ABSTRACT

The CH₄ is one of the six Greenhouse Effect Gases (GEG) that is mentioned in the Kyoto Protocol. The GEG is generated by the anthropic activities which are conducive to climate changes if their management is not conducted in a proper way. The main purpose of the environment policy is the reduction of the GEG emission. It is well-known that the CH₄ gas emission from municipal solid waste MSW landfills is responsible for 4 ÷ 5% of the total Greenhouse Effect. It is necessary to have a practical method to calculate the quantitative CH₄ gas emission, in order to apply an efficient management of the CH₄ gas emission from MSW landfills, conforming or non-conforming. This method has to be transparent, credible, coherent, and applicable both for conforming and non-conforming MSW deposits. This paper proposes a new estimation calculation method of the CH₄ gas emission from all MSW deposits in Romania. The IPCC group of experts has made recommendations related to the estimation of CH₄ but the European Union (EU) admits that the environmental conditions are not the same in every Member State. The annual evolution of CO₂ for the CH₄ gas emission at every MSW location is valuable information for the Environment Authority with a view to realistic environmental planning and for an efficient policy to be applied in order to reduce the greenhouse effect of MSW landfills.

Keywords:

Ecological Condition, GEG, Landfill, MSW, Urban Area

1. Introduction

In May 2013, the United Nations (UN) adopted the KYOTO Protocol [1] relating to the pollution emission agents and the transfer registers (based on the so called PRTR Protocol or Kiev Protocol) [2] together with the UN Convention on climate changes.

This Convention is referring, among others, to the landfills having a daily activity of more than 10,000 tons/day MSW which amounts to more than 450,000 tons/year. For these landfills, starting with 2007, the individual CH₄ emission rate [3] has to be calculated and the results have to be communicated to the public. EU has adopted the European Emission Register in order to be in conformity with the PRTR Protocol. This Register provides some criteria to be fulfilled: transparency, coherence, the possibility to compare results. These criteria are a condition for the calculated results to be accepted into a national data base. Romania has adopted the UN PRTR Protocol and for the MSW landfills with more than 10,000 tons/day, the CH₄ emission will be included in a register. The Member State governments have to report all aspects related to the Climate Changes [3] to an inter-governmental group.

It is very clear that a method to estimate the CH₄ methane gas emission from MSW landfills is absolutely necessary [3] .

This method has to cover the calculation of the CH₄ emission from both conforming and non-conforming MSW Romanian landfills [4] [5] . This method was applied for the CH₄ emission calculation of 13 MSW landfills―conforming and non-conforming. In this paper the calculated values for CH₄ emission [4] [5] [6] and the equivalent CO₂ for 1 non-conforming and for 2 conforming landfills are presented.

Analyzed landfills are located in Satu Mare, Ilfov and Bucharest municipality, Romania. The proposed method has a high degree of efficiency.

The CH₄ emission calculus for those 13 Municipal landfills (msw) and the drawing up adjacent graphics related to the equivalent of CO₂ demonstrate that the GEG is present. The Romanian Environmental Authorities have to act on this matter and to acknowledge about the GEG intensity and its duration [7] , in the same time.

The Proposed method allows us the quantitative evaluation of CH₄ emission to be used as a natural energy source. Within the actual management of wastes only the sort of wastes having economical energy value is applied, according to the Europe Council provisions. It is to be mentioned also that only 20% of the generated wastes is sorted. In the deposit body, they are not included: metallic wastes, plastics, tires, recyclable wood or with energetic value, paper wastes and recyclable cartoon. It is to be mentioned also that, from information delivered by the local source, within the landfill body they are not included: inert wastes (construction and demolition), plastics, soils and stones, asbestos; the total contents of these wastes are not considered to be more than 10%.

I have to make a remark: the drawing up graphics were obtained by manual calculation rather than using specific software.

2. Present Situation

All types of wastes were deposited together [4] , in specially designated MSW deposit areas, those coming from the anthropic activities as well as those generated by the agriculture and live-stock farm activities, e.g. animal and bird dejections. The bio-degradable wastes (rubbish) generated by intensive agriculture have to be taken into consideration as well.

The problem of the global warming and the obligation to apply the Kyoto Convention requirements involve the fulfillment of the rules regarding the limitation of the MSW gas emission [7] and the prohibition to have MSW landfills which do not comply with the rules of environmental protection [2] .

Since 1999 Romania has started to have MSW landfills, in ecological condition, in accordance with the European regulation in the field, and, from 2007, when Romania adhered to the European Union (EU), all the MSW landfills have to respect, strictly, the EU legislation, as provided within the 75/442/CE Directives [5] [8] provisions.

This Directive [5] [8] was adapted [4] to the Romanian legislation by Government Decision [4] order no. 349/2005.

3. Estimative Methods for Ch₄ Gas Emission Calculation

The quantity of the CH₄ gas emission from MSW landfills can be estimated, by calculus applying two methods, as follows:

METHOD No. 1

IPCC 2006 Method-Default Method (DM).

This method supposes that a non-dangerous MSW deposit will generate [9] [10] , within a year, a certain quantity of CH₄ and, in the next year, it will be a new amount of CH₄ This method will not take into consideration the hypothesis that an MSW deposit is a conglomerate mixed wastes one (see Table 1). Another factor to be taken into consideration is the time-the basic factor for GES emission [10] . Different MSW components are gradually, deteriorated in time, so CH₄ and CO₂ as well as the non-methane gases, and are generated.

In order to illustrate results due to the method 1 use, the conform MSW calculus equations regarding CH₄ emission [10] [11] will be indicated, as follows.

These calculus equations are:

where:

・ L₀-CH₄ generated potential which depends by the MSW morphological composition it will be calculated by using the following relation, [7] [11] ;

・ R-CH₄ recovered at the inventory year of, the recommended value, supposing that CH₄ is burned and not collected; if not, the recovered quantity of CH₄ calculated by using this method will be reduced from the CH₄ generated quantity.

・ 0X-oxide factor having a fractionary values-0 for non-conforming deposits and 0.1 for the well arrangements (conforming) deposits.

CH₄ generated potential, where:

・ MCF-CH₄ correction factor, whose values are dependent by the location and the management of MSW;

・ DOC_f-the DOC dissimilated fraction-0.55 having values within the interval 0.5 ÷ 0.6;

・ F- CH₄ fraction part-from deposit gas (LFG) [5] , given value is 0.5;

・ 16/12-the C conversion coefficient within CH₄;

The Dissolved Organic Carbon (DOC) is determined [11] [12] by using the relation:

where:

・ A-the MSW fraction represented by paper and non-reciclable textiles [6] [10] [13] [14] .

・ B-the MSW fraction represented by garden and parks wastes, and other bio-degradable organic wastes, excepted food wastes [6] [10] [13] [14] .

・ C-the MSW fraction represented by food wastes and other bio-degradable wastes, [6] [10] [13] [14] ;

・ D-the MSW fraction represented by woods or straw wastes, [IPCC], [6] [10] [13] [14] ;

This method has the following difficulty:

-Don’t take into consideration that in the last 6 months deposited MSW are not degradable

-The CH₄ emission quantity is very high (inadmissible)

It is supposed that a MSW landfill will generate, within a year, a certain amount of CH₄ gas emission which can be estimated [10] . This method doesn’t take into consideration the hypothesis that a MSW landfill is a mixed conglomerate of wastes (rubbish).

Another factor to be considered is the time which is the basic factor for CH₄ gas emission [10] . Different components of the MSW landfill are, gradually, degraded in time, and CH₄, other gases are produced [6] .

METHOD No. 2

I developed a new calculation method for the methane gas emission estimation, from the Romanian waste landfills [7] [11] , method called: “DANILA VIERU METHOD FOR A CONFORMING AND NON-CONFORMING MSW LANDFILLS CH₄ GAS EMISSION ESTIMATION IN ROMANIA, BY CALCULUS”.

According to the above- mentioned method, it is assumed that the waste (rubbish) from MSW landfills will be gradually degraded [11] based on the following factors [10] [12] :

Ÿ Structure of the wastes (rubbish) composition;

Ÿ Environmental factors existing in that area;

Ÿ The thickness of the waste (rubbish) layer;

Ÿ The compacting grade (level);

Ÿ The depth of the place where the MSW is located;

Ÿ Time passed from the first deposition of wastes (rubbish).

Due to the time factor, this method was called: “DANILA VIERU METHOD FOR CONFORMING AND NON-CONFORMING MSW LANDFILLS CH₄GAS EMISSION ESTIMATION IN ROMANIA, BY CALCULUS”.

The IPCC-International Experts Group on Climate Change makes recommendation [9] related to the use of some coefficients concerning the estimation of CH₄ gas emission from MSW landfills but no to the use a specific calculus formula.

In the case of a MSW conglomerate landfill, having a broad range of types and amounts of wastes (rubbish), Romania did not possess an adequate (proper) formula for the MSW CH₄ gas emission estimation up to the year of 2012. The statistics of the wastes (rubbish), under the rule of the

Regulations no. 2150/2002 on waste statistics [17] do not solve the problem of the composition of the waste (rubbish) from MSW. The use of waste statistics assumes that the waste (rubbish) should be analyzed by means of a representative sample of economic operators and human agglomeration [12] .

Taking into consideration that every district of Romania has approx. 200 economic operators and urban agglomeration we shall have approximately 8400 economic operators, in total [9] .

Approximately 500,000 economic operators are assumed to be in the country which means that statistics representation will cover only 1.6% of the total country economic operators. This fact is quite unacceptable.

DESCRIPTION OF”DANILA VIERU METHOD FOR CONFORMING AND NON-CONFORMING MSW LANDFILLS CH₄ GAS EMISSION ESTIMATION IN ROMANIA, BY CALCULUS”

The method: “Danila Vieru method for conforming and non-conforming MSW landfills CH₄ gas emission estimation, in Romania, by calculus”, makes use of the following formula:

(1)

This formula (equation) has some advantages, e.g.:

1) The hierarchy [6] of degraded MSW, IN TIME, under the environmental factors [atmospheric precipitations, annual average temperature, alternating periods of rain and drought, freezing and non-freezing periods, the degree of compression, the thickness of waste (rubbish) layers, etc. [13] ;

2) The use of time periods for the degradation of MSW;

3) The use of IPCC recommendation related to the application of the methodology calculation formula of CH₄ gas emission from MSW landfills;

4) Taking into consideration the specific environmental conditions of every district of Romania;

5) The specific economic conditions of every district, such as: industrial development, hand-made production, various branches of agriculture, etc. are taken into consideration;

It is well-known that CH₄ methane is a specific gas, and its contribution (percentage) to global warming is about 4 ÷ 5% so that the need for the quantification of CH₄ gas emission is imperative. In the meantime, measures to reduce the contribution of the CH₄ gas emission from MSW landfills have to be taken into account.

In July 16, 2009, due to the presence of non-conforming MSW landfills in Romania, some of them are closed while others will be in transition periods, in the case of MSW landfills, the emission of CH₄ methane gas will continue even after the closing period of non-conforming MSW landfills until approximately the year 2017. Before wastes (rubbish) are deposited within the body of MSW and a rational sorting have to be are done.

After the closure of MSW landfills, the quantity of the CH₄ gas emission will decrease but still will continues to exist [14] . Following the legal conditions for opening a new MSW landfill it is absolutely necessary to know the evolution of CO₂ (in equivalent), the location of the new MSW landfill and the potential impact over the environment. As it is known, in approximately years, the warming effect will be intensified due to the collection of the gas MSW landfill.

In my opinion, the above mentioned remarks should be taken into consideration when a CH₄ methane gas emission calculus formula is applied, for the entirely territory of Romania.

4. Example of Calculus, Methodology―The Assessment

Basic consideration:

a) The percentage composition of MSW landfill body is in accordance with the data provisions given in Table 1.

b) The wastes (rubbish) from the MSW landfill body are gradually degraded in accordance with the environment conditions;

c) To calculate the quantity of CH₄ gas emission from degraded MSW, at the year of calculation, the

IPCC recommended values [9] have been taken into consideration.

d) The MSW degraded quantity has the same percentage composition as the MSW landfill body;

e) The MSW degraded quantity generates DOC-Dissolved Organic Carbon, and, as a consequence, the CH₄ gas emission is produced.

f) The MSW degraded quantity calculated, in the year T, is given by the expression: Q_mswdegrad.T

Within Table 1 the waste composition, as% from total, was established following information delivered by:

・ Local Environmental Authorities, in accordance with the Regalement of the Council of Europe no. 2150/2002 and the European Parliament information with referring to the waste statistics (November 25/2002) [17] . For example, for the Region 8 Bucharest Ilfov-landfill Chiajna, the information delivered (see Figure 1, also) are: “Methane Vol.?54.4%, Carbon Dioxide Vol.?38.1%, Oxygen Vol.? 1.3%, Nitrogen Vol.?6.1%, etc. As an important remark, within the year 2011 about 7.5 million cubic meters of Methane gas has been extracted.”

・ Direct observation done at the MSW landfills location with referring to the wastes composition;

・ Direct information delivered by local authorities regarding annually collected wastes quantities and the way of the management;

・ Information delivered by the MSW landfills administrators related to the collection area, quantities and type of wastes included in MSW.

Table 2 presents the composition of the MSW landfills wastes, located within 3 environmental regions areas-region 8 Bucharest Ilfov, Satu Mare County and Bihor county. It is to be mentioned that the Waste composition, as a conglo- merate landfill, is subjected to the environment factors, and as a consequence, the LFG gas (mainly, CH₄) is generated, covering the total lifetime of the deposit.

5. The Evaluation of Q_mswdegrad.T in the T Year of Calculation

To determine the MSW degraded quantity, in the first year of emission, the following formula has been used:

(2)

After the first year, the calculation formula became:

(3)

where:

・ Q_msw.T-MSW, the amount deposited in the account, [Gg];

・ Q_mswT-1)-MSW deposited one year ago; [Gg];

・ Q_{mswundergradT-1}-the remaining amount of MSW degraded after year calculation [Gg];

・ K: is the degradation rate of MSW. This factor depends on waste composition and site conditions, and describes the degradation process rate. The IPCC Guidelines [9] give, for K, a very wide range of values between 0.005 and 0.4.

・ t: time of degradation

・ t: time of wastes degradation within deposit body; during calculation process, t is replaced with relation (13 − m)/12 or (25 − m)/12, where m re- present the no. of months when msw wastes were degraded within deposit body, at the calculation year. m?within the interval 7 ≤ m ≤ 12, m- within the interval 7 ≤ m ≤ 18, represents no. of months when 45% of the wastes is degraded in the proportion of 45%. The m values are established in accordance with the deposit nomograme, based on the deposit equation, [15] . The deposit

equation has an unique solution, but in every year has another expression i.e. in the year [15] , in the year, [14] etc. How to drawing up the Nomograme [15] of the MSW deposit will be explained in another paper.

・ T-represent the year of calculation not the current calendar year.

A certain MSW deposited quantity remains undegraded every year [8] [12] . This quantity will be taken into consideration in the next year as the Q_{mswundegrad.T}.

This quantity can be estimated by using the formula:

(4)

The calculation of the total Dissolved Organic Carbon?(TDOC_dissolved.T)- quantity from MSW degraded, at the year T, Q_mswdegrad.T has been done by means of the following formula

(5)

where:

A = DOC generated by Q_mswdegrad.T which contains% MSW_biodegrad stated;

(6)

k₀: in accordance with [9] DOC generation ratio by% MSW_{biodegrad.degrad.T}, deposited;

B = DOC generated by Q_{msw(G+P)degrad.T} which contains %MSW_(G+P), stated;

(7)

k₁: in accordance with [9] , DOC generated ratio by% MSW_{(G+P)degrad.T}, deposited;

C = DOC generated by Q_mswdegrad.T which contains %MSW_H+C+text., stated;

(8)

k₂: in accordance with [9] , DOC generated ratio by %MSW_{(H+C+ text.)degrad.T} , deposited;

D = DOC generated by Q_mswdegrad.T which contains %MSW_(wood+straw), stated

(9)

k₃: in accordance with [9] , DOC generated ratio by% MSW_{(wood+strawdegrad.)T}, deposited;

E = DOC generated by Q_{msw degrade.T} which contains %MSW_sludge, stated;

(10)

k_n: in accordance with [9] , DOC generated ratio by% MSW_{sludg.degrad.T}, deposited;

G = DOC generated by Q_mswdegrad.T which contains %MSW_industry, stated;

(11)

k₄: in accordance with [9] , DOC generated ratio by% MSW_ind.degrad.T, deposited.

The total composition of MSW wastes within the body can be changed annually, at two years, at three years or five years depending on the best environment information detained.

% TDOC_dissolved.T is the ratio because DOC is distributed within total wastes deposited but it is considered to be generated only by Q_mswdegrad.T and it is determined by using the following formula:

(12)

where Q_{msw taken into consid.T} is calculated by using the relation:

(13)

・ DOC_f = fraction [%] of DOC dissolved under anaerobic conditions (taking into consideration the environmental condition from landfill) which generated CH₄.

The calculus can be done in this way:

・ Empirical [16] by using the formula: 0.014 T + 0.28, where T?is the annual average temperature, in C⁰, in the district where MSW is located.

By using IPCC recommended values for the temperate-continental zones, in Eastern and Central Europe, [5] [9] we found the following percentage values: 50%, 55%, 60% and 77%.

If we take into consideration the Romanian districts climate zone conditions the recommended values (as percentage) are to be: 43%, 45%, 50%, 55% and 60%.

・ 1.3333(16/12) is the conversion factor of the carbon from CH₄ emission.

・ F-MSW landfill CH₄ gas emission correction factor and depends on the management of landfill; this factor assumes the compacting level of the solid municipal waste (rubbish) MSW landfill body and its values are:

a) 0.4 ÷ 0.5-if landfill is not compacted;

b) 0.6 ÷ 0.7-if the landfill is compacted by means of a compactor and a bulldozer;

c) 0.8 ÷ 0.9-if landfill is compacted with two bulldozers and two compactors. It is to be observed that there is not value 1 because there are no perfect ways of management.

・ F_r-is a correction factor of CH₄ gas emission fraction from gas deposit [Landfill Gas-], according to the IPPC recommended values; these values of F_r are within interval 40 ÷ 60%,

Taking into consideration the above formula and using adequate input data, the graphical representations for the evolution of the equivalent CO₂ of MSW landfills [4] [9] [13] ―Landfill Rudeni-Chitila-Iridex, Landfill Vidra-Ecosud are presented in Figure 1 and Figure 2.

The evolution of the equivalent CO₂ for a non-conforming MSW landfill is presented in Figure 3. It is to be observed that the CH₄ gas emission continues, after the closing date?the year 2010, as shown.

Wastes deposited quantities (msw) within deposit body are shown in Table 3. These quantities, due to “m” values, according to the Nomograme [15] , generated CH₄ quantities as presented within Figure 1, with the following signi-

ficance [9] [13] [15] : in the year 2011 there were collected 7.5 million cubic meters of CH₄ which have been used for green energy production.

For the period 2000 to 2011, the percentage (%) of MSW composition has been considered, as shown in Table 1. Plastic wastes, inert waste, construction and demolition have not to be taken into consideration because they will not affect the CH₄ gas emission [8] [14] .

The data were confirmed by collection data.

6. A Case Study

Within 2000 ÷ 2011 period (see Figure 1) quantities belonging to the interval 250 ÷ 400 Gg, there were deposited, annually. The GEG Effect has been intensified has been intensified, so that in the year of 2011 and a quantity of 7.5 million cubic meters of CH₄ has been used for electric energy production. As a direct consequence the GEG Effect decreased considerably, see Figure 1.

For the period 2000 to 2011, the CH₄ calculated values of gas emissions are presented in Figure 1, by using Formula (1):

(1)

Using some indicators related to the MSW landfills CH₄ gas emission, a calculation model is presented below. These indicators are those recommended by IPCC group of experts, group for the Central and Eastern Europe, [9] as follows:

MSW landfill deposited at the Year 2000;

MSW landfill deposited at the Year 2001;

(2)

At the starting year of emission within the Equation (2) can be used the expression:

[3] where represents the number of months in which maximum 45% of deposited are degradeted, [3] .

After the emission starting the expression, [15] , [15] can be used. -the number of months is allocated to the Nomograme [15] .

is degraded quantity, Equation (2) Which generated (Organic Carbon Dissolved), and, finally, , at the year 2001.

[3] , no. of months for the period 2000-2001, when MSW are degradeted, according to the MSW landfill Nomograme [15] .

(3)

By using Equation (4) the is calculated.

(4)

, [Gg], calculated by using the Equation (4)

[Gg], quantity remained un-degraded in the end of 2001.

By using formula shown below the percentage of has been determined:

(12)

, was determined such as:

(5)

The terms A, B, C, D, E, G are calculated at the year 2001, by using adequate equations

(6)

, the bio-degradable wastes DOC generation ratio, is in accordance with [IPCC, 2006], Chapter V, wastes;

(7)

, the park and garden wastes DOC generation ratio, in accordance with [IPCC, 2006], Chapter wastes;

(8)

, the papers + cartoon + textiles wastes DOC generation ratio, in accordance with [IPCC, 2006], Chapter V, wastes;

(9)

, the wood + straw wastes DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes;

(10)

, the containing sludge wastes DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes;

(11)

, the industrial wastes (similar to home wastes) DOC generation ratio, in accordance with [IPCC, 2006], Chapter V, wastes;

(5)

(12)

(13)

The gas emission quantity at the year 2001 is calculated by applying the, as follows:

where:

[Gg] is MSW degraded quantity at the year 2001 which generated DOC and, later on, CH₄ methane gas [5] [7] [10] ;

・ 1.52% is the percentage% TDOC within landfill body;

・ 0.5 represent DOC_f taking into consideration the existing condition from the analyzed emission;

・ 1.3333 (16/12) represent C from CH₄;

・ represents the management level of the analyzed MSW landfill, at the year 2001;

・ 0.5 represents the% content of CH₄ Methane gas within Landfill Gas (LFG).

It is to be observed that the CH₄ gas emission increased gradually, but not suddenly, in accordance with the environmental condition of the landfill location [6] . A certain wastes (rubbish) quantity of landfill will remain un- degraded and will be taken into consideration in the next year, so the process of MSW degraded will generate again DOC, and, as a consequence, CH₄ Methane gas:

At the year 2011, for the same MSW landfill-Chitila-Rudeni-Iridex, the quantity of emission will be [8] [12] [15] ;

MSW, deposited

, the quantity of landfill un-degraded, remained from the year 2010;

(13)

MSW landfill deposited taken into consideration for the calculus of :

By using the Formula (2)

(3)

in accordance with MSW deposit nomograme [3] [13] [17] .

the non-degraded quantity of remained in the end of the year 2011; the is used:

(4)

By using the Equation (12), the percentage has been calculated, as follows:

(12)

was calculated by using the Equation (5)

(5)

The parameters-A, B, C, D, E, F, G, are determined at the year 2011, by using corresponding equations.

(6)

the biodegradable DOC generation ratio, in accordance with [IPCC, 2006], Chapter V, wastes.

(7)

, parks and garden wastes DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes [7] [9] [10] .

(8)

, the papers + cartoon + textiles wastes DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes.

(9)

, the wood + straw wastes DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes.

(10)

, wastes (containing sludge) DOC generation ratio in accordance with [IPCC, 2006], Chapter V, wastes [9] [10] [17] .

(11)

, MSW landfill containing industrial wastes (similar to home wastes) DOC generation ratio, in accordance with [IPCC, 2006], Chapter V wastes,

(5)

(12)

(13)

0.0607;, respectively.

The quantity of in the year 2011 gas emission is calculated by applying Formula (1) as follows:

where:

Ÿ [Gg] is MSW degraded quantity of in 2011 which generated DOC and, later on, CH₄

Ÿ Methane gas;, is the percentage % TDOC within landfill body;

Ÿ represent DOC_f taking into consideration existing condition from the analyzed emission;

Ÿ (16/12) represent C from CH₄;

Ÿ represents the management level of the analyzed MSW landfill, in the year 2001;

Ÿ The content of CH₄ methane gas within Landfill Gas (LFG).

It is to be observed that the CH₄ gas emission increased gradually, but not suddenly, in accordance with the environmental condition of the landfill location [6] . A certain waste (rubbish) quantity of MSW landfill will remain un-de- graded and will be taken into consideration in the next year, so the process of degraded will generate again DOC, and, as a consequence, CH₄ Methane gas:

It is to be observed that the CH₄ gas emission increased gradually, but not suddenly, in accordance with the environmental condition of the landfill location [4] [6] . A certain waste (rubbish) quantity of MSW landfill will remain un- degraded and will be taken into consideration in the next year, so the process of MSW degraded will generate again DOC.

The sludge from MSW can be taken into consideration, separately or may be incorporated within bio-degraded waste (rubbish).

7. Conclusions

This article doesn’t comment on the present calculation model but rather draws the attention to a more adapted to the real conditions estimation, by calculus, of the CH₄ gas emission from the actual MSW landfills in Romania, which have to be estimated by the end of 2017. Even if deposited MSW quantities were up to 30 (Gg), in the beginning of 1979 and reached 90 (Gg) in 2010, the evolution of CO₂ exists and has to be known by the Romanian authorities.

It is considered that this estimation has to be determined up to the life-end of the considered landfill. As an example, at the existing MSW landfill, in the Satu Mare County, the evolution of the equivalent CO₂ for a period of 42 years up to 2010 when it was closed is presented. The authorities have to inform the public about the evolution of the equivalent CO₂ for existing MSW landfill and also for the location of the new MSW landfills.

On the other hand, for the non-hazardous MSW landfills having a capacity between [Gg] it was observed that the top management of this MSW landfills issued estimated quantities of CH₄ gas at unrealistic values, sometimes more than two times lower with respect to the real one, estimated by usual calculation models.

To reduce the greenhouse effect, the evolution of the equivalent CO₂ for the existing MSW landfills in Romania has to be estimated in such a way as to be useful for an applicable environmental planning in accordance with the government’s and the European policy in the field of environmental protection. Other gas emissions such as: NON-METHANE ORGANIC COMPOUNDS, , , , , have not been taken into consideration.

The real estimation of the CH₄ emission quantity from MSW landfills, in Romania, will contribute to a better environmental planning and a better understanding of the contribution that different gases have on the general warming effect and climate changes greenhouse effect.

Finally, it is to be noted that the calculation of the CH₄ emission quantity, by using the Danila Vieru’s Method, , will help Romanian environmental authorities to implement the legal and right decisions regarding the adequate moment when the collected emission can be burned, and thus be used in an economical manner.

The proposed method could be applied for the CH₄ emission calculation at MSW landfills quantities between 100 ÷ 200 (Gg/y) e.g. the Satu Mare non- conforming MSW landfill (see Figure 3).

This method which was verified for Romanian landfills could be easily adapted for other countries too, paving the way for a real estimation of the methane gas emission, as real as possible.

The proposed method can be applied either to the MSW landfills which respect legal providing and those (MSW) which not respect such provisions. The quantitative CH₄ estimation is beneficial for the Environmental Authorities but also for the potential investors interested in the CH₄ management. It is to be noted that potential investors have to know the emission quantity and its duration. After MSW depositing is over, it is absolutely necessary to the time-dura- tion when the emission is stopped. In the same time, after the CH₄ emission is over, the resulted compost should be of interest for the farmers.

Acknowledgements

The author would like to express thanks for their support and understandings to the staff members of the Environmental Protection Agency (EPA) and to the local and regional subsidiaries of ETA’s for their help and suggestions.

The author would like to express deep thanks and gratitude, including for the moral support, to Prof. Dr. Eng. Vladimir Rojanski for his advices in order to complete my work in order to estimate the CH₄ gas emission, by a calculus formula, both for conforming and non-conforming MSW solid landfills.

Cite this paper

Vieru, D. (2017) A New Approach Method of CH₄ Emission Estimation from Landfills Municipal Solid Waste (MSW). Atmospheric and Climate Sciences, 7, 191-209. https://doi.org/10.4236/acs.2017.72014

References