Frequently Asked Questions
 Is the disposer safe?
Sure it is! The majority of people are thinking that the disposer is fitted with blades or knives, but this is not the case! Against frequent heard prejudices, a food waste disposer doesn't contain any rotating knives. It can rather be described as an electrical grinder in which moisty wastes are ground on the rough external wall of the grinding chamber by a grinding ring. This works with the help of a turntable disk, on which two swivel impellers are fastened. The disk is provided with 5 mm. large holes, by those the suspension of water and ground food waste finally is led into the drain and sewerage system.
To increase the performance of the grinding system, especially on "tougher" food waste (long fibre vegetables), following a series of specific tests, Ecofast has modified the design of the grinding system, making it more suitable for the Mediterranean diet. The main changes effected are the following: - two "fixed" impact bars have been added opposite to the two original "free" swivel impellers.
- the diameter of the drainage holes on the rotating disk has been reduced whereas the number of holes has been increased.
Thanks to the high performance obtained, we can certainly say that these disposers are the only ones considered suitable for the Mediterranean diet currently available on the market.
As you would expect, all our disposers are marked CE and have got the D quality and safety mark.
Which kind of waste can I dispose of? With the aid of a food waste disposer all organic kitchen waste, such as vegetable and fruit peelings, coffee grounds, tea filters, scraps of cooked dishes (vegetables, meat, fish), small bones (chicken), etc. can be ground. Non food-waste like: metal, glass, porcelain, leather, cotton, rubber, plastics and in addition hard organic material such as wood, fruit stones and large bones cannot be ground, since the mechanism of the device is not intended for such materials.
The attempt to grind such materials will cause a resistance, which causes a switch off of the engine (overload protector). Additionally an intense noise is connected with the attempt of grinding hard materials which has an educational effect on the user.
How much maintenance is necessary? The disposer has been designed and manufactured in such a manner as to do away with preventive maintenance. When cleaning, besides using our biological product "Biofast - L'Ecologico" in tablets, it may be a good habit to simultaneously feed ice cubes and a cut lemon into the disposer. This removes residues and odours and, in case of prolonged absence, leaves it perfumed, clean and disinfected.
What if something drops into the disposer? If something that shouldn't be ground falls into the disposer (for example a teaspoon), the disposer must be switched off immediately in order to recover the object manually. Although there are no blades that can cut or scratch you, a tool such as long-handled pliers may be used to perform such an operation.
Should you have failed to switch off the disposer immediately, you must press the overload protector switch located at the bottom of the machine in order to restart operations!
The accidental fall of objects into the disposer is nevertheless a rare event, especially considering the fact that our disposers are equipped with a special "inlet valve". This part, which is made of rubber, besides carrying out the function of Silent Block and non-return device, effectively prevents the accidental dropping of elements that are not to be ground thanks to its particular shape.
Is it necessary to have a special sink? | All our disposers have been designed and manufactured to be installed on a large majority of existing sinks. ECOFAST offers a series of optional accessories that allow the disposer to be fitted to 2" and 3" sink openings, even if these are in marble. Our disposer is easily installed under the sink in less than half an hour (the outlet of the disposer is attached to the siphon of the sink) and does not required too much space! |  |
Is the disposer noisy? Most of the people are astonished to discover that the disposers are relatively silent (much more than other small household appliances). The "deluxe" models contain additional soundproofing materials, lowering noise levels further. In any case, its usage time simply boils down to a couple of minutes, daily!
Can the disposer be used if the house is linked to a septic tank? By using our biological product "Biofast L'Ecologico" it greatly contributes to the biological activity of your septic tank besides keeping the pipes clean and odour-free. In fact, these microorganism digest both food and household waste inside your septic tank- helping to reduce the accumulation of solids.
How much water and electricity does a disposer consume? The monthly average consumption of electricity for a 1/2 HP disposer is equivalent to the electrical energy consumed by a 100 Watt light bulb in five hours, whereas water consumption amounts to approximately 5 litres per day. However, if properly used, such consumptions is of meaningless impact!
What is a "press" for food waste?"
A compact or modular food waste reduction system is an equipment composed by a food waste disposer (FWD) and an apparatus for the separation of the ground food waste from the process water (normally a self discharging centrifugal machine).
Whilst the solid part ( the ground material mechanically squeezed) is stocked in a container so it may subsequently be disposed of in a composting plants to be recycled in a good fertilizer, the process water part goes into the drain to the sewerage system where it may be profitably used in the depuration plants (especially in those with low organic load), for the biological removal process of the nitrogen and phosphorous.
The utilization of this machine is for commercial users such as restaurants, hotels and supermarkets, but Ecofast has developed new applications in the domestic field (see SNOP and Food Waste Reduction System for Multiple Apartment Buildings)
Why is the "Compact Food Waste Reduction System" useful?
Because they perform a reduction: drastic in volume, lower in weight, of food waste, thus facilitating the increase of the source separated collecting system.
Thanks to their use the following advantages may be obtained:- Fewer costs for separate collection, transport and disposal of food waste;
- More waste collected in a separate way;
- Positive logistic impact: fewer trucks on the road, fewer malodorous bins on the street;
- No sedimentation problem in the sewerage system;
- Increase of the organic load in the waste water treatment plants for the the removal of nutrients (RBCOD);
- Dryer waste and so less polluting.
- The food waste collected, lastly, is ready for the composting cycle because it is ;
- homogeneous;
- highly selected;
- at low conductability;
and so usable as an amendent in agriculture rather than as a "stabilised urban fraction" to be disposed of in a dump.
Can the use of food waste disposers bring benefits to the depuration of waste-water and more in general to the environment?
Yes, and in particular in wastewater treatment plants (WWTP) with a "low organic load" where normally expensive chemicals, such as acetic acid, methanol or other (which are important expenses in the management of a WWTP) are used to remove nutrients, in particular nitrogen and phosphorous. Infact, by using food waste disposers, the carbon discharged into the sewerage system is rapidly available for the BNR (Biological Nutriment Removal) process at the cost of next to nothing for the WWTP's manager.
What is more, if the plant is provided with an anaerobic digester for the production of bio-gas, the saving on electric energy for self consumption can be very important (€2,8/AE per year).
In the present table reviews the data of a recent study conducted, in 2001, by the University of Hannover (ISAH) by the professors Rosenwinkel and Wendler, on the impact of the ground organic fraction in the depuration plant.
| |
Domestic waste water loads*
g/(capita*d) |
Additional loads
due to FWD
g/(capita*d) |
Application % |
| Flow |
128 l/(capita*d) |
4,5 l/(capita*d) |
3,5 |
| Screenings |
0,016 |
0,17 |
5 |
| Grit |
0,04 |
0,042 |
5 |
| COD tot. |
120 |
18-36 |
15-30 |
| BOD tot. |
60 |
6-15 |
10-25 |
| TKN |
11 |
1,5 |
5-10 |
| P tot. |
1,8 |
0,13-0,25 |
7-14 |
| SS |
70 |
28-40 |
40-60 |
| C/N |
2/1- 5/1 |
25/1 |
+++ |
| Primary sludge |
45 - 54 |
20 - 40 |
50 - 70 |
| Surplus sludge |
10 - 35 |
5 - 20 |
10 - 40 |
| Raw sludge |
ca. 80 |
ca. 50 |
ca. 62 |
| Digested sludge |
48 - 60 |
15 - 18 |
30 - 50 |
| Biogas |
16 - 25 L/(E*d) |
16 - 25 L/(E*/d) |
90 - 100 |
*for Germany (after the German waste water associations working paper A 131 (ATV,2000))
As concerns the environment, the reduction of emissions (see our environmental impact assessment) and leakage may be seen as more evident advantages: general improvement of hygiene and public health. For your information, the city of New York, after an experiment which lasted two years, conducted in certain zones of the city: (Queens, Brooklyn and Manhattan) not provided with a separate sewerage system, has removed the ban on the use of disposers, which had been existing since 1994, and, by starting from 2000, it has encouraged their utilization with a contribution of 300 US dollars for each disposer installed.
Can the use of food waste disposers jeopardize the correct functioning of the sewage system?
While their is no damage to separate sewage systems, that is, a distinct pipe for white and black waters, for the mixed sewerage systems, that is, those in which both the black waters and those of meteoric origin flow together, some problems could occur due to the fact that, in the periods of heavy rainfalls, the flooding of the increased loads may happen with the consequent emission into the environment of the solid waste transported. This occurs in particular in times of heavy rainfalls which follow extended dry periods.
It is necessary to point out that phenomena of this type, which were at the basis of the concern of the Municipal Administration of New York City, were denied by specific experiments conducted in the field. However, in the event of this phenomenon should worry the sewage's manager, some countermeasures may be taken to prevent it, through the adoption, for example, of well-traps where to retain volumes of rain-water to release, from time to time, during periods of drought in order to keep clean the sewerage. As the food waste, once ground, have a similar composition and density of the sewage, sewers' malfuncion should't be occured even at low speed.
| Chemical composition of |
%C |
%H |
%O |
%N |
%S |
| Sewage |
59,7 |
9,5 |
23,8 |
7,0 |
0 |
| Ground food waste |
50,5 |
6,7 |
39,6 |
2,7 |
0,4 |
(University of Wiconsin-Engineering comparison of 5 systems for the managementof food waste-1998). Concerning sedimentation of suspended solids, we would like, instead, to summarise the studies on the granulometry of the various merceological components of the OF-MSW and on their velocity of sedimentation conducted, recently by the Marche Polytechnical University - Ancona. A comparison between the sedimentability of the OF-MSW ground down and the suspended solids of the civil sewage systems may be carried out considering the behaviour of the wastewater taken at the entrance of a treatment plant, upstream of the station lifting, in conjunction with the dry peak flow and concentrating preventively the solids contents by about ten times. This measuring condition implies that the velocity of sedimentation measured are markedly inferior to the real ones so, in the case of a comparison with the ground matters of OF-MSW, extremely cautious. In such conditions the behaviour of the wastewater in entrance at the depuration plants of Ancona-ZIPA, Falconara (AN) and Jesi (AN), are shown in tab.2 (Bolzonella et al,2002):
Tab.1 Data on sedimentability of the different granulometric fractions of food waste (Bolzonella et al.; 2002)
Product
fraction |
Dimension
(mm) |
Floating fraction
(%) |
Sedimentation speed
(mh-1) |
| |
Avg. |
Dev. Std. |
| Fruit |
>=0.84 |
78.0 |
16.6 |
4.0 |
| <0.84 |
54.7 |
3.3 |
0.8 |
| Pasta-Bread |
>=0.84 |
0.0 |
22.7 |
3.1 |
| <0.84 |
8.0 |
1.7 |
0.4 |
| Vegetable |
>=0.84 |
0.0 |
19.4 |
3.3 |
| <0.84 |
37.3 |
2.3 |
0.4 |
| Meat |
>=0.84 |
62.0 |
17.3 |
1.1 |
| <0.84 |
30.3 |
4.0 |
0.5 |
| Fish |
>=0.84 |
0.0 |
24.5 |
1.6 |
| <0.84 |
40.0 |
11.3 |
1.2 |
Tab.2 Sedimentation speed of the solids in the sewerage system
| Sewage |
TSSmg/l |
Sedimentation speed (m/h) |
Dev. Std. |
| Ancona-ZIPA |
3289 |
15.5 |
1.8 |
| Falconara- AN |
2125 |
14.0 |
2.9 |
| Jesi - AN |
800 |
10.1 |
0.4 |
A further term of comparison is constituted by the velocity of sedimentation of other solid materials present in the depuration system, during the various stages of the process, see Tab.3 (Metcalf & Eddy, 1991)
Tab.3 Sedimentation speed of some kind of solids in WWTP
| MATERIAL |
SEDIMENTATION SPEED
m/h |
| Sand 65 mesh |
69 |
| Sand 100 mesh |
46 |
| TSS in primary clarifier |
1,8 |
| TSS in secondary clarifier |
1,1 |
From the comparison of Tab.2 with Tab. 3 it can see that the gravitational behaviour of the wastewater in the studied plants (Tab.2) is perfectly coherent with the various materilas which may be introduced into the depuration plants. Different experimental results would have reduced the meaningfulness of the methodology and of the materials used and underlined an anomalous behaviour to be attributed principally to the constructive elements of the sewerage system. The application of the results of Tab.2 to those of the gravitational behaviour of the various granulometrical fractions of the OF-MSW (Tab.1) permits to define the Tab.4, therefore the contribution to the settled solids in the sewerage system of the ground food waste discharged into it.
Tab.4 Behaviour of the suspended solids in the sewerage systems (Bolzonella et al.; 2002)
| Food waste |
Granulometric
distribution (%) |
TSS load
into
WWTP
(%) |
TSS
settled
(%) |
| |
< 0.84 mm |
> 0.84 mm |
< 0.84 mm |
> 0.84 mm |
|
| Fruit |
79.0 |
21.0 |
79.0 |
19.5 |
1.5 |
| Pasta-bread |
42.1 |
57.9 |
42.1 |
37.5 |
20.4 |
| Vegetable |
56.1 |
43.9 |
56.1 |
36.2 |
7.7 |
| Meat |
33.4 |
66.6 |
33.4 |
57.7 |
8.9 |
| Fish |
63.9 |
36.1 |
63.9 |
26.8 |
9.3 |
| Food waste |
50.1 |
49.9 |
50.1 |
33.1 |
16.8 |
Definitively no more than 17% of the solids transferred with the OF-MSW ground settled in the sewerage whilst all the others arrive to the wastewater treatment plant. Considering the fact that this result comes from:- the application of velocity of sedimentation of suspended solids which are transported in real sewerage systems measured at a concentration ten times higher;
- the determination of the velocity of sedimentation of the different merceological fractions which compose the OF-MSW, where only the fastest particles which sediment are taken into consideration;
it may suppose that the final result is extremely positive, expressing the complete discharging possibility of the ground OF-MSW in the black and mixed sewerage systems.
What is RE-WISE and Si.Qu.R.O.?
RE-WISE is a project in European partnership financed by EACI (European Agency for Competitiveness and Innovation) within the context of IEE (Intelligent Energy Europe) coming from a technology property of Ecofast Italia S.r.l. (sistema SI.QU.R.O.).The Re-WISE purpose is the promotion of a integrated system for the decentralised production of electricity and heat from biogas from food waste, made with the massive use of domestic food waste disposers of second generation, able to quantify the waste introduced into the sewerage system. By using this infrastructure as a means of transport for the ground food waste, it is possible to increase, in a substantial way, the production of biogas in the depuration plants equipped with anaerobic digestors.
What is FUS 20? FUS stands for Organic and Dry Fraction (ODF), thus highlighting that for the correct recycling of domestic waste, it is necessary to separate the two fractions: the organic and dry ones by starting from every household. "20", on the other hand" stands for 20th century, which saw this system become widespread in the European countries. The main objective of the FUS 20 System is to channel all the domestic waste into a hygienically safe system, with a smaller environmental impact than road transport, requiring less effort and less expensive both for the citizen and for the public administration.
in this way, the percentage of separate waste could increase markedly, thus allowing for a definite step forward towards the achievement of the objectives set by the European Authorities.
In practice, the system is based on the use of a domestic appliance, the disposer which is placed under the kitchen sink, which reduces the food waste to a sort of liquid pulp which goes directly into the sewage system. From here, without the need for any type of container or truck, it reaches the depuration plant and in the form of sludge may be transformed quite easily into a source of energy (by means of anaerobic digestion), and then in compost, adding the so called "green leftovers" (leaves, grass and cut branches) and other bulk waste such as the waste produced by the greengrocers and vegetable markets. The complete elimination of the domestic organic fraction achievable thanks to the disposer, not only increases the energy value of the remaining dry fraction, but limits the polluting capacity of municipal solid waste. The FUS20 System is applicable anywhere there is a sewage treatment plant. It is however suitable that the installations could be regulated by the WasteWater Companies, who better than any other are able to evaluate the opportunity of this service in relation to the flexibility of their depuration plants and to the conditions of the sewerage systems. Ecofast suggests a gradual implementation of this new system in the form of a new service comprehensive of disposer's installation and service on behalf of specialized firms which guarantee the safety of the installation.
The modality of installation is checked case by case, trying not to modify the sink and the electrical system. The saving on costs relative to the source separate collecting system and the disposal of the organic fraction
greatly covers the cost of the FUS 20 System and the depuration costs. What is more, thanks to Si.QU.R.O. technology, a quantifing system able to measure the waste processed by a disposer, it is possible to charge the user of the exact quantity disposed of in compliance with the European rule: "pay as you throw".Calculate the economic advantage of the FUS 20 System The disposer has a cost like its installation. A cost that may be amortized in a short time thanks to the saving which the system allows.
Thanks to this system it is possible to calculate the total investment that providing with a disposer all or a part of the citizens resident in your city, and then, comparing it with the cost of collecting and disposing of the organic waste produced by the same citizens, the time necessary to absorb such an investment reaching the "break even point".
The data obtained limits itself to providing an order of the proportion of the economic return of the investment and so it could vary more or less in function of the final destination of the greater quantity of sludge produced in the depuration plant consequent to the spreading of the disposer. More if their disposal is limited to the dump, less, in the eventuality that they may be reused to produce quality compost;
(For the calculation refer to: calculation).
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