Standards for Drinking Water (GB5749–2006), the test statistics (detection rate,
excess rate) of inorganic and organic components of groundwater samples are as
shown in Tables 5.21 and 5.24. The groundwater monitoring results of monitoring
wells during the wet season are as shown in Tables 5.20, 5.22 and 5.23.
A total of 13 sample groups (six for monitoring wells, one for environmental
background, two for household wells, and four for surface water) were collected
during the wet season, with the distribution of sampling sites as shown in Fig. 5.12.
The temperature, pH, chromaticity, turbidity, and conductivity of samples were test
on-site, and other indicators tested in the lab. Among them, 39 inorganic components were monitored for groundwater samples, with wide differences in the content
and detection rate. Toxic mercury was not detected; anionic surfactant, cyanide and
selenium were found in individual boreholes, with a detection rate of 7.6%; and
other components have been detected to different degrees.
A total of 44 inorganic components were monitored for surface water samples
after the addition of COD, biochemical oxygen demand (BOD 5 ), volatile phenol,
sulfides and fecal coliforms. Anionic surfactant, toxic cyanide and arsenic, and
volatile phenol were detected only in landfill leachate to varying degrees, of which
volatile phenol exceeded the limits. The total coliforms and fecal coliforms are not
discussed here because their content in surface water exceed the upper threshold
value that can be tested in the lab. As the landfill leachate looks dark black and
shows high degrees of turbidity and chromaticity, the turbidity values of samples
taken in individual boreholes are also relatively high. The remaining indicators
exceeded the limits of relevant standards to different degrees.
• pH and permanganate
The pH and permanganate were all detected in all groundwater samples. The pH
value ranged from 5.61 to 9.36 (with an average of 7.31), and the permanganate
concentration ranged from 1 to 61.8 mg/L (with an average of 10.36 mg/L).
According to the Quality Standards for Groundwater (GB/T14848–2017), the pH
and permanganate exceeded the limits in 55.56% of the groundwater samples. More
specifically, the pH value in ZK1, ZK6, BJ7, MJ9 was higher than the limits, and
noticeably in ZK3, it represented 1.1 times of the standard value. Excessive permanganate was detected in all boreholes except for ZK3, and the maximum concentration was found in ZK2, hitting 20.6 times of the standard value, which
implies serious groundwater pollution.
• Conventional ions, TDS, and total hardness
The detection rate reached 100% for conventional ions (F
− , K
+
, Ca
2+ , Mg
2+ and
Na
+
), TDS and total hardness, and 44.44 and 66.67% for SO 4
2− and Cl
− respectively. According to the Quality Standards for Groundwater (GB/T14848–2017),
TDS, Cl
− and Na
+ exceeded the limits as the observed concentration ranges read
110–1290 mg/L (with an average of 333.11 mg/L), 10–466 mg/L (with an average
of 122.17 mg/L), and 3.11–283 mg/L (with an average of 49.50 mg/L) respectively. The excess occurred in 11.11% of the groundwater samples, which were
126
5 Application Cases
excess rate) of inorganic and organic components of groundwater samples are as
shown in Tables 5.21 and 5.24. The groundwater monitoring results of monitoring
wells during the wet season are as shown in Tables 5.20, 5.22 and 5.23.
A total of 13 sample groups (six for monitoring wells, one for environmental
background, two for household wells, and four for surface water) were collected
during the wet season, with the distribution of sampling sites as shown in Fig. 5.12.
The temperature, pH, chromaticity, turbidity, and conductivity of samples were test
on-site, and other indicators tested in the lab. Among them, 39 inorganic components were monitored for groundwater samples, with wide differences in the content
and detection rate. Toxic mercury was not detected; anionic surfactant, cyanide and
selenium were found in individual boreholes, with a detection rate of 7.6%; and
other components have been detected to different degrees.
A total of 44 inorganic components were monitored for surface water samples
after the addition of COD, biochemical oxygen demand (BOD 5 ), volatile phenol,
sulfides and fecal coliforms. Anionic surfactant, toxic cyanide and arsenic, and
volatile phenol were detected only in landfill leachate to varying degrees, of which
volatile phenol exceeded the limits. The total coliforms and fecal coliforms are not
discussed here because their content in surface water exceed the upper threshold
value that can be tested in the lab. As the landfill leachate looks dark black and
shows high degrees of turbidity and chromaticity, the turbidity values of samples
taken in individual boreholes are also relatively high. The remaining indicators
exceeded the limits of relevant standards to different degrees.
• pH and permanganate
The pH and permanganate were all detected in all groundwater samples. The pH
value ranged from 5.61 to 9.36 (with an average of 7.31), and the permanganate
concentration ranged from 1 to 61.8 mg/L (with an average of 10.36 mg/L).
According to the Quality Standards for Groundwater (GB/T14848–2017), the pH
and permanganate exceeded the limits in 55.56% of the groundwater samples. More
specifically, the pH value in ZK1, ZK6, BJ7, MJ9 was higher than the limits, and
noticeably in ZK3, it represented 1.1 times of the standard value. Excessive permanganate was detected in all boreholes except for ZK3, and the maximum concentration was found in ZK2, hitting 20.6 times of the standard value, which
implies serious groundwater pollution.
• Conventional ions, TDS, and total hardness
The detection rate reached 100% for conventional ions (F
− , K
+
, Ca
2+ , Mg
2+ and
Na
+
), TDS and total hardness, and 44.44 and 66.67% for SO 4
2− and Cl
− respectively. According to the Quality Standards for Groundwater (GB/T14848–2017),
TDS, Cl
− and Na
+ exceeded the limits as the observed concentration ranges read
110–1290 mg/L (with an average of 333.11 mg/L), 10–466 mg/L (with an average
of 122.17 mg/L), and 3.11–283 mg/L (with an average of 49.50 mg/L) respectively. The excess occurred in 11.11% of the groundwater samples, which were
126
5 Application Cases