Table 5 shows the emergy evaluation of low temperature incinerator in 12 HCFs of Bujumbura. The total emergy input to treat 1284 tons of SMW by 12 HCFs was calculated as 1.36E+20 seJ/yr (Table 5). The machineries (bulldozer, compactor and truck) used for land area preparation such was a total of 21,200 g/yr (Table 5). The materials for the construction of furnace and small building such as sand, fire bricks, gravel, stone, galvanised metal, nails, wood, concrete and water was a total of 1.92E+07 g/yr and 8.80E+10 J/yr, 4.44E+10 J/yr and 1.80E+10 J/yr for fuel, lubricants and electricity, (estimated with 3.52E+7 J/liter, 3.70E+7 J/liter, and 3.6E+6 J/kWh), respectively. In other hand, the materials used for construction of septic tank for metal residues such as sand, fire bricks, gravel, galvanised metal and concrete was a total of 1.84E+06 g/yr. Labor cost of masons, help masons and drivers of trucks that were involved for land preparation and construction process was calculated to be 19,152 USD. Services related to the different items used during land preparation and construction process were 22,725 USD.

>UEV [12] [16] [29] - [34]. >All UEVs were adjusted to the global renewabel emergy baseline of 15.83. > Data related use life of different materials and life time of incinerator were collected from the ministry of health public of Burundi through its department in charge of construction and infrastructures and in some societies in charge of construction in African.

Chemical like chlolexidine used yearly for to treat SMW was 3.82E+05 g/yr (estimated with 1.06 g/ml of density). The fuel used during operation phase was the largest quantity compare to that used during construction processes (1.69E+11 J/yr to 8.80E+10 J/yr). Labor cost (yearly) to treat SMW was 1277 USD/yr and services cost was 1515 USD/yr. The cost for labor and services during operation was highest compare to the cost for labor and services during construction processes with 4262.4 USD, and 8880 USD, respectively. The cost to treat one ton of SMW was calculated to be 2.12E+14 USD/ton/yr (Table 9). Labor and services to treat SMW accounted different percentages among the expenses, i.e. 34.7% and 65.3%, respectively (Table 8). The contribution of labor for the treatment was (smaller or highest) that that in emergy investment.

The emergy evaluation of organic pit in twelve HCFs of Bujumbura is presented in Table 6. The total emergy input to treat 1617.85 tons of SMW by 12 HCFs was calculated as 1.68E+18 sej/yr (Table 6). Truck used for land area preparation was a total of 5000 g/yr (Table 6). Moreover, the materials used for construction such as gravel, sand, cement, galvanised metal, fire bricks, metallic cover, PVC and water was a total of 1.E+07 g/yr. Labor cost such as masons, help masons and driver of truck during the land area preparation and construction processes was 215 USD/yr and the cost related to the services was 825 USD/yr. The materials used during operation such as wheelbarrow (with life time of 2 years) and charcoal was a total of 15,000 g/yr, 60,000 g/yr, respectively. Labor cost to treat SMW was 595 USD/yr and services cost was 1250 USD/yr. The total money used for labor and services during construction was 2580 USD and 9905 USD, respectively. The annual cost for labor and cost was 215 USD and 825 USD, respectively. The labor cost and services cost used during construction and operation was in the following situation 28.04%, and 71.96%, respectively (Table 8). The cost to treat one ton of SMW was calculated to be 2.27E+13 USD/ton/yr (Table 6).

>UEV [12] [16] [29] [30] [31]. >All UEVs were adjusted to the global renewabel emergy baseline of 15.83. > Data related use life of different materials and life time of organic pit were collected from the ministry of health public of Burundi through its department in charge of construction and infrastructures and in some societies in charge of construction in African.

Table 7 shows the emergy evaluation for landfill in twelve HCFs of Bujumbura. The total emergy input to treat 4060 tons of municipal solid (77.74%) and 1162.53 tons of SMW (22.26%) by 12 HCFs was calculated as 3.54E+17 seJ/yr (Table 7). The machineries used for land area preparation such as bulldozer, compactor and truck was a total of 38,000 g/yr (Table 7). The materials used for landfill area preparation such as dry mund, clay and sand was a total of 1.47E+07 g/yr. The materials used for the office building construction such as sand, fire bricks, gravel, galvanised metal, sheet metal, concrete, wood and water was a total of 3.04E+07 g/yr. Labor cost related to the masons, help masons and drive of truck was 3098 USD/yr, and service cost was 2257 USD/yr for the total of 46,468 USD and 33,860 USD, respectively. The machineries used during operation such as excavator and truck was a total of 280,800 g/yr. Moreover, the raw data for chemical, fuels and electricity used during operation phase was 3.05E+06 g/yr, 1.06E+12 J/yr, 1.74E+09 J/yr, (estimated with 1.06 g/ml, 3.52E+7 J/liter, and 3.6E+6 J/kWh), respectively. In the same phase of operation, labor cost such as driver of excavator and workers for landfill was 17,164.8$/yr and service was 64,710$/yr. The cost to treat one ton of SMW was calculated to be 2.12E+14 USD/ton/yr (Table 9). Labor and services to treat SMW accounted different percentages among the expenses, i.e. 23.22% and 76.78%, respectively (Table 8).

*Total of SMW and general wastes treated into the landfill. >UEV [12] [16] - [34]. >All UEVs were adjusted to the global renewabel emergy baseline of 15.83. > Data related use life of different materials and life time of landfill were collected from the ministry of health public of Burundi through its department in charge of construction and infrastructures and in some societies in charge of construction in African.

*Total of SMW and general wastes treated into the landfill.

Table 9 presents the comparison of money-equivalent cost and pure market-based cost of SMW treatment between low temperature incinerator and organic pit. The emergy invested for one ton per year (seJ/ton/yr) was 1.06E+17 seJ, 1.04E+15 seJ, respectively for low temperature incinerator, and organic pit. This shows that the high money-equivalent cost was observed for the low temperature with 8,346.4 times compare to the organic pit presenting 81.8 times (Table 9). The monetary cost invested or pure market-based cost of these two methods for treating one ton of waste per year (USD/ton/yr) was 1.57E+14, and 2.27E+13 for temperature incinerator and organic pit, respectively. The findings show that the low temperature incinerator was highest with 6.91 times compare to organic pit (Table 9). The organic pit presents the lowest money-equivalent cost and pure market-based cost in this study. It is explained by the fact that the construction

and operation phases of organic pit presented few materials and equipment compare to those used for low temperature incinerator (Appendix A, footnotes Tables 5-7). Moreover, the materials allocated for construction and operation present a total different amount (Table 5, Table 6). In addition, the services and labor account in all two treatment methods were totally different and it is the same for their ratios (Table 9). Even the organic pit in this part was assessed to be the method with lowest money-equivalent cost and pure market-based cost, it cannot explain to be a better method than low temperature incinerator even if it was used for treating a large quantity of wastes compare to the low temperature incinerator ((6471.4 tons (38.15%) than 5837.4 tons (34.42%)) (Table 3, Table 4). It was used to treat one type of SMW (pathological waste and tissues, and placenta), however, the low temperature was used for several types of wastes (sharps wastes, infectious wastes, chemical and radioactive wastes, and absorbent cotton waste). In term of safety, the organic pit is recommended by WHO in the case of absence of the incinerator with high temperature (WHO, 2014). Therefore, the low temperature incinerator should be replaced by the high temperature with air control pollution recommended by WHO to treat different types of wastes including pathological waste (infectious waste, pharmaceutical waste, chemical waste, absorbent waste, pathological waste, and placenta) (WHO, 2014). Currently, in Bujumbura, these two methods are not protected and covered (Figure 4(a), Figure 5(c)). This shows that the risks could happen during the rainy season or flooding, especially for the organic pit and the presence of carbon monoxide, particulate matter, hydrogen chloride, polycyclic aromatic hydrocarbons, toxic materials, metals (mercury lead, arsenic cadmium), Dioxins (plastic, polyvinyl chloride: PADS, and PCDD: polychloro-dibenzo-p-dioxin or toxic air polluants), furans (PCDF: polychloro-dibenzofuran), polycyclic hydrocarbons (PAHS) for low temperature incinerator [2] [35]. Based on the lowest emergy cost and safety treatment of organic pit, it is important to maintain it temporary by ensuring its improvement first with fence, roof, drainage channel, and adequate maintenance (monitoring always). Burundi government should take account to the high risk caused by the low temperature incinerator and replace it by a high temperature incinerator with air pollution control in the reason of its capacity for to treat several types of wastes [2]. In all situations, the distance between the resident area of site area of treatment and households should be respected as recommended by WHO [2].

Even if the emergy evaluation was not conducted for SMW, however, it was applied for the municipal solid wastes management in some countries [12] [13] [14]. The results of this study can be compared to the results developed in the previous studies or literature in other countries. It is important to compare the emergy investment per ton/yr with the capacity of new technologies for to reduce the potential risks in Bujumbura. Through these results, Burundi government can improve the current treatment methods by focusing on cost and the reducing risks. In this study, the emergy investment per ton/yr for low temperature incinerator and uncontrolled landfill was 1.06E+17, and 3.04E+14, respectively. The results of this study show that the low temperature incinerator present a high emergy investment, but it was used for to treat several types of wastes in twelve HCFs of Bujumbura. However, the landfill was used for to treat one type of waste (Table 3). A study conducted in Italy for emergy assessment of incineration and landfilling of municipal solid waste in Italy has shown that the incineration and landfilling require almost the same emergy investment per ton/yr with 1.27E+14 and 1.47E+14 Sej/t/yr, respectively. The incineration was found to be more efficient compare to the landfill, because it presents the advantage for reducing the final volume of wastes to less than 30% and it was found to contribute for preventing the environmental problems because its air control pollution. However, the landfilling has been assessed with the largest inputs for construction materials and management, and with a big land surface required for wastes disposal [13]. Based on the results developed in the previous study in Italy, Burundi government can plan how to improve the final treatment of SMW by considering in priority to change the low temperature incinerator by high temperature incinerator with air control pollution, considering its advantages related to the treatment of several times of wastes and its capacity of reducing risks to human health and environment. The study conducted in China (Beijing) on the emergy-LCA analysis of municipal solid waste management: Modelling source-separated collection and transportation based on the emergy investment per ton/yr of two types of landfill (with leachate disposal and without leachate disposal), and high temperature incinerator. The results have shown that the cost was significantly different between different types of landfills and incinerators. The landfill without leachate disposal system was the least expensive (1.02E+ 13 seJ/t), the landfill with leachate disposal system was expensive (1.35E+13 seJ/t), but it was assessed to be adequate method with safety. The more emergy in puts were observed for fluidized bed incineration for 4.27E+13 seJ/t. In this study, they have considered the sanitary landfill as the best performance, considering the demand for ecological services and negative impact related to the emission [12]. This study can help Burundi government for to choose the type of landfill (leachate disposal) based on the efficiencies in terms of ecological, human health and current economic situation of the country.

In conclusion, the results developed in these two countries could help Burundi government to improve the final treatment methods currently used by replacing the low temperature incinerator with the high temperature with air control of pollution and uncontrolled landfill with sanitary landfill for reducing the risk caused.

Except the organic pit that can be used for treating the SMW when it respects the engineering condition as recommended by WHO, however, the low temperature incinerator and landfill are not recommended by WHO in reason of their incapacity to treat completely the wastes and their bad design (engineering condition). High temperature incinerator with air pollution control and sanitary landfill are highly recommended by WHO [2]. Developed countries like USA, EU and Canada use the high temperature incinerator with air pollution control and sanitary landfill for to treat the SMW and general wastes in the majority HCFs, respectively [36] [37]. High temperature incinerator with air pollution control is the first method used for to treat several types of wastes. In this study, except organic pit recommended by WHO for to treat the pathological waste and placenta, however, low temperature incinerator and landfill used in Bujumbura were not adequate for to treat safely the SMW (Figures 4(a), Figure 4(b), Figures 5(a)-(c)).

Considering the current situation, organic pit could be more efficient treatment method than low temperature incinerator and landfill in terms of cost and safe (reducing of risks to human health and environment), however its poor design (lack of fence, roof, drainage channel) could cause a high risk to the ground water, soil, surrounding environment, nearby resident, and waste workers. Therefore, its maintenance in all HCFs by fence, roof, drainage channel and regular monitoring is an emergency situation. It could be used temporal by pending the implementation the high temperature incinerator with air pollution control by the government. Because several types of wastes (sharps waste, infectious waste, pharmaceutical waste and discarded medical plastics, chemical waste, radioactive waste and absorbent cotton) were treated by using low temperature incinerator. For to reduce the risk in all HCFs, high temperature incinerator with air pollution control should be implemented. The area should be protected by fence for avoiding the entrance of people and animals inside of its location area. The distance between the residence area of incinerator and households should be respected. One type of SMW (pharmaceutical waste and discarded medical waste) was treated by using uncontrolled landfill. Therefore, to reduce the risk to the human health and environment, Burundi government should introduce the sanitary landfill with leachate disposal. The distance separating the households and landfill should be respected for preventing the transmission of diseases. In addition, a national program for SMW treatment could be an option for resolving the great issue related to the improper SMW treatment in Bujumbura and could contribute for reducing the impacts on human health and environment. However, the effectiveness of the programs varies according to the condition of countries [38]. In developed countries like USA and Korea, there are different centers where the wastes from different HCFs are treated referring to the norms set out by the program in charge of medical waste management. For example, in Korea, a work process of RFID system was set out, that system covers all process, from generation to final disposal [2] [12] [35] [36]. Specific policies and proper treatment methods based on the emergy and money cost should be introduced by Burundi government in order to promote the proper SMW management.