The chemical reduction technique is widely used to remediate Cr(VI)-contaminated soil due to its cost-effective and convenient operation. However, it also suffers from the "yellowing" issue and re-migration of Cr(VI) after onsite remediation. This study hence investigated a new combined treatment material, (NH4)2HPO4 and FeSO4, to enhance the immobilization of Cr(VI) in soil, ultimately inhibiting the "yellowing" phenomenon. The Cr(VI) remediation efficiency, mechanisms, and the long-term stability using FeSO4 with (NH4)2HPO4 were investigated. The Cr(VI) immobilization mechanisms were elucidated using the European Community Bureau of Reference (BCR) sequential extraction procedure, X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The results suggested that, following the reduction of Cr(VI) to Cr(III) by FeSO4, the presence of (NH4)2HPO4 promoted the formation of residual Cr (CrPO4). At the optimal dose of FeSO4:(NH4)2HPO4:Cr(VI), 5:10:1, 88 % of the 450 mg/kg Cr(VI) in soil was reduced, all the HOAC-extractable Cr (58.67 %) disappeared, while the residual Cr was increased from 6.74 % to 50.61 %. The H2O2 oxidation and simulated rainfall experiments suggested that the extra addition of (NH4)2HPO4 significantly inhibited Cr reoxidation and leachability, possibly due to the formation of residue CrPO4 and FexCr1-x(OH)3, especially when the rainfall`s SO42-:NO3ratio was 8:1. It is believed that the combination of FeSO4 and common synthetic fertilizer (NH4)2HPO4 is a promising method for in-situ remediation of Cr(VI)-contaminated soil due to its strong resistance to oxidation and acid rain erosion.

The application of parathion (PTH) in agriculture can result in its entry into the soil and threaten the soil environment. Monitoring the PTH residues and assessing toxicity on soil health are of paramount importance to the public. Herein, the dissipation of PTH and concomitant influence on microbial activities [FDA hydrolase (FDA‒H), microbial biomass carbon (MBC) and basal respiration (BR)] in coastal solonchaks were investigated. Results showed that the dissipation of PTH in tested soil declined linearly, and the half-lives varied from 5.6 to 56.8 days, depending on pollutant concentrations. The FDA‒H activity and MBC were negatively affected by PTH pollution and exhibited a significantly positive correlation. Two‒way ANOVA analysis demonstrated that microbial activities were affected not only by PTH dose and incubation time but also by their interactions. The integrated biomarker response (IBR/n) index values on day 120 were between 1.02 and 2.89, larger than those on day 1 during PTH dissipation. This implied that the soil quality did not recover though there was no PTH residue in the soil at the end of the experiment. These findings suggested that microbial activities integrated with IBR/n index could elucidate the hazardous impacts of PTH dissipation on biochemical cycling and microorganisms in soil.

Silver nanoparticles (AgNPs) are released into the sewage pipes and ultimately wastewater treatment plants during manufacturing, use, and end–life disposal. AgNPs in wastewater treatment plants aggregate or dissolve, and may affect the microbial community and subsequent pollutant removal efficiency. This study aims to quantitatively investigate the fate of AgNPs in synthetic high ammonia nitrogen wastewater (SW) and sludge from an up–flow anaerobic sludge blanket (UASB) anammox reactor using a nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), transmission electron microscope (TEM), and atomic absorption spectroscopy (AAS). Results showed that 18.1 mM NH4+, 2.11 mM Mg2+ in SW caused less negative zeta potential (ζ−potential, −18.4 vs. −37.4 mV), aggregation (388.8 vs. 21.5 nm), and settlement (80%) of citrate−coated AgNPs (cit−AgNPs) in 220 min. The presence of 18.5 mM Cl− in SW formed AgCl2−, AgCl(aq) and eventually promoted the dissolution (9.3%) of cit−AgNPs. Further exposure of SW−diluted AgNPs to sludge (42 mg L−1 humic acid) and induced a more negative ζ−potential (−22.2 vs. −18.4 mV) and smaller aggregates (313.4 vs. 388.8 nm) due to the steric and hindrance effect. The promoted Ag dissolution (34.4% vs. 9.3%) was also observed after the addition of sludge and the possible reason may be the production of Ag(NH3)2+ by the coexistence of HA from sludge and NH4+ from SW. These findings on the fate of AgNPs can be used to explain why AgNPs had limited effects on the sludge−retained bacteria which are responsible for the anammox process.

Persulfate (PS) oxidation is a promising soil remediation technology. Information regarding pollutant degradation in soil by PS-based technique under different oxidizing atmospheres is still lacking. In this study, p-chlor-onitrobenzene (p-CNB) degradation in soil in a microwave (MW) activated persulfate (MW/PS) system was evaluated under aerobic and anaerobic conditions. The experimental results demonstrated that anaerobic condition was more conducive to p-CNB degradation. Only 46% of p-CNB was degarded within 60 min treatment under aerobic conditions, but it increased to more than 80% under anaerobic conditions. The increase of PS dosage and MW temperature both promoted p-CNB degradation. SO(4)(center dot- )and center dot OH played important roles inp-CNB degradation under aerobic conditions, and p-CNB was mainly converted to hydroxylated byproducts including 4nitrophenol and hydroquinone. The reductive radical S(2)O(8)(center dot- )was responsible for p-CNB degradation under anaerobic conditions, and aminated byproducts were generated. The residual toxicities of these byproducts were predicted to be decreased, compared with those of p-CNB. Furthermore, by regulating the aerobic and/or anaerobic conditions, other pollutants including pyrene and ethion were also effectively removed in the MW/PS system. Overall, this study highlighted new insights into degradation behaviors of pollutants by MW/PS treatment via aerobic and anaerobic regulation.

以铅砷复合污染土壤为研究对象,采用硫酸亚铁和氧化钙作为稳定剂,通过正交实验得出各因素对土壤中铅的稳定率影响程度的大小顺序为:氧化钙添加量>硫酸亚铁添加量=养护周期>两种稳定剂的交互作用.最佳实验条件为硫酸亚铁添加量2 g/kg,氧化钙添加量10 g/kg,养护时间2 d.添加硫酸亚铁后,土壤pH对砷的稳定化效果影响不大,砷的浸出质量浓度均较低.过低和过高的pH均不利于土壤中铅的稳定化,当土壤pH=10.06～12.20时,土壤中铅的浸出质量浓度低于目标值.两种稳定剂对土壤中的砷均有稳定化效果,但硫酸亚铁起主要作用,氧化钙起次要作用;氧化钙在土壤中铅的稳定化过程中起主要作用.

为掌握氧化剂和活化剂添加量、氧化周期,以及氧化剂和活化剂之间交互作用对硫酸亚铁(FeSO4·7H2O)活化过硫酸盐氧化降解土壤中多环芳烃(苯并[a]蒽、苯并[b]荧蒽、苯并[a]芘、二苯并[a,h]蒽)效果的影响,通过正交试验考察了以上因素对多环芳烃降解效果的影响.结果表明,试验最佳活化条件为过硫酸钠(Na2S2O4)与FeSO4·7H2O添加量的摩尔比为46.7:1;各因素对污染物去除率的影响程度为:氧化剂添加量>氧化剂添加量和活化剂添加量的交互作用>活化剂添加量>氧化周期.

In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar (SSB) to the alkaline soil, this field study investigated the influence of moderate biochar amendments (0, 1500, 4500, and 9000 kg/hm 2 ) on corn growth, alkaline soil properties, and the uptake of potentially toxic elements (PTEs). The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations, which inhibited corn plant growth because of high background nutrient levels of the alkaline soil. When the alkaline soil was amended with 1500 kg/hm 2 SSB, the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g. There was no significant variation in the total concentration of PTEs in the soil. The concentrations of Mn, Ni, Cu, and Zn in niblets decreased from 5.54, 0.83, 2.26, and 27.15 mg/kg in the control to 4.47, 0.62, 1.30, and 23.45 mg/kg, respectively. Accordingly, the health risk from corn consumption was significantly reduced. Furthermore, the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs. Therefore, considering the increase in corn fruit yield and the decrease in consumption risk, applying 1500 kg/hm 2 of biochar to alkaline soils is a realistically achievable rate, which can broaden the utilization of SSB for remediation of different types of soil.

针对搬迁化工场地遗留高色度地下水处理过程中存在的色度来源不明、处理水量较大、需原地处理等问题,采用共沉淀法制备水滑石,并使用壳聚糖进行改性,脱除化工场地遗留高色度地下水色度.利用扫描电镜(SEM)、比表面积分析仪(BET)和傅里叶变换红外光谱仪(FT-IR)分析材料,研究色度脱除的原理,通过动力学和热力学实验,验证色度脱除的效果.分析表明,改性水滑石材料孔隙结构发达,层状结构清晰,与未改性水滑石相比吸附速率快、容量高,是有效的色度脱除材料.吸附前后的红外光谱对比与C1-浓度实验表明,脱色的机理包括表面吸附、离子交换、表面微絮凝等3种作用;在pH值为7,药剂投加量为0.3g/L,反应温度为25℃,反应时间为2h的条件下,废水色度的脱除率可达90％.处理1m3该类高色度地下水,总处理成本约为4.9元,价格较低,处理单位可接受.

采用共沉淀法制备锌铁水滑石类(LDH),并使用十二烷基硫酸钠(SDS)对其进行改性.利用比表面积与孔径分析、扫描电镜与透射扫描电镜、X射线衍射、傅立叶变换红外光谱和多功能电子能谱等手段分析材料,研究材料的改性机制,通过动力学和热力学实验,验证材料的吸附效果.结果 表明,锌铁LDH材料孔隙结构发达,层状结构清晰,改性后的材料层间距扩大,吸附容量进一步提高,是更为优秀的吸附材料.对于Cr(Ⅳ)的质量分数30 mg/g的溶液,改性后的锌铁LDH吸附剂优化投加量为0.2～0.4 g/L;溶液pH对除铬效果影响较大,pH为4时吸附效果最好;反应温度较高时除铬效果较好.改性后的锌铁LDH吸附剂对Cr(Ⅳ)的最大吸附容量可达到117 mg/g.

Potentially toxic elements in municipal sewage sludge can be effectively immobilized during biochar production via pyrolysis. However, the bioavailability of these elements when biochar is applied in soilless cultivation to improve substrate quality has yet to be sufficiently established. In this study, we investigated the chemical speciation and cucumber plant uptake of potentially toxic elements in soilless cultivation when the growth substrate was amended with sewage sludge biochar (0, 5, 10, 15, and 20 wt%). It was found that the addition of 10 wt% biochar was optimal with respect to obtaining a high cucumber biomass and achieving low environmental risk considering the occurrence of hormesis. When the substrate was amended with 10 wt% biochar, cucumber fruit contained lower concentrations of As, Cr, and Zn and smaller bioavailable fractions of As, Cd, Cr, Ni, Cu, and Zn compared with the fruit of control plants, thereby meeting national safety requirements (standard GB 2762-2012, China). Most of the As and Cd taken up by cucumbers accumulated in the leaves and fruit, whereas Cr was found primarily in the roots, and most Ni, Cu, and Zn was detected in the fruit. Importantly, only small proportions of the potentially toxic elements in biochar were taken up by cucumber plants (As: 0.0075%; Cd: 0.038%; Ni: 0.0064%; Cu: 0.0016%; and Zn: 0.0015%). Given that the As, Cd, Ni, and Zn speciation in sewage sludge biochar was effectively immobilized after cultivation, the findings of this study indicate that sewage sludge biochar is a suitable substrate amendment in terms of the risk posed by potentially toxic elements.

介绍了过硫酸盐氧化作用的活化方法和机理,在此基础上设置了对比试验,分析了氢氧化钠和硫酸亚铁活化过硫酸钠氧化修复多环芳烃污染土壤的效果,探究了pH、硫酸亚铁与过硫酸钠物质的量之比及反应时间对硫酸亚铁∕过硫酸钠体系去除多环芳烃的影响,并分析了反应产物的组分.结果表明:硫酸亚铁比氢氧化钠活化过硫酸钠氧化修复多环芳烃污染土壤的效果好;在pH为酸性或中性、硫酸亚铁与过硫酸钠物质的量之比为1:2.0、反应时间为5 d时,对多环芳烃的去除效果最佳.在控制反应条件的基础上,过渡金属离子活化过硫酸钠是修复多环芳烃污染土壤的可行方法之一.

Microplastic (MP) pollution and its potential to concentrate and transport organic contaminants in environments have recently gained widespread attention. Compared to traditional nonpolar plastics such as polypropylene (PP) and polyethylene (PE), study about the environmental behavior of polyurethane (PT), polyuria (PU) and urea-formaldehyde resin (UF), which are typically used as shell materials for pesticide microcapsules and have polar structure is scarce. In the present study, we investigated the sorption capacities and binding mechanisms of PT, PU and UF for three polycyclic aromatic hydrocarbons (PAHs, naphthalene, phenanthrene (PHE), and pyrene) and two PHE derivates (ethylphenanthrene-2-carboxylate (2-CPHE) and 2-methylphenathrene (2-MPHE)) selected as the model compounds, and the effects of salinity and UV and/or H2O2 aging treatments on PHE sorption to MPs. The results showed that PT, PU and UF had negative surface charges, micron-scaled sizes and abundant polar functional groups containing O and N elements. PT, PU and UF could sorb PAHs efficiently with sorption coefficients (Kd) being in the range of 8.11 × 103-9.53 × 105 (L/Kg) and partitioning was the main sorption mechanism with polar interactions (H-boning and p/π-π EDA interactions) also contributing. The sorption capacity of the three MPs changed mainly depending on their glass transition temperatures (Tg). Furthermore, high salinity decreased the surface zeta-potential of the MPs and enhanced PHE sorption to MPs. In addition, aging treatments with UV and/or H2O2 markedly decreased the Tg of PT and enhanced its sorption capacity for PHE, while opposite results were obtained for PU. The findings on the sorption mechanisms of PAHs to agricultural MPs are useful for predicting the transport, fate and persistence of the co-existing HOCs in agricultural ecosystems and provide a scientific basis for the comprehensive risk assessment of agricultural MPs.

本项目针对天津市化工行业遗留工业场地的环境污染问题,以天津市某农药厂污染场地修复工程为依托,依靠自主研发与技术集成,以前期数据收集和实验研究为基础,建立了包括微波催化萃取预处理、污染土壤低温热脱附和脱附气体浓缩热分解等关键技术在内的热脱附场地修复工艺.通过关键技术节点进行技术创新和工程示范,建成一套具有处理污染物范围广、污染物去除效率高、不会造成二次污染的生态工程修复关键技术及成套装备,为建设生态城市和美丽天津提供技术支撑.

The effects of sewage sludge biochar (SSB) on the microbial environment, Chinese cabbage yield, and heavy metals (HMs) availability of soil were comprehensively investigated in this study. Results showed that the concentrations of the dehydrogenase (DHA) and urease in the soil added with 10% SSB were 3.60 and 1.67 times as high as that of the control soil, respectively, after planting; the concentrations of the bacteria, fungi, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) in the soil added with 10% SSB after planting reached 2.84, 2.62, 1.76, and 2.23 times, respectively, compared with those of the control group; the weights of the aboveground and underground parts of Chinese cabbage were 5.82 and 8.67 times as high as those of the control group, respectively. Moreover, the addition of SSB enhanced the immobilization of Cr, Ni, and Cd. All in all, SSB can improve the microbial environment of soil and inhibit the availability of HMs, which is very important for their utilization in barren soil.

研究了干燥后的污泥对盐碱土土壤理化性质及污染的影响,并在此基础上设置了盆栽试验,以观察不同泥土比中植物的生长情况.结果表明:干化污泥既能为作物生长提供有效养分,又能明显地提高土壤肥力.虽然施用污泥后土壤中的全盐量增加,但对所选取植物的生长影响较小;当泥土配比低于一定的比例时,污泥中的重金属不会对土壤造成污染.因此,在盐碱土壤中严格按照标准并合理控制干化污泥的用量可作为解决污泥问题的途径之一.

In this study, used tea leaves (UTLs) were pyrolyzed to obtain used tea-leaf biochar (UTC), and then the UTC was used as an adsorbent to remove ciprofloxacin (CIP) from aqueous solutions. Batch experiments were conducted to investigate the CIP adsorption performance and mechanism. The results showed that the CIP-adsorbing ability first increased and then declined as the UTC pyrolysis temperature increased. The UTC obtained at 450°C presented excellent CIP-absorbing ability at pH6 and 40°C. The maximum monolayer adsorption capacity was 238.10mg/g based on the Langmuir isotherm model. The pseudo-second-order kinetic equation agreed well with the CIP adsorption process, which was controlled by both external boundary layer diffusion and intra-particle diffusion. The characterization analysis revealed that the OH groups, CC bonds of aromatic rings, CH groups in aromatic rings and phenolic CO bonds play vital roles in the CIP adsorption process, and that the NC, NO, OCO and COH groups of UTC were consumed in large quantities. π-π interactions, hydrogen bonding and electrostatic attraction are inferred as the main adsorption mechanisms. The present work provides not only a feasible and promising approach for UTLs utilization but also a potential adsorbent material for removing high concentrations of CIP from aqueous solutions.

Electrowinning of zinc from alkaline solutions is a promising technology which can directly produce metallic zinc powder from the treatment of zinc-containing ores and wastes. Fine zinc powder is of great interest in a variety of industries, such as paints, battery electrodes and cementation. This study investigated the effect of Poly (ethylene glycol) (12) tridecyl ether (PTE) on the dendritic growth and the particle size distribution of Zn electrodeposits in alkaline solutions that have similar content as used in industry. The dendritic growth of Zn electrodeposits was studied using current-time technique and scanning electron microscopy (SEM) while the purity was analyzed by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The particle size distribution was investigated by sieve analysis, laser particle size analyzer and cathodic potentiodynamic polarization, respectively. The results suggest that the presence of PTE can effectively inhibit the dendritic growth of Zn electrodeposits, where small, flat and layer-less dendrites with high Zn purity (99.34 wt.%) were electrodeposited. The data from the sieve analysis shows that 77.16 wt.% of electrodeposits can pass the sieve up to 150 μm in size after the addition of PTE. This was significantly higher than from the additive-free electrolyte (19.21 wt.%). The cathodic polarization curves suggest that, after the addition of PTE, more negative overpotential of Zn electrodeposition was observed, which increased the nucleation rate of Zn nuclei and more fine zinc particles were produced. These results indicate that PTE is an effective additive for the particle size refinement of Zn electrodeposits in alkaline zincate solutions.

对酸性重金属污泥（AS）、碱性重金属污泥（BS）及其混合物（MS）进行水热联合热解处理,探讨了固相产物中重金属（Cr、Mn、Ni、Cu和Zn）的BCR形态变化与TCLP浸出毒性特征,并开展潜在生态风险评价。结果表明:AS经水热联合热解处理后得到的固相产物（ASC）中重金属的稳定性得到改善,Ni和Zn的残渣态比例显著增加,分别从8.33%和28.08%升至27.04%和51.31%;BS经水热联合热解处理后得到的固相产物（BSC）中重金属的稳定性改善不明显,Cr和Cu的残渣态比例分别从69.25%和65.42%升至82.09%和66.69%,而其他重金属的残渣态比例有所下降。MS经过水热联合热解处理,固相产物（MSC）中重金属的固化效果进一步提高。与理论值相比,Cr、Mn、Ni、Cu和Zn的残渣态比例分别从89.03%、55.85%、47.33%、55.39%和73.19%提高至98.09%、66.72%、48.49%、89.07%和86.70%,其浸出毒性均在USEPA标准以下,潜在风险程度为轻微水平,这为水热联合热解工艺处置重金属污泥提供新的思路。

以某发电厂污染地块为研究对象,分析该场地污染物含量,并研究了多环芳烃类物质在不同功能区域的分布特征.结果表明:场区内土层分布自上而下依次为粉质粘土、淤泥质黏土和粘土,垂直渗透系数范围为1.0×10-8~1.0×10-6cm/s;该场区浓度较高的污染物主要为苯并(a)蒽、苯并(b)荧蒽和苯并(a)芘,主要集中在杂填土层.初步勘察筛选出的浓度偏高的多环芳烃类物质虽未超过标准,但必要时仍需实施场地环境管理措施.

煤气化技术的应用是我国能源战略的重要一环,但同时也会产生大量的煤气化炉渣,亟需研究可批量消纳的资源化利用技术.煤炭灰分中各种矿物相在气化炉内会随温度发生变化,通过对该变化的研究和总结,描述了煤炭灰分中各种矿物相在气化炉内的物化反应过程,并指出煤炭灰分对煤气化炉渣的最终形态特点具有决定性的影响;对煤气化炉渣中残碳的组成及其变化特点的研究表明,残碳对煤气化炉渣的最终利用途径具有重要影响;此外,通过分析煤气化炉渣利用技术研究现状,指出建材化利用技术和掺烧循环流化床原料技术是目前的主流途径;最后,展望了煤气化炉渣利用技术的发展方向,并提出了煤气化炉渣用于混凝土和水泥原料以及井下回填的技术途径.