Reduction of NOx Emission from the Cement Industry in South Korea: A Review

As climates change around the world, concern regarding environmental pollutants emitted into the atmosphere is increasing. The cement industry consistently produces more than 4000 million metric tons of cement per year. However, the problem of air pollutants being emitted from the calcination process is becoming more critical because their amount increases proportionally with cement production. Each country has established regulatory standards for pollutant emission. Accordingly, the cement industry is equipped with facilities to reduce air pollutants, one of which is the NOx removal process. NOx reduction processes under combustion conditions are modified to minimize NOx generation, and the generated NOx is removed through post-treatment. In terms of NOx removal efficiency, the post-treatment process effectively changes the combustion conditions during calcination. Selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) processes are post-treatment environmental facilities for NOx reduction. Accordingly, considering the stringent NOx emission standards in the cement industry, SNCR is essential, and SCR is selectively applied. Therefore, this paper introduces nitrogen oxide among air pollutants emitted from the South Korean cement industry and summarizes the technologies adapted to mitigate the emission of NOx by cement companies in South Korea.

Single-atom nanocatalysts for biosensing application

Single-atom (SA) catalysts, as a rising star in catalytic field, have many advantages over traditional nanocatalysts. The enhanced catalytic activity, variable and simple structure as well as clear active sites of SA catalysts advance the innovation of biosensing techniques. In this review, we will provide the latest research progress of SA catalysts in biosensing field, and systematically summarize their sensing applications, especially emphasing on the biosensing strategies on the determination of disease-related biological matrices (H2O2, biological enzyme, NO, etc) and environmental pollutants (organophosphorus pesticides, heavy metal ions and volatile organic compounds). Finally, we will provide the challenges that SA catalysts still faced.

1,3-Butadiene: a ubiquitous environmental mutagen and its associations with diseases

Abstract1,3-Butadiene (BD) is a petrochemical manufactured in high volumes. It is a human carcinogen and can induce lymphohematopoietic cancers, particularly leukemia, in occupationally-exposed workers. BD is an air pollutant with the major environmental sources being automobile exhaust and tobacco smoke. It is one of the major constituents and is considered the most carcinogenic compound in cigarette smoke. The BD concentrations in urban areas usually vary between 0.01 and 3.3 μg/m3 but can be significantly higher in some microenvironments. For BD exposure of the general population, microenvironments, particularly indoor microenvironments, are the primary determinant and environmental tobacco smoke is the main contributor. BD has high cancer risk and has been ranked the second or the third in the environmental pollutants monitored in most urban areas, with the cancer risks exceeding 10-5. Mutagenicity/carcinogenicity of BD is mediated by its genotoxic metabolites but the specific metabolite(s) responsible for the effects in humans have not been determined. BD can be bioactivated to yield three mutagenic epoxide metabolites by cytochrome P450 enzymes, or potentially be biotransformed into a mutagenic chlorohydrin by myeloperoxidase, a peroxidase almost specifically present in neutrophils and monocytes. Several urinary BD biomarkers have been developed, among which N-acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine is the most sensitive and is suitable for biomonitoring BD exposure in the general population. Exposure to BD has been associated with leukemia, cardiovascular disease, and possibly reproductive effects, and may be associated with several cancers, autism, and asthma in children. Collectively, BD is a ubiquitous pollutant that has been associated with a range of adverse health effects and diseases with children being a subpopulation with potentially greater susceptibility. Its adverse effects on human health may have been underestimated and more studies are needed.

Biosorption Potentials of Pleurotus tuber-regium (Fr.) Sing in Lead and Cadmium Polluted Soil

Background/Aim: The heavy metals, cadmium (Cd) and lead (Pb), are often implicated as environmental pollutants. Therefore, the biosorption potential of Pleurotus tuber-regium in lead and cadmium polluted soil was investigated by this work. Methods: Four kilograms of each humus soil sample was weighed into eight different black nursery cellophane bags and polluted with 0.5 g, 1.0 g and 2.0 g of lead and cadmium in triplicate. Pleurotus sclerotia were then planted in these polluted soil samples, and distilled water was added ad libitum. Results: The results showed that the growth performance was dose-related in lead-polluted soil. The Pleurotus tuber regium mushroom in the lead-polluted soil samples indicated a dose-dependent absorbed lead concentration in the results. Cadmium-polluted soil samples did not support the growth of the Pleurotus tuber regium mushroom at the various concentrations of cadmium used after day 30. Therefore, the findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium. Conclusion: The findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium.

Morphological, Gene, and Hormonal Changes in Gonads and In-Creased Micrococcal Nuclease Accessibility of Sperm Chromatin Induced by Mercury

Mercury is one of the most dangerous environmental pollutants. In this work, we analysed the effects of exposure of Mytilus galloprovincialis to 1, 10 and 100 pM HgCl2 for 24 h on the gonadal morphology and on the expression level of three stress genes: mt10, hsp70 and πgst. In this tissue we also evaluated the level of steroidogenic enzymes 3β-HSD and 17β-HSD and the expression of PL protein genes. Finally, we determined difference in sperm chromatin accessibility to micrococcal nuclease. We found alterations in gonadal morphology especially after exposure to 10 and 100 pM HgCl2 and hypo-expression of the three stress genes, particularly for hsp70. Furthermore, decreased labelling with both 3β-HSD and 17β-HSD antibodies was observed following exposure to 1 and 10 pM HgCl2 and complete absence at 100 pM HgCl2 exposure. Gonads of mussels exposed to all HgCl2 doses showed decreased expression of PL protein genes especially for PLIII. Finally, micrococcal nuclease digestions showed that all doses of HgCl2 exposure resulted in increased sperm chromatin accessibility to this enzyme, indicative of improper sperm chromatin structure. All of these changes provide preliminary data of the potential toxicity of mercury on the reproductive health of this mussel.