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This study assesses the seasonal variations, potential sources, and health risks of fine particulate matter, PM2.5. Samples (n = 83) were collected at two urban sites of Ulaanbaatar. Inorganic ions, organic/elemental carbon, and metals were analyzed. Results exhibited a distinctive seasonality for all chemical compositions with sulfate being the dominant species of PM2.5 in winter. Comparably high concentrations of sulfate, nitrate, and ammonium were measured in winter, while concentrations of calcium and magnesium were higher in spring and summer rather than in other seasons. The results revealed that dominant sources of atmospheric PM2.5 are mainly due to emissions of coal combustion in the heating period, and soil dust resuspension is in the non-heating period.
Хураангуй Монгол Улсын нийслэл Улаанбаатар хот нь сүүлийн жилүүдэд хурдацтай хөгжихийн хирээр тухайн бүс нутагт хүн амын төвлөрөл, аж үйлдвэрлэл нэмэгдсэний улмаас байгаль орчинд үзүүлэх сөрөг нөлөөлөл ихэссээр байна. Энэхүү судалгаагаар Улаанбаатар хотын хөрсөн дэх металлуудын тархалт, геохимийн фракц, хуримтлалын фактор, бохирдлын түвшин, эх үүсвэрийг тодорхойлох зорилгоор хотын гэр хороолол, хотын төв болон зах, үйлдвэрийн бүс орчмын хөрсний өнгөн давхрагаас нийт 22 дээж цуглуулж хүнд металл (Al, Fe, Mn, Cr, Cu, Cd, Co, Zn, V, Mo, As, Sb, Pb)-ын шинжилгээ хийсэн. Шинжилгээний үр дүнг NIST 2702, BCR 701 гэсэн стандарт дээжтэй харьцуулж баталгаажуулсан. Судалгааны үр дүнгээр металлын бохирдол дараах дарааллаар буурсан үзүүлэлттэй байна: Sb> As> Pb> Zn> Cd> Cu> Mo> V> Cr> Mn> Co> Fe. Хуримтлалын факторыг тооцоолоход Sb, Zn, As, Pb, Cu, Cd-ын хувьд хүний үйл ажиллагаагаар ихээхэн бохирдсон байсан. Хөрсөн дэх металлын хөдөлгөөнт байдлыг тодорхойлоход цайрын хүчилд уусдаг фракц хамгийн өндөр буюу 28.2%. Харин Sb, As, Co, V, Fe, Mn-ын хувьд үлдэгдэл фракц давамгайлсан учир хүрээлэн буй орчинд хөдөлгөөнт байдал болон экологийн эрсдэл бага гэж үзсэн. Үйлдвэрийн хаягдал, замын хөдөлгөөний эх үүсвэр, ахуйн үнс, нүүрсний шаталтын зохицуулалт хангалтгүй байгаа нь судалгааны бүс дэх хүнд металлын бохирдлын гол эх үүсвэр болохыг харуулсан.
Mongolia is a rapidly developing country that has experienced growing industrialization and urbanization in recent decades. This study was conducted to evaluate the enrichment and labile fractions of metals in urban soils of Mongolia and to identify major sources of soil metal pollution. The concentrations and geochemical fractions of Al, Fe, Mn, Cr, Cu, Cd, Co, Zn, V, Mo, As, Sb, and Pb in soils of the city Ulaanbaatar were investigated. The results demonstrate that only Fe, Mn, Co, Mo, and V occur at natural levels with enrichment factors close to unity. The majority of investigated toxic metals, including Cu, Zn, Cr, Sb, As, Cd, and Pb, are serious pollutants in urban soils, with enrichment factors of up to 2.8, 5.1, 2.1, 16, 13, 15, and 11, respectively. Studies of the chemical fractions of metals demonstrate that Zn is mainly found in its labile form and is considered a high risk to humans and biota. Industrial release, household ash, coal combustion, and tire abrasion were identified as key sources of toxic metals entering into the soil of Ulaanbaatar City, which should be controlled effectively to prevent the population as well as pollution distribution over a wider area by long-range atmospheric transport.
Mongolia is a major source of Asian dust. Our objective is to study a section of the Tuul River to evaluate present condition of this pristine environment. Sediment metals (Al, Fe, Cu, Zn, Pb, Ni, Cd, Hg, and Cr) concentrations and Pb-210 were sampled and analyzed. Results showed that metal concentrations are much higher at areas near the capital city and near the municipal sewage outlet, with enrichment factor values up to 18 for Cu and 26 for Cr. Furthermore, higher copper concentrations were found at sites about ~50 km downstream from the source, an indication that pollutions are spreading further down the river. Vertical heavy metal concentration profiles show unusual accumulation of metal pollution that could be traced back to 1960s’, reached the highest level when coal-fired power facilities and ash ponds started. Inefficient sewage treatment plants and the power plants ash ponds were major sources of metals leaking into the study Tuul River. Poorly treated sewage waste water is carrying metals through Tuul River to the lower river basin. Dusts from ash ponds are airborne and transport to greater area. These findings indicate that new and alternative measures have to be enforced to prevent further pollution entering the Tuul River drainage basin and airborne dust to other broader regions of the Asia and ocean.
The remediation of heavy metal-polluted soils has become one of the problems to solve in Mongolia. In this study, one of the remediation technologies which is stabilization of heavy metals in polluted soils was used amendment for the environment-friendly minerals. The purpose of this study was to investigate stabilization of heavy metals using cost effective minerals, which is cost effective and environmentally friendly. Four different minerals such as Fluoride Apatite (FA), zeolite (Z), magnetite and hydroxyapatite (HAP) were used in this study to investigate immobilization of some heavy metals as Cu, Zn, Cd, Hg, Cr and As. The polluted urban soils have collected from Ulaanbaatar and Erdenet. The mixed samples are contained 5% of these minerals. After treating soil samples, the mobility of heavy metals determined by sequence extraction procedure (BCR 701 method). During the test, the concentrations of some heavy metals such as Cr, Cu, Fe and Pb measured by ICP-OES and ICP-MS. The results show that concentration of Ni, Cu, V, Fe and Pb was above earth crust of these metals. The test results show that zeolite’s adsorption capacity had a higher (Qmax=79.3 mg/g) than other minerals. Zeolite had a good effect on stabilization of Cr, Ni, and Cd in soil samples. Compared to untreated sediment, Cr, Ni, and Cd in residual fraction increased by 3%, 10%, and 21.3% with treatment after 2 months, respectively. When using FA, the mobility of Pb and Ni were reduced by 9% and 12%, respectively. In order to improve the immobilization of heavy metals, the various or effective minerals should be studied for further study.
This study was focused to identify solid waste sources and its characterization and to estimate the ecological footprint at national park during cold season. Gorkhi-Terelj National park (GTNP) locates in Nalaikh district of Ulaanbaatar, is Mongolian one of most well-known and attractive place for tourists. The number of camps and resorts at GTNP have been increasing due to the decline of air quality in the city, increase of domestic and foreign tourists. Recently, one of the environmental problem is solid waste issue which is generated in the surrounding of national park. The main sources of solid waste generation in GTNP are mainly from tourists, camp houses and residents. Currently there is no official waste collection points at GTNP and collection company do not collect on regular basis due to long distance to Nalaikh District’s dumpsite. The source, amount and composition of generated solid waste in GTNP measured mainly in three sites and also including illegal littering during November 2017 to January, 2018. The components of solid wastes were divided into ten categories as glass, PET bottle, plastics, papers, cans, construction wastes, coal ashes, textiles and tires. Result shows that total 1.1 tons of solid waste generated in a month during cold seasons and waste generation rate was 0.016 kg-waste per tourist per day. The ecological footprint was also calculated for determined waste composition. Contribution from tourists to solid waste generation was 51.4% while tourist camp and residents was 48.6%.
