function. X-ray diffraction analyses (XRD) were obtained using a Bruker D8
advanced diffractometer equipped with a Cu seal tube to generate Cu K a radiation
(k = 1.5406 A) within the Bragg angles 10 \ 2h \ 80° in steps of 0.01°. Raman
spectroscopy measurements were acquired with LabRAM HR, Horiba Scientific
equipment with an Nd:YAG laser (k = 532 nm, output power of 80 mW). The
samples were analyzed with a power of 6 mW over an area with a diameter of
1.5 lm using a microscope on 10X objective.
3.2.2.2 Photocatalysis Tests
The photocatalytic activity of the synthesized samples was evaluated in disinfection process in a real residual-treated water at pH = 7, by quantification of the
more likely number of pathogen agents to form colonies and by differentiation of
those microorganisms by biochemical reactions in diverse mediums. In each test,
50 mg of the photocatalyst was dispersed in 100 mL of the residual-treated water
magnetically stirred for 30 min in the darkness before irradiation. The system was
illuminated using the solar radiation of a spring day in the city of Santiago de
Querétaro, Qro. This represents between 800 and 1,000 Wm
-2 around 12:00 am
and 03:00 pm. At given irradiation time intervals and after 3 h of total reaction
time, the samples were taken out and the pathogen microorganism removal was
evaluated.
3.2.2.3 Microbiological Identification and Differentiation Test
Using a bacteriological water test based on the microorganism growth in two
presumptive mediums (Lactose and Sodium Lauryl Sulfate, BD Bioxon) at concentrations of 10
-1 , 10
-2 , and 10
-3 , the disinfection effectiveness process was
tested. In the presumptive test, the mediums once seeded were incubated at 35 °C
for 24 h. If the samples show the presence of gas, it can be noticed as a positive
sample. After the presumptive test, the positive samples were seeded inoculant
1 ml in the confirmative mediums, EC, MIO, and Green Bright Billis (BD Bioxon). The tubes were incubated for 24 h at 35 °C, and the presence of gas means a
positive sample. Finally for the differential tests, the positive samples from the
confirmative tests, were seeded in a petri dish containing shigella and salmonella
medium (BD Bioxon) and Macconkey agar (BD Bioxon) for 24 h at 35 °C (Ervin
et al. 2010; Gilbride 2014; Scaglia et al. 2014).
3.2.3 Metal Removal
Chitosan synthesis was made in two ways: in the traditional method with several
modifications, which include four-steps depigmentation, decalcification,
3 Water Recycling in Biosystems for Food Production
85
advanced diffractometer equipped with a Cu seal tube to generate Cu K a radiation
(k = 1.5406 A) within the Bragg angles 10 \ 2h \ 80° in steps of 0.01°. Raman
spectroscopy measurements were acquired with LabRAM HR, Horiba Scientific
equipment with an Nd:YAG laser (k = 532 nm, output power of 80 mW). The
samples were analyzed with a power of 6 mW over an area with a diameter of
1.5 lm using a microscope on 10X objective.
3.2.2.2 Photocatalysis Tests
The photocatalytic activity of the synthesized samples was evaluated in disinfection process in a real residual-treated water at pH = 7, by quantification of the
more likely number of pathogen agents to form colonies and by differentiation of
those microorganisms by biochemical reactions in diverse mediums. In each test,
50 mg of the photocatalyst was dispersed in 100 mL of the residual-treated water
magnetically stirred for 30 min in the darkness before irradiation. The system was
illuminated using the solar radiation of a spring day in the city of Santiago de
Querétaro, Qro. This represents between 800 and 1,000 Wm
-2 around 12:00 am
and 03:00 pm. At given irradiation time intervals and after 3 h of total reaction
time, the samples were taken out and the pathogen microorganism removal was
evaluated.
3.2.2.3 Microbiological Identification and Differentiation Test
Using a bacteriological water test based on the microorganism growth in two
presumptive mediums (Lactose and Sodium Lauryl Sulfate, BD Bioxon) at concentrations of 10
-1 , 10
-2 , and 10
-3 , the disinfection effectiveness process was
tested. In the presumptive test, the mediums once seeded were incubated at 35 °C
for 24 h. If the samples show the presence of gas, it can be noticed as a positive
sample. After the presumptive test, the positive samples were seeded inoculant
1 ml in the confirmative mediums, EC, MIO, and Green Bright Billis (BD Bioxon). The tubes were incubated for 24 h at 35 °C, and the presence of gas means a
positive sample. Finally for the differential tests, the positive samples from the
confirmative tests, were seeded in a petri dish containing shigella and salmonella
medium (BD Bioxon) and Macconkey agar (BD Bioxon) for 24 h at 35 °C (Ervin
et al. 2010; Gilbride 2014; Scaglia et al. 2014).
3.2.3 Metal Removal
Chitosan synthesis was made in two ways: in the traditional method with several
modifications, which include four-steps depigmentation, decalcification,
3 Water Recycling in Biosystems for Food Production
85