Carbon performance analysis of upgraded wastewater treatment plants in key control areas of the Ziya River Basin in China.

Wastewater treatment plants (WWTPs) are one of the largest sources of greenhouse gas (GHG) emissions, and they are also one of the largest energy consumption industries in urban systems. With the progression of upgrading and standard-rising, WWTPs both directly and indirectly increase carbon emissions from the increased investments in facilities and usages in electricity as well as chemical agents. Here, we collected operational data from 15 WWTPs in the key control areas of the Ziya River Basin in North China and accounted for the changes in carbon performance at different technical upgrade methods. Results showed that the average carbon emission performance increased by 0.487 kg CO2/m3 after the upgrade. Carbon emissions from electricity consumption, chemical usage, biochemical process and sludge treatment accounted for 42%, 17%, 24%, and 17% of the total improvement in carbon emission performance, respectively. Reducing energy consumption, regulating chemical use and sludge comprehensive utilization are the key to carbon emission reduction. It further proposes that the development of wastewater treatment discharge standards should fully consider the comprehensive utilization of water quality classification. Regions with favorable natural conditions should make full use of their advantages by adopting economically feasible, low-energy-consuming technologies such as constructed wetlands, which offer carbon sequestration and landscaping benefits. This study provides guidance on the selection of technological pathways for pollution reduction and carbon mitigation in the wastewater treatment industry and on achieving sustainable water resource utilization.

Procedures from samples to sulfur isotopic data: A review.

RATIONALE: Sulfur isotopes have been widely used to solve some key scientific questions, especially in the last two decades with advanced instruments and analytical schemes. Different sulfur speciation and multiple isotopes analyzed in laboratories worldwide and in situ microanalysis have also been reported in many articles. However, methods of sampling to measurements are multifarious, and occasionally some inaccuracies are present in published papers. Vague methods may mislead newcomers to the field, puzzle readers, or lead to incorrect data-based correlations. METHODS: We have reviewed multiple methods on sulfur isotopic analyses from the perspectives of sampling, laboratory work, and instrumental analysis in order to help reduce operational inhomogeneity and ensure the fidelity of sulfur isotopic data. We do not deem our proposed solutions as the ultimate standard methods but as a lead-in to the overall introduction and summary of the current methods used. RESULTS: It has been shown that external contamination and transformation of different sulfur species should be avoided during the sampling, pretreatment, storage, and chemical treatment processes. Conversion rates and sulfur isotopic fractionations during sulfur extraction, purification, and conversion processes must be verified by researchers using standard or known samples. The unification of absence of isotopic fractionation is needed during all steps, and long-term monitoring of standard samples is recommended. CONCLUSION: This review compiles more details on different methods in sampling, laboratory operation, and measurement of sulfur isotopes, which is beneficial for researchers' better practice in laboratories. Microanalyses and molecular studies are the frontier techniques that compare the bulk sample with the elemental analysis/continuous flow-gas source stable isotope ratio mass spectrometry method, but the latter is widely used. The development of sulfur isotopic measurements will lead to the innovation in scientific issues with sulfur proxies.

Technology characteristics and flavor changes of traditional green wheat product nian zhuan in Northern China.

Nian zhuan has its aroma as one of the perceived principal characteristics. The current study was aimed mainly to investigate the potential to include the aroma of nian zhuan as a new target criterion into the green wheat product chain. By improving the conditions for the traditional processing of nian zhuan, the optimal processing conditions were determined as green wheat (GW) 14 d, steaming the green wheat with the skin (SGWS) 26 min and cooked green wheat peeled (CGWP) 280 min, to evaluate the feasibility of using electronic nose (E-nose) and gas chromatography mass spectrometry (GC-MS) to discriminate nian zhuan in different stages. E-nose was used to recognize nian zhuan odors in different processing stages, and GC-MS to identify the individual volatile compounds. A total of 139 volatile compounds were detected by GC-MS, of which 71 key were screened by t-test (P < 0.01). The W1W, W1S, W2W and W2S sensors of E-nose gave higher responses to all samples, and effectively discriminated the samples. The most volatile compounds were produced in the millstone milling (MSM) stage of nian zhuan, and millstone could promote the release of volatile compounds from cooked green wheat by milling.

Preliminary Investigation on the Relationship between Raman Spectra of Beef and Metmyoglobin and Metmyoglobin Reductase Activity.

A hand-held Raman spectroscopic device was used as a rapid nondestructive testing device to predict the metmyoglobin (MetMb) and metmyoglobin reductase activity (MRA) values on the surface layer of fresh beef. Longissimus dorsi muscles were from 10 young bulls (Holstein-Friesian) from two different cattle farms (group A = 5 and B = 5). The Raman spectra of 100 samples were correlated with the MetMb and MRA values using partial least squares regression (PLSR). Two groups could be discriminated, and the separate correlation models were better than the joint correlation model for the fresh beef. The coefficients of determination are R 2 = 0.81 (group A) and R 2 = 0.87 (group B) for MetMb and R 2 = 0.80 (group A) and R 2 = 0.85 (group B) for MRA. The results show the usefulness of Raman spectra in predicting the inner traits such as MetMb and MRA during meat storage. In conclusion, it is feasible to determine the MetMb and MRA values by Raman spectroscopy. Color is an important indicator of beef freshness and can vary depending on the age, sex, and breed of the cow. They play a very important role in human nutrition. The color of meat is an important indicator of meat freshness, and many researchers are already investigating the causes of color changes. The research was conducted in this environment.

Analysis of Optic Nerve in Adults With Amblyopia Using OCTA.

Objective: The aim was to quantify and compare papillary and peripapillary vessel density in amblyopic eyes of adults and age-matched controls. Methods: This cross-sectional study involved 20 eyes from 10 subjects with anisometropic amblyopia and 12 eyes of 6 age- and gender-matched healthy controls. Optical coherence tomography angiography (OCTA) was performed on all participants. SPSS 20 was used for data analysis. Results: The mean subject age was 35.7 ± 10.04 years (range 18-47) in the amblyopia group and 34.67 ± 6.92 years (range 23-42) in the control group. The diopter of amblyopia ranges from +3 to +5 ds. The mean inside optic disk capillary vessel density (CVD) was 41.88 ± 6.55% in amblyopic eyes, 49.23 ± 6.55% in fellow eyes, and 50.23 ± 4% in control eyes (p < 0.05). The mean inside optic disk all vessel density (AVD) was 52.97 ± 6.71% in amblyopic eyes, 59.87 ± 4.59% in fellow eyes, and 60.45 ± 2.8% in control eyes (p < 0.05). The amblyopic eye of participants showed a decrease in vessel density in the inside optic disk than in the fellow eyes and healthy subjects. Conclusion: Our present study revealed lower vessel density inside the optic disc of adult patients with anisometropic amblyopia. However, further studies are really needed to determine the clinical relevance of this finding.

Formation of volatile flavor compounds, maillard reaction products and potentially hazard substance in China stir-frying beef sao zi.

The effects of stir-frying stages on the formation of flavor volatile compounds, Maillard reaction products (MRPs) and potentially hazardous substances with time in stir-fried beef sao zi were investigated. A total of 122 volatile compounds were identified in beef sao zi after stir-frying. Most of the volatile compounds were produced in the stir-frying fat (SFF) process of beef sao zi. Furosine, fluorescence intensity, Nε-(1-Carboxymethyl)-L-lysine (CML), Nε-(1-Carboxyethyl)-L-lysine (CEL) polyaromatic hydrocarbons (PAHs), heterocyclic aromatic amines (HAAs) and acrylamides (AA) are mainly presented in stir-fried beef sao zi. The furosine peaked at MSF 120 s as the Maillard reaction progressed. The fluorescent compound gradually increased with time during the stir-frying process. The CML and CEL peaked at MSF 120 s. AA reached its maximum in MSF 90 s and then decreased. The quantities and content of HAAs and PAHs were increased by prolonging the stir-frying time, but ended up far lower than the maximum permissible value specified by the Commission of the European Communities. The extended stir-frying promoted MRPs and some hazardous substances, but the content of potentially hazardous substances was still within the safety range for stir-frying beef sao zi.

Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction.

Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes ((32)S, (33)S, (34)S and (36)S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction.

On the coevolution of Ediacaran oceans and animals.

Fe speciation and S-isotope of pyrite data from the terminal Proterozoic Sheepbed Formation in Canada and Doushantuo Formation in China reveal that ocean deep waters were anoxic after the global glaciations (snowball Earth) ending 635 million years ago, but that marine sulfate concentrations and inferentially atmospheric oxygen levels were higher than before the glaciations. This supports a long-postulated link between oxygen levels and the emergence of eumetazoa. Subsequent ventilation of the deep ocean, inferred from shifts in Fe speciation in Newfoundland (previously published data) and western Canada (this report), paved the way for Ediacaran macrobiota to colonize the deep seafloors.