CHARACTERIZATIONS OF SOME ORGANIC MATERIALS SOURCES AND ANALYSIS OF THE HUMIC ACIDS EXTRACTED FROM THEM | ||||
| Zagazig Journal of Agricultural Research | ||||
| Article 7, Volume 46, Issue 3, May and June 2019, Page 685-698 PDF (2.69 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/zjar.2019.40954 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
Marwa I.M. Ibrahim  1; E. A.M. Awad2; S. M.M. Dahdouh2; Wafaa M.T. El- Etr1; A. S.M. Ibrahim2
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| 1Soils, Water and Environ. Res. Inst. Agric. Res. Cent. (ARC), Egypt | ||||
| 2Soil Sci. Dept., Fac. Agric., Zagazig Univ., Egypt | ||||
| Abstract | ||||
| Different organic materials such as town refuse, compost, sewage sludge and biogas have been used as sources of humic acids (HA). However, a systematic characterization of these organic materials and their comparison of humic acids which extracted from them have not been reported. This is essential to decide the relative merits and demerits of these substances as sources of humic acids. The objective of this work was to extract and characterize the chemical compositions of the different four organic materials and humic acids which extracted from them. Results showed that the four organic materials which used in this study were, generally, different in all studied properties. Sewage sludge sample recorded high values of moisture content, saturation percent, cation exchange capacity, organic carbon and organic matter content and lower values in each of bulk density, pH and EC as compared to other organic samples. Also, the highest value for each of total and available nitrogen (NH4 + and NO3 -) was shown with sewage sludge and town refuse, respectively, while total and available phosphorus and potassium along with C/N ratio were recorded with compost sample. Furthermore, the four organic materials were different in total micronutrients and heavy metals. The highest value for each of Fe, Co and Ni was recorded with compost sample as well as similar results of Pb, Zn and Cu were observed with sewage sludge sample. Moreover, elementary composition of humic acids extracted from different samples was rich in carbon, nitrogen and oxygen and poor in sulfur except for sewage sludge sample. The C/N ratio was relatively high in HA extracted from biogas as well as HA from compost was superior in C/H, O/H, N+O/C and E4/E6 values. The lowest value of N/H was observed in HA extracted from biogas. On the other hand, obtained results reported that HA percentage was relatively high in biogas sample and the four organic materials can be arranged as following biogas > town refuse > compost > sewage sludge. Also, total acidity of humic acid samples reveals that, HA of sewage sludge was superior as compared to the other organic materials. The highest value for each of total carboxyl groups and carboxyl/phenol ratio was found with HA extracted from town refuse sample, whereas the greatest value of total phenolic groups was recorded with HA derived from sewage sludge. Furthermore, Infrared spectral (IR) analysis provides further useful information concerning the molecular structures and characteristic bonds and scanning electron microscopy (SEM) showed some crystal forms found in all HA samples. These results elucidated that the chemical composition and the molecular structure of HA samples varies as per the origin and environment where decomposition has occurred. Present study also documented that the spectroscopic and imaging techniques can be successfully used to bring out the finer differences among HA extracted from different organic sources. | ||||
| Keywords | ||||
| organic materials; Town refuse; compost; sewage sludge and biogas; Humic acids; infrared spectrophotometer IR; scanning electron microscopy SEM | ||||
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