Analyses of wastewater

Wastewater is water that is polluted by human activity and cannot be returned to the environment without adequate treatment. Wastewater is treated at a wastewater treatment plant (WTP).

Why is monitoring wastewater quality so important?

It should be noted that 99% of wastewater is discharged into surface waters, which means practically 100% recycling. Wastewater becomes surface water after it is discharged into a watercourse and can be retaken from the stream and used, e.g. for drinking water production.

According to the origin, wastewater can be divided into:

• Municipal wastewater

  • generated by households
  • contains a high amount of organic substances, substances rich in nitrogen and phosphorus, disinfectants, substances originating from pharmaceuticals, surfactants from shampoos and other hygiene products
  • is treated in municipal wastewater treatment plants (smaller municipalities, domestic sewage treatment plants, mixed wastewater treatment plants in larger cities)

• Industrial wastewater

  • generated by industrial or agricultural production
  • producers of such water discharged into a watercourse must operate an industrial wastewater treatment plant (IWTP) or at least a simple treatment plant, e.g. a gravity separator (lapol)
  • treatment technology differs according to the type of production and the nature of the wastewater; most often, it is a mechanical-chemical principle
  • the producer substantiates the fulfilment of limits set by the contract with the sewerage and water supply operator and submits accredited analyses of wastewater at the inflow to/outflow from the WTP based on the decision of the Water Management Authority

• Mixed wastewater

  • results from the mixing of municipal and industrial wastewater - typical in large cities and agglomerations
  • treatment in large WTPs with a combination of mechanical, biological and physical technologies

Principle of wastewater treatment in wastewater treatment plants (WTPs)

• Mechanical treatment

  In large WTPs, the water from the sewerage system is fed into a gravel trap, which captures coarse undissolved substances. The next step is usually a coarse screen to remove coarse floating dirt. This is followed by sand and grease traps. These mechanical parts of wastewater treatment plants are collectively called the protective part of WTP. The last part of the mechanical treatment stage is the sedimentation tank, where fine particles settle out; the result of scraping these particles from the tank is so-called primary sludge.

• Biological treatment

  In a biological reactor, organic pollution is removed with the help of microorganisms. These microorganisms are collectively called activated sludge. Activated sludge is highly effective in removing organic pollutants, nitrogen and phosphorus.

Who are our clients?

• Operators of buildings and facilities discharging wastewater into sewerage systems, surface or underground water
• Water management experts
• Operators of wastewater treatment plants (WTPs) – companies, cities, municipalities
• Natural persons - citizens - domestic sewage treatment plant operators

What do we offer?

• Accredited wastewater sampling
• We are manufacturers of automatic samplers - professional equipment for taking samples, primarily of wastewater
• Measurement of permissible pollution of wastewater discharged from municipal treatment plants according to Annex No. 1 to Government Regulation No. 401/2015 Sb., as amended (COD-Cr, BOD₅, suspended solids, ammoniacal nitrogen, total nitrogen and phosphorus)
• Measurement of permissible pollution values of industrial wastewater (discharged by selected industrial and agricultural sectors) according to Table 2 of Government Regulation No. 401/2015 Sb.
• Measurement of permissible pollution values of wastewater containing particularly dangerous substances according to Table 3 of Government Regulation No. 401/2015 Sb. – monitored are mercury, cadmium, hexachlorocyclohexane (HCH), tetrachloromethane (CCl₄), DDT, pentachlorophenol (PCP) and its salts, selected insecticides and pesticides (aldrin, dieldrin, endrin, isodrin), hexachlorobenzene (HCB), hexachlorobutadiene (HCBD), trichloromethane (CHCl₃), 1,2-dichloroethane (EDC), trichloroethene (TRI), tetrachloroethene (PER), trichlorobenzene (TCB)
• Measurement of charged indicators in wastewater discharged into surface water according to Annex No. 2 to Act No. 254/2001 Sb., as amended (COD-Cr, RAS, suspended solids, ammoniacal nitrogen, inorganic nitrogen (sum of ammoniacal, nitrate and nitrite nitrogen), total phosphorus, AOX, Cd, Hg)
• Analyses during accidents - monitored are group indicators NEL, C10-C40, AOX, TOC, EOX, surfactants, phenolic index, PAH, pesticides, volatile organic substances (BTEX, ClU) and others.

Legislation

• The discharge of wastewater into surface or underground water must be in accordance with the Water Act No. 254/2001 Sb. For discharge, a permit for the management of water must be issued by the relevant Water Management Authority as a time-limited document. The decision on water management includes the obligation to monitor wastewater characteristics by taking samples and having them analysed in an accredited laboratory. The method of sampling (spot or poured sample) and the frequency and scope of required analyses are determined.