Chemical analysis of effluents is required by owners of industrial enterprises. It is also needed by the owners of personal plots if there is a septic device with the function of volley discharge. Crude liquid can pollute the environment.
The purpose of the study of sewage
Strict sanitary standards are established for sewage waste. This is especially true of industrial complexes that can cause significant harm to the environment.
The need for expertise may appear:
- in the implementation of production control;
- when creating an information base for the subsequent compilation of regulatory documents;
- regularly in wastewater treatment organizations.
If violations are found, an emergency check is possible.
Wastewater is also subject to expert testing at the request of the owners in order to assess the situation after detecting cases of violation of sanitary rules and norms. In such situations, research is carried out simultaneously in several directions, taking into account the dumping method that is used at the facility.
Classification and degree of pollution
Atmospheric, household and industrial effluents merge into the sewer. The first include mineral impurities. They are usually not harmful to human health and the environment.
Domestic sewage contains all liquid substances that are sent to the sewer system from plumbing fixtures in apartments and private houses connected to a centralized network. In the pipeline, the effluent forms a homogeneous hosefcal mass. The concentration of hazardous impurities in it depends on the volume of water used by one person.
The level of pollution in domestic wastewater is determined by the following parameters:
- biological - the presence of protozoa, fungus, mold;
- mineral - the presence of salt and sand suspensions, alkaline and acid compounds;
- organic - detection of fractions of animal and plant nature.
Effluents coming from industrial complexes are extremely dangerous, as they are capable of containing radioactive waste, toxic chemicals. The most stringent requirements apply to such liquids, and production owners must provide preliminary treatment of effluents before they enter the city network to avoid an environmental catastrophe or an epidemic of infectious diseases.
The specifics of the examination
Sewer fluids are examined in laboratory conditions at the industrial facility itself or in the sanitary and epidemiological station. The cost of conducting quality chemical analysis of wastewater in different laboratories depends on how much testing should be done. The average price of a full comprehensive study for industry organizations is about 16,000 rubles. For private needs, a sample analysis of 3,500 rubles is sufficient.
Expertise is always carried out according to the standard scheme:
- Order a service, call specialists.
- Drive to the object to collect samples.
- Samples are taken for examination and draw up an official act.
- Perform laboratory analysis.
If violations are found, a decision is made with a list of recommendations for their elimination.
When conducting an unscheduled inspection, the responsibility for collecting samples lies with the owner of the sewer facility. To do this, perform the following steps:
- Find a clean jar or bottle of plastic or glass with a volume of at least a liter. Rinse thoroughly with running water.The container must be equipped with a sealed lid. Such containers can be taken in the laboratory, where they will be tested.
- Before collecting a sample of liquid, rinse the container with this water.
- Fill the container almost to the top, leaving a small gap between the water level and the lid. Sampling is carried out at the very exit of the sewage pipeline.
No later than two hours later, samples should be brought to the laboratory. At the same time, try to keep the sample in a cool, darkened place during transportation.
If an increased degree of contamination is detected, a second study will be needed after the violations have been eliminated.
Key study indicators
When conducting quantitative chemical analysis (KHA), the following indicators of the quality of sewage water are evaluated:
- Chemical - the balance of acids and alkalis. The fluid is checked against a basic pH reaction. At an acceptable concentration of polluting chemicals in wastewater, the pH value is from 6.5 to 8.
- Biological - the concentration of intestinal bacteria, viruses and fungi.
- The value of dry and total residue. Checking the first is carried out on an untreated sample, the second on a liquid passing through a filter. The maximum presence of a total residue of more than 10 g / l is not allowed.
- Measurement of oxidizability according to biochemical oxygen consumption (BOD). The number of aerobic microorganisms using organic impurities as substrates is estimated for life.
- The content of phosphorus and nitrogen compounds. They indicate the presence of nitrites, nitrates and ammonium nitrogen, contributing to the biological treatment of sewage.
- The presence of surface-synthetic active substances. Residual content indicates that the oxygen in the drain fluid is normal.
- The presence of organic and inorganic toxins. Toxicity is expressed in units of LD50 with acceptable values depending on the specific substance.
A qualitative analysis of effluents involves physical methods for determining contamination - color, transparency, smell, temperature. Evaluation of each aspect is performed visually.
Also, contaminated liquid is checked for the presence of sulfates and chlorides, traces of oil-containing products, and radioactive substances.
The list may be increased taking into account the aspects of the enterprise, the number of existing risks of infection or insufficient treatment of effluents.
To determine the composition of wastewater in an autonomous sewer system, criteria such as transparency, acid-base balance, the presence of suspended impurities and bio-pollutants, and the concentration of dissolved oxygen are usually examined.
Express analysis
If it is not possible to conduct testing in the laboratory, it is possible to determine the approximate composition of effluents in the “field conditions”. The procedure will require a minimum of devices and time.
The physical criteria of the liquid, colometric readings are analyzed.
To study the latest data, a photocolorimeter or standard solution is used, as well as coloring chemicals. The acid-base balance, the presence of surfactants, chlorine, salts of heavy metals, the concentration of soluble oxygen are clarified. If the indicators are exceeded, a more accurate laboratory analysis will be needed.
If the pollution of wastewater surges, installation of treatment facilities is required. Their choice is determined by the possibility of a positive effect on indicators that are exceeded in a chemical study.
