The impact of contamination of the sampling bucket and pipeline of the water sampler on the sample cannot be determined, and the problems of data marking and application are prominent.
Due to the inevitable presence of suspended solids adhering during wastewater discharge and the physical and biochemical reactions of sewage in the pipelines and sampling buckets, the stable operation of the peristaltic pump tubes for sampling is affected, and it also has an uncertain impact on the water samples. Meanwhile, technical specifications require that automatic water samplers have a rinsing function. In practical applications, this rinsing function is often not realized or applied. When the monitoring data exceeds the standard, it is marked that there are many doping problems in the sampling process, and the entire process is difficult to verify.
In response to the contamination issues of the sampling buckets and pipelines of water samplers, the automatic rinsing function of water automatic samplers should be effectively applied. The automatic rinsing of samplers is preferably selected during the period of automatic standard solution verification of water quality analyzers. During rinsing, the sampling pipelines (sampling tubes and sample supply tubes) and sampling buckets should be thoroughly cleaned and soaked. Pipeline cleaning can be carried out multiple times using tap water. The automatic rinsing of the sampling bucket can be carried out by soaking in tap water and stirring. The influence of the measurement data before and after rinsing should be tested regularly. That is, before rinsing, the sampler collects pure water for the analyzer to measure, and after automatic or manual rinsing, the sampler collects pure water for the analyzer to measure. The effect and influence of rinsing can be judged based on the changes in the measurement data of the two times. When performing automatic rinsing, the automatic water quality sampler should monitor and record the execution of related actions during the rinsing process, such as the amount of tap water used for rinsing, the number of rinses, and the soaking time, among other parameters and procedures.
For the data that exceeds the standard due to the presence of particulate matter in the sample during the normal sampling process, the internal conditions of the sampler pipeline and the sampling bucket should be verified on-site after the data exceeds the standard, and the relevant sample and pipeline video images should be retained. If it is marked as adulteration in the sampling process, the relevant images should be kept for future reference.
With the gradual improvement of technical standards, the software and hardware of equipment for online monitoring of water pollution sources are also gradually increasing. Just as water quality automatic samplers have completed the process from nothing to something in most regions during the five years of the implementation of technical standards, the effective application of water quality automatic samplers still requires further refinement and improvement of technical standards. In addition, the environmental management department should strictly supervise the implementation of technical standards. At the same time, polluting units should also be made aware of the benefits brought to them by the efficient application of automatic water quality samplers.