Emergency Treatment Technology Research Articles

The synthesis of an acrylamide copolymer and its synergistic effects on clay flocculation of red tide organisms

The modified clay (MC) method is a common emergency treatment technology for red tides, and the selection of surface modifiers is the key to the MC technology. A cationic polymeric modifier, the copolymer of dimethyl diallyl ammonium chloride and acrylamide (P (DMDAAC-co-AM), PDA) was optimized via a visible-light-induced polymerization technique. The PDA-modified clay (PDAMC) was prepared with strong salt tolerance and achieved efficiencies of 86% at the concentration of 50 mg L−1, and the dose was 90% lower than that of aluminum polychloride-modified clay (PACMC). While polyacrylamide and commercial PDA can achieve efficiencies of only 25 and 67%, respectively, but high doses were required. This is because PDA changed the surface charges of clay particles from negative to positive, which promotes the formation of the polymer-chains bridging network to overcome the difficulties of curling in seawater. According to the analysis of flocculation parameters and spatial conformation of PDAMC, the high salinity tolerance of the PDAMC was attributed to the synergistic processes of charge neutralization and the three-dimensional network bridging. Therefore, this study has developed a highly effective flocculant material used in seawater and provided an important reference for the management of red tide organisms.

Research on emergency treatment technology for water pollution accidents where the pollutants are not included in the emergency database

Abstract At present, emergency treatment methods are selected based on case or technical database, and it is limited to chemicals in pollution accidents covered by the database. Based on the existing emergency treatment technical database, this paper adds a new chemical characteristics database from the physicochemical properties of chemicals such as toxicity and solubility. Combining the weight of characteristic indexes calculated by the Criteria Importance Though Intercriteria Correlation method combined with the Entropy Weight (CRITIC-EW) method and Manhattan distance, a model is constructed to preliminarily select alternative technologies for a target pollutant. Then, Decision-Makers (DMs) can evaluate alternative technologies using the compound language combined comparative language based on hesitant fuzzy linguistic term set (HFLTS) and single language. And alternative technologies are ranked by applying Technique for order performance by similarity to ideal solution (TOPSIS) method. The closest alternative technology is the most suitable. Taking Bisphenol A (BPA) pollution accident as an example, this method is verified. By analyzing physicochemical properties, forms, and uses between similar chemicals and BPA, as well as applicability of alternative technologies, the emergency treatment method proposed in this study is proved feasible.

Emergency treatment technology and case study of sudden environmental pollution caused by oil spill in river basin

Based on the characteristics of sudden oil spill environmental pollution in a river basin, this paper presented a method for emergency treatment of sudden oil spill environmental pollution in a river basin by analyzing and summarizing a large number of oil spill emergency treatment cases. Stratigies such as pollution source blocking, sluice dam controlling and pollutant interception were applied to control and eliminate the pollution situation. Besides, typical oil spill emergency response cases were picked and analyzed to provide a reference and guidance for the emergency treatment of oil spill incidents in China.

Pulmonary Function of 449 Hospitalized COVID-19 Patients Which Including 141 Asymptomatic Carriers and 308 Mild and Moderate Cases

Background: Since the COVID-19 outbreak, there has been a few articles on pulmonary function studies in COVID-19 patients discharged one month later or three month later. However, there is no literature mentioned about the pulmonary function of hospitalized COVID-19 patients so far.Methods: In this study, we firstly performed a retrospective study to identify the pulmonary function changes with 449 COVID-19 inpatients including 141 asymptomatic carriers compared with 228 non-COVID-19 outpatients which accepted pulmonary function test in health examine center.Results: We found that COVID-19 patients included asymptomatic carriers had worse pulmonary function compared to non-COVID-19 patients even when they were hospitalized. In addition, age may be an important factor which contributes to pulmonary dysfunction in COVID-19 patients. Besides, the IL-6 level in the blood may affect the evaluation of lung function results and may be used to predict the pulmonary function of COVID-19 patients.Conclusion: Early rehabilitation training for COVID-19 patients is critical to their recovery.Funding Information: Supported by Novel coronavirus pneumonia emergency treatment and diagnosis technology research project of Heilongjiang provincial science and Technology Department, the National Natural Science Foundation of China (No.81571871, 81770276), Harbin Medical University Cancer Hospital Haiyan Fund (JJMS2021-10), Heilongjiang Postdoctoral Fund (LBH-Z20070).Declaration of Interests: All the authors have no conflict of interest to declare.Ethics Approval Statement: A written informed consent was regularly obtained from all patients upon admission into the 1st affiliated hospital of Harbin Medical University (the intensive care center for severe COVID-19 patients in Harbin, Heilongjiang province). The study was approved by the Ethics Committee of 1st affiliated hospital of Harbin Medical University.

The identification research of emergency treatment technology for sudden heavy metal pollution accidents in drainage basin based on D-S evidence theory.

As a sudden heavy metal pollution accident occurs in a drainage basin, decision makers need to quickly select the optimal emergency treatment technology and formulate emergency schemes according to the actual accident characteristics. Therefore, a two-step identification method of emergency treatment technology for sudden heavy metal pollution accidents based on Dempster-Shafer (D-S) evidence theory is proposed, in order to screen the optimal emergency treatment technology effectively and solve the conflict among fusion data in the process of index quantification. Firstly, the available technologies were screened preliminarily by the primary identification indexes (technical characteristic indexes). Secondly, the weight synthesis method based on the D-S evidence theory and attribute assignment was utilized to score the secondary identification indexes (technical evaluation indexes) of each available technology comprehensively. Finally, the optimal emergency treatment technology for this sudden pollution accident was obtained. Taking the sudden arsenic pollution accident of the Picang flood diversion channel in Linyi, Shandong Province as an example, the activated alumina adsorption dam technology was extracted successfully, which is in accordance with the actual treatment situation. The result shows that the method has strong feasibility and practicability, which can provide strong decision support for dealing with sudden pollution accidents in drainage basins efficiently.

Rapid and effective removal of Cr(VI) from aqueous solutions using the FeCl3/NaBH4 system

A new emergency treatment technology for rapid and effective removal of hexavalent chromium [Cr(VI)] from aqueous solutions by direct addition of ferric chloride (FeCl3) and sodium borohydride (NaBH4) in sequence to Cr(VI) solutions under magnetic stirring conditions was proposed in this study. Various reaction conditions, such as solution pH and Fe(III)/Cr(VI) and FeCl3/NaBH4 molar ratios were investigated. The results showed that 97.6–99.9% of 50mg/L Cr(VI) can be removed from aqueous solutions within 3min in the initial pH range of 3.5–6.0 with Fe(III)/Cr(VI) and FeCl3/NaBH4 molar ratios of 1.0:1 and 1:3.0 respectively at 298K, which was significantly better than that of FeCl3 and NaBH4 alone. This indicated that a synergistic effect existed. Jar tests demonstrated that Cr(VI) was reduced to Cr(III) mainly by NaBH4 under a strong acidic condition in which the hydrogen ions were largely provided by the hydrolysis of FeCl3. In addition, co-precipitation of ferric and trivalent chromic ions occurred. The adsorption of ferric compounds also contributed to the loss of a relatively higher concentration of Cr(VI). Experimental results and especially theoretical calculations of redox potentials suggested that the expected nanoscale zero-valent iron (nZVI) or ferroferric oxide (Fe3O4) was formed only with the addition of excess FeCl3/NaBH4. X-ray photoelectron spectroscopy (XPS) indicated that these precipitates were complex Fe–Cr oxides/hydroxides. The results demonstrated the potential use of the FeCl3/NaBH4 system in copping with Cr(VI) pollution accidents.

Research on an emergency treatment technology for black-odor water caused by macrophytes decaying

水草腐烂加速水体耗氧和水体还原性物质的溶出进程,在夏、秋季高温条件下极易引发局部水体黑臭.以太湖沉水植物优势种马来眼子菜(Potamogeton malaianus)、苦草(Vallisneria natans)及浮叶植物优势种莕菜(Nymphoides peltatum)为受试材料,利用太湖原位底泥培养模拟水草腐烂形成的黑臭水体,考察不同的环境材料处置方式(壳聚糖(CTS)、聚合氯化铝(PAC)、聚丙烯酰胺(PAM)、CTS+PAC和PAC+PAM)对黑臭水体浊度、溶解氧浓度、挥发性硫化物等黑臭水体特征污染物的絮凝沉降规律及去除机理.结果表明:(1)絮凝处理24 h后,CTS+PAC组合对黑臭水体的浊度去除效果最佳,浊度去除率达70.3%,上覆水溶解氧浓度明显提高,增加率为261.5%;(2)加石英砂悬浊液加速絮体沉淀,形成絮体之后加石英砂使水体浊度稳步下降,4 h之后,浊度去除率达74.9%,显著高于与絮凝剂一起加入的处理组(29.8%);(3)植物腐烂释放的含硫特征嗅味物质主要为硫化氢(H₂S)、甲硫醚和二甲基三硫醚.不同植物体腐烂释放的含硫挥发性有机物浓度差异显著,马来眼子菜释放的4种含硫有机物总和分别为莕菜和苦草释放的319.8%和252.2%;(4)CTS+PAC处理后苦草及马来眼子菜腐烂水体中挥发性有机硫化物浓度较对照组分别降低了18.6%和44.5%.PAC+PAM组合絮凝处理组对莕菜腐烂水体中H₂S有较好的去除效果,去除率达到52.4%.CTS+PAC絮凝剂组合处理的H₂S浓度均低于对照组,苦草、马来眼子菜和莕菜腐烂后黑臭水体中H₂S浓度分别降低了27.4%、41.0%和28.6%.CTS+PAC组合对H₂S和二甲基硫醚类物质等致臭物释放的抑制效果优于PAC+PAM组合絮凝处理.;Aquatic plants decaying will accelerate the process of dissolved oxygen depletion and promote the dissolution of reducing substance, which can easily lead to partial water black-odor in a hot summer. In this study, dominant species of submerged plants Potamogeton malaianus, Vallisneria natans and floating-leaved dominant species Nymphoides peltatum in Lake Taihu were selected as test material. Then the macrophytes decayed in cylindrical sediment in the culture system in which simulated conditions in situ. The black-odor waters were formed to study the flocculation and sedimentation kinetics, removal mechanism of water turbidity, volatile sulfide, dissolved oxygen and other water and soil interface characteristics which were treated with different environmental material disposals(chitosan(CTS), poly aluminum chloride(PAC), polyacrylamide(PAM), CTS+PAC and PAC+PAM). The results suggest that:(1) After 24 h, the turbidity removal of black smelly water treated by CTS+PAC was optimal, when turbidity removal rate was 70.3%. The CTS+PAC combination can increase the dissolved oxygen in overlying water more significantly than other environmental material disposals, and the increase rate is 261.5%.(2) Taking flocculation experiments by joining flocculants in the black smelly water with different flocculants, the suspension of quartz sand was added at different timing. Quartz sand suspension can accelerate flocculant precipitation, adding quartz sand before flocculant is significantly better than after it with turbidity removal rate 74.9% compared to 29.8%.(3) Sulfur characteristic odor compounds released by decay aquatic plants are mainly hydrogen sulfide(H₂S), dimethyl sulfide and dimethyl trisulfide. volatile organic sulfur compounds(VOSCs) released by difference decayed plants was significantly different. The sum of the four forms of organic sulfur released from Potamogeton malaianus were 319.8% of Nymphoides peltatum and 252.2% of biter grass.(4) Volatile organic sulfur compounds contents of Vallisneria natans and Potamogeton malaianus decaying water treated by CTS+PAC was reduced by 18.6% and 44.5%. Treatment PAC+PAM has a good deodorizing effect on Nymphoides peltatum for the removal rate of H₂S reached 52.4% when treatment CTS+PAC affected both three kind of plants. The content of H₂S reduced by 27.4%, 41.0% and 28.6% in Vallisneria natans, Potamogeton malaianus and Nymphoides peltatum, respectively. The inhibitory effect of odorant(such as H₂S and dimethyl sulfide) in treatment CTS+PAC was higher than that in treatment PAC+PAM.

Evaluation and selection of emergency treatment technology based on dynamic fuzzy GRA method for chemical contingency spills

A robust scheme to address emergency pollution accident is becoming more and more important with the rise of the frequency and intensity of the emergency pollution accidents. Therefore, it is crucial to select an appropriate technology in an emergency response to chemical spills. In this study, an evaluation framework based on dynamic fuzzy GRA method has been developed to make forward optimum scheme for the selection of emergency treatment technology. Dynamic analysis and linguistic terms are used to evaluate alternatives to improve efficiency of emergency treatment procedures by addressing the vagueness and ambiguity in decision making. The method was then applied in a case study to evaluate emergency arsenic treatment technology and demonstrate its applicability and feasibility in emergency arsenic pollution under two scenarios associated with different arsenic levels. Therefore, not only the results can be used for selecting emergency treatment technology, but also help decision-makers identify desired decisions for contaminant mitigation with a quick response and cost-effective manner.

Study on Assessment Method of Emergency Disposal Technology Based on Threat Evaluation

s:In order to predict the harm of sudden pollution to source water,screen out appropriate emergency disposal technologies,an evaluation index system of emergency treatment technology in urban drinking water source based on threat evaluation was established by analytic hierarchy process (AHP) from the points of pollution situation,pollution position,water source scale,emergency management and alternative water source.Threat was divided into four levels, and different threat-levels corresponded with different weight of the evaluation index system of emergency disposal technologies. When pollution event occurred, emergency experts graded every index, got the threat-level according to the linear weighted method and selected corresponding set of weights of the emergency disposal technologies The method proved to be an scientific and accurate.

Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents

The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012.