Fine particulate speciation profile and emission factor of municipal solid waste incinerator established by dilution sampling method.

UNLABELLED: In this study, fine particulate matter (PM2.5) emitted from a municipal solid waste incinerator (MSWI) was collected using dilution sampling method. Chemical compositions of the collected PM2.5 samples, including carbon content, metal elements, and water-soluble ions, were analyzed. Traditional in-stack hot sampling was simultaneously conducted to compare the influences of dilution on PM2.5 emissions and the characteristics of the bonded chemical species. The results, established by a dilution sampling method, show that PM2.5 and total particulate matter (TPM) emission factors were 61.6 ± 4.52 and 66.1 ± 5.27 g ton-waste(-1), respectively. The average ratio of PM2.5/TPM is 0.93, indicating that more than 90% of PM emission from the MSWI was fine particulate. The major chemical species in PM2.5 included organic carbon (OC), Cl(-), NH4(+), elemental carbon (EC) and Si, which account for 69.7% of PM2.5 mass. OC was from the unburned carbon in the exhaust, which adsorbed onto the particulate during the cooling process. High Cl(-) emission is primarily attributable to wastes containing plastic bags made of polyvinyl chloride, salt in kitchen refuse and waste biomass, and so on. Minor species that account for 0.01-1% of PM2.5 mass included SO4(2-), K(+), Na, K, NO3(-), Al, Ca(2+), Zn, Ca, Cu, Fe, Pb, and Mg. The mean ratio of dilution method/in-stack hot method was 0.454. The contents of water-soluble ions (Cl(-), SO4(2-), NO3(-)) were significantly enriched in PM2.5 via gas-to-particle conversion in the dilution process. Results indicate that in-stack hot sampling would underestimate levels of these species in PM2.5. IMPLICATIONS: PM2.5 samples from a municipal solid waste incinerator (MSWI) were collected simultaneously by a dilution sampling technique and a traditional in-stack method. PM2.5 emission factors and chemical speciation profiles were established. Dilution sampling provides more reliable data than in-stack hot sampling. The results can be applied to estimate the PM2.5 emission inventories of MSWI, and the source profile can be used for contribution estimate of chemical mass balance modeling.

Imaging presentation highly manifested as tuberculosis in a case of spinal metastatic carcinoma.

Usually the clinical manifestations between spinal tuberculosis (Pott's disease) and metastasis are not characteristic. Nevertheless, their respective imaging presentations are typical and specific, which makes it relatively easier to attain a correct diagnosis. Imaging features of Pott's disease, in general, include narrowing of intervertebral disk space, collapse of vertebral bodies with eventual progression to kyphotic deformity, destruction of the anterior parts of adjacent vertebrae, formation of a large paravertebral abscess, and calcifications or sequestra within the paravertebral abscess. Spinal tuberculosis is usually endemic, especially in Eastern countries. However, the trend of cancer incidence is also increasing in modern society, which makes it difficult to diagnose spinal osseous lesions. This article presents a case of a 45-year-old man with a 9-month history of low back pain. Both computed tomography and magnetic resonance imaging of the lumbar spine supported the initial diagnosis of spinal tuberculosis. However, pathological examination on the excised specimen resulted in the diagnosis of spinal metastatic adenocarcinoma. We suggest that a definitive diagnosis of spinal metastasis or tuberculosis should not be based on imaging alone. Instead, more attention should be paid to atypical imaging presentations. In addition, biopsy is usually necessary for final diagnosis.

Evaluation of the modified Albee arthroplasty for femoral head loss secondary to septic arthritis in young children: surgical technique.

BACKGROUND: Surgical treatment options for femoral head deficiency in infants secondary to septic arthritis of the hip are varied and associated with uncertain long-term outcomes. The modified Albee arthroplasty has been considered an acceptable procedure; however, the long-term outcomes of this procedure have not been reported, to our knowledge. We evaluated the long-term outcomes of the modified Albee arthroplasty in young patients with severe sequelae of septic arthritis of the hip. METHODS: We retrospectively studied twenty-one children (twenty-one hips) in whom Choi type-IVB sequelae of septic arthritis of the hip had been treated with a modified Albee arthroplasty and six patients with the same sequelae who had been managed with simple observation. The Trendelenburg sign, pain, the range of motion, hip function, the Harris hip score, and limb-length discrepancy were assessed clinically. Remodeling of the femoral head, hip stability, and arthritic changes in the hip were evaluated radiographically. RESULTS: The twenty-one patients with the modified Albee arthroplasty were followed for an average of 121.2 ± 38.6 months and had better outcomes, in terms of the Trendelenburg sign, the Harris hip score, pain, the hip range of motion, and limb-length discrepancy, than the six patients who underwent simple observation. Patients who were two years of age or younger at the time of the arthroplasty exhibited a significantly less severe limb-length discrepancy and less loss of motion than those who were older than two at the time of the surgery. Furthermore, limb-length discrepancy was positively correlated and the range of motion of the hip and the Harris hip scores were negatively correlated with the patient's age at the time of the surgery, suggesting that early surgery in patients with severe sequelae of septic arthritis of the hip is associated with a better clinical outcome. CONCLUSIONS: The modified Albee arthroplasty is a feasible and clinically useful procedure for the treatment of severe sequelae of septic arthritis of the hip, particularly in children who are two years of age or younger.