The basic principles of infrared spectroscopy and
Infrared spectrum analysis of microorganisms after adsorption of lead and adsorption-flotation of lead
It can be seen from the infrared spectra of lead adsorption by three adsorbents, Nocardia bitter, Mycobacterium herba, and Bacillus gliformis. After Nocardia bitter adsorbs lead, the stretching vibration absorption peak of an NH- in the infrared spectrum becomes stronger, and drifts to a high wavenumber to 3300cm-1. The adsorbed amide (ⅰ) peak on the microbial surface also moves to 1655cm-1, indicating that Pb2 + has an effect on the amide group (-NH-C-CH3) and carbonyl group (-C-) on the cell surface, which may be due to the coordination of the lone pair electrons provided by the N atom in the amino group, acetamide group and amide group on the cell surface with the lead in the empty orbit. Foreign studies have also proved that there are chelating bonds in the metal complexes of amino acids and, and the formation of N-metal coordination bonds can change the polarity of N-bond, resulting in changes in vibration frequency and absorption intensity; in addition, the flexural vibration peak of phthalamine (ⅱ =) at 1536cm-1 also moved to 1540cm-1, while the stretching vibration of OH in the 1073cm-1 sugar ring only changed slightly (1070cm-1). Mycobacterium phleus did not change significantly after adsorbing lead.
It can be seen that the infrared spectrum of Bacillus gliae changed greatly after adsorption of lead. Among them, the stretching vibration intensity of -OH was significantly enhanced, and the vibration peak strength shifted from 3440cm-1 to 3433cm-1; the one-CH2 of 2967cm-1 moved to 2956cm-1 due to the influence of nearby C == O; while 1648cm-1 drifted to 1655cm-1 due to the reduction of Pb2 +; the one-C-O-vibration at 1080cm-1 in the sugar ring weakened, which in turn affected the one-C-O vibration in the sugar ring shifted to a low wavenumber of 18cm-1 from 1080cm-1 to (1062cm-1). It can be seen that sugars containing COO-, -OH, and C == O affect the bonding of metal cations, resulting in complexation or redox action.
Infrared spectrum analysis of microorganisms after adsorption of tin and adsorption-flotation of tin
It can be seen from the infrared spectra of Grodonella gordonella after adsorption pick and flotation by dibutylamine after adsorption pick that before and after the adsorption of Grodonella gordonella, the peak shape and peak position changed in the entire wavenumber range, 3448.39cm-1 drifted to 3444.24cm-1, 2971.43cm1 drifted to 2958.99cm-1, 2921.66c-1 drifted to 2929.95cm-1, 1544.7cm-1 drifted to 154.55cm-1, 1457.6cm-1 drifted to 1453.46cm-1, 1407.83cm-1 drifted to 1403.69cm-1, 1324.88cm-1 drifted to 1320.74cm-1, 1237.79cm-1 drifted to 1241.94cm-1, 1076.04cm-1 drifted to 1080.18cm-1. The hydroxyl group, amide group, nitro group, carboxyl group and mercapto group all have obvious changes, which may be because the lone pair electrons provided by the atoms of C, N, S, O in these functional groups in the proteins, polysaccharides and other substances on the cell surface coordinate with cadmium ions in empty orbitals, and chemical complexation occurs, changing the polarity of the groups.
The changes of -CH2, -OH and other groups indicate that there are hydrogen bonds and weak intermolecular forces. It can be seen that before and after the adsorption-flotation of cadmium by Gordonella sulfate, the peak of one NH2 association and one OH of 3448.39cm-1 drifted 20cm-1 to the low wavenumber, and the peak shape became smaller, indicating that one OH and one NH2 played a major role in the adsorption process; the hydrocarbon peaks 2971.43cm-1, 2921.66cm-1, 1457.60cm-1 drifted 4cm-1 to the low wavenumber, respectively, indicating that there were hydrogen bonds and weak intermolecular forces; the amide peak of 1644.24cm-1 drifted 4cm-1 to the low wavenumber, indicating that the amide group participated in the adsorption process of cadmium by cells, because the ammonia in dibutylamine participated in the adsorption process; the peak of 1237.79cm-1 drifted 4cm-1 to the high wavenumber, indicating that the phosphorus group of bacterial cells also participated in the adsorption process of cadmium.
It can be seen from the infrared spectra of Bacillus glialis adsorbed cadmium and the Bacillus glialis floated by dibutylamine that some peaks and peaks changed before and after the adsorption of cadmium by Bacillus glialis. The peaks of one NH2 and associated one OH at 3440.09cm-1 drifted towards the low wavenumber to 3435.94cm-1, and the peak shape became wider, indicating that one NH2 and one OH played a role in the adsorption process; the overlap peaks of one CH2 shear vibration absorption and one CH3 antisymmetric bending vibration absorption of 1457.6cm-1 drifted towards the low wavenumber to 1461.75cm-1, indicating that there were hydrogen bonds and weak intermolecular forces; the amino groups C-N and P = O at 1233.64cm-1 drifted towards the high wavenumber to 1246.08cm-1, indicating that C-N and P == O played a major role in the adsorption of cadmium by cells; 1080.18cm-1 was the C-O telescopic vibration absorption and S == O telescopic vibration peak in polysaccharides drifted towards the low wavenumber to 1076.0lcm-1, indicating that the C-O of bacterial cells And S == O participated in the adsorption process of cadmium; the P == S and P-O (C) peaks at 532.72 cm-1 changed greatly, which may contain P groups.
Bacillus glialis adsorbed cadmium, and then floated with dibutylamine, the peaks 3440.09cm-1, 1544.70cm-1, 1457.60cm-1, 1080.18cm-1, 532.72cm-1 drifted 25cm-1, 4cm-1, 4cm-1, 62cm-1 to low, high, high, respectively, indicating the corresponding one NH2, one OH; one C == O-NH-1; one CH3 and one C-O-1, one P == SP-O and other groups play a role in adsorption-flotation, and the change of one NH2 is the most obvious, which may be caused by the adsorption of amine groups on cells in the flotation agent.
Bacillus subtilisBefore and after adsorption, the peak shape and peak position changed significantly in the whole wavenumber range
The peaks of one NH2 and associated one OH of 3440.09cm-1 drifted 29cm-1 to low wavenumber, and the peak shape became wider and stronger, indicating that one NH2 and one OH played a major role in the adsorption process; the hydrocarbon peak 2963.13cm-1,2925.81cm-1 drifted 4cm-1 and 8cm-1,1457.6cm-1 drifted 6cm-1 to low wavenumber, indicating that there were hydrogen bonds and weak intermolecular forces; the amide peak of 1648.39cm-1 drifted 7cm-1,1544.7cm-1,1403.69cm-1 drifted 9cm-1 and 4cm-1 to low wavenumber, respectively, indicating that amide groups and carboxyl groups participated in the adsorption process of cadmium by cells, but the change was not as obvious as -OH; the peak of 1071.89cm-1 drifted 7cm-1 to low wavenumber, indicating that the polysaccharides in bacterial cells C-O and S == O also participated in the adsorption process of cadmium; the P == S and P-O-C peaks of 523.32 cm-1 changed significantly, and the phosphorus-containing groups played a role in the adsorption process.
Before and after the adsorption of cadmium by Bacillus subtilis, the one-NH2 and associated one-OH peaks of 3440.09cm-1 drifted to high wavenumber by 12cm-1, and the peak shape became smaller, indicating that one-OH and one-NH2 played a role in the adsorption process; the hydrocarbyl peaks of 2963.13cm-1 and 2925.81cm-1 all drifted to high wavenumber by 4cm-1, and the peaks became stronger and wider, indicating that there were hydrogen bonds and weak intermolecular forces; 1648.39cm-1 and 1544.7cm-1 amide peaks drifted 8cm-1 and llcm-1 to low wavenumber, respectively, and the amide peaks of 1403.69cm-1 drifted 4cm-1 to high wavenumber, indicating that amide groups participated in the adsorption process of cadmium by cells, and the effect was more obvious than after cadmium adsorption, because ammonia in dibutylamine also participated in the adsorption process; 1071.89cm- The peak position of 1 drifted 4 cm-1 to a high wavenumber, indicating that the polysaccharides of bacterial cells also participated in the adsorption process of cadmium.
It can be seen from the infrared spectrum of the adsorption of cadmium in the electroplating wastewater by the washed industrial waste bacteria that some peaks and peaks changed before and after the adsorption of cadmium by the washed industrial waste bacteria. The peaks of one NH2 and associated one OH of 3419.35cm-1 drifted about 4cm-1 to high wavenumber, and the peak shape became wider, and the amide peak of 1528.llcm-1 drifted about 13cm-1 to high wavenumber, indicating that one NH2 and one OH played a role in the adsorption process; the hydrocarbon peaks of 2929.95cm-1 drifted 4cm-1 to high wavenumber, and 1457.6cm-1 drifted 4cm-1 to low number, indicating that there were hydrogen bonds and weak intermolecular forces; the peak position of 1047.00cm-1 drifted 8cm-1 to the start wavenumber, indicating that C-O and S == O of bacterial cells participated in the adsorption process. 549.51Cm-1 with P == S, P-O peak position drifts 16cm-1 to high wavenumber, indicating that the phosphorus-containing group P == S in bacterial cells, P-O plays a greater role in adsorption. The atoms of S, O, N, C, and C in the groups P == S, P-O, N-H, C-H, and OH can provide a common electron pair for chemical complexation with cadmium with empty orbits. It can be seen that chemical complexation is the main adsorption form.
The above determination results show that the adsorption process and adsorption-flotation process of four kinds of microorganisms, namely Gordenia sulfate, Bacillus colloides, Bacillus subtilis and washed industrial waste bacteria, the main groups that play an adsorption role are one OH, one NH2, one CONH2, C == O, CH2 and one CH2, etc. Since the elements such as N and O in one OH, one NH2, one CONH2, and C-C that can provide lone pair electrons are prone to chemical complexation with cadmium ions with empty orbits. Therefore, the adsorption process is mainly chemical complexation, and there are hydrogen bonds and van der Waals forces.
