1. Water quality sampling work
Adopt different analytical methods
In the process of environmental monitoring work, whether the application of analytical methods is correct will have a direct impact on the scientific accuracy of the final monitoring results. For the same monitoring samples, due to the differences in their source forms, the analytical methods adopted for them can also vary significantly. The best monitoring method should be selected in accordance with the concentration level of the monitoring items in water bodies or sewage and the determination of specific implementation standards. The detected limit should be lower than one fifth of the standard value to ensure that the monitoring work can fully meet the basic requirements of the monitored sample.
When choosing an analytical method, the anti-interference ability should be given priority first. The sampling staff should have a detailed understanding of the properties of the samples they collect. For instance, in some chemical enterprises in our country, the wastewater generated during the production process is high-chlorine wastewater. When conducting wastewater monitoring and collecting COD samples, it is necessary to clearly define the standard and use the chlorine gas correction method for monitoring and analysis. Only in this way can the accuracy of the final monitoring results be effectively guaranteed.
(2) Analysis of environmental factors' influence
In the process of on-site sampling for environmental monitoring, natural factors are ever-changing, and the variations in natural factors can have a certain impact on the collected samples. For instance, factors such as wind speed, ambient temperature, rain and snow can all cause changes in the distribution of pollutants existing in the environment. In the process of surface water sampling, the distribution of several points needs to be on the same soil section. If the monitoring sampling is close to the riverbank, the impact of the resulting error will be greater. At the same time, with the change of seasons, the time of high tide in the river course will also change to a certain extent. Therefore, the sample collection personnel need to carry out thorough on-site research preparations before work. Prevent the collection of samples from the wrong time period, which may affect the final monitoring results.
(3) Preservation conditions for water samples
To reduce the influence of environmental conditions, the metabolic activities of microorganisms and other chemical reactions, the most commonly used methods for sample preservation include refrigeration, freezing and adding protective agents, etc. Because the main components of surface water and sewage samples are different, it is difficult to ensure that the same preservation conditions are completely feasible for the substances awaiting monitoring in the same type of samples.