As a crucial component of modern energy, lithium is becoming ever more vital. As a result, lithium-ion-containing wastewater is being created in huge quantities, causing resource loss and environmental damage that must be effectively treated. Adsorption techniques are popular for lithium extraction and recovery due to their benefits of low energy usage, straightforward procedures and excellent recycling. The lithium-ion sieves (LISs) adsorption technique, which has the qualities of high lithium selectivity and adsorption capacity, low energy consumption, environmental protection and safety, is now regarded as the most promising lithium extraction technology. LISs composite forming technology (such as granulation, foaming, fiber forming, film forming and magnetization) and the adsorption technique, specifically the LISs adsorption mechanism, are discussed in this review. The effectiveness of extracting lithium from lithium-containing solutions using LISs adsorbents is reviewed and the difficulties of recovering lithium resources by LISs are presented, thereby offering a guide for their use in treating wastewater containing lithium.

Discharging low-concentration rare earth ions from ion-absorbed rare earth deposits results in resource loss and environmental pollution. Precipitation is a simple and efficient rare earth recovery technology, yet there are few reports on using sludge-derived humic acid as a precipitator. This study used the sodium pyrophosphate method to extract humic acid (SHA) from excess sludge to precipitate low-concentration rare earth wastewater. Textural and elemental analyses showed that SHA is an amorphous solid composed primarily of C, O, N, and H. It contains many carboxylic and hydroxyl functional groups, exhibiting H/C, C/N, and O/C of 0.950, 9.46, and 0.544, respectively. SHA shows a lower oxidation degree and higher aromaticity and humification degrees than the humic acids extracted from various sources in other studies. In addition, we observed that the precipitation involved rapid and slow stages by fitting the SHA precipitation data of rare earth ions with kinetic and isotherm models. The precipitation equilibrium time was 60 min, and the precipitation curve followed the quasi-second order kinetic model. Also, the adsorption isotherm conformed to the Langmuir isotherm model as the precipitation progressed favorably. Further study of the rare earth ion precipitation mechanism revealed that the SHA molecule and rare earth element precipitate was an amorphous-amorphous mixture. It also showed that carboxylic, amino, and hydroxyl groups participated in the precipitation. Therefore, we speculate that rare earth ions were precipitated by chemical reactions of such chemical groups on SHA during precipitation. This discovery provides a reference for future recovery studies of rare earth resources.

The widespread detection of zearalenone (ZEN) in cereal crops and feeds poses a significant threat to both humans and animals. Consequently, the urgency for the international community to address this issue is evident in the demand for safe and effective measures to mitigate zearalenone contamination and explore detoxification methods. In this study, a dye-decolorizing peroxidase (PoDyP4) from Pleurotus ostreatus is characterized for its impressive ZEN degradation effectiveness. PoDyP4 was demonstrated that the ability to almost completely degrade ZEN at pH 6.0 and 40 °C for 2 h, even at high concentrations of 1 mM. The promotion of enzymatic degradation of ZEN was most pronounced in the presence of Mg2+, while Cu2+ and Fe2+ exhibited a notable inhibitory effect. The degradation mechanism elucidated the detoxification of ZEN by PoDyP4 through hydroxylation and polymerization reactions. The resulting metabolic products displayed significantly reduced toxicity and minimal impact on the viability and apoptosis of mouse spermatocytes GC-2 cells, in comparison to the original ZEN. Hydrophobic contacts and hydrogen bonds were found to be crucial for ZEN-PoDyP4 stability via molecular docking. This finding suggests that PoDyP4 may have a promising application in the field of food and feed for zearalenone detoxification.

A low-temperature carbonization technique conducted under limited oxygen has been used to recycle excess sludge. The obtained low-temperature carbonized sludge (LCS) has been used in adsorption experiments with low-concentration rare-earth wastewater (rare-earth ion content of 103.45 mg/L, calculated on the basis of rare-earth oxides (REO)) to identify the most suitable carbonization conditions. Moreover, a response surface method has been used to optimize the adsorption conditions, focusing on the kinetics, isotherm, and thermodynamics of the process. Finally, the rare-earth ions loaded on the LCS were desorbed to assess the regeneration performance of the material. The results showed that the maximum degree of adsorption of low-concentration rare-earth ions on LCS was 94.1% under operation conditions optimized by the response surface method. Analysis of the kinetics and isotherm of the adsorption process showed it to be controlled by both liquid film diffusion and particle diffusion, corresponding to a pseudo-first-order kinetic model and the Langmuir adsorption isotherm. Analysis of the thermodynamics of the process showed the adsorption of rare-earth ions on LCS to be a non-spontaneous, exothermic, entropy-reducing process at high temperature. The results of desorption tests showed that the optimal conditions involved the treatment of LCS (1 g) loaded with rare-earth ions with 0.5 mol/L HCl (50 mL) for 1 h. The degree of desorption remained at about 70% after six desorption and regeneration cycles. Based on characterization results, it is inferred that the adsorption is a physicochemical process involving surface adsorption supplemented by chemical complexation.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

采用焦磷酸钠法和碱溶酸析法分别从剩余污泥中提取污泥源腐殖酸.利用扫描电镜、红外光谱和三维荧光光谱对2种腐殖酸进行表征分析,并对比了二者对低浓度稀土离子的沉淀效果.结果表明:2种腐殖酸中均含有大量的羧酸类、胺类、羟基类官能团,但焦磷酸钠法提取的S-HA-1中官能团的种类更多、含量更高;当沉淀稀土离子浓度为103.40 mg/L时,2种腐殖酸对稀土的沉淀率分别达 97.30％和 91.18％,沉淀物中稀土元素重量百分比总和分别为 31.73％和28.64％,S-HA-1沉淀效果较优.采用S-HA-1为沉淀剂,稀土离子浓度为51.70 mg/L时,通过单因素实验与响应面优化实验确定了较优反应条件:腐殖酸浓度0.25 g/L,反应时间56.53 min,搅拌速率106.27 r/min,反应温度40℃,pH=5.90,在此条件下,稀土沉淀率≥98％.利用能谱和红外光谱分析稀土沉淀物发现,沉淀过程中稀土离子与S-HA表面的酚羟基和羧基等官能团发生了一系列物理化学反应,形成腐殖酸-稀土絮状体沉淀.研究结果表明,从剩余污泥提取腐殖酸低浓度稀土离子沉淀剂,既能实现沉淀剂再利用,又能回收稀土资源.

The active ingredients from tobacco extracts were continuously separated and purified using a homemade free-flow electrophoresis apparatus. A rectangular free flow electrophoresis device was constructed for the continuous separation and preparation, and the operating conditions of the device were optimized. The fractions obtained from the free-flowing component collection unit were then detected by HPLC and GC-MS. The results showed that a 90% methanol-water solution could maximize the extraction of the active components from tobacco. Chlorogenic acid and nicotine were enriched in three and four of 24 fractions, respectively, after free-flow isoelectric focusing electrophoresis. 2-Hydroxy-2-cyclopentene-1-one, 1-(2-methyl-1,3-oxathiolan-2-yl) ethanone, nornicotine, cotinine, and scopolamine were separated and enriched synchronously. Overall, the use of free-flow electrophoresis technology for the separation and purification of the active substances in tobacco can improve the comprehensive utilization rate of tobacco.

为研究从多种有色金属冶炼过程产生的浸出渣、黑铜泥和铜砷饼等有色冶炼固废中稀散金属Te可控富集过程资源消耗及环境影响情况,运用生命周期评价(LCA)技术评估了该过程对环境的负荷.在eFootprint上建立相应的LCA模型,并对研究范围、清单数据、环境影响结果等进行分析.结果表明,该工艺生产过程对初级能源消耗、水资源消耗、全球变暖潜值、酸化及生态毒性的影响较大.从1.00 t多源有色冶炼固废中富集1.46 kg碲粉,要消耗8089.53 MJ的初级能源和11645.43 kg水资源,还排放803.45 kg造成温室效应的气体,产生5.10 kg酸性物质,并且生态毒性指标值为2.98.结合工艺特点,通过对LCA结果和清单数据敏感度分析,为整个生产过程提供了绿色改进方案.

传统水质污染扩散跟踪方法忽略了对水体横向扩散系数的考虑与计算,导致污染垂向跟踪结果与实际情况不符.为此,提出基于布谷鸟搜索(Cuckoo Search,CS)算法的水质污染垂向扩散跟踪建模方法.以混合区域外边界的标准曲线特征尺度作为基础,建立流速分布函数,在各向同性的紊动条件下,获取水体垂向扩散系数.将沿着水深均匀流动量视作水体污染垂直方向上的流场,跟踪水体内水流垂向与污染物浓度变化,完成水质污染垂向扩散跟踪的建模.实验证明:所提模型与实际跟踪结果对比,垂向扩散系数基本相同,验证了模型所得结果符合真实情况.

Experimental study on the adsorption of low concentration rare earth wastewater (rare earth ion concentration 185.70 mg L−1) by different carbonization products prepared from excess sludge by different carbonization processes.

以铜尾矿为研究对象,运用生命周期评价(LCA)法对铜尾矿堆存以及3种铜尾矿资源化利用方法的环境影响进行比较.结果表明,处理1t的铜尾矿,方案1:堆存,对环境的主要影响为生态毒性(ET:7.05×10-1)和人体毒性(HT:1.467×10-7);方案2:铜尾矿代替水泥熟料中的黏土,主要环境影响类型初级能源消耗(PED)降幅高达10.25％;方案3:铜尾矿代替蒸压加气混凝土生产中的砂,全球变暖潜值(GWP)的降低幅度最高,降低了19.51％;方案4:铜尾矿代替泡沫微晶材料生产中的硅质材料,水资源消耗(WU)的降低幅度最高,降低了70.35％.3种资源化利用方案都有不同程度的环境效益.

针对离子型稀土开采提取过程中极易产生的低浓度离子型稀土废水难处理、污染环境等问题,对近5a来国内外低浓度离子型稀土的富集回收技术进行了总结,综述了反渗透、溶剂萃取、离子交换、吸附以及沉淀等多种不同稀土资源回收技术的作用原理和研究进展,分析了各类稀土资源回收技术的优劣势,并提出了未来低浓度稀土资源绿色高效安全回收技术的重点研究方向,为离子型稀土资源的高效开发利用研究提供有益参考.

The disposal of bulky low-concentration rare earth solutions (usually ≤ 200 mg L−1) is difficult and it can easily lead to the waste of rare earth resources. The precipitant separation method is a simple and effective technique that is commonly used for rare earth recovery, but the application of biological component precipitants is rarely reported. In this study, the effects of the precipitation of low concentrations of rare earth ions by excess sludge humic-like acids were evaluated. Scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) and infrared (IR) spectroscopy revealed that the addition of humic-like acids to low-concentration rare earth solutions could produce a flocculent precipitate. The precipitation rate was more than 89%. The content of rare earth metals such as Nd, Y, and La in the rare earth precipitate reached 23.72%, and the elution rate of 1.25 mol L−1 hydrochloric acid was 90.50%. It was concluded that the humic-like acids might contain many functional groups capable of adsorbing rare earth ions. It was inferred that the possible mechanism might be that rare earth ions were precipitated by a series of net catch, ion exchange, and adsorption processes. These findings provide a reference for the future recovery of rare earth resources.

On the basis of collecting the latest exploration data of the study area, the authorsmade the research of the coal quality characteristics and coal accumulation patterns of seam No.4 at medium depth, which provided geological basis of the construction of high production and efficiency coal mine and the next coal resources exploration. The results show that the seam No.4 is black - brown-black, semi bright coal type, at the VII phase of the medium rank coal, high calorific value, easy to grind, nonagglutinating, noncoking and at the relatively high - high softening temperature gray level. The raw coal of seam No.4 generally belongs to middle ash coal, ash yield gets higher from south to north. It’s given priority to a low ash coal in the south and middle ash yield coalin the north. The seam No.4belongs tolow-sulfur coal, and shows “dumbbell” type in sulfur contour map, withthe basic characteristics of low in the middle, high on both east and west sides and higher in southwest, lower in northeast. The thickness and deposition range of the seam were controlled by ancient fluvial erosion after the coal-accumulating period around the Qiao8-11 holes in the south of study area and in the other area, during the coal-accumulating period were controlled by syndepositional structures.

As a byproduct of activated sludge process, excess sludge has become one of the current problems in the field of environmental protection for its yield huge, high moisture content and easy to pollution. In this study, the joint technology combining ozone with ultrasonic was applied in treatment of excess sludge by strong ozone oxidation and prominent ultrasonic cavitation. The effect on lysis excess sludge cells was explored comprehensively. The lysis mechanism of excess sludge cells degraded by ozone + ultrasonic was revealed by analysis of three-dimensional spectral fluorometer, optical microscope and scanning electron microscopy (SEM). The results showed that the MLSS was 22.92% lower than the untreated sludge, the SCOD and NH4+ -N content in the supernatant of the sludge was 1792 and 105.77 mg/L, which was 96.49% and 17.67% higher than the untreated. The supernatant of treated excess sludge contained macromolecular organic matters composed of proteins, polysaccharides, humic acids, and fulvic acids, etc. The whole process of lysis cells of excess sludge degraded by ozone + ultrasonic could be inferred that the microbial particles of excess sludge were exposed after EPS destructed, and then the cell walls of these exposed microbial particles were broken so that a great number of intracellular materials were released. Furthermore, these intracellular material composed of macromolecular organic matters were degraded into small molecule organic matters, H2O, CO2, etc. Finally, the excess sludge was treated gradually by ozone + ultrasonic. [GRAPHICS] .

离子吸附型稀土矿开采过程中易产生大量低浓度稀土溶液,亟待对其有效回收处理.采用“臭氧+超声波”联合工艺处理城市剩余污泥,从剩余污泥破解后的上清液中获得提取液.通过光学显微镜和扫描电镜研究反应时间对剩余污泥絮体结构变化的影响,利用单道ICP和X荧光分析提取液成分及沉淀效果.结果表明:剩余污泥破解后,SCOD由1052 mg·L-1增加至5088 mg·L-1,多糖和蛋白质含量分别增加215.26,115.55 mg·L-1;三维荧光检测出剩余污泥提取液含有大量类腐殖酸类物质;当反应时间为60 min时,剩余污泥形态由团状变成了颗粒状,污泥表面出现褶皱,具有空隙和层状结构,粒径减小,呈现碎片化;相对于NH4HCO3和草酸,提取液具有优秀的沉淀效果,稀土元素沉淀率均在89％以上;絮状沉淀物中Nd,Y,La和Ce等稀土元素占有比例相对较高,含量主要在3％～8％(质量分数).

工业园区废水成分复杂、可生化性差、难降解,常规的生化法难以有效处理.针对以木薯酒精废水为主的某工业园区废水性质,首先单独进行混凝沉淀、臭氧试验,确定了加药量、臭氧投加浓度和pH等最佳控制条件.在此基础上,采用混凝沉淀-臭氧组合工艺对废水进行处理.结果表明:采用混凝沉淀-臭氧联合工艺,在进水流量为10 L/min时,pH=9-10,CODcr去除率可达到75.4％,B/C由0.1最高提高到0.62,该工业园区废水可生化性得到极大提高,为后续进一步有效处理提供重要依据.

Effect of tempering temperature between 400℃ and 700℃ on microstructure and carbide transformation of H13 steel was studied by means of mechanical property test and microstructure and second phase analysis. The results indicate that when tempered at 400-450 ℃, microstructure of the quenched H13 steel is characterized by tempered martensite, and the carbides mainly consist of VC and Fe3 M3 C. The hardness peak of the steel can be observed when tempered at 550 ℃, because of secondary hardening effect caused by a large number of Mo2 C precipitate. When tempered at 600-650℃, the martensite decomposes substantially, the size of carbides grow gradually, the hardness decreases sharply and the toughness grows quickly. The microstructure becomes tempered troostite, and the primary carbides are Fe3 M3 C, Cr7 C3 and VC while tempered at 650 ℃. When tempered at 700 ℃, the H13 steel shows overaging phenomenon as the matrix becomes tempered sorbite, and the dimension of carbides increase significantly.

Using Streptomyces erythreus isolated from pharmaceutical residues as a biosorbent, the characteristics and mechanism of its absorbing Pb2+ was studied. The results showed that absorptive ability of bacterial mycelia modified by sodium hydroxide was improved greatly. The reaction mechanism of modified bacterial mycelia uptake Pb2+ was analyzed by back scattered electron microscope(BSEM) and infrared spectroscopy (IR). The results of experiments indicated that some chemical groups such as -COO-、C-H and O-H among cell walls of bacterial mycelia might play the key functions adsorbing Pb2+. It was presumed that the process of modified bacterial mycelia lead uptake might be a chemical and physical process collaboratively which occurred on the cell surface of bacterial mycelia chiefly based on exchangeable reaction.

Enzymes encoded by genes biodegrading microcystins (MCs) can help reveal the function of genes and biodegradation pathway of MCs. Here the first and important gene (USTB-05-A, 1,008 bp) involved in biodegradation of microcystin-RR (MC-RR) was cloned from Sphingopyxis sp. USTB-05 and firstly expressed in Escherichia coli BL21 (DE3) with an expression vector of pGEX4T-1 successfully. The nucleotide sequences of cloned USTB-05-A possessed 92.5% homology to that of mlA reported in Sphingomonas sp. strain ACM-3962. The deduced amino acid sequences containing the cleavage sites of 26th (alanine) and 27th (leucine) showed 83% identical to that of MlrA. The cell-free extract (CE) of recombinant E. coli BL21 (DE3) containing USTB-05-A had high activity for biodegrading MC-RR. Initial MC-RR of 40 mg L−1 was completely biodegraded under total protein of 350 mg L−1 within 0.25 h. A product derived from MC-RR appeared distinctly with the decrease of MC-RR peak on the profile of HPLC. The product (m/z 1056.5) had molecular weight of 18 higher than that of MC-RR (m/z 1038.7). The findings provided the positive evidences that biodegradation of MC-RR began with the breakage of cyclic MC-RR and then it was converted to linear MC-RR as the first product catalyzed by first enzyme of Sphingopyxis sp. USTB-05.

The environmental protection status of dyeing and printing industry in China is summarized in this paper.The characteristics and source of printing and dyeing wastewater are analyzed fully.Furthermore,the paper introduces tow main methods of printing and dyeing wastewater,physic-chemical treatment and biochemical treatment are emphasized.The current printing and dyeing wastewater processes are investigated comprehensively.According to the current situation,cleaner production,end-treatment and industry orientation are provided for reference.