DE19609605A1 - Waste water treatment method suitable for rural households based on natural methods - Google Patents

Abstract

Waste water purificn. method, is suitable for households in rural areas. It includes a first purificn. stage of physical pretreatment. Coarse material carried in the fluid phase is sepd. by a detritus filter. This has two series-connected phyto-mechanical cleaning stages. In the second stage, the settled sewage arising is further purified by physical and biochemical means, using a reed bed system. The waste water then passes to the third stage, which is a sand filter, where further physical and biochemical purificn. takes place.

Description

Basic ideas

At the present time, the question of "disposal" is being asked of all locations. and "further processing" or "final storage" of the artificially produced sewage sludge. However, this question should not be put first - the following will focus exclusively on rural areas and the associated decentralized Location-related - but first and foremost the question of "avoidable speed "of this follow-up product.

The prerequisite for finding an adequate solution to this problem is not to look at the "waste" product per se, but at thinking in Circuits.

• - Basic questions:
• - starting material,
• - (natural) biodegradability,
• - microorganisms involved in the breakdown,
• - biochemical, physical (e.g. bioelectronics) processes.

These processes, each of which is viewed and analyzed as a separate cycle in nature, however, do not run separately, but always together, partly overlapping or in complex dependency among each other.

This means that if the individual circuits are considered separately, this can lead to a quite incorrect assessment of the end result come because others are in sync ongoing or ongoing processes are not included in the overall view were.  

Characteristic of the known prior art

At the moment there are only plant clarification beds in front of and / or after mechanical filter systems horizontal sequence of wastewater treatment known.

Are disadvantageous

• - Any residues (faeces, raw or digested sludge) that are costly to ent are worried
• - high costs for external energy (pumps, distributors etc.),
• - odor emissions,
• - Frost resistance due to large areas,
• - high construction and maintenance costs.

In the professional world there is currently only the view of a horizontal sequence of the Klä wastewater treatment with plant clarification beds.

The term "wastewater" applies to the legally available definition and water of comparable quality and / or water with the origin:
Irrigation, precipitation, groundwater, layer (s) water.

Aim of the invention

The aim of the invention is

• - Purification of wastewater at the place where it is created and returned falling faecal matter in the natural cycle (humus) under the avoidance formation of otherwise occurring faecal / raw or sewage sludge,
• - No / or minimal use of external energy (see page 4),
• - neutral odor (see page 14),
• - winter resistance (see pages 4 and 14),
• - Minimal construction and maintenance costs (high own contribution possible through self-construction),
• - No follow-up costs (e.g. through disposal of problematic materials).

State the nature of the invention

The task was to remedy the shortcomings of the above. Fix it and the posed To achieve goal.

The object is achieved according to the invention by the following Method.

Reasons for vertical system

• - topographical location,
• - natural gradient,
• - no technical Tools (pumps) → Utilization of the natural flow behavior of the water.

benefits

• 1. small footprint,
• 2. Heat development through oxidation (winter operation),
  This means that in the vertical system the base area is of secondary importance. A corresponding thickness of the filter layer and its structure is mandatory, since the cleaning performance depends on the distribution accuracy of the inflowing waste water and the resulting dense vegetation.

Description and functioning of the process method

The medium enriched with dirt freight ("drinking water") is said to be from the dirt freight to be separated and then fed cleaned into a receiving water become

• - Action
• - Separation of the coarse substances carried from the liquid phase (physical Pre-cleaning) in the first cleaning stage (coarse fabric terry filter),
• - Physical and bio-chemical purification of the resulting gray water in the second cleaning stage (reed bed),
• - Physical and bio-chemical cleaning in the third cleaning stage (Sand filter),
• - Introduction of the cleaned medium into a receiving water.

When choosing an appropriate cleaning method, the first question was according to the nature of the dirt load carried by a household / farmer commercial operation:

• - house faeces (coarse matter),
• - rinse water,
• - washing machine lye.

Since in the first cleaning stage (pre-cleaning) only the coarse material from the carrier medium should be separated is a process with a physical filter effect sufficient.

Since the coarse material partly consist of protein or protein-containing compounds the decisive factor in the "recycling" of these organic components Question:

• - Conversion to an anaerobic abiotic state (putrefaction process) with the The problem of appropriate disposal

or

• - Conversion into an aerobic biological state (rotting process) and the poss possibility of returning to the natural cycle.

Under the premise of "avoidance", only the second option treated further.  

Embodiment

In the exemplary embodiment, represented by a sectional view ( FIG. 1), the sequence of the method and the structure of the coarse material terry filter and the two subsequent phytomechanical cleaning stages are shown.

The detailed description is given on page 7 ff.  

functionality Coarse terry cloth filter (cleaning level I) ( 7 )

Via an inlet pipe ( 1 ), which ends freely above the coarse terry filter ( 7 ), the dirt load is thinly distributed on the straw meal layer ( 3 ) by means of a mechanical distributor ( 2 ). The wastewater is sucked up by the large surface of the straw meal litter, slowly seeps down through the other layers (chopped wood ( 4 ), fine sand layer ( 5 ), coarse gravel layer ( 6 )) and is drained through a drain pipe ( 18 ) into the reed bed ( 9 ) headed.

The coarse material is retained by the layer of straw flour and through it constantly existing components air, water, carbon (C) and nitrogen (N) is the ba sis laid for the start of rotting.

The constant supply of C, O₂ and water leads to heating of <50 ° C and thereby killing any pathogens.

After filling one half of the pit, the material becomes, after another one to two weeks Storage in the container, removed and in a prepared place until the end valid humification composted.  

Rotting or rotting

Rotte = conversion of the protein-containing coarse material into various stages stable permanent humus

• 1. Supply of C-containing materials (desired balanced C: N ratio = 20: 1) in this case straw flour (→ large surface = large contact surface for microorganisms = rapid implementation).
• 2. Constant air supply to create aerobic conditions.
• 3. Continuous humidification.
• 4. Periodic bedding of rock flour (basalt / diabase) due to its rich content of cobalt (trace element) → formation of cobalamin (= Vitamin B₁₂) via Azotobacteria.

On the recurring question about the hygienic aspects, the Er Results of the large scale experiments of the then institute for "Humus economy and composting "in Berlin.

It has been demonstrated "that the high in a trial compost rent dangerous pathogens, such as anthrax, paratyphoid, tuberculosis, glaucoma and the like. a., are killed by the biological processes during composting. Ins in total there were 18 of the most dangerous pathogens, those of medical and hy engineers have been tested. . . . So u. a. pure penicillin in the compost will be. Even the hard chitin shells of the ascarids, the roundworms, were in destroyed and killed within a few days as a result of active enzymes (chitinase) tet. "Erhard Hennig, Humustrilogie, 1988, 2nd part p. 12.  

ERGO

The main element to prevent putrefaction is only the atmospheric oxygen.

The aeration and feeding of the microorga which is abundant in the faeces nisms with carbohydrate-rich straw meal particularly promotes the aerobic bacteria strong.

The straw meal provides the microbes with the energy, the nitrogen in the feces-urinary gemi It serves to build up protein.

The volatile ammonia nitrogen (NH₃) is then as bacterial body protein (bound) before, stinking putrefactive substances are avoided.

Conversely, organic matter is already in the real putrefaction process (Withdrawal of carbon) are transferred (e.g. digested sewage sludge), themselves convert more into rotting.  

functionality Reed bed (cleaning level II) ( 9 )

After the physical pre-cleaning in the coarse material terry filter ( 7 ), the wastewater for main cleaning is evenly distributed over the reed bed ( 9 ) via a line ( 18 ) with a vertically oriented nozzle through a parabolic distributor ( 8 ) in the center.

Advantage of the parabolic distributor

• - uniform circular distribution,
• - no short circuit currents,
• - avoiding channel formation,
• - no deformation of the floor by impact forces (more even, calm river).

construction

• - reeds ( 10 ),
• - Soil substrate ( 11 ) (compost mixed with straw flour → C-containing starter for the plants),
• - fine sand layer ( 5 ),
• - fine gravel layer ( 12 ),
• - Coarse gravel layer ( 6 ).

The dimensions of the areas are based on the information in the applicable notice leaves of the sewage technology association (ATV) in Hennef.  

Effect of the reed bed ( 9 )

The wastewater treatment is based on the interaction of physical, chemical shear and biological processes:

• - filtering out any coarse particles (physical),
• - Binding of phosphorus and partially nitrogen-containing compounds Soil particles (physico-chemical),
• - Bacterial breakdown of protein, carbohydrates, fats, urea and the like. a. to Water, carbon dioxide, ammonium, nitrate and finally nitrogen.

functionality Sand filter (cleaning level III) ( 13 )

After the main cleaning in cleaning stage II ( 9 ), the wastewater for fine purification and fining is distributed in the same way via a line ( 19 ) with vertically aligned nozzle through a centrally attached parabolic distributor ( 8 ) evenly on the overgrown sand filter ( 13 ).

The embellished carrier medium is passed in the sole area via a drainage line ( 20 ) into the downstream control shaft ( 15 ) and from there via a PVC line ( 21 ) into the receiving water ( 16 ).

construction

• - reeds ( 10 ), cattails ( 14 ) and / or other plant species ( 17 ),
• - soil substrate ( 11 ), (humus-straw meal-sand mixture),
• - fine sand layer ( 5 ),
• - Fine gravel layer ( 12 ).

The dimensions of the areas are based on the information in the applicable notice leaves of the sewage technology association (ATV) in Hennef.  

Mode of operation of the sand filter

Fine cleaning (fining) of the carrier medium pre-cleaned in the sloping pool ( 9 )

• - Elimination of any nutrients nitrogen and especially Phosphorus through an iron-containing sand filter layer (fixing capacity).

To ensure the year-round functionality of the system, it is also too note:

Reed basins ( 9 ) and sand filters ( 13 ) should be installed at a minimum distance of 15 m from deciduous trees, as there is a risk of a compact (water and air impermeable) layer on the soil body due to falling leaves.

If this minimum distance cannot be maintained, the two cleaning stages II ( 9 ) and III ( 13 ) should be screened preventively with a network in order to avoid a possible malfunction of the operation.

Function of the reduction plants

• - Creation of favorable conditions for microorganisms in the root area (They can use the offered organic compounds and dismantle).
• - Accumulation, fixation and partial deposition of non-biodegradable possible substances in the biomass by the plants.
• - Mineralization of organic substances in the water body and soil substrate through root excretions.
• - Nutrient binding and partial mineralization through the plant top layer.
• - Keeping the ground surface open for the infiltration of the surface water.
• - Oxygenation in the root area.
  The rhizomes of the aquatic, swamp and reed bed plants are connected to the atmosphere and exchanged through a rich cavity system (thereby changing the redox ratios in the immediate root area, release of carbon compounds and root exudates etc.).
• - Formation of an attachment surface for bacteria and other microorganisms the slowly rotting parts of the dying plants (Provision of carbon).
• - high evaporation rate during the growing season.
• - Dampening of possible odor emissions and heat removal in winter.

Function of the floor

• - Phosphorus-containing compounds are retained (especially by iron and aluminum minerals containing minerals).
• - Ammonium (NH₄⁺) originated from the breakdown of proteins and urea u. a., will "nitrified" from bacteria to nitrate (NO₃⁻), this then to nitrogen (N₂) "denitrified".

Plant species

• - reeds (Phragmites australis) ( 10 ).

benefits

• - is the only plant rooted in coarse-grained filter materials up to 1 m depth (with the exception of pure gravel and coarse sands),
• - shows greatest performance with regard to the influence on redox conditions,
• - grows your own dead biomass without any problems.

Other possible plants

• - Broad-leaved cattail (Typha latifolia) ( 14 ).
• - Narrow-leafed cattail (Typha angustifolia) ( 17 ).
• - Iris (Iris pseudacorus) ( 17 ).
• - Braided bulrush (Schoenoplectus lacustris) ( 17 ).
• - Calamus (Acorus calamus) ( 17 ),
  especially if the filter is not flowing horizontally but vertically (formation of a dense root near the surface).

Planting technology

All year round planting of bales is possible (on best between October to April).

In the case of reeds ( 10 ), planting can also be carried out using rhizome cuttings and / or stalk cuttings.

It is important that the plants are supplied with sufficient water from the start.

Experience shows that run-in phases are unfavorable.

Precautions against dehydration

As a result of the constant high evaporation rate of the plants during the growing season an adequate supply of water to the plants must be ensured.  

ERGO

The effect of the plants is based on the purely physical filter process in the Zu retention of suspended matter from the water body, especially on the supply of the Root space with oxygen via a rich cavity system in sprouts and hal until the root area.

In addition, the plants come into direct contact with the Bo via pores in the roots the substrate and water, by excreting various metabolic processes products in the root area (hormones, organic acids, vitamins, amino acids, Koh lenhydrate) comes d. H. microbicidal or bactericidal substances that kill coli bacteria and reduce the total number of bacteria.

It should be noted that the procedure mentioned is a dynamic system: it evolves over time.

That means e.g. B. based on the lifetime for phosphate determination that the ur original sorption capacity given by the type of filter material ver can prolong - enrichment of iron or aluminum etc. in the organic Be share.

It can also decrease if there is more iron or aluminum in the wastewater stream off than is entered. This also depends on the redox and pH ratios Soil and waste water together.

The filter material used does not only affect permeability, sorption and Plant growth, but also on the microbial activities.

Overall, the process mentioned then achieves its optimal long-term performance ability if not only individual parts are optimized for individual options, but when the overall system is optimized according to the task.

The method mentioned represents a multifunctional element in the landscape.

In addition to wastewater treatment, the areas involved in the process also serve Purposes of nature conservation, enrichment of the landscape, minimization of interventions in the landscape and water retention.  

References

- Hennig, E. (1988)
Humtrilogy
Eigen-Verlag, part 2, p. 12.

Claims (3)

1. Natural wastewater treatment process for households in decentralized areas
characterized,
that the procedure

• - separation of the coarse substances carried from the liquid phase (physical pre-cleaning) in the first cleaning stage (coarse material terry filter),
• - Physical and bio-chemical cleaning of the gray water produced in the second cleaning stage (reed bed),
• - Physical and bio-chemical cleaning of the carrier medium in the third cleaning stage (sand filter)

from a coarse terry filter with two downstream phytomechanical cleaners levels. 2. The method according to claim (1) with vertical flow, characterized, that the procedure in the distinctive order of the cleaning step shown fen (coarse material terry filter, reed bed, sand filter) and their corresponding depicted Structure is marked.