CN101148279A - Treatment of sewage and reclaiming of active ingredient in kitchen castoff regenerative feedstuff preparation - Google Patents

Abstract

The present invention relates to sewage treatment for producing regenerated feed with kitchen refuse, and is especially technological process of treating slurry from dewatering kitchen refuse and recovering most grease and solid nutritious matters. The technological process for treating slurry, percolate and flushing water simultaneously includes aeration deoiling in an air floating machine to recover oil and grease for industrial use, and subsequent neutralizing, coagulating, pressure filtering, etc to recover solid nutritious matters. The process can eliminate most organic components from the sewage, reduce sewage discharging amount and make sewage reach discharging standard.

Description

The sewage disposal in the kitchen castoff regenerative feedstuff preparation and the recovery of effective constituent

Technical field

The present invention relates to the sewage disposal in the kitchen castoff regenerative feedstuff preparation, the recycling of the slurries of particularly discharging in dehydration procedure processing and effective constituent.

Technical background

China's city kitchen castoff has the advantages that quantity is big, quality is high, foreign material are many.Removing operations such as foreign material, dehydration, sterilization, oven dry, pulverizing through letter sorting, it is prepared into nutritious protein fodder, is the new technology of succeeding in developing in recent years.

Sewage in the regenerative feedstuff preparation process, natural filtration liquid, the slurries of discharging during dehydration and small number of devices wash-down water when mainly receiving and sorting from kitchen castoff.Yet for the sewage that produces in the preparation process, especially the slurries of discharging for dehydration do not find the rational and effective treatment process so far as yet.At present, for percolate and wash-down water, generally take the mode of water drain discharging; Then often take the water mixing dilution discharge or make the mode that feed directly feeds pigs for slurries.The direct discharging of sewage, inevitable serious environment pollution is especially to the pollution of water body; Though it is nutritious that slurries directly feed pigs, but wet, greasy, the sticking proterties that reaches the organism enrichment that slurries have is very easily putrid and deteriorated, also often contains pathogenic bacterium, parasite and worm's ovum, various variations in the decay process and go mouldy and all may produce new toxin, edible this class pork of people will jeopardize health.No matter directly discharging or feed pigs as feed, all with the serious harm existent environment of people, all is again that country and local regulation are prohibited already.Therefore, solving as early as possible above-mentioned sewage, especially slurries are carried out the loss that effective constituent was handled and avoided to rational and effective, is an important and urgent subject.

Summary of the invention

Slurries when dewatering in order to solve above-mentioned kitchen castoff, the effectively processing rationally of natural filtration liquid and equipment wash-down water; Reclaim effective constituent wherein, avoid the loss of grain resource; Prevent environment and the forgetful harm of human body, the invention provides and a kind ofly handle slurries, percolate and wash-down water simultaneously, and therefrom reclaim the processing method that grease and eutrophy such as expect admittedly at effective constituent.

This processing method is that earlier with above-mentioned slurries, percolate and wash-down water import in the lump in the sewage storage tank and mix, and import and remove in the oil drum, adopt the air supporting machine to carry out aeration oil removing and grease recovery.Slurries after the oil removing change over to give and handle in the bucket, add alkaline solution and carry out neutralization reaction under the state that slurries are stirred, and the pH value of control slurries is 7～8, and neutralization reaction is finished.Slurries after the neutralization add flocculation agent equally and carry out coacervation under agitated conditions, when more clarifying water and floss appearance, the coacervation process was finished when both obviously separated.Liquid after the coacervation imports that belt filter press dewaters and filter cake again, i.e. the eutrophy recovery of expecting admittedly.Practice shows, as long as the oil removing of slurries, and neutralization and coacervation respond well, then last dehydration in belt filter press is just very smooth and easy, and solid material reclaims very easy.

In the percolate of kitchen castoff, especially in the slurries that dehydration is discharged, the organic content of grease and eutrophy is quite high.Put into practice statistics and show, the slurries that dehydration is discharged in the kitchen castoff per ton adopt processing method provided by the invention to handle at 450～500 kilograms, and about 35 kilograms of recyclable greases dewater through heating, and the crude oil behind the decon is as the prepared using of industry oil; The filter cake that reclaims, promptly eutrophy is expected about 150 kilograms admittedly, being mixed in the diet and kitchen wastes of dehydration back can increase about 80 kilograms of high-quality protein feed after sterilizing, dry, pulverizing, and has further improved the nutritive ingredient of feed; Because most organic is removed in the waste water, the organic concentration in the waste water meets the requirement of the relevant discharging of country, and reduces wastewater flow rate about 40%.Processing method provided by the invention, its beneficial effect be, eliminated sewage in the kitchen castoff regenerative feedstuff preparation process to the pollution of environment and to the harm of HUMAN HEALTH; Avoided the mass efficient composition, i.e. the loss of grain resource; Quality of the fodder and output have been improved.

Description of drawings

Accompanying drawing is sewage disposal and an effective constituent recovery process flow sheet in a kind of kitchen castoff regenerative feedstuff preparation.

Embodiment

Referring to accompanying drawing, the sewage disposal in a kind of kitchen castoff regenerative feedstuff preparation and the recovery of effective constituent, its processing method can be divided into the sewage collection and mix, aeration oil removing, neutralization and coacervation, four processes such as press filtration.

(1) sewage compiles mixing

The first-selected slurries that press dewatering is discharged, wash-down water in the natural filtration liquid of material reception and letter sorting section and the equipment collects in the lump in the sewage storage tank and mixes naturally.Wherein the slurries amount accounts for about 90% of sewage total amount, and percolate and wash-down water generally only have about 10%, if handle respectively, then flow process is loaded down with trivial details and very uneconomical, handles simultaneously after concentrating, and flow process is much simple and direct and economical.Sneaking into of percolate and wash-down water can be reduced the concentration and the viscosity of slurries, helps the further raising of aeration deoiling effect.

(2) aeration oil removing

The shut-off valve K of elder generation ₂With valve K ₃, open valve K ₁, start the vertical screw pump, the input of the sewage in the storage tank is removed in the oil drum, treat to close the vertical screw pump when liquid level rises to apart from 200 millimeters in bung face, leave 200 millimeters high volumes and be the space that holds for oily foam that aeration produces.Restart the air supporting machine and carry out the aeration oil removing, the grease behind the approximate number minute in the material particles of liquid separates and floats, and forms the oily foam layer of about 150 mm thick on liquid level, can adopt artificial or mechanical means oil skimming, collects through grease receiving tank and pipeline barrelling.The key equipment of aeration oil removing is an aerator, and aerator is of a great variety in the market, and performance is different, and to discharge the aerator of the special composition of slurries and proterties few but can adapt to kitchen castoff dehydration.Practice shows that mechanical type air supporting machine is fit to the aeration oil removing of above-mentioned slurries.Simultaneously, remove the structure and the volume of oil drum, must determine according to the requirement of mechanical type air supporting machine.The quality of slurries deoiling effect will directly influence last dehydrating effect in belt filter press.

(3) neutralization and coacervation

Sewage in the kitchen castoff often presents certain acidity, and prolongs acidity in time and increase to some extent.Being tart sewage will influence the coacervation effect, and therefore must add certain amount of alkaline solution carries out neutralization reaction.The add-on of alkaline solution is decided by its concentration and sewage quantity, is example with sodium hydroxide, and concentration is that the add-on of 10% sodium hydroxide is about 8% of barrel interior sewage quantity.The operation of neutralization reaction is referring to accompanying drawing, first shut-off valve K ₆, open K in the valve ₂, restart the slurries in-line pump, the sewage after the oil removing is imported to give again handle in the bucket.Start and give the stirrer of handling bucket, under the state that sewage is stirred, open valve K ₄, inject alkaline solution, simultaneously with the pH value of sewage in the phenolphthalein test paper observation bucket, also to directly observe the pH value of sewage with the instrument of PH meter, when pH value near 7 hours, variable valve K ₄Flux of alkaline liquor reduces, when pH value arrives 7.5 left and right sides, and shut-off valve K ₄, stopping alkali lye and inject, neutralization reaction is finished.

Still carrying out coacervation in giving the processing bucket after neutralization is finished handles.Concrete operations are referring to accompanying drawing, and are same under the state that sewage is stirred, and open valve K ₅, inject flocculation agent, when clarifying water and floss engender variable valve K ₅, reduce the injection rate of flocculation liquid, when observing water and obviously separate with floss, shut-off valve K ₅, the coacervation process is finished.The adding of flocculation agent, changed the state that has the identical polar electric charge in the original sewage with a kind of colloidal solid, destroyed colloidal stability, make that fine suspension and colloidal solid attract each other in the sewage, be combined into the floss of larger particles, more clarifying water separates gradually with floss, coacervation process that Here it is.Show in numerous flocculation agent kinds, to have only the sewage in the suitable kitchen castoff of APM type cation polymeric flocculant through a large amount of tests, coacervation is respond well.The preparation of flocculant solution must be carried out according to selected flocculant product service requirements in the medicinal liquor barrel.The add-on of flocculant solution is also decided by composition, quantity in its concentration and the sewage, and generally the solution add-on by the preparation of 0.3% concentration is about 8% of a sewage quantity, and this consumption during than the other industry sewage disposal is much bigger.Give the stirring earthquake intensity of handling stirrer in the bucket, should control its blade outer peripheral lines speed and be no more than 8% meter per second, to prevent the degraded of polymkeric substance.

(4) press filtration

Liquid after the coacervation is by valve K ₆Adjusting, utilize drop, import automatically and dewater in the belt filter press and filter cake is collected, be i.e. the eutrophy recovery of expecting admittedly.The belt filter press that the present invention adopts has been done improvement to the control of press filtration power and the regeneration of guipure on the basis of existing technology, has promptly increased a pair of pressure roller and the cleansing power of having strengthened guipure, with the characteristic trait of sewage in the further adaptation kitchen castoff.

Because kitchen castoff is from different scales, units such as dissimilar catering trades and enterprises and institutions, complicated component in its material is changeable, water content also has nothing in common with each other, cause the sewage in its regenerative feedstuff preparation, especially the composition of slurries, the unstable of concentration, proterties and quantity is so processing method provided by the invention has solved this technical barrier.

Claims (2)

1. the processing of sewage, especially dehydrated slurry during a kitchen castoff regenerative feedstuff prepares and the processing method that effective constituent reclaims is characterized in that the mixing that compiles of sewage, four processes such as aeration oil removing, neutralization and coacervation and press filtration.

2. processing method according to claim 1, its feature also is the slurries with press dewatering, the natural filtration liquid in the material and the wash-down water of equipment, handle and from sewage, reclaim effective constituents such as most greases and eutrophic solid materials simultaneously, most organic is removed, made waste water decrement and qualified discharge significantly.

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