Vocabulary of terms

Activated sludge in the sublime
particles of activated sludge, i.e. a mixture of micro organisms mixed with waste water and air; ensures the process for the treatment of waste water.
Biological treatment of water
in this case the activity of micro organisms ensuring the decomposition of organic and anogranic substances present in water, i.e. impurities up to the treatment of water; if these organisms need dissolved oxygen (air) in the water, these processes are called aerobic, if decomposition is in the environment without oxygen, they are called anaerobic.
Biologically degradable
everything what can degraded biologicaly.
BOD5
biochemical (biological) oxygen demand is a test used to measure the concentration of biodegradable organic matter present in a sample of water. It can be used to infer the general quality of the water and its degree of pollution by biodegradable organic matter. It is used in water quality management and assessment, Ecology and environmental science. BOD is not an accurate quantitative test and should be considered as providing an indicator of the quality of a water body; water from households has an average value of usually 300 - 400 mg/l, treated water has this value less than 30 mg/l.
WWTP
waste water treatment plant.
Levelling function
the levelling function ensures levelling of non-proportional inflows and ensures the stable treating function of the waste water treatment plant.
Population equivalent (PE)
as a rule one person, the producer of the contamination; an artificially introduced unit which represents the production of waste water 150 l/day and the production of contamination 60g BSK5/day.
COD
in environmental chemistry, the chemical oxygen demand (COD) test is commonly used to indirectly measure the amount of organic compounds in water. Most applications of COD determine the amount of organic pollutants found in surface water (e.g. lakes and rivers), making COD a useful measure of water quality. It is expressed in milligrams per liter (mg/L), which indicates the mass of oxygen consumed per liter of solution. Older references may express the units as parts per million (ppm); chemical consumption of oxygen, i.e. the index of contamination; its value (usually stated in mg/l) states how large a part of the contamination has an organic origin; water from households has an average value of 600 - 800 mg/l, treated water has less than 100 mg/l.
Fine-bubble aeration
aeration characterized by bubbles with the size of 1 – 4 mm.
Root waste water treatment plant
a root (vegetation) waste water treatment plant is a set of equipment ensuring waste water treatment. The usual set is rough pre-treatment using a screen on the inflow (sometimes not installed). The waste water flows into a septic tank where there is the pre-treatment of waste water and sedimentation. The final treatment is ensured in the consequent flowing through the system of selected hydrophilous plants with a wide root system artificially created in the water-proof body of the wet system.
Mineralized sludge
stabilized activated sludge, mainly of an organic nature whose organic ratio is reduced to a minimum due to the process of aerobic stabilization; it is a substance similar to mould without any odour which is not decomposed and can be composted.
N – NH4
ammoniacal nitrogen (generally); one of the contaminating elements of waste water.
Nitrification x de-nitrification
aerobic process during which is the oxidation of nitrogenous substances, e.g. ammonia (NH3) activities of bacteria present in waste water to oxidise forms of nitrogen – nitrite (NO2), mono-nitrate (NO3) x anoxic process for the reduction of nitrates (NO3) nitric oxide (N2O) and then up to molecular nitrogen (N2); this process is important for the reduction of nitrogen in ground water and the prevention of the development of water flower during the summer period.
TSS
TSS are the amount of filterable solids in a water sample. Samples are filtered through a glass fiber filter. The filters are dried and weighed to determine the amount of total suspended solids in mg/l of Hample; (on the outflow for functioning waste water treatment plants this is usually up to 25 mg/l).
Aerobic x anoxic environment (or anaerobic)
an environment with the presence of dissolved oxygen (there are processes of oxidation due to the presence of oxygen, i.e. cleaning of streams) x an environment without the presence of dissolved oxygen, i.e. without all forms of oxygen (there are reduction processes due to the exhaustion of oxygen in the water, i.e. fermentation as in contaminated tanks and rivers).
Continuous through flow x discontinuous through flow operation
non-stop operation, i.e. waste water is treated by flowing through technology x batch operation, i.e. waste water is treated by batches.
Septic tank
passing tank (practically the same as a domestic waste water treatment plant) where waste water is collected and pre-treated. For this reason the septic tank is divided by partition units to prevent mixing of fresh waste water with out-flowing water. The usual efficiency of treating the waste water in a septic tank is about 20% provided that it is collected for at least 5 days. The discharged waste water is usually without mechanical impurities with a typical fermentation odour. Legally it is not possible to discharge such water without further treatment, i.e. through a sand filter.
Septic tank with ground filter
is a facility where the water from the septic area flows into the space filled with sand. On the basis of experience it is recommended to consider the area behind the septic tank to be a minimum of 4 m2 per inhabitant which must be insulated and filled in with a filtrating filler (sand) with the layer of about 1 m. A septic tank with a ground filter has the advantage that compared with most treatment plants it functions in recreational houses more reliably in the case of variable loading if it is well designed. At the same time, it has zero consumption of electric energy. However, during operation it is necessary to clean the sedimentation space 1 x every one or two years. Another disadvantage is the anaerobic processes in a septic tank which can be the source of odour.
Waterworks
Waterworks are a structure which serves for the collection of water, artificial regulation of the outflow regime of the ground water, protection and use of water, water management, protection against harmful effects of water, regulation of water properties or other purposes as stated by Law, in particular:
a) dams, barriers, water basins, overflow dams and basins
b) structures by which the course of water flows are modified, changed or established
c) structures of water series and water-management objects, including water treatment plants, sewerage systems and sewerage structures, including waste water treatment plants, as well as structures for the treatment of waste water before its discharge into sewerage systems, …

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