Performance Analysis of a Solar Continuous Adsorption Refrigeration System

A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September 21st).The cooling capacity,system performance coefficient and the daily rate of available cooling energy are assessed.The main goal is to compare the performances of a solar adsorption chiller equipped with a hot water tank(HWT)with an equivalent system relying on solar collectors with no heat storage module.The daily cooling rates for the solar refrigerator are found to be 102.4 kWh and 74.3 kWh,respectively,on June 21st and on September 21st,using a total collector’s area of 43.47 m2.The corresponding values for the adsorption chiller equipped with a hot water tank of 2 m3(and using a total collector’s area of 72.45 m2),are 127.1 kWh and 106.13 kWh,respectively.

Blood hemoperfusion with resin adsorption combined continuous veno-venous hemofiltration for patients with multiple organ dysfunction syndrome

BACKGROUND:Blood hemoperfusion with resin adsorption can clean larger molecules that exceed the molecular weight cutoff of combined continuous veno-venous hemofiltration(CWH).Hence blood hemoperfusion with resin adsorption combined CWH(HP+CWH) has higher ability of mediator clearance,and can improve clinical outcomes in theory.This study aimed to investigate the effect of blood hemoperfusion with resin adsorption combined continuous veno-venous hemofiltration(HP+CWH) on plasm cytokines like TNF-α,IL-1β,IL-6,cellular immunity and prognosis in patients with multiple organ dysfunction syndrome(MODS).METHODS:This was a prospective,randomized clinical trial.A total of 30 patients who had been diagnosed with MODS were enrolled in this study.Patients were randomly allocated to routine treatment+HP+CWH group(treatment group) and routine treatment+only CWH group(control group).In the treatment group,patients received blood hemoperfusion with resin adsorption for 2hours,and then received CWH for 10 hours every day.In the control group,patients received CWH for 12 hours only every day.The patients in the two groups received blood purification therapy for three days.The plasma of patients in the treatment group was obtained at 0,2,12,24,26,36,48,50,60 hours,5th day,7th day and 10 th day,respectively.The plasma of patients in the control group was obtained at 0,12,24,36,48,60 hours,5th day,7th day and 10 th day,respectively.APACHE Ⅱscore,T-lymphocytes subpopulations,blood lactate acid concentration,heart rate,breathing rate,and oxygenation index were observed.RESULTS:Plasma cytokines like TNF-α,IL-1β,IL-6 decreased markedly after HP(P<0.01);T-lymphocytes subpopulations CD3+,CD4+,CD8+,CD4+/CD8+ increased after HP+CWH or only CWH.The plasma concentrations of TNF-α,IL-1β and IL-6 in the two groups were not markedly different at 12,36,and 50 hours.But on the 5th day,the plasma concentrations of TNF-α,IL-1β and IL-6 in the treatment group were lower than those in the control group(P<0.05).On the 28 th day,5patients died in the treatment group,and 6 patients in the control group.CONCLUSIONS:Both HP+CWH and CWH can clean plasma cytokines like TNF-α,IL-1β,and IL-6,and improve cellular immunity and clinical symptoms and signs of patients.Compared with only CWH,the plasma concentrations of TNF-α,IL-1β and IL-6 were lower on the 5th day,and patients have an increased survival rate on the 28 day in the HP+CWH group.

Clinical effects investigation of continuous plasma filtration with adsorption and continuous hematodialysis on improving the immune level of patients with sepsis in ICU

Objective:To investigate the clinical effects of continuous plasma filtration with adsorption and continuous hematodialysis on improving the immune level of patients with sepsis in ICU. Methods:A total of 80 patients with sepsis were randomly divided into study group and control group, 40 patients in each group. All the patients were treated by routine treatment. Patients in study group were treated by continuous plasma filtration with adsorption and patients in control group were treated by continuous hematodialysis. The blood samples were collected before and after treatment. The immune cell level, inflammatory factors level, APACHEⅡ score and death rate were compared between two groups.Results:All immune cell indexes were significantly improved in both groups. All immune cell indexes in study group were significantly better than those in control group, after treatment. All inflammatory factors were significantly decreased in both groups. All inflammatory factors in study group were significantly better than those in control group, after treatment. The APACHEⅡ in study group was significantly better than that in control group, after treatment. The death rate in study group was significantly less than that in control group.Conclusion:Continuous plasma filtration with adsorption has a great clinical efficacy on patients with sepsis in ICU, which can improve the immune level and prognosis, makes it worth for clinical application.

Carbon Dioxide/Methane Separation by Adsorption on Sepiolite

In this work, the use of sepiolite for the removal of carbon dioxide from a carbon dioxide/methane mixture by a pressure swing adsorption （PSA） process has been researched. Adsorption equilibrium and kinetics have been measured in a fixed-bed, and the adsorption equilibrium parameters of carbon dioxide and methane on sepiolite have been obtained. A model based on the LDF approximation has been employed to simulate the fixed-bed kinetics, using the Langmuir equation to describe the adsorption equilibrium isotherm. The functioning of a PSA cycle for separating carbon dioxide/methane mixtures using sepiolite as adsorbent has also been studied. The experimental results were compared with the ones predicted by the model adapted to a PSA system. Methane with purity higher than 97% can be obtained from feeds containing carbon dioxide with concentrations ranging from 34% to 56% with the proposed PSA cycle. These results suggest that sepiolite is an adsorbent with good properties for its employment in a PSA cycle for carbon dioxide removal from landfill gases.

Column adsorption of Cu(Ⅱ) by polymer-supported nano-iron oxides in the presence of sulfate: Experimental and mathematical modeling

Polymer-supported hydrous iron oxides(HFOs) are promising for heavy metals removal from aqueous systems.The ubiquitous inorganic ligands, e.g., sulfate, are expected to exert considerable impacts on pollutants removal by these hybrid sorbents. Herein, we obtained a hybrid sorbent HFO-PS by encapsulating nanosized HFO into macroporous polystyrene(PS) resin. Both batch and column sorption experiments of Cu(Ⅱ) by HFO-PS were carried out in the presence of sulfate. Obviously, the presence of sulfate is favorable for Cu(Ⅱ) sorption onto HFO-PS.The performances of column Cu(Ⅱ) removal were fitted and predicted with Adams–Bohart, Clark, Thomas and BDST models. Thomas model is suggested best-fit to predict the breakthrough curves. Besides, a linear correlation is observed between breakthrough time and column length based on BDST model, which might be useful for predicting the breakthrough time for Cu(Ⅱ) removal by HFO-PS.

Optimization and mechanisms analysis of indigo dye removal using continuous electrocoagulation

Electrocoagulation(EC) is among the most effective techniques that remove color and decontaminate effluent.Coagulants are delivered in situ by anode corrosion.In this research,indigo dye removal using iron electrodes in continuous electrocoagulation process and the responsible species for decolorization were investigated.The Response Surface Methodology(RSM) was used to optimize the process parameters.The finding in this study shows that at fixed conductivity at 15,000 μS·cm^(-1) the neutral conditions(pH from 6 to 8),the low absorbance,the low flow rate and the high voltage level enhance the color removal efficiency.The high R~2 value of 97.8% and ANOVA analyses show a good correlation between the experimental and predicted results.Under the optimum conditions,which are pH of 7.5, solution concentration of 60 mg·L^(-1), inlet flow rate of 2 L·min^(-1) and voltage of 47 V, the predicted decolorization of 94.083% was achieved at 93.972% with a total cost of 0.0927 USD·m^(-3) of treated effluent.At the optimum pH(7.5),the zeta potential value(-4 mV) of the effluent during EC match with the one of iron Ⅲ hydroxide.The dye removal is ensured thanks to physical adsorption and flocculation.The results exposed in this work prove that the continuous electrocoagulation process could be successfully used for indigo dye removal at industrial scale.

The adsorption properties of NaY zeolite for separation of ethylene glycol and 1,2-butanediol: Experiment and molecular modelling

The separation of ethylene glycol(EG)and 1,2-butanediol(1,2-BDO)azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental importance.Selective adsorption is deemed as the most promising methods because of energy saving and environment favorable.In this paper,NaY zeolite was used to separate 1,2-BDO from EG,and its adsorption properties was then investigated.The isotherms of EG and 1,2-BDO in vapor and liquid phases from 298 to 328 K indicated that they fitted Langmuir model quite well,and the NaY zeolite absorbent favored EG more than 1,2-BDO.The Grand Canonical Monte Carlo(GCMC)and molecular dynamics(MD)simulation techniques were conducted to investigate the competition adsorption and diffusion characteristics in different adsorption regions.It was observed that EG and 1,2-BDO molecules all have the most probable locations of the center of the 12-membered ring near the Na cations.The diffusivities of EG are lower than those of 1,2-BDO at the same adsorption concentration.At last,the breakthrough curves of the binary mixture regressed from the empirical Dose–Response model in fixed-bed column showed that the adsorption selectivity of EG could reach to as high as 2.43,verified that the NaY zeolite could effectively separate EG from 1,2-BDO.This work is also helpful for further separation of other dihydric alcohol mixtures from coal and biomass fermentation.

DETERMINATION OF PARAMETERS IN A TWO-DIMENSIONAL MODEL FOR FIXED-BED ADSORBERS

A new method is proposed for the determination of the parameters in a two-dimensionalmodel which characterizes the properties of axial and radial mixing and mass transport in afixed-bed adsorber.Parameter estimation for the model is carried out with methane-air-5A molecularsieve in a bed under the condition of step injection of tracer from a point on the main axis of thebed by the curve fitting method in the time domain.

血浆炎性因子吸附在脓毒症治疗中的应用研究进展

脓毒症和脓毒性休克是重症监护室常见病种,全球每年有超过1 800万严重脓毒症病例。国外流行病学调查显示,脓毒症的病死率已经超过心肌梗死,成为重症监护室非心脏病人的死亡主要原因。医学的进步带来越来越多治疗脓毒症的创新治疗方式,连续血液净化逐渐成为脓毒症患者早期治疗的重要手段,同时体外血液吸附在脓毒症患者中的治疗价值也逐渐受到重视。本文旨在总结近些年血浆炎性因子吸附在脓毒症治疗中应用的研究进展,对现有研究报道或已在临床应用的常见的几种体外血液吸附技术及其相关研究进展进行总结,以期为更好认识其在临床治疗中的运用价值及对预后的改善提供参考,从而为脓毒症及脓毒症休克患者治疗提供帮助。

双重血浆分子吸附系统序贯血浆置换联合连续性肾脏替代疗法治疗慢加急性肝衰竭合并急性肾损伤的效果分析

目的观察双重血浆分子吸附系统(DPMAS)序贯血浆置换(PE)联合连续性肾脏替代疗法(CRRT)治疗慢加急性肝衰竭(ACLF)合并急性肾损伤(AKI)患者的临床效果。方法回顾性纳入2019年1月—2022年12月于贵州医科大学附属医院住院治疗的ACLF合并AKI的90例患者临床资料,依据不同的血液净化方式,分为DPMAS序贯PE联合CRRT组(观察组,n=31),DPMAS序贯PE组(对照组,n=59)。收集所有患者入院一般资料、血液净化治疗前后实验室指标,包括肝肾功能、凝血功能、炎症指标等,计算eGFR、MELD-Na评分。正态分布的计量资料两组间比较采用成组t检验;非正态分布的计量资料组内前后比较采用Wilcoxon符号秩和检验,两组间比较采用Mann-Whitney U检验。计数资料两组比较采用χ^(2)检验或Fisher精确检验。结果观察组治疗有效率为48.4%(15/31),高于对照组治疗的有效率27.1%(16/59)(χ^(2)=4.071,P=0.044)。两组血液净化方式均可有效改善TBil、ALT、AST、PTA、Scr、PCT、CRP、e GFR及MELD-Na评分(P值均<0.05);两组治疗后PLT及Hb均显著降低(P值均<0.05);而BUN、Alb、INR治疗前后差异均无统计学意义(P值均>0.05)。对照组与观察组的AST、Scr、PCT、e GFR、MELD-Na评分、Hb、PLT治疗前后差值比较,差异均有统计学意义(P值均<0.05)。结论DPMAS序贯PE联合CRRT模式可有效清除炎症介质,改善肾功能,稳定机体内环境,获得较好的临床疗效。

PE、DPMAS、CVVHDF模式治疗乙肝相关慢加亚急性肝衰竭患者的效果对比

目的探讨血浆置换(PE)、双重血浆分子吸附(DPMAS)、连续性静脉-静脉血液滤过透析(CVVHDF)模式治疗乙肝相关慢加亚急性肝衰竭(HBV-ACLF)患者的效果。方法选取2021年11月至2023年2月于福建医科大学孟超肝胆医院进行治疗的HBV-ACLF患者90例,根据治疗方式不同分为PE组,DPMAS组,CVVHDF组,每组均30例。对比三组患者肝功能指标、凝血功能、内毒素(ET)及高迁移率族蛋白B1(HMGB1)水平,随访60 d生存情况。结果治疗后,三组患者总胆红素(TBIL)、谷丙转氨酶(ALT)、谷草转氨酶(AST)、凝血酶原时间(PT)、凝血酶原活动度(PTA)比较,差异有统计学意义(P<0.05);CVVHDF组TBIL、ALT、AST、PT低于DPMAS组及PE组,CVVHDF组PTA高于DPMAS组及PE组(P<0.05);治疗后,三组患者ET、HMGB1比较,差异有统计学意义(P<0.05);CVVHDF组患者ET、HMGB1水平低于DPMAS组及PE组(P<0.05);随访60 d后,CVVHDF组患者生存率高于DPMAS组及PE组(P<0.05)。结论三种人工肝模式均可改善患者的肝功能、凝血功能、ET和HMGB1水平,提高生存率,但采用CVVHDF效果更优。

Review:Mathematically modeling fixed-bed adsorption in aqueous systems

Adsorption is one of the widely used processes in the chemical industry environmental application.As compared to mathematical models proposed to describe batch adsorption in terms of isotherm and kinetic behavior,insufficient models are available to describe and predict fixed-bed or column adsorption,though the latter one is the main option in practical application.The present review first provides a brief summary on basic concepts and mathematic models to describe the mass transfer and isotherm behavior of batch adsorption,which dominate the column adsorption behavior in nature.Afterwards,the widely used models developed to predict the breakthrough curve,i.e.,the general rate models,linear driving force(LDF) model,wave propagation theory model,constant pattern model,Clark model,Thomas model,Bohart-Adams model,Yoon-Nelson model,Wang model,Wolborska model,and modified dose-response model,are briefly introduced from the mechanism and mathematical viewpoint.Their basic characteristics,including the advantages and inherit shortcomings,are also discussed.This review could help those interested in column adsorption to reasonably choose or develop an accurate and convenient model for their study and practical application.

Continuous flow removal of acid fuchsine by dielectric barrier discharge plasma water bed enhanced by activated carbon adsorption

Continuous processes which allow for large amount of wastewater to be treated to meet drainage standards while reducing treatment time and energy consumption are urgently needed. In this study, a dielectric barrier discharge plasma water bed system was designed and then coupled with granular activated carbon (GAC) adsorption to rapidly remove acid fuchsine (AF) with high efficiency. Effects of feeding gases, treatment time and initial concentration of AF on removal efficiency were investigated. Results showed that compared to the N2 and air plasmas treatments, O2 plasma processing was most effective for AF degradation due to the strong oxidation ability of generated activated species, especially the OH radicals. The addition of GAC significantly enhanced the removal efficiency of AF in aqueous solution and shorten the required time by 50%. The effect was attributed to the ability of porous carbon to trap and concentrate the dye, increasing the time dye molecules were exposed to the plasma discharge zone, and to enhance the production of OH radicals on/in GAC to boost the degradation of dyes by plasma as well as in situ regenerate the exhausted GAC. The study offers a new opportunity for continuous effective remediation of wastewater contaminated with organic dyes using plasma technologies.

Mass transfer mechanisms in fixed-bed adsorption of erythromycin

The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.

分子吸附再循环系统治疗脓毒症肝衰竭的临床疗效

目的探讨分子吸附再循环系统(MARS)治疗脓毒症肝衰竭的临床疗效。方法回顾性分析2020年11月—2021年9月天津市人民医院重症医学科收治的15例脓毒症肝衰竭患者的临床资料。15例患者均接受包括针对脓毒症的抗感染治疗,基础疾病和并发症治疗,依据患者血液净化治疗方式分为MARS组及对照组。MARS组9例患者共进行MARS治疗25次,平均每例2.5次;对照组6例共进行连续血液透析滤过(CVVHDF)治疗14次治,平均每例2.3次。比较两组患者治疗前后心率、平均动脉压、肝功能、肾功能、凝血功能、炎症因子及治疗效果等方面的变化。结果治疗后MARS组在稳定心率、平均动脉压,清除胆红素及炎症因子IL-6、TNF-α、IL-10等明显优于对照组(P<0.05);两组清除血氨、乳酸、尿素、肌酐及凝血功能(血小板、PT-INR)比较差异无统计学意义(均P>0.05)。在治疗效果方面,MARS组优于对照组(64.00%vs 28.60%,χ^(2)=4.509,P=0.034)。结论对于脓毒症肝衰竭患者MARS治疗较CVVHDF治疗血流动力学稳定性好,清除毒素更为全面,既能清除与蛋白结合的毒素,又能清除水溶性毒素,凝血方面具有安全性,具有更好的临床疗效。

臭氧催化-吸附联用处理煤化工高盐废水COD研究

为解决煤化工高盐废水COD去除率低带来的蒸发结晶杂盐率高,危废处理费用高的难题,考察了臭氧催化氧化-活性炭吸附耦合工艺对煤化工高盐废水COD的去除效果。对二次反渗透浓盐水开展臭氧催化氧化试验,对其出水开展活性炭吸附试验,最后在最佳工艺下开展臭氧催化氧化-活性炭吸附耦合工艺连续试验。结果表明:臭氧催化氧化试验最佳参数:催化剂投加量700 mg/L,臭氧气体浓度300 mg/L,臭氧通气量1.5 L/min;活性炭吸附试验最佳参数:活性炭投加量80 g/L,吸附时间60 min;在最佳工艺参数下开展耦合工艺100 h连续试验,结果表明:COD去除率稳定在78%~80%,出水COD的质量浓度稳定在80~90 mg/L,臭氧催化氧化-活性炭吸附耦合工艺对高盐废水COD去除效果明显。

钛系吸附剂在西藏碳酸盐型盐湖中的应用研究

钛系吸附剂具有吸附容量高、选择性好、寿命长、稳定性高等特点,在西藏碳酸盐型盐湖提锂方面具有广阔的应用前景。基于转盘式连续离子交换装置,研究了钛系吸附剂在西藏碳酸盐型盐湖中的工艺影响因素,考察了该吸附剂的多周期吸附性能和稳定性。研究结果表明:高进料Li+质量浓度可有效提高吸附驱动力,从而提高吸附容量;当使用优化分配后的吸附柱,进料流速为10 BV/h、水洗卤流速为8 BV/h、水洗酸流速为8 BV/h时,吸附容量为7.53 mg/g,解吸液锂平均质量浓度为1 500 mg/L,平均选择性为S((Li/Na))=4.67、S((Li/K))=36.48、S((Li/Ca))=13.49、S((Li/Mg))=32.51,具有较高的吸附和分离效率。此外,串联或并联解吸形式对于解吸液Li+质量浓度影响较小,主要影响解吸液pH,因此可以根据实际项目需求进行工艺调整。

连续性血浆吸附联合血液滤过治疗脓毒症急性肾损伤的临床观察

目的 探究连续性血浆吸附联合血液滤过治疗脓毒症急性肾损伤(AKI)的临床疗效及对炎症因子的影响。方法 72例脓毒症AKI患者,采用随机数字表法分为研究组和对照组,各36例。对照组采用连续性静脉-静脉血液滤过(CVVH)治疗,研究组在对照组基础上给予连续性血浆吸附治疗。比较两组治疗前后炎症因子[超敏C反应蛋白(hs-CRP)、白细胞介素-6(IL-6)]水平、急性生理学与慢性健康状况评价系统Ⅱ(APACHEⅡ)评分、肾功能指标[血尿素氮(BUN)、血清肌酐(SCr)]、氧合指数及28 d存活率。结果 治疗后,两组hs-CRP、IL-6水平及APACHEⅡ评分均显著低于本组治疗前,且研究组hs-CRP(31.06±9.58)mg/L、IL-6(56.36±43.98)ng/ml、APACHEⅡ评分(10.48±3.41)分低于对照组的(54.08±12.52)mg/L、(97.75±68.17)ng/ml、(13.56±3.95)分,差异均有统计学意义(P<0.05)。治疗后,两组BUN、SCr水平均显著低于本组治疗前,氧合指数显著高于本组治疗前,且研究组SCr(63.14±15.62)μmol/L、BUN(7.89±3.17)mmol/L均低于对照组的(84.51±17.35)μmol/L、(13.51±4.02)mmol/L,氧合指数(358.63±111.92)mm Hg(1 mm Hg=0.133 kPa)高于对照组的(290.76±102.02)mm Hg,差异均有统计学意义(P<0.05)。研究组患者28 d存活率为80.56%,明显高于对照组的58.33%,差异有统计学意义(P<0.05)。结论 连续性血浆吸附联合血液滤过治疗脓毒症AKI患者,可进一步降低炎症因子水平并改善预后。

人工湿地基质在污水净化中的选择与再生研究

通过吸附和吸附再生2个阶段的试验,探究了不同人工湿地基质对污染物的去除效果和持续吸附能力,结果显示:在同一吸附阶段,不同的单一基质对氨氮、TP、COD的去除程度均不同,麦饭石对氨氮的吸附率最高为61.81%,陶粒对TP的吸附率最高为83.63%,珍珠岩、沸石对COD的吸附率最高均可达100.00%;混合基质麦饭石+珍珠岩/火山石组合的吸附效果均得到增强,但吸附饱和点提前。在吸附再生阶段,单一基质在5 d内达到最大吸附量的时间平均为1~2 d;各基质对污染物的吸附能力明显下降,麦饭石对氨氮的吸附率最大值仅为18.08%,混合基质麦饭石+火山石组合对氨氮、COD多为释放状态,但麦饭石+珍珠岩组合恢复对COD的持续吸附作用。因此,基质种类及其再生效果对人工湿地污水的持续性处理至关重要。

玉米秸秆还田及施磷量对黑土磷吸附与解吸特性的影响

以探究松嫩平原玉米连作条件下,秸秆还田与施磷量互作对黑土磷吸附与解吸特性的影响为目的。该试验采取二因素裂区试验设计,主因素为玉米秸秆还田方式,分别为秸秆不还田(S0)、秸秆翻埋还田(S1)和秸秆焚烧还田(S2);副因素为施磷水平,分别为0(P0)、34.50(P1)、69(P2)、103.50(P3)kg/hm2(P2O5)。结果表明:1)Langmuir等温吸附方程最适合拟合黑土对磷的吸附特征。2)秸秆还田与施磷量均显著影响黑土对磷的吸附与解吸特性,且两者互作效应显著。在相同秸秆还田方式下,随着施磷量的增加,土壤对磷的吸附能力均逐渐降低,而土壤中磷的解吸量和解吸率均逐渐增加,其中以S0条件下差异最大,S2条件下次之,S1条件下差异最小。在相同施磷水平下,与S0处理相比,S1和S2均能降低土壤对磷的吸附能力,增加土壤中磷的解吸量和解吸率,其中以不施磷肥(P0)处理下差异最大,而在施高磷(P3)处理下差异不显著,此外,S1与S2在各施磷水平下差异均不显著。3)不同施磷处理下的标准需磷量(standardPrequirement,SPR)为71.02~91.67 kg/hm2,其中以S1P2处理的SPR(73.58 kg/hm2)与P2施磷水平(69 kg/hm2)最相近,是松嫩平原黑土区较为适宜的施磷方式。