CS234232B1 - Method of biological sewage treatment - Google Patents

Abstract

Biological waste treatment method water, in particular from the processing plants textile materials. The cleaning is carried out by means of stabilized lactacidogenic bacteria cultures when carbohydrate-based impurities a proteins are cleaved in the acidic region up to a pH of 7 and purification takes place in two stages. During the first degree, the performs dosing of the stabilized culture lactacidogenic bacteria in amounts 0.01 mg.l_i to 10 g.l “1 dissolved directly in wastewater, optional and added revitalizing mixtures of 400 g ' sucrose and 400 g sodium formate for every 10 g of stabilized culture lactacidogenic bacteria and in the second biological activation is used purification or chemical partial sludge recirculation.

Description

The invention relates to a biological process for the purification of waste water by means of a stabilized culture of lactacidogenic bacteria which cleaves at an appropriate pH in an aqueous solution of high molecular weight substances, such as, for example, carbohydrates and eliminates proteins. The use is possible especially in waste water from bleaches and dyes of natural materials, where the pH of the waste water entering the treatment plant is in the acid range, up to pH 7.8, and also in other waste waters containing these high molecular weight substances. pH range.

In the treatment process, the waste water pollution is determined by the sum of the pollution resulting from the loss of material from the original amount of processed material and from the chemicals used in the treatment technology. The mutual reaction of chemicals, material and water then gives the resulting pH of water and a set of contamination of organic and inorganic character entering the sewage treatment plant, eventually flowing into the stream.

In particular, the amount of organic substances degraded in the treatment process and the amount of suspended solids retained in the treatment plant are taken into account for assessing the efficacy of wastewater treatment. During cleaning, when organic substances are only partially broken down and undissolved substances are poorly captured by the treatment plant, the flow in the stream worsens the self-cleaning ability, threatens the life in the stream, especially fish, and serious accidents may also occur. Therefore, it is advisable to reduce the effluent before discharge. to clean up the amount of organic substances and suspended solids to the smallest possible amount.

Various types of cleaning equipment are used for this purpose.

Basically, these are:

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Dry cleaning, where neutralization and precipitation in a sludge cloud removes some organic contaminants and suspended solids, or neutralizes inappropriate pH.

This treatment is mainly used where there is no wastewater treatment, since the paint is difficult to remove during biological treatment. The disadvantage of this purification method is the low efficiency of degradation of organic substances. The cleaning effects of the chemical cleaning process rarely exceed 60%, but are also lower, while the added chemicals are usually a defect in the self-purification itself in the flow, where they increase salinity and can destroy their biological recovery by their toxicity. Another disadvantage of dry cleaning is the large amount of sludge produced, which is mostly unsuitable for agricultural use and is exported to landfills. This leads to the subsequent devastation of nature and groundwater.

Other types of wastewater treatment are types of biological treatment, aerobic treatment and wastewater treatment.

two basicerobic

While aerobic biological wastewater treatment has a high efficiency in the degradation of organic substances, it is at the expense of a considerable energy demand for the amount of oxygen supplied.

Another disadvantage is the poor degradability of the textile dyes and the sensitivity to toxic chemicals which are mainly used for bleaching.

There is no need to inject oxygen in anaerobic biological treatment, so its energy consumption is less, but the cleaning takes considerably longer. At the same time, many organic substances are only partially degraded during cleaning; heated tanks are used to increase the degradability, which means an increase in investment costs.

In recent years, the enzymatic cleavage of organic substances by appropriate types of enzymes has intensified both biological treatment processes. This pre-cleavage reduces both energy and investment costs, but has the disadvantage that it does not produce the appropriate enzymes either pure or in combination so that most of the organic contamination can be covered and thus the cleaning effects do not exceed 70% of the cleaning effects.

These disadvantages are largely eliminated by the biological wastewater treatment process wherein carbohydrate and protein impurities are cleaved in an acidic region, up to pH 7.8, by a stabilized culture of lactacidogenic bacteria, metabolizing carbohydrates into organic acids and utilizing proteins, which are produced industrially. . The purification process according to the invention consists in that the purification is carried out in two stages, optionally with recirculation of the sludge, with 0.01 to 10 g / ^{l of a} stabilized culture of lactacidogenic bacteria dissolved before use in the first purification stage. in waste water in 20 - 100 liters, optionally with the addition of a revitalizing mixture of 400 g sucrose and 400 g calcium formate, either without aeration of the waste water or with aeration.

In the second step, precipitation of the resulting biomass and organic and inorganic impurities can be advantageously carried out either by a flocculent cloud from subsequent biological treatment or by a flocculent cloud formed by chemical refinement. optionally into pure water with the addition of a revitalizing mixture composed of sucrose and sodium formate, allowed to revitalize for 15 minutes to one hour at room temperature and then inoculated either continuously or once into the waste water in the first stage. This revitalized culture of lactacidogenic bacteria in wastewater metabolizes the carbohydrate and protein components of the technological eluate.

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Fermentation of organic substances and subsequent sedimentation of the inoculated culture with the non-metabolized residue results in the biological purification effect. It is not necessary to aerate the water in the first stage at all, or it can be aerated only intermittently, when the water flows through the purification system. As a result, considerable savings are made on the way oxygen is introduced into the waste water, especially electricity.

The process according to the invention has the advantage that by penetrating substances which are toxic to conventional biological treatment, by increasing the inoculum of a live bacterial culture, it allows to replace the natural loss caused by toxicity and thus reduce the volatility of biological waste water treatment.

Another advantage of the purification according to the invention is the possibility of inclusion in the first purification stage either conventional biological purification, where the resulting first stage biocal reduces the oxygen consumption in the second stage by reducing the organic load and then sediments itself with the second stage sludge kupř. colors or colored colloids can first. degree classify chemical finishing. Here, the formed first-stage biocal sludge is precipitated together with the chemical coagulants, preferably a substantial reduction in the chemical coagulant dose and thus a reduction in the amount of waste sludge formed. With an appropriate combination of chemical coagulant and biocal sludge from the first stage, the waste sludge can then be used for agricultural processing.

The following examples illustrate the possibility of carrying out the wastewater treatment process according to the invention.

Example 1.

Waste water from flax spinning plant and bleach bleaching plant, _{which contained organic} contamination in the form of polysaccharides, proteins, pectins and chlorlignin, was purified from the spinning mill, and contamination with mineral oils and fats and waxes of plant origin was added to the pre-spinning plant.

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The resulting pH of the mixed wastewater was 5.5, in the water there were residues of active chlorine from bleaching with sodium chlorite-1 up to 10 mg / l «

The purification was carried out in two stages, given by the construction of the treatment plant, where a revitalized culture of lactacidogenic bacteria was continuously added to the first stage, which simultaneously serves as an oil separator.

-1 —1 in an amount of 0.05 mg.l - 0.1 mg.l. Revitalization was. made in 20 liters of spinning water without revitalizing mixture.

The bacterially revived water was fed to a buffer and mixing tank where it was mixed with bleaching waters. The resulting bio-sludge was collected by a mos rake into a sludge tank, where it was recirculated back to the second purification stage by means of a pump.

Despite the unsuitability of the treatment plant, the treated wastewater showed a cleaning effect of up to 70% on organic substances »

Example 2.

Waste water from the plant, which mainly processed wool and half-wool substances, was treated, and besides waste water containing polysaccharides, proteins and fats, it also contained a significant proportion of textile dyes. The purification was carried out in two scales. In a first step, a revitalized culture of lactacidogenic bacteria dissolved in pure water was added to the batch, with the addition of a revitalizing mixture of 400 g sucrose and 400 g calcium formate in an amount of 0.1 mg.l · ¹ · while aerating with simple ejectors. In the second stage, a continuous chemical refinement with green vitriol and lime is then carried out to remove the colored component from the effluent.

The resulting chemical sludge and biocal of the first stage were partially returned to the first stage and the remainder was concentrated on the filter presses and / or exported./ 1 concerned the intensification of the former chemical treatment plant, an unsuitable biological treatment plant yet substance was up to 90 l.

Claims (1)

SUBJECT OF THE INVENTION 234 232 Process for biological treatment of waste water with a pH of not more than 7.8 containing carbohydrate-based and protein-based impurities which are removed from the wastewater by means of a stabilized culture of lactacidogenic bacteria, characterized in that the wastewater treatment is carried out in two stages. In the first stage, a stabilized culture of lactacidogenic bacteria is added to the wastewater in an amount of 0.01 mg.i " ¹ " to 10 gl " ^-1 " revitalized directly in the waste water or in pure water using a revitalizing mixture of 400 g sucrose and 400 g. g of calcium formate for every 10 g of a stabilized culture of lactacidogenic bacteria for one hour prior to dosing, with or without aeration of the first stage, or in the second stage, biological sealing or chemical treatment with partial sludge recirculation.