Anaerobic ammonium oxidation (anammox) is an energy-efficient technology for wastewater nitrogen removal. However, the byproduct nitrate has hindered development and application of anammox process. Meanwhile, the knowledge of nitrate formation during anammox process is insufficient, which prohibits high nitrogen removal. This review firstly summaries and discusses valuable findings on nitrate formation, including molecular mechanism of nitrate production, microbial pathway of nitrate reduction and its net formation. Specially, influences of operating conditions on mechanisms and patterns of nitrate formation are analyzed. Then, based on nitrate formation mechanism, current strategies of nitrate removal from anammox process are reevaluated. Finally, the key knowledge gaps and further process development are presented. Overall, this review sheds light on the understanding of nitrate formation of anammox process, which would further facilitate and optimize the process design and operation for high performance nitrogen removal.

In this work, salicylic acid (SA) was used to induce the self-assembly of octadecyl trimethyl ammonium chloride (OTAC), a cationic surfactant, into three-dimensional wormlike micelle aggregates. These aggregates act as a soft template for hierarchical MgAl hydrotalcite (LDH) to create a multi-level pore structure adsorption material. Scanning electron microscopy characterization showed that the surface of the hierarchical hydrotalcite exhibited a dense layered structure, unlike the monolayer structure of ordinary hydrotalcite. Furthermore, the hierarchical MgAl-LDH possesses a significantly larger specific surface area (113.94 m2/g) and wide pore size distribution ranging more extensively from 2 to 80 nm, which significantly has an impressive adsorption effect on sulfonated lignite (SL), with a maximum adsorption capacity of 192.7 mg/g at pH = 7. Extensive research has been conducted on the adsorption mechanism of hierarchical MgAl-LDH, attributing it to surface adsorption due to the unique multi-level structure of the adsorbent. After two cycles of regeneration experiments, the adsorption capacity of the adsorbent remained at a high level of 179.1 mg/g, demonstrating the excellent renewability of hierarchical MgAl-LDH. Moreover, the hierarchical hydrotalcite showed high adsorption capacity in the adsorption of sulfonated lignite, which was attributed to its larger specific surface area and superior pore structure to expose more active sites.

In this article, surfactants such as cetyl trimethyl ammonium chloride (CTAC) and coconut oil amide propyl betaine (CAB) were compounded (TCJ) and used as a double function with foam drainage and hydrate anti-polymerization. According to the result it was found that 0.05% of CTAC and 0.7% of CAB exhibited both excellent foam property and hydrate anti-polymerization property. For further clarifying the stability characteristic of foam, the foam half-life, drainage process, microcosmic liquid film structure, and stability mechanism were investigated in this article. The high initial foam volume of 415 mL with relatively long half-life time of 5.5 min under high-speed agitation at 50 degrees C after 25 min indicated a good temperature resistance. The excellent foam properties still remained even amount of methanol and NaCl was added, which indicated its well stability and salt resistance. Furthermore, it was found that TCJ exhibited high liquid carrying rate of 62.5% at 65 degrees C and good compatibility with poly vinyl pyrrolidone (PVP), which played great potential to the application in oil field. By the results of DSC curves, it can be found that the phase transformation point of hydrate decreases after addition of TCJ, which indicates the inhibition to the formation of hydrate as thermodynamic inhibitors.

A large quantity of polyacrylamide containing wastewater is generated during polymer flooding every year and it poses great threats to the environment. As highly efficient technology for polyacrylamide wastewater treatment with potential for engineering application is rare, magnetic flocculation represents a promising alternative. It usually takes minutes for complete sedimentation to occur. However, we found in experiments that viscosity reduction in advance was essential to improve the performance of magnetic flocculation. So, a cascade of heterogeneous Fenton and magnetic flocculation process was proposed. Effect of Fe3O4 dosage, flocculants type and dosage, flocculation pH, stirring conditions and flocculation methods on the removal efficiency of PAM was investigated. The cascade process turned out to be one of the most efficient technologies and achieved 92% PAM removal rate in the shortest time (45 min) for 500 mg/L of PAM when Fe3O4 dosage was 1.5 g/L, AlCl3 dosage was 100 mg/L and flocculation pH was 8.0 under optimized stirring conditions. Nano-Fe3O4 exhibited good stability after at least 3 successive runs. The water quality of polymer flooding wastewater from Nanyang Oilfield reached the required standards for reinjection after treatment by the cascade process. The study provides a new and highly efficient technology for PAM wastewater treatment with promising potential for engineering application.

The soil environment is a critical component of the global ecosystem and is essential for nutrient cycling and energy flow. Various physical, chemical, and biological processes occur in the soil and are affected by environmental factors. Soil is vulnerable to pollutants, especially emerging pollutants, such as microplastics (MPs). MPs pollution has become a significant environmental problem, and its harm to human health and the environment cannot be underestimated. However, most studies on MPs pollution have focused on marine ecosystems, estuaries, lakes, rivers, and other aquatic environments, whereas few considered the effects and hazards of MPs pollution of the soil, especially the responses of different environmental factors to MPs. In addition, when many MPs pollutants produced by agricultural activities (mulching film, organic fertilizer) and atmospheric sedimentation enter the soil environment, it will cause changes in soil pH, organic matter composition, microbial community, enzyme activity, animals and plants and other environmental factors. However, due to the complex and changeable soil environment, the heterogeneity is very strong. The changes of environmental factors may react on the migration, transformation and degradation of MPs, and there are synergistic or antagonistic interactions among different factors. Therefore, it is very important to analyze the specific effects of MPs pollution on soil properties to clarify the environmental behavior and effects of MPs. This review focuses on the source, formation, and influencing factors of MPs pollution in soil and summarizes its effect and influence degree on various soil environmental factors. The results provide research suggestions and theoretical support for preventing or controlling MPs soil pollution.

Sewage sludge (SS) is a by-product of sewage treatment plant and a typical solid waste, which has dual properties of pollution and recycling. Using SS as raw material to prepare biochar-based catalytic materials for catalysis in water environment is a new way of sludge reduction and resource utilization. Sludge is a mixture of biomass organic matter, various inorganic oxides, metal ions and microorganisms; hence, carbon-based catalyst or carrier material prepared by sludge has readily available raw materials, excellent pore structure, dispersed active sites, easy regulation of surface chemical functional groups, and high specific surface area. It has been widely used in advanced oxidation processes (AOPs) and catalysis fields, such as catalytic H2O2 heterogeneous Fenton reaction, catalytic degradation based on persulfate (PS) and peroxymonosulfate (PMS), composite photocatalytic reaction, heterogeneous catalytic wet air oxidation and electrochemical catalytic oxidation. In this paper, the modification method for sludge biochar-based catalyst material is described. The key active sites and catalytic mechanism of sludge biochar-based catalysts in different oxidation systems are further revealed by examining the structure-activity relationship between the physical and chemical properties of the material and catalysis and their characteristics in the field of catalysis in water environment. Lastly, the main problems in this field and the future development direction were put forward to provide important reference for the further realization of the highvalue-added resource utilization of sludge biochar.

将配伍性、耐水洗率和防膨性等作为指标,对以环氧氯丙烷、多乙烯多胺缩聚物及氯化钾为主剂的系列复合型防膨药剂(NW-DJ-01～08)进行了筛选.并在此基础上,应用JMP软件结合混料实验方法进一步分析了上述药剂中3种最优黏土防膨剂和氯化铵进行复配后的防膨性能.结果表明:NW-DJ-02、NW-DJ-06和NW-DJ-08防膨率较为优异,体积分数为1.0%防膨率分别为84.21%、88.42%、77.89%.3种防膨剂与氯化铵在复配体积比为2.0∶3.4∶2.6∶2.0,体积分数为2.0%时,具有最优防膨率(93.68%),总体性能优于目前常用防膨剂.

采用高铁酸盐处理难降解有机物磺化酚醛树脂(SMP),研究了各影响因素对SMP的CODCr去除率的影响,确定了最佳条件,当SMP初始浓度为0.05％(质量分数)时,高铁酸盐投量为1.2g/L、反应体系pH为13、反应2h,SMP的CODCr去除率为79.4％.高铁酸盐的投量对SMP的CODCr去除率有很大的影响,不同浓度的SMP应当选择不同的高铁酸盐投量.絮凝作用对SMP的去除效果占总去除率一定比例,但SMP的去除仍以氧化作用为主.结合紫外-可见分光光度法(UV-Vis)、凝胶渗透色谱(GPC)和气相色谱-质谱联用(GC-MS)分析可以断定SMP分子结构中磺甲基结构基本完全降解,SMP的大分子主链发生断裂生成分子量为1300左右的带有苯环结构的物质,当主链降解到一定程度后,苯环结构开始被氧化发生开环反应,生成烃类小分子有机物,最终氧化成CO2 和 H2O.

针对含油污泥热解处理后的热解残渣仍属危险废物,其处理处置已成为制约含油污泥热解技术发展的重要问题之一,文章对含油污泥热解残渣的应用进行研究总结.将几种用作绿植化的污泥与含油污泥热解残渣的组成、性质等进行分析对比,发现其性质组成具有很大的相似性,所以其他污泥的绿植化方法对含油污泥热解残渣的绿植化处理具有一定的参考价值,可以通过向含油污泥热解残渣中添加城市污泥或有机质及氮、磷、钾等营养物质,同时选择耐盐碱的超富集植物对含油污泥热解残渣进行绿植化处理.绿植化技术具有处理量大、应用范围广、二次污染小等特点,具有一定的应用前景.

Oilfield chemicals prepared with natural products is an effective way of green oilfield chemistry development. The konjac gum is used as the flocculant for waste drilling fluid, and it is used as a multifunctional oil field additive. By the single factor experiments, the optimal flocculation conditions were screened out. The conditions are as follows: the adding amount is 0.10%, flocculation temperature is at 40(degrees)C, pH 7, stirring rate is 200 rpm and stirring is for 5 min. the flocculation efficiency can be significantly improved using composite flocculant with konjac gel and orange peel, and get puff and large flocs. The flocculation efficiency is the best under the mass ratio of 1:5 between konjac gum and orange peel. The flocculation efficiency of the compound flocculant is between polyacrylamide and polyaluminum chloride, but it has obvious an advantage in filtration loss. Experimental results show that the "adsorption bridging" and "charge neutralization" mechanisms in the composite flocculant may coexist and reinforce each other. This research will be beneficial for improving the environmental performance of flocculants in waste drilling fluid treatment.

The reduction of oily sludge and scum with high water content by hot washing and analysis of the main factors that affect the reduction and oil recovery rate of oily sludge and scum in hot washing were investigated. Best process conditions for the reduction of tank bottom sludge, refining sludge, and oily scum were carried out, which can make the oil recovery rate and reduction rate of tank bottom sludge after reduction reach 96.30% and 93.00%, respectively, the oil recovery rate and reduction rate of refining sludge after reduction reach 95.36% and 92.60% respectively, and the oil recovery rate and reduction rate of oily scum after reduction reach 95.92% and 93.60% respectively. After treatment, the oil content of the residue is reduced to below 5.1%, and the water content is reduced to below 59.0%. Oil content in the separated water is lower than 200 mg.L-1, and the water content in the separated oil is lower than 0.2%, far below the requirement of 0.5% in the oilfield’s crude oil gathering and transportation standard.

Coal is the main source of energy for China's economic development, but coal gangue dumps are a major source of heavy metal pollution. Bacterial communities have a major effect on the bioremediation of heavy metals in coal gangue dumps. The effects of different concentrations of heavy metals on the composition of bacterial communities in coal gangue sites remain unclear. Soil bacterial communities from four gangue sites that vary in natural heavy metal concentrations were investigated using high-throughput sequencing in this study. Correlations among bacterial communities, heavy metal concentrations, physicochemical properties of the soil, and the composition of dissolved organic matter of soil in coal gangue dumps were also analyzed. Our results indicated that Actinobacteriota, Proteobacteria, Chloroflexi, Acidobacteriota, and Gemmatimonadota were the bacterial taxa most resistant to heavy metal stress at gangue sites. Heavy metal contamination may be the main cause of changes in bacterial communities. Heavy metal pollution can foster mutually beneficial symbioses between microbial species. Microbial-derived organic matter was the main source of soil organic matter in unvegetated mining areas, and this could affect the toxicity and transport of heavy metals in soil. Polar functional groups such as hydroxyl and ester groups (A226-400) play an important role in the reaction of cadmium (Cd) and lead (Pb), and organic matter with low molecular weight (SR) tends to bind more to mercury (Hg). In addition to heavy metals, the content of nitrogen (N), phosphorus (P), and total organic carbon (TOC) also affected the composition of the bacterial communities; TOC had the strongest effect, followed by N, SOM, and P. Our findings have implications for the microbial remediation of heavy metal-contaminated soils in coal gangue sites and sustainable development.

不同于井下用耐蚀管材,含CO2、H2S流体会使油气输送管线产生较严重的腐蚀穿孔、断裂,进而造成流体泄漏,不仅污染周围环境,还会引发安全事故.以常用管线钢为研究对象,对其在湿CO2、H2S单独存在环境及其共存环境中的腐蚀行为进行综述,对腐蚀影响因素进行分析.结果表明,CO2分压、H2S分压和温度变化对湿相CO2、H2S单独存在情况下管线钢的腐蚀速率起主要影响作用;而在CO2与H2S共存时,CO2/H2S分压比和Cl-会对管线钢的腐蚀速率产生较大影响.对CO2与H2S环境中的腐蚀研究进行总结展望,以期为油气田防护措施的制定以及新型耐蚀管材的研发提供参考.

含油浮渣是石油化工企业常见的一种污染物,因其成分复杂、乳化絮凝严重、沉降性能极差、难于分离和清洗,导致其处理难度较大.本文以长庆石化含油浮渣为研究对象,探究了含油浮渣的处理思路和实验方法,结合浮渣自身特点,制定了破乳-混凝-离心脱水的处理思路.结果表明,当实验温度为60℃、搅拌速度为200 r/min、搅拌时间为30 min、CaO加量为 0.20%、PAM(0.1%,相对分子质量 1600 万)加量为 8 mg/L、静置时间为 30 min、离心机转速为 2400 r/min、离心时间为 15 min时,处理后的含油浮渣体积减量化率可达 91.5%,最终固相中的含油率为 6.74%、含水率为 60.03%、固体质量分数为33.23%.处理后水中的悬浮物含量最终可降低至30.63 mg/L,水中的含油量最终可降低至150.52 mg/L.

从处理技术的原理、应用与研究进展三个方面梳理了生物法的国内外研究现状,全面分析了硝化、反硝化、厌氧氨氧化(Anammox)的优缺点,使该领域的研究人员以更加科学的方法了解生物法处理含氮废水的研究现状与发展趋势.指出氮作为一种营养物质,可以直接进行回收利用.阐述脱氨氮技术未来可以着重放在工艺联用及氨氮回收方面,而大规模性的应用还需要我们的进一步研究与探讨.

Process intensification is one way of developing new efficient production pathways for the chemical industry to overcome the increasing global energy demand and solve global energy and environmental problems. Process intensification plays an important role in the gas-liquid mass transfer processes. Herein, an overview of the development in gas-liquid mass transfer enhancement is provided. Classical mass transfer models such as two-film theory, penetration theory, and surface renewal theory are analyzed. Major enhancement methods, namely, mechanical modification of reactor, are summarized and discussed here. The most recent accomplishments in gas-liquid mass transfer engineering are also provided. This review is expected to inspire new research on gas-liquid mass transfer engineering to enhance the future development and potential applications of gas-liquid mass transfer in scientific and industrial fields. Suggestions for the enhancement of gas-liquid mass transfer are also provided.

简述了含油污泥的来源及危害.介绍了热解、焦化、焚烧和阴燃等含油污泥热处理技术及其特征,并重点介绍了含油污泥焚烧处理装备的种类和特点.针对焚烧及阴燃过程会产生大量酸性气体,进而加剧设备腐蚀的问题,总结了含油污泥热处理设备腐蚀行为的影响与控制技术,以期更好地为含油污泥热处理过程中腐蚀控制的方法及发展提供参考.

垃圾渗滤液是一种高浓度且成分复杂的有机废水,而膜处理技术以其低成本和高效的优点在垃圾渗滤液处理过程中得到了广泛的应用,但同时会产生一种浓度更高且难处理的浓缩液.浓缩液成分较渗滤液更为复杂,其主要包含各种有机污染物、无机盐、重金属和氨氮等,而且可生化性较差,若不能妥善处理,将会造成严重的二次污染.本文根据相关研究,总结了浓缩液的形成及水质特性,针对浓缩液的先进处理技术进行综述,讨论了各方法操作条件及处理效率,希望对浓缩液处理的深入研究提供参考.

收集整理陕西省下辖 10 个地级市的表层土壤 9 种重金属(As、Co、Cr、Cu、Mn、Ni、Pb、Zn、Cd)含量、3 个主要国民经济指标(GDP、人均GDP、常住人口)、8 种污染物排放量(工业固废、工业废水、COD、NH3-N、工业废气、SO2、NOx、烟(粉)尘)和 7 个大气环境监测指标(空气质量指数AQI、PM2.5、PM10、SO2、NO2、CO、O3)数据.研究陕西省城市土壤重金属污染水平,利用Arc-GIS软件研究各重金属元素的空间分布特征,并通过地统计学方法进行来源解析.结果表明:陕西省城市土壤重金属含量差异较大,As和Mn的最高含量出现在西安,Cr、Cu和Ni的最高含量出现在渭南,Co、Pb、Zn和Cd的最高含量分别出现在榆林、铜川、宝鸡和商洛.地累积污染指数Igeo的均值排序为:Cd>Co>Pb>Cu>Zn=Ni>Cr>Mn>As.As与Mn、Zn之间存在正相关性,Cr与Cu、Ni的相关性较好,Co、Pb和Cd与其他元素相关性不明显.Cr、Cu和Ni主要来自工业源,As、Mn和Zn主要来自自然源和交通源,Co和Cd主要来自工业源和农业源,Pb主要来自工业源和交通源.