*4.2.1 Extraction of humic acid from DCP*

Literature survey confirms that till today HA has been extracted from the different Abiotic origin worldwide, but a successful pioneering research of extraction from a Biotic Animal origin DCP, has been carried out by authors, employing Green Chemistry Principles as described earlier. We have obtained 9–10% extraction of HA from DCP.

The following technique was devised for extracting HA from dry cow dung powder.


**35**

India in Mumbai.

*Dry Cowdung Powder - Novel Unearthed Humus: Sustains Water-Food-Energy Nexus*

**Functional groups Compounds DCP Signal (cm−1)** N-H Amines 3413.50 -COOH Carboxylic Acid O-H Stretch 2851.31

C-H Alkane 2851.31

C=OR 6-membered cyclic ketone 1716.65 C=C Alkene 1653.24

6-membered and 5 - membered lactone

(C=O stretch)

Alkyl halide stretch clay, minerals

Si-CH3 Silicon functions 1241.80 C-O Saturated secondary or cyclic tertiary amine 1055.10

C-Cl Chlorine 667.77 -Na metal group 467.00

Nonconjugated 1653.24 Conjugated 1558.62

CH2 1456.95

CH3 1375.37

2919.52

2919.52

1733.47

1716.65 1733.47

1541.12

1420.87

1319.29

558.90 667.77

1162.36

The decantation procedure was used to remove hay and other light non-humic particles by mixing DCP (100mesh) with purified water and stirring for 20 minutes at room temperature. After filtering non-humic materials from cow dung, the resulting slurry was stirred with 0.1 M NaOH for 24 hours. After that, the whole mixture was allowed to settle before being purified. The soluble HA, FA, and other biological matter are found in the filtrate, while the residual contains Humins, Ulmic acid, and insoluble bio-organic matter. Since HA is insoluble at low pH, the filtrate was acidified by slowly applying 0.1 M HCl at room temperature (pH 1) with continuous stirring to mitigate the heat of neutralization and centrifuged for HA precipitation. Fulvic acid and other organic acids are found in centrifugate. To extract HA, the HA was carefully washed with double distilled water until it passed a chloride inspection and dried in an oven at 383 K. We were able to remove 9–10% of the content. FTIR and Raman spectroscopy were used to identify and characterize HA, which was then compared to standard HA from IHSS [61]. At Indian Institute of Technology, Mumbai, we obtained FTIR spectra on a Nicolet Instrument Corporation-USA model-MAGNA 500 with a specification scale of 4000 cm-1 to 50 cm-1. Raman spectra were obtained using a RENISHAW Laser Raman Spectrometer with 325, 514.5, and 785 nm laser excitation and a CCD detector with confocal microscope at the Gemological Institute of

*DOI: http://dx.doi.org/10.5772/intechopen.98476*

C=C

C-H

C-Br or

**Table 4.** *FTIR data of DCP.*

(Stretching Vibrations)

(Bending Vibrations)

Inorganic Impurities

C=O & (RCOOR) Esters & Lactones

C=O Carboxylic acid,

c. 15 mL of 0.1 M HCl is desirable for 100 mL of neutralized supernatant.


*Dry Cowdung Powder - Novel Unearthed Humus: Sustains Water-Food-Energy Nexus DOI: http://dx.doi.org/10.5772/intechopen.98476*

#### **Table 4.** *FTIR data of DCP.*

*Humic Substances*

sulfhydryl, hydroxyl, phosphonate, thioester, secondary amine, imines participates in ligand formation [60] Lignin derivative contain an abundance of oxygen containing functional group such as phenolic, alcoholic and enolic structure which forms lignin- metal complexes. **Figure 5** and **Table 4** explains the same in brief. Also, the FTIR analysis of DCP after and before the metal ion adsorption has been carried out to confirm the biosorption process with the observed shifts in wavelength of

Literature survey confirms that till today HA has been extracted from the different Abiotic origin worldwide, but a successful pioneering research of extraction from a Biotic Animal origin DCP, has been carried out by authors, employing Green Chemistry Principles as described earlier. We have obtained 9–10% extraction of

The following technique was devised for extracting HA from dry cow dung powder.

b.Acids such as HCl, HNO3, and H2SO4 in the molarity range of 0.1–1.0 M were tested for the re-acidification process. With around 0.1 M HCl, the best results

a.For the neutralization of dry cow dung powder, different series of alkali with concentrations ranging from 0.1 to 1.0 M of NaOH, KOH, Na2CO3, and NaHCO3 were studied. With 0.1 M NaOH, the best results were obtained.

c. 15 mL of 0.1 M HCl is desirable for 100 mL of neutralized supernatant.

functional group involved in biosorption.

*4.2.1 Extraction of humic acid from DCP*

**4.2 Chemical assay**

**Figure 5.**

*FTIR spectra of DCP.*

HA from DCP.

were obtained.

**34**

The decantation procedure was used to remove hay and other light non-humic particles by mixing DCP (100mesh) with purified water and stirring for 20 minutes at room temperature. After filtering non-humic materials from cow dung, the resulting slurry was stirred with 0.1 M NaOH for 24 hours. After that, the whole mixture was allowed to settle before being purified. The soluble HA, FA, and other biological matter are found in the filtrate, while the residual contains Humins, Ulmic acid, and insoluble bio-organic matter. Since HA is insoluble at low pH, the filtrate was acidified by slowly applying 0.1 M HCl at room temperature (pH 1) with continuous stirring to mitigate the heat of neutralization and centrifuged for HA precipitation. Fulvic acid and other organic acids are found in centrifugate. To extract HA, the HA was carefully washed with double distilled water until it passed a chloride inspection and dried in an oven at 383 K. We were able to remove 9–10% of the content. FTIR and Raman spectroscopy were used to identify and characterize HA, which was then compared to standard HA from IHSS [61]. At Indian Institute of Technology, Mumbai, we obtained FTIR spectra on a Nicolet Instrument Corporation-USA model-MAGNA 500 with a specification scale of 4000 cm-1 to 50 cm-1. Raman spectra were obtained using a RENISHAW Laser Raman Spectrometer with 325, 514.5, and 785 nm laser excitation and a CCD detector with confocal microscope at the Gemological Institute of India in Mumbai.

**Figure 6.** *FTIR spectra of standard HA.*

#### *4.2.2 Results and discussion*

Two FTIR Spectrum were compared - Standard HA (**Figure 6**) from International Humic Substances Society (IHSS) and HA extracted from DCP (**Figure 7**). **Table 5** elucidates the absorption peaks and their corresponding bonds/ functional groups. Certain shifts in absorption bands may be observed due to inter and intramolecular hydrogen bonding, varying degrees of conjugation, steric hinderances, physical factors and matrix effect. This is mainly because the extracted HA is from a biotic source (cow) and the standard HA has an abiotic origin.

At 3421.0 and 3422.8 cm−1, we observed the band for N-H stretch of primary amine for the standard HA and extracted HA respectively. Whereas the N-H bend

**37**

**Figure 8.**

*Raman spectra of standard HA.*

*Dry Cowdung Powder - Novel Unearthed Humus: Sustains Water-Food-Energy Nexus*

1. N-H stretch Aromatic Monomeric Alcohols, Phenols 3421.0 3422.8 2. O-H Carboxylic acid — 2932.3

4. N-H bend Primary Amines 1648.1 1648.1 5. C-N Aryl or alkyl substituted tertiary amines 1114.2 1114.2 6. C-O Primary alcohols 1049.3 1042.1 7. C-Cl Chloroalkanes 551.5 544.3

Ketones

**Compounds Std HA IHSS** 

**(cm−1)**

**Ext. HA DCP (cm−1)**

2860.1

— 1720.2

was seen at 1648.1 cm−1, in both the spectra. Both spectra showed identical bands at 1114.2 cm−1 for aryl or alkyl substituted tertiary amines. The band for primary alcohols (C-O) was observed at 1049.3 and 1042.1 cm−1 for the standard HA and extracted HA respectively. Similarly, the band for chloroalkanes was observed at 551.5 and 544.3 cm−1, in the two spectra respectively. In the extracted HA, a band is seen at 1720.2 cm−1 which is very important as it describes the presence of lactones, which is also influenced by conjugation and ring size and standard HA does not show any band in this region. Thus, we confirm the matrix of extracted HA is from

The absorption patterns are depicted in the Raman spectra of standard HA in **Figure 8** and extracted HA in **Figure 9**. **Table 6** lists the absorption bands and their descriptions. Absorption of (C=C) aromatic ring chain heavy vibration was visible at 1580 & 1600 cm−1; (C-NO2) asymmetric mild vibration at 1530–1590 cm−1

(N=N) aliphatic mild vibration at 1550–1580 cm−1; and (X-Metal-O) heavy vibration at 150–450 cm−1. The presence of heavy metals such as iodine, selenium, and silicon is shown by a sharp small absorption band at 150–450 cm−1 in the spectra of standard HA. A spectrum of extracted HA is devoid of absorption band at that

;

*DOI: http://dx.doi.org/10.5772/intechopen.98476*

3. C=O Carboxylic acid, Aldehydes, Esters,

**No. Functional group**

**Table 5.** *FTIR data of HA.*

bovine species i.e., fecal residue of cow.

**Figure 7.** *FTIR spectra of extracted HA.*

*Dry Cowdung Powder - Novel Unearthed Humus: Sustains Water-Food-Energy Nexus DOI: http://dx.doi.org/10.5772/intechopen.98476*


**Table 5.** *FTIR data of HA.*

*Humic Substances*

*4.2.2 Results and discussion*

*FTIR spectra of standard HA.*

**Figure 6.**

Two FTIR Spectrum were compared - Standard HA (**Figure 6**) from International Humic Substances Society (IHSS) and HA extracted from DCP (**Figure 7**). **Table 5** elucidates the absorption peaks and their corresponding bonds/ functional groups. Certain shifts in absorption bands may be observed due to inter and intramolecular hydrogen bonding, varying degrees of conjugation, steric hinderances, physical factors and matrix effect. This is mainly because the extracted

HA is from a biotic source (cow) and the standard HA has an abiotic origin.

At 3421.0 and 3422.8 cm−1, we observed the band for N-H stretch of primary amine for the standard HA and extracted HA respectively. Whereas the N-H bend

**36**

**Figure 7.**

*FTIR spectra of extracted HA.*

was seen at 1648.1 cm−1, in both the spectra. Both spectra showed identical bands at 1114.2 cm−1 for aryl or alkyl substituted tertiary amines. The band for primary alcohols (C-O) was observed at 1049.3 and 1042.1 cm−1 for the standard HA and extracted HA respectively. Similarly, the band for chloroalkanes was observed at 551.5 and 544.3 cm−1, in the two spectra respectively. In the extracted HA, a band is seen at 1720.2 cm−1 which is very important as it describes the presence of lactones, which is also influenced by conjugation and ring size and standard HA does not show any band in this region. Thus, we confirm the matrix of extracted HA is from bovine species i.e., fecal residue of cow.

The absorption patterns are depicted in the Raman spectra of standard HA in **Figure 8** and extracted HA in **Figure 9**. **Table 6** lists the absorption bands and their descriptions. Absorption of (C=C) aromatic ring chain heavy vibration was visible at 1580 & 1600 cm−1; (C-NO2) asymmetric mild vibration at 1530–1590 cm−1 ; (N=N) aliphatic mild vibration at 1550–1580 cm−1; and (X-Metal-O) heavy vibration at 150–450 cm−1. The presence of heavy metals such as iodine, selenium, and silicon is shown by a sharp small absorption band at 150–450 cm−1 in the spectra of standard HA. A spectrum of extracted HA is devoid of absorption band at that

**Figure 8.** *Raman spectra of standard HA.*

**Figure 9.** *Raman spectra of extracted HA.*


#### **Table 6.**

*Raman spectral data of HA.*

region which indicates the absence of any contamination of metal ion. This concludes that DCP does not induce any undesirable matrix effect.
