This study aimed to evaluate the effect of combination of chemical treatments and solarization on cleaning and chemical and physical composition of sewage sludgea waste from sewage treatment systemfrom an upflow anaerobic sludge blanket reactor and UASB (Upflow Anaerobic Sludge Blanket Reactor) of Treatment Plant -ETE Uberabinha located in Uberlândia-MG. It is known that the presence of pathogenic organisms and heavy metals are major limiting the use of this sludge in agriculture. For this, we used the split plots in time, in an experimental design of randomized blocks 5x3 + 1, with four replicates, in four (4) evaluation periods (0, 7, 14 and 21), and the zero time (0) corresponded to additional treatment, totaling 64 plots. The treatments consisted of pure sludge, sludge more peracetic acid (260 mg L -1 ), homogenized with hydrated lime sludge (CaOH 2 ) in the proportion of 30% of the dry mass of sludge, sludge with sodium hypochlorite (2500 mg L -1 ) and more quaternary ammonium sludge (2400 mg L -1 ). Treatment with hydrated lime reduced levels of total and thermotolerant at 7 days after mixing with the sludge, meeting the requirements specified in environmental legislation for agricultural use coliforms. A solar radiation alone did not reduce the concentration of fecal coliforms to acceptable limits by environmental standard. Evaluated treatments did not cause temperature differences in the mass of sewage sludge limed sludge showed the highest levels of calcium (302 g kg -1 ), magnesium (4.2 g kg -1 ) and total solids, lower levels of Zn, Cu, Cd, Cr, Ni, volatile solids and moisture after mixing with sewage sludge. Concentrations of heavy metals (Zn, Cu, Cd, Cr, Ni and Pb) were below the limits specified in Resolution CONAMA n. 375/2006. The limed sludge showed the highest pH (12.65) lower levels of aluminum (20.10 g kg -1 ), phosphorus (1.6 g kg -1 ), organic matter (368, 6 g kg -1 ), carbon (213.80 g kg -1 ), nitrogen (20.88 g kg -1 ) and sodium (0.61 g kg -1 ). In treatment with sodium hypochlorite, sodium highest values (4.10 g kg -1 ) were recorded. The evaluation periods did not influence the concentration of nutrients and heavy metals. Considering Resolution CONAMA n. 375/2006, limed sludge in the ratio of 30% by weight of silt meets the parameters of fecal coliform, being more efficient. You can use the limed sludge in agriculture provided it meets the other requirements explicit in CONAMA Resolution n. 375/2006.
In Brazil, about 80% of the 60 million hectares of pasture are in some state of degradation. Among the causes of this degradation is the lack of investment in liming and fertilization at the time of planting. Phosphorus is especially critical because it stimulates root growth in the establishment phase of forage growth. The objective of the study was to evaluate different sources of phosphorus in the formation of Marandu and Xaraés forages. An experimental design of randomized blocks in a factorial arrangement, 2 x 4, with 5 repetitions was used. Treatments consisted of two cultivars of Urochloa brizantha: Marandu and Xaraés and three sources of phosphorus: triple superphosphate (41% P 2 O 5 ), natural reactive phosphate (28% P 2 O 5 ) and organic mineral (4-14-8) plus the absence of phosphate fertilizer (control). Plant height, stem diameter, chlorophyll A and B content and fresh and dry matter mass were evaluated 60 days after germination. Leaf content was also examined for the following mineral nutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). The Marandu cultivar was superior to the Xaraés cultivar in terms of height. Among the sources of phosphorus examined, there were no significant differences among organic mineral, triple superphosphate and reactive phosphate, for any of the characteristics considered. All the sources, however, differed from the control. The maximum extraction of soil macronutrients by Urochloa brizantha was, in descending order: the macronutrients K>N>Ca>Mg>P>S and micronutrients Mn>Fe>Zn>Cu. These nutrients, thus, needed to be replaced as they were removed through grazing, to replenish the soil. The sources of phosphorus evaluated were not associated with differences in the leaf contents of Cu, Zn and S. The leaf content of the Xaraés cultivar had higher values of N, P, K, Ca, Mg, S, Mn and Zn in relation to Marandu.
Recycling of sewage sludge for agricultural purposes is recommended as one of the most adequate forms of final disposal of this waste. This study evaluated the effectiveness of solarization combined with chemical treatments by acid and alkali during different periods of cleaning. The experiment was conducted at the Experimental Farm of the Federal University of Uberlândia (UFU) in Uberlândia-MG. The experimental design used randomized blocks in a 5x3+1 factorial arrangement with four replications. The factor plots consisted of sanitizing products (260 mg L-1 peracetic acid, 2400 mg L-1 quaternary ammonium compounds, hydrated lime equivalent to 30% of the dry mass of the sewage sludge, 2500 mg L-1 sodium hypochlorite, and pure sludge) for different times: T1 = 7 days, T2 = 14 days, and T3 = 21 days. Data were also collected from the pure mud at time zero. The concentration of fecal coliforms, pH, N (Nitrogen), Na (Sodium), Al (Aluminium), Ca (Calcium), Mg (Magnesium), K (Potassium), OM (Organic Matter), C (Carbon), Cr (Chromium), Ni (Nickel), Cd (Cadmium), Pb (Lead), Cu (Copper) and Zn (Zinc) were all evaluated. Lime increased the concentration of Ca and Mg in the biosolids, reduced the level of fecal coliforms below the limits specified by environmental standards from seven days and decreased the levels of available N, Al, OM, C, Na, Cr, Ni , Cd, Cu and Zn in the biosolids.
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