in the case when the largest dose was applied to soil with the highest pH (about 6.0). Bioaccumulation indexes (BI) for Cd, Pb, Zn indicate the mobility and bioavailability of Cd, Pb and Zn in soils. The BI for particular heavy metals were generally low, with the lowest in the case when the largest dose of Rekulter was applied to all cuts of the test plant


2014 ◽  
Vol 160 ◽  
pp. 123-128 ◽  
Author(s):  
Xudong Dong ◽  
Chi Wang ◽  
Hao Li ◽  
Min Wu ◽  
Shaohua Liao ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 546 ◽  
Author(s):  
Agata Gryta ◽  
Magdalena Frąc ◽  
Karolina Oszust

Loss of organic matter content of cultivated soils is observed in many regions of Europe. The possibility of using organic waste as a soil additive that enriches the soil with organic matter and essential components is important in soil quality protection and waste management. This research concerned the influence of six organic wastes—two industrial composts, three digestates and meat bone meal—on soil microbial properties. The study of functional microbial diversity concerns the determination of the catabolic capacity of bacterial, fungal and anaerobic communities in relation to carbon substrates in metabolic profiling plates (Biolog® ECO, FF, AN (Biolog Inc., Hayward, CA, USA)). The assessment of genetic diversity was made on the basis of analysis of the restriction profile of ammonia-oxidizing archaea. Additionally, soil dehydrogenases activity was determined. The research showed that the type of organic waste used had an influence on the microbiological parameters. The application of exogenous organic matter caused increases in functional and genetic microbial diversity. The nature of the noted changes was short term and periodic. The values of the microbiological parameters in soils with organic waste were similar to those of the control samples. This indicates an improved microbiological balance and stability of the soil environment after the application of exogenous organic matter.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Bernard Fei-Baffoe ◽  
Jeffery Amo-Asare ◽  
Alhassan Sulemana ◽  
Kodwo Miezah

The study focused on levels of selected heavy metals (Pb, Zn, and Cu) in sewage sludge, soil, and in lettuce and cabbage grown on sewage sludge amended soil. Also, the effect of sewage sludge on soil properties (pH, soil organic matter, and soil conductivity) was studied. Three treatments were used based on nitrogen application rates of the sewage sludge: 100, 150, and 200 kg N/ha for lettuce while 160, 210, and 260 kg N/ha for cabbage. A pot experiment was conducted with pots arranged in a completely randomized design and under local climatic conditions. The study revealed that soil organic matter content and conductivity increased significantly with increasing nitrogen application rates. Levels of heavy metals in the soil increased significantly with increasing application rates. The controls for both plants recorded the lowest heavy metal uptake. Cabbage had an uptake of 0.48 ± 0.13, 1.36 ± 0.23, and 2.60 ± 0.29 mg/kg for Pb, Zn, and Cu, respectively, while lettuce had 0.34 ± 0.19, 1.35 ± 0.31, and 2.30 ± 0.14 mg/kg uptake for Pb, Zn, and Cu, respectively. Highest metal uptake was recorded at the highest application rate in both plants (0.66 ± 0.17, 2.66 ± 0.09, and 4.33 ± 0.14 mg/kg for Pb, Zn, and Cu, respectively, for cabbage and 0.54 ± 0.01, 2.24 ± 0.17, and 3.88 ± 0.19 mg/kg of Pb, Zn, and Cu, respectively, for lettuce). The uptake of Zn and Cu was significant, while Pb uptake was insignificant for both plants. Yields increased significantly with increasing application rates. The study provides information on yield enhancement resulting from cultivating plants on soil amended with sewage sludge and the associated health risk implication.


Proceedings ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 74
Author(s):  
Adelcia Veiga ◽  
Carla Ferreira ◽  
Luís Pinto ◽  
Anne-Karine Boulet ◽  
Eunice Louro ◽  
...  

Intensification of agriculture worldwide has led to a growing awareness on their environmental impacts, namely on soil quality and long term impact on crop productivity. As a consequence, there is an increasing concern regarding best agricultural management practices and their impact on physical, chemical and biological soil properties. In the Centre region of Portugal, maize is one of the most important arable crops and represents more than 32% of the cultivated area. Maize fields have been intensively managed under conventional practices, but increasing land degradation is leading farmers to adopt improved management practices, such as the application of composted sludge from urban wastewater treatment plants. This study aims to assess the long term impact of composted sludge application as soil amendment in maize cropping fields. The study was performed in Baixo Mondego, in central region of Portugal, largely devoted to agriculture and where maize is one of the most relevant crops. The study was performed in two study sites with similar soil and weather characteristics - one managed under conventional practices, with intensive application of fertilizers, and another field where a significant part of mineral fertilizers is replaced by composted sludge. Both sites use these agricultural management practices for more than 5 years. In 2018, two soil sampling campaigns were performed to assess the physical (texture and bulk density) and chemical soil properties (organic matter content, total nitrogen, total and extractable phosphorus, exchangeable cation (K+, Ca2+, Na+, Mg2+) and heavy metals (Cd, Cr, Pb, Zn and Ni)). Results show that composted sludge improves soil organic matter content (1.2% vs. 2.2%), total (2747 mg kg-1 vs. 1134 mg kg-1) and available phosphorous (821.85 mg kg-1 vs. 98.44 mg kg-1) comparing with conventional management practices. Higher contents of heavy metals, specifically Cu, Zn, Cd and Cr, were found in the field with sludge application than in the conventional one, which may represent a long term risk for soil contamination. Information regarding the long term impacts of best management practices on soil quality is relevant and should guide farmers and policy makers to attain agricultural sustainability.


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