This study introduces a comprehensive experiment for the preparation of a magnetic adsorbent using Enteromorpha prolifera,focusing on its structural characterization and efficacy in purifying heavy metal-contaminated wastewater.Integrating fundamental theoretical knowledge and experimental skills from courses in physical chemistry,analytical chemistry,inorganic chemistry,and instrumental analysis,this experiment bridges these foundations with cutting-edge research in chemistry,materials science,environmental science and engineering.It enables students to deeply comprehend and apply the critical scientific principle that "structure determines properties,and properties dictate function",facilitating a transition from solidifying theoretical and practical foundations to enhancing innovative thinking.Moreover,this experiment embodies the principle of "treating waste with waste",subtly instilling the concept of ecological cultivation in students'minds.

In this study, a new red mud/fly ash composite material (RFCM) for phosphate removal was prepared by granulation and activation methods, using bauxite residue (red mud, RM) as the main raw material, adding with some fly ash and a few adhesives. The effects of different types of RM and adhesives on RFCM for phosphate removal were discussed. It was found that RFCM prepared from sintering red mud and cement waste performed better on phosphate removal than that prepared from Bayer red mud and common industrial adhesives. After calcination activated at appropriate temperature around 800–900℃, the specific surface area of RFCM increased, and new substances with hydroxyl (–OH) appeared on the surface of RFCM, which were the functional groups for phosphate removal. Mechanism of RFCM for phosphate removal was speculated as a combination of physical adsorption, chemical adsorption and chemical precipitation, which mainly depended on ligand exchange and chemical reaction. This research will provide a potential application of bauxite residue in environmental remediation.

Red mud/biochar composite material (RMBC), which was applied as heavy metal passivator in this research, was prepared with red mud (the bauxite residue) and cornstalk under anoxic sintering condition. Based on the batch experiments in Pb contaminated soil, the passivating properties of several materials, including red mud (RM), biochar (BC), RMBC and phosphate-containing RMBC (PRMBC), were investigated in comparison with each other. Some interesting results are as follows: through anoxic thermal activation, a rough and porous structure of RMBC was obtained. Substances such as Fe3O4 and metal-organic complexes generated in RMBC provided effective sites for Pb passivation; and the mechanisms were speculated as the precipitation between Pb2+ and the carbonate (or hydroxide), as well as the complexation reaction between Pb and metal organic complexes through ligand bonding. The pot experiments showed the promotion effects of four passivators on the growth of red onion were in the following order: PRMBC > RMBC > BC > RM. PRMBC stabilized Pb content in soil significantly due to the formation of insoluble substances, with the minimum transfer factor and bioconcentration factor for plant growth. The evidences above implied the composite materials (PRMBC and RMBC) would be potential passivators for heavy metal-contaminated soil.

以生物质稻壳为原料、偏铝酸钠为活化剂,采用微波活化法方便地制备了生物质基新型吸附材料.通过扫描电镜、红外光谱、比表面积分析仪对材料进行结构表征,并将其对阳离子染料(以亚甲基蓝为例)的吸附和脱附性能进行了测试.该综合实验涉及材料制备、表征分析、材料性能测试三大板块,需要用无机化学、有机化学、分析化学与物理化学四大化学和仪器分析的基础理论知识去探究分析;实验将科学研究热点融入实践教学中,激发了学生对大学化学实验的热情和兴趣,在潜移默化中提高学生的独立思考、科学实践以及创新的能力.

Preferential removal of phosphate from aqueous was conducted by a novel biomass-based nanocomposite (EP-N+-Zr) with encapsulated hydrous zirconium oxide, and the biopolymer EP-N+-Zr features were described. EP-N+-Zr exhibited high selective sequestration toward phosphate when humic acid or other competing anions (Cl−, SO42−, NO3−, ClO4−) coexisted at relatively high levels. Such excellent performance of EP-N+-Zr was attributed to its specific two site structures; the embedded HZO nanoparticles and quaternary ammonia groups [N+(CH2CH3)3Cl−] bonded inside the biomass—Enteromorpha prolifera, which facilitated preferable capture towards phosphate through specific affinity and nonspecific preconcentration of phosphate ions on the basis of the ion exchange, respectively. The maximum adsorption capacity of phosphate (20 °C) as calculated by Langmuir model was 88.5 mg(P)/g. Regeneration tests showed that EP-N+-Zr could be recycled at least five times without noticeable capacity losses using binary NaOH-NaCl as eluent.

Easily separated novel magnetic composite, derived from a kind of green macroalgae-Enteromorpha prolifera, was employed for effective adsorption of radioactive cobalt (Co-60) and nickel (Ni-63). The characteristics and adsorption mechanisms of the magnetic E. prolifera composite (MEPE) were investigated by VSM, XRD, FT-IR, SEM, TEM, BET, and XPS. The results indicated that the saturated magnetization exceeded 4.90 emu/g. The surface area and average pore diameter of MEPE were 10.995 m(2)/g and 5.49 nm, respectively. The biosorbent had a good affinity to both Co(II) and Ni(II) with the maximum adsorption capacity of 135 and 137 mg/g, respectively. Coexisting nonradioactive ions, like Na+, K+, Mg2+, and Ca2+, affected the sequestration of Co and Ni to a limited degree. Compared with the single-component system, the uptake of Co(II)/Ni(II) for the binary-component adsorption decreased due to competitive adsorption. The potential mechanism of Co(II)/Ni(II) removal by MEPE was mainly electrostatic attraction and surface complex formation. Hydroxyl groups and amine groups in MEPE could be involved in the reaction and adsorption process, and the novel biosorbent MEPE could achieve rapid separation from radioactive wastewaters and effective uptake of Co(II) and Ni(II) simultaneously.

以KOH为活化剂,采用微波活化法处理农业废稻壳,制备生物质吸附材料,通过静态吸附实验考察了其对阳离子染料亚甲基蓝的吸附性能.结果表明,所制生物质材料对亚甲基蓝的最大吸附量为109.9 mg/g,吸附过程符合伪二级动力学方程和Langmuir等温吸附模式,为快速吸附和单分子层吸附,膜扩散是速率控制步骤,吸附过程为生物质材料孔道内部物理吸附和O-H官能团吸附的共同作用.

A continuous fixed-bed study was carried out utilizing Enteromorpha prolifera (EP) biosorbent for removing methylene blue (MB) from aqueous solution. Effect of operating conditions such as bed depth, influent flow rate, pH, MB initial concentration, and column shape were investigated. Results confirmed that excellent sorption is a neutral condition of MB at appropriate flow rate (2mL/min), and maximum dynamic adsorption capacity of EP for MB was estimated to be 348.06mg/g. The Thomas and Yoon-Nelson models both described the entire breakthrough curve well at all experimental conditions, while Bohart-Adams and Bed Depth Service Time (BDST) models were only suitable for an initial part of dynamic behavior of the column. Regeneration of the column was conducted by using 1M NaCl solution as an eluent. Dipole-dipole interactions and the hydrogen bonding were proposed to interpret the mechanisms of the observed biosorption.

Enteromorpha prolifera adsorbent (EA) has been prepared by treating enteromorpha prolifera with CaCl2 solution,the adsorption capability of the adsorbent for crystal violet by static adsorption experiments investigated. The surface morphology and surface functional groups of EA have been analyzed. The analytical methods include scanning electron microscopy (SEM) and fourier transformed infrared (FT-IR). The research results show that adsorbent dosage,pH,contact time and temperature have relatively great influences on adsorption capability. The adsorption process complies with pseudo-second-order-kinetics equation and Langmuir isothermal adsorption model , and is rapid and monolayer adsorption process. The maximum adsorption capacity of EA for CV reaches 1000 mg/g. The adsorption mechanisms are that there has been electrostatic attraction between dye molecules and —OH,—C—O,etc. functional groups of cellulose and pectin in enteromorpha prolifera cell walls,hydrogen bond action, and van der Waals forces action.

对目前高校环境工程专业实习教学存在的问题进行了分析,从培养环境工程专业核心能力的角度进行生产实习教学改革,设计了校内实训+校外实习相结合的方式,将生产实习单位的工作内容设计成教学内容,让学生在校内实习实训场所进行实际操作.教学改革实践表明:学生实习教学目标具体化,考核方式多样化,既可以提高环境工程专业学生核心应用能力,又可以解决实习经费不足、实习基地建设困难、实习光看不做、形式大于内容的问题.经过12、13、14三届学生的实践,取得良好的教学效果.

比喻教学法是提高教学效果的有效途径。文章介绍了比喻教学法的含义,并通过实际案例论述了比喻教学法在环境工程专业核心课程《环境工程原理》教学中的应用,最后指出了比喻教学法在《环境工程原理》教学中使用的注意事项。

A cellulose-rich biomass was modified as a new amphoteric sorbent to eliminate toxic Cu(II) and Cr(VI) from wastewater. The product (WSCA, which stands for modified wheat straw containing both cationic and anionic characters) presents high sorption capacities for the two ions which was evidenced by the comparison with unmodified wheat and other similar samples. Kinetic data and sorption equilibrium isotherms were conducted in batch process. The sorption kinetic analysis revealed that sorption of Cu(II) and Cr(VI) followed the pseudo second-order model well during the whole sorption process. The linear Langmuir isotherm model could perfectly describe the equilibrium data for Cu(II), while the sorption data of Cr(VI) were well fitted by the Freundlich. Results of the static test illustrated the complicated interactions between Cr(VI)/Cu(II) and WSCA including complexation and/or electrostatic attraction mechanisms.

以麦草为原料、以三乙胺和氯乙酸分别为氨基和羧基官能团接枝反应剂,制备秸秆基两性吸附剂;以产品对Cu(II)和Cr(VI)的去除效果为指标,考察了合成过程中单一影响因素,并结合正交实验得出优化改性条件。结果表明,氯乙酸投加量是影响两性秸秆改性效果的主要因素,温度的影响最小;优化改性条件为:当固定阳离子型麦草秸秆投加量为6.69g时,氢氧化钠投加量、氯乙酸投加量、反应温度和反应时间分别为5mL、3.402g、60℃和2.5h。该吸附剂对Cu(Ⅱ)和Cr(Ⅵ)的最大吸附量可达到90.9和241.1mg/g。

A novel amphoteric resin derived from wheat straw (WS) was created. Its physicochemical properties as well as biosorption properties in single and binary systems for Cu(II) and Cr(VI) were discussed in depth. The characteristics of the products indicated that the required binding sites (amine and carboxyl groups) have been grafted onto the agricultural residue biomass. The adsorption capacities for Cu(II) and Cr(VI) are 73.53 and 227.3mgg−1, respectively, which can be in competition with other similar adsorbents. In binary systems, the two ions exhibited competitive adsorption and the interference of Cu(II) with Cr(VI) was much more obviously attributed to the higher affinity and selectivity for Cr(VI) onto wheat straw amphoteric adsorbent (WSAA).

With the increase of large number of data, multi-clusters structure has been adopted for data storage. Therefore, the demand for file metadata sharing across global scale clusters is quickly rising. However, today’s software can not provide features to reflect these desires well. In this paper, We propose and develop a metadata sharing management method called Shedder. First Shedder can allow customized multi-clusters metadata sharing structure. Next, Shedder can provide highly efficient global synchronization for all clusters. Finally, Shedder allows customized user view generated from global namespace. Our evaluation for Shedder shows that Shedder provides low latency for global synchronization. Dynamic transformation from global namespace to customized user view also has low time cost for different size of workloads.

With the increasing scale of I/O servers, nice load balancing algorithm among I/O servers is becoming more and more important in parallel file systems. However, seldom systems have focused their attentions on the imbalance between I/O servers. In order to address this problem, we have proposed a self-acting load balancing strategy. In this paper, data consistency between I/O servers is mainly discussed. A method called re-migration is adopted to reduce the concurrent data-access impact on the self-acting load balancing strategy. According to some experiments, this method is proved to be able to reduce the average response time and improve performance of parallel I/O obviously. Besides, it also improves the flexibility of systems.

For removing the dye from wastewater,the wheat residue was modified into an anion exchanger.The adsorption kinetics of Reactive Brilliant Red K-2BP(RBR K-2BP) from aqueous solutions onto modified wheat residue(MWR)were studied in a batch reactor.Adsorption experiments were carried out as a function of pH and adsorbent dosage.In addition,the kinetic data were respectively fitted by pseudo-first-order equation,pseudo-second-order equation,Elovich equation and the intra-particle diffusion model.It was found that the pseudo-second-order equation could provide the best correlation to the data.The intra-particle diffusion was the main rate-controlling step for the adsorption of RBR K-2BP onto MWR.The adsorption activation energy of dye was 17.21kJ/mol,which indicated that the adsorption type whole process was mainly of the physical adsorption.

A new cellulosic amine-crosslinked copolymer was prepared after the amination reaction with cotton stalk peel (CSP). The physicochemical characteristics of amine-crosslinked cotton stalk peel (AC-CSP) and raw CSP were determined after the surface analysis (including specific surface area, micropore volume and SEM), zeta potential analysis and spectrum analysis (FTIR and Raman spectrum). The sorption properties of AC-CSP for Cr(VI) were evaluated in the static, column sorption and desorption tests. The surface characteristics indicated the absence of porous adsorption in the potential Cr(VI) sorption mechanism. Zeta potential and spectrum analysis of AC-CSP illustrated the involvement of amine groups in the Cr(VI) sorption process. The sorption capacity of AC-CSP for Cr(VI) was 129.0mg/g as comparison with 14.8 mg/g of raw CSP. Flow rate and influent Cr(VI) concentration were demonstrated as two influencial factors in the column sorption tests. NaCl was used as the eluent, and the desorption efficiencies during three successive cycles were 75.9%, 69.8% and 64.3%, respectively. In addition, the results of the static, column sorption and desorption tests illustrated the complicated interactions between Cr(VI) and AC-CSP including complexation and ion exchange mechanisms.

This paper presents a study of the adsorption of ammonium and phosphate ions from aqueous solution using a new fertilizer controlled release agent (FCRA) which is produced through graft copolymerization with wheat straw, acrylic acid (AA), acrylic amide (AM) and dimethyl diallyl ammonium chloride (DMDAAC). A series of batch experiments were conducted to examine the effects of solution pH, adsorbent dosage, the initial concentration of adsorbate and contact time. The findings indicated that the new fertilizer controlled release agent had a significant effect on the adsorption of ammonium and phosphate ions. The adsorption could reach equilibrium through 4h reaction, and had the best adsorption amount at the pH values from 4 to 8. The adsorption amount increased with the increasing initial concentration of adsorbate. The adsorption amount of NH4+ decreased with the increasing of adsorbent dosage while the adsorption of PO43− showed the opposite trend. Kinetic analysis showed that the adsorption of ammonium and phosphate ions on the new fertilizer controlled release agent followed the pseudo-second-order model well. Equilibrium isotherm data of adsorption of NH4+ were well fitted to the linear Langmuir and Freundlich models, while the data of adsorption of PO43− were well fitted to the Freundlich model. The desorption experiments also showed that the desorption of NH4+ and PO43− on FCRA could reach saturation at the time of 5h and 4h, respectively. And the pH had a large effect on desorption.

Several new types of anion exchange resins were prepared from wheat straw (WS) and their applications in the removal of various toxic anions (PO4-P, NO3-N, Cr (VI) and organic anionic dye) were investigated intensively. The preparation method and their synthesis costs are presented. The required binding sites (amine groups) have been grafted onto the agricultural products and tested. Results show that the synthesis costs (0.45–1.9US$/kg) for these exchange resins can be regulated according to practical utilizations and their physicochemical properties will be beneficial to the exchange capacities for various anions. The initial total capacities for the PO4-P, NO3-N, Cr(VI) and organic anionic dye are in the ranges of 16.5–52.4mg/g, 27.5–89.8mg/g, 119.7–405.7mg/g and 311.0–805.0mg/g, respectively, which can be in competition with some commercially available exchange resins.