A commentary on: “Nomograma of a landfill (MSW)—setting m parameter values”

OPEN ACCESS This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http:// creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes. For commercial reuse, contact reprints@pulsus.com A type of the municipal solid wastes known as MSW (excluding the potential radioactive waste) are continuous generated and must have an increasing concern from all factors involved, such as: waste generators, economical operators belonging to the waste management, local and central authorities, all of them being involved into a friendly waste management regarding the environment. At the legitimate question: how the adequate management of the landfill (MSW) wastes will influence the climate changes is possible to answer as follows:

A ny type of the municipal solid wastes known as MSW (excluding the potential radioactive waste) are continuous generated and must have an increasing concern from all factors involved, such as: waste generators, economical operators belonging to the waste management, local and central authorities, all of them being involved into a friendly waste management regarding the environment. At the legitimate question: how the adequate management of the landfill (MSW) wastes will influence the climate changes is possible to answer as follows: • Bio-degradable wastes, without economic value, have potential gas emission leading to greenhouse effect; • Un-recyclable wastes, e.g. paper and cartoon, textile, wood and straws from garden and parks are also responsible and have a contribution to the greenhouse effect; • The mud from used industrial water treatment plants, water connected with the house using, mud from zootehnic farms have an important contribution to the greenhouse effect gas emission generation; • Industrial wastes (MSW) together with the wastes from medical sector have also an important potential for greenhouse effect.
It is already known that the greenhouse effect gases (6 identified gas types were identified) are dangerous for the global atmosphere heating, among them CH 4 is the most dangerous one. CH 4 present a special attraction for investors, in the same time, because of its economic value (1-3). At an MSW landfill the waste depositing is happening within a calendaristic year, AC (which starts at 01.01 and ends at 31.12). The calculus year, AT related to the estimation of gas emission, is smaller with 6 months than AC (international community accepted that the waste deposited within last 6 months of the AC -31.07 ÷ 31.12-remains undegraded or with an incipient one. The calculus year AC is the year after the calendaristic year AT of the waste (MSW) depositing is over. The equation of the first year calculation, after the 2nd year of depositing is over, is (for n=1): 11t+7=25-t.
The equation of the 2nd year calculation n =2, is 19t+7=37-t, etc. • The person who is in charge for setting up NOMGRAMA of an MSW landfill has to have enough experience in the waste management field. If a computer software it will be used, there is the possibility to have a blockage it in waste management and to say that "the approaching of NOMOGRAMA setting up values is wrong". environment authority, annually (9).
For the CH 4 gas emission calculation period belonging to the calculation year 1 -AT1 and the year 8-AT8, the m parameter establishing relation is: , known as the Vieru 1 relation. Where: • F.T.R -free right term of the eq. 2; • 7-a natural number which means: if 7 accumulate at 3 times the time of stationing a quantity of municipal waste (MSW) on a site, the same result is obtained when a time (expressed in months -m-) of number (12n+13) is obtained). • for the m establishing values, starting with the 9 th calculus year (eq. 2-9) • 75t+7=121-t) up to the year 30, the following relation should be used: The established calculus relation can be applied to all conform or nonconform MSW landfill deposits to capacity >10 Gg/year.

The friendly environmental MSW depositing management significance
It is known that having deposits with capacity between 80÷800 Gg or more (deposits with capacity less than 80 Gg being closed), this measure will lead to the followings: y y Increasing Auto Park for wastes collecting, y y Road infrastructure improvement in order to be able to collect the waste from all locations and increasing the lifetime of the MSW waste collection trucks, y y Proper identification of the CH 4 gas emission moment when it can be burned or collected, y y Adding of CH 4 in significant quantities, so the investors should put in practice their projects, y y Investments within the friendly environment waste management condition will lead to new job opportunities (10).
Collection of the CH 4 gas emissions, on site, for MSW landfill deposits will lead to an annually reducing of the greenhouse gas effect with a percentage of 1 ÷ 2%. This aspect will have, as a consequence, an environmental temperature reducing by minimum 1°C. Increasing of CH 4 gas emission as an energetically resource, it is to be noticed, also.

CONCLUSION
The approach of a deposit gas emission (LFG), mainly CH4 taking into account the degraded MSW quantities, at the calculus year A C , will lead to a correct estimation of CH 4

gas emission quantities
It is clear that the Vieru's (1,2) application method for the estimation of the CH 4 quantity from the Romanian MSW landfill waste deposits, conforming or nonconforming, should be an important alternative among the existing calculus relations already, on international level too.
It is to be noted that MSW deposited quantities are absolutely necessary to be known, as a common factor but the approach way has to be as follows: time, expressed in months-m-is the factor which have a decisive contribution to the MSW wastes degradation up to the DOC (dissolved organic carbon) phase.
Another example of the Vieru's (1,2) method application related to the CH 4 gas emission calculation is given in the Figure 1.