FR2465688A2 - Pollution control using binders - for treating oil pollution, residual sludges or waste waters (BR 11.12.79) - Google Patents

Abstract

Pollution control process, e.g. for (a) removing oil spills from beaches, (b) removing oil slicks from the sea or (c) treating residual sludges or waste waters, comprises applying hydraulic binders and/or natural or synthetic organic binders (esp. alpha- or beta-CaSO4.1/2H2O) which have setting, hardening, sequestering and retention properties such that a product which is easy to handle and recover is formed.

Description

 The present addition essentially relates to a process, products and devices for treating pollutants and in particular waste water and residual sludge, whatever their origin and consistency, and more particularly those coming from treatment plants. sewage effluent.

The main patent describes a certain number of applications of various products and especially those consisting of
Calcium sulphate hemihydrates in the form of ALPHA used pure or in a mixture with the sequestration of hydrocarbons discharged into the sea accidentally or deliberately. by oil tankers.

 The process according to the addition calls for the use and implementation of different products capable of first promoting, accelerating and then maintaining, the process of decanting and reducing the volume of the residual sludge to a greater or lesser extent. high water content by separation and rapid concentration of suspended particles; allowing easy removal and disposal of most of the excess water.

It uses an intimate mixing device for the pre-confined ingredients.

 It provides sludge sufficiently concentrated and of optimum consistency to be handled.

 It provides for their possible stabilization by spontaneous agglomeration as well as their IN SITU bacterial transformation.

 It makes it possible to incorporate them into certain building materials or to use them as organic fertilizers and fertilizers or as additional chemical or organic fertilizer substrates generally required by Agriculture. Finally, they can be packaged for burning in incineration plants household garbage.

 In particular, this process allows the complete treatment and final disposal of the residual sludge from wastewater treatment plants.

 In the current state of practical technology, it is known that residual sludge constitutes a bulky waste and difficult to dispose of which poses problems of all kinds and constantly increasing in communities, factories, laboratories, hospitals, etc ... and whose physicochemical resolution can only be organized punctually at great cost ;; up to and including the creation of an infrastructure for transport by land or river. The techniques applied to their stabilization, to their reduction in volume as well as their integration or disintegration depending on the case, are always expensive because of their complexity, the needs for monitoring and maintenance in foul-smelling environments, energy costs. They face incredible difficulties, either that they require the construction of large surface tanks in the case of "drying beds", occupied for months by stagnant water subject to the natural but random and seasonal phenomenon evaporation ;; either that they use significant filtration, centrifugation and dehydration equipment obtained thermally. In addition, the difficulties of separation of the liquid and solid elements are aggravated by the colloidal character generally presented by sludge.

The purpose of this addition is to solve all the problems posed by the previous more or less rudimentary, incomplete or unsanitary processes or considered too expensive; to avoid the drawbacks and proposes for this purpose a particular technique, simple and appropriate to the requirements public health, reliable and adaptable to all types of waste water or residual sludge whatever their origin and consistency, whether or not produced aerobically or anaerobically; and occupying only a limited area and can still if necessary be integrated in certain cases inside existing installations without requiring major transformations; including in particular
I-THE CHOICE of basic products taken together or separately, additives or adjuvants of complementary products depending on the desired degree of purification of free water and the consistency of the resulting mineralized waste composed of sequestered particles and combined ingredients.

2-The easy and simple USE of the aforementioned materials taken separately or mixed beforehand, as well as their mixing with waste water or with residual sludge; suitable for initiating, accelerating, maintaining the process of separation and segregation in order to succeed
IN FINE to the sequestration of all the solid particles in suspension whatever their form and their mineral or organic origin: LEAVING A FREE, CLEAR AND MORE OR LESS PURE WATER IN
FUNCTION OF THE GOAL TO BE ACHIEVED; IN A SHORT LAPS OF THE ORDER OF
APPROXIMATELY FIFTEEN MINUTES.

3-THE USE of specific inexpensive brewing equipment easily adaptable to existing or non-existing tanks.

4-THE TRANSFORMATION of solid particles in the form of a cake with a consistency previously defined, either in a friable and shovelable form with the appearance of a moist light earth, or in the more resistant form of an easily removable plate or slab.

5-INTEGRS.TION in different forms of amendments and fertilizers or substrates of additional chemical or organic fertilizers, or DESINTEGRATION by incineration, or STERILIZATION or MINERALIZATION in the form of construction materials.

 To this end, the present addition proposes a process for the treatment of sewage effluents - in particular waste water and residual sludge, treated or untreated - stored in tanks; either continuously or discontinuously, mixed with a binder according to a flow or in predetermined quantities.

According to another characteristic of the addition, the basic binder used can be calcium sulphate semi-hydrate in the BETA form, (and) (or), more favorably sulphate hemi-hydrate calcium in the ALPHA form of ordinary quality, or the mixture of the two semi-hydrates mentioned above, added or not, adjuvanted or not, mixed or not with other hydraulic binders of mineral or organic origin, with chemicals themselves mineral or organic origin having the effect for example of purifiers, sterilizers, disinfectant, flocculant, agglomerant, bactericides, fungicides or on the contrary vectors of bacteria or fungi, etc. possibly subject or not to influxes electric or magnetic.

 The results of the systematic tests undertaken within the framework of these applications and more particularly those concerning the choice of mineral and organic binders prove to be extremely variable; whether they are used pure for some, (and) (or), associated for others; between themselves, (and) (or), with other materials, and on condition of taking various precautions for use and proceeding according to the general line of the scheme retained by the spirit of the 'addition and although the description thereof is only one of many examples that it would be easy to highlight and with many variations; ; it appears that it is the calcium sulphate hemihydrate in the ALPHA form which allows - more than other binders - to sequester more easily the particles in suspension whatever the volume of water present. remember here that the combination reaction of calcium sulphate semi-hydrates in the BETA form generally results in much greater liquid retention in the presence of largely excess water than does that of calcium sulphate hemi-hydrates under the ALPHA form; also less sensitive to the presence of humic waste. As a result, the range of use of calcium sulphate hemihydrates in the ALPHA form is hardly modified and the rate of sedimentation remains substantially constant in all cases.

 The transformation of waste water and sludge into clear and limpid-looking open water, separated from suspended particles, collected and sequestered at the bottom of the basin in the form of a "cake of predetermined consistency", calls in the present case on the following concepts the quotation is not exhaustive nor the summary examination limiting.

After vigorous stirring of the calcium sulphate hemi-hydrate in the selected ALPHA form, used pure or mixed with other products, either in the aqueous medium considered, or 11 continuously "at the time of filling the basin and which occurs initially in a powdery appearance, generally with a density greater than I and which can frequently reach that of I, 5 and even more; there is a latent reaction prephase corresponding to the phase of "wetting of the grains of the binder and which can vary according to the qualities products used from a few seconds to a few minutes.

The subsequent hydration of the grains has the effect of increasing their density, releasing a ph slightly different from the initial ph which "breaks" the phenomenon of suspension. Very quickly then a few millimeters of released water appear on the surface of the bottom sin L colloidal agglomeration then begins, maintains, accelerates during the whole phase of maneuverability also called "range of use" which in fact corresponds to a pre-setting of the binder or the start of latent resyncrystallization. The crystals grow larger, (and we know that their shapes and textures can be predetermined at the time of manufacture of calcium sulphate hemihydrates in the ALPHA form; appearing at will in the appearance of more or less long needles or parallelepipeds This is of particular interest for the optimized determination of a calcium sulphate hemihydrate in the particular ALPHA form required by the best r treatment of waste water or residual sludge in this or that case. This is why we cannot speak of ONE calcium sulphate hemi-hydrate in the form ALPHA in the singular but of calcium sulphate hemi-hydrates in the ALPHA form in the plural.

 The crystals then begin to descend towards the bottom of the basin, creating a vertical autokinetic filtration effect directed from top to bottom which explains the relative slowness of sedimendation due to the "braking" of the particles in suspension. the crystal lattice and are drawn faster and faster downwards as the crystals grow bigger and agglomerate while increasing their density under the action of chemical combinations. The separation stabilizes in a short time short, about fifteen minutes and clearly reveals two well-defined parts: one characterized by its limpid appearance consisting of clear water from the decomposition of the elements in suspension compared to the other represented by the binder combined sequestration and containing all the solid particles of the initial liquid.

 It should be noted that the volume of water collected is maximum: I-By using a calcium sulphate hemi-hydrate in the appropriate ALPHA form. 2- When the intake is itself completed.

The hardening of the plate makes it possible to recover the two decomposition products in an easy way: free water to be rejected or re-cycle the plate to be reduced and constitute, as the case may be, an amendment and a fertilizer, or even a fertilizer substrate. chemical and organic supplements, or transformed into building materials or simply incinerated.

In general, the addition relates to the main patent and is in no way limited to the choice of the products mentioned, and (or), to the precasted mixtures, (and) (or), to the embodiment described, as well as '' to the results envisaged in the description and which have been given for information only. ; ; constituting technical equivalents, products, (and) (or), extrapolated means, (and) <or), reduced, described as well as their combinations, in association between themselves, (and) (or), to those of existing technology in the most diverse materials used for agglomeration, transformation, expansion, hardening, heating, etc. as well as their mobile means, (and) (or), fixed station, reduction, flow electric, (and) (or), magnetic; pumping, delivery, mixing, vibration, suction effect, segregation, etc .; if these are executed according to his spirit, their implementation and their uses within the framework of the claims that follow:

Claims (1)

 I-Process for the treatment of pollutants, according to one of the claims of the main patent; characterized in that it also makes it possible to treat substances other than hydrocarbons, such as sewage effluents and in particular waste water and residual sludge originating from the treatment plants of cities, factories, hospitals and communities in general.  2-A method according to claim I, in particular allowing the treatment of waste water and residual sludge whatever their origin and consistency, previously treated or not, whether or not resulting from an aerobic or anaerobic transformation, stored or not in tanks , characterized in that it consists either in brewing in the liquid present, or mixing "continuously" at the time of filling of the basins a binder used pure or associated such as a hemihydrate of calcium sulphate in the form ALPHA, in quantities or at a predetermined flow rate. Allow the suspension to decompose and decant to collect the free water from the sequestered particles gathered at the bottom into a solidified "cake" and to extract it by appropriate means and in a very easy.  3-A method according to claim 2, characterized in that it also consists in using various binders, added, (and) (or), adjuvants of specific products such as substances of mineral origin: for example metalloids; or organic: for example flocculants; intended to modify the nature of the liquids considered: for example to make them sensitive to the influence of electric or magnetic currents; (and) (or); resulting waste such as bactericides, fungicides or on the contrary seeds of various germs: for example "acinetobacter phosphadévorus.  4-A method according to claims 2 and 3, characterized in that the above-mentioned decomposition operation is carried out in a single phase and very quickly: of the order of a few minutes.  5-Process according to one of the preceding claims, characterized in that the solid waste recovered comes in different consistencies at the discretion of the user and are amendments and organic fertilizers and substrates of chemical and organic complementary fertilizers intended to Agriculture.  6-Method according to one of the preceding claims characterized in that the resulting waste can be used in building materials or disintegrated by incineration.