Elemental Composition of Pm2.5 Emitted From Rice Straw Burning in Combustion Chamber
Biomass open burning emits significant amount of atmospheric pollutants to the atmosphere which affects air quality and can be with numerous negative health impacts. This study aims to determine particulate matter with diameter less than 2.5 μm (PM2.5) and its elemental composition emitted from rice straw burning. Agricultural residues burning are a common practice in Southeast Asia (SEA) and rice straw is one of the major part of residues. Rice straw samples were collected during harvest season from five locations (n=15) in Northern Thailand where air pollution is critical during the dry season due to open burning. The average emission factor (EF) of PM2.5 of rice straw burning was 3.7 ± 2.0 g/kg(dry biomass). Overall 11 elements were detected in composition of PM2.5. EF of K emitted from rice straw was 514 ± 249 mg/kg(dry biomass) which makes up 66% of all measured elements in the composition of PM2.5. The EF of elements in descending order were K>Na>Ca>Mg>Fe> Al>Sb>Cr >Sn>Zn and Si. PM2.5 EF was strongly correlated (r=0.62) to EF of K, but with same strength and negative correlation showed with EFs of Sb (p < 0.05) and strong adverse relation with EF of Cr (r = -0.64, p < 0.01), and aggregate mass of measured elements consisting 18% mass of emitted PM2.5 from rice straw. Presence of such complex and toxic matter in atmospheric air increases the toxicity of emission from biomass open burning of rice straw, and has potential environmental and health effects.
Keywords- Air Pollution, Open Burning, PM2.5, Emission Factor.
Pm2.5 iliyotolewa kutoka kwa kuchoma mchele katika chumba cha kuchoma, kuchoma wazi kwa biomass hutokeza kiasi kikubwa cha uchafuzi wa anga katika anga ambayo huathiri ubora wa hewa na inaweza kuwa na athari nyingi mbaya kwa afya. Utafiti huu unakusudia kuamua chembechembe zenye kipenyo cha chini ya 2.5 μm (PM2.5) na muundo wake wa msingi uliotolewa kutoka kwa kuchoma nyasi ya mchele. Kuungua kwa mabaki ya kilimo ni jambo la kawaida katika Asia ya Kusini Mashariki na nyasi ya mchele ni moja ya sehemu kubwa ya mabaki. Sampuli za nyasi za mchele zilikusanywa wakati wa msimu wa mavuno kutoka maeneo matano (n = 15) kaskazini mwa Thailand ambapo uchafuzi wa hewa ni muhimu wakati wa msimu wa ukame kutokana na kuchoma wazi. Kiwango cha wastani cha PM2.5 kutoka kwa mchele wa mchele ni 3.7 g kwa kilo. Kwa ujumla, elementi 11 ziligunduliwa katika muundo wa PM2.5. Kiasi cha K kilichotolewa na nyasi ya mchele kilikuwa 514 mg (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) (k) EF ya vipengele katika utaratibu wa kushuka walikuwa K>Na>Ca>Mg>Fe>Al>Sb>Cr >Sn>Zn na Si. PM2.5 na K2 (r = 0.62) zilikuwa na uhusiano mkubwa, lakini kwa nguvu sawa na uhusiano hasi ulionyeshwa na EFs ya S2 (p < 0.05) na uhusiano mkubwa wa hasi na EFs ya Cr (r = -0.64, p < 0.01), na wingi wa jumla wa vipengele vilivyopimwa unajumuisha 18% ya wingi wa PM2.5 iliyotolewa kutoka kwa nyasi ya mchele. Uwepo wa vitu hivyo tata na sumu katika hewa ya angahewa huongeza sumu ya uzalishaji kutoka kwa biomass wazi kuchoma ya nyasi ya mchele, na ina athari za mazingira na afya. Maneno muhimu- Uchafuzi wa hewa, Kuungua wazi, PM2.5, Kiwango cha Utoaji.