Biochar was derived from rice straw pyrolyzed at 400°C, and biochar was added to the excess sludge at the ratio of 10% DS, 25% DS, and 50% DS as a supplementary skeleton for sludge Fenton pre-treatment. Rice husk biochar mixed with fungus residue as compost conditioner. In this study, we explored the effects of seven groups of composting materials on the composting effect and fertilizer quality under different pre-treatment methods of Fenton-pretreated sludge cake and conventional dewatered sludge cake, and different biochar additions. Specifically, we conducted a 22-day composting experiment using a composting reactor to investigate the effect of rice husk biochar combined with Fenton oxidation on the physicochemical properties of sludge composting. The results of this study showed that the FB50 group significantly increased the composting rate. Nutrient analysis showed that the FB50 group was rich in fertilizer nutrients, such as available phosphorus, and alkali-hydrolyzable nitrogen content increased. Heavy metals (Cu, Cd, Cr, Pb, Zn, Ni) met China's 'Agricultural Sludge Pollutant Control Standard' GB 4284-2018 Grade A standard, with obvious passivation and significantly reduced bioavailability. All these results suggested that biochar coupled with Fenton oxidation was more beneficial to sludge composting.

In this study, readily available inexpensive water treatment sludge (WTS) was used to prepare adsorbent for the removal of Congo red (CR) and tetracycline (TC) from aqueous solutions. The structural characteristics and adsorption properties of WTS biochar were characterised via scanning electron microscope, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller and Fourier Transform infrared spectroscopy. In batch experiments, the adsorption factors, kinetics, isothermal curves and thermodynamics of the adsorption properties were investigated. The optimum preparation condition of WTS biochar was 400 °C for 4 h under O2-limited pyrolysis, which exhibited increased specific surface area and pore structures. The best adsorption was observed when the pH of the CR and TC solutions was 7 and 4, respectively. The adsorption process followed the pseudo-second-order model, indicating that the main control step was the chemical adsorption process. Isotherm data were best described by the Langmuir model, and the maximum adsorption capacities for CR and TC were 116.4 and 58.5 mg·g-1, respectively. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. According to the analysis, the adsorption mechanism of CR could be attributed to electrostatic attraction, π-π conjugation and hydrogen bonding, whereas that of TC was potentially associated with cation exchange, complex precipitation, π-π conjugation and hydrogen bonding.

在pH为3和5的条件下,研究了芬顿氧化钙体系联合十二烷基二甲基苄基氯化铵(DDBAC)对污泥破解效果及脱水性能的影响,以期减少CaO的用量并同时提高芬顿反应的适用pH.以脱水泥饼含水率(WC)、毛细吸水时间(CST)、过滤时间(TTF)、污泥沉降比(SV)和胞外聚合物(EPS)中蛋白质(PN)与多糖(PS)的含量作为评价指标,对DDBAC投加量做单因素分析,找出其最佳投加量;并比较在不同pH条件下,DDBAC对污泥脱水性能的影响.结果表明,在pH为3条件下,H2O2、Fe2+、CaO、DDBAC投加量分别为60、30、60、60 mg·g-1(DS)时,污泥脱水效果最佳,其Wc为68.57％、CST为24 s、TTF为44 s、SV为72％.最佳脱水条件污泥EPS中的PN、PS总量大幅降低,其中T-EPS含量变化相较于S/L-EPS与污泥脱水性能的变化有更强的联系.在pH为5的条件下,该联合体系也有较好的脱水效果,对芬顿体系在弱酸性环境下使用有一定的参考价值.该联合体系能有效降低CaO的用量,同时能避免处理后的污泥pH过高、易板结的问题,且不会造成二次污染.

以内蒙古阿拉善某地下水为水相背景,Fe3 O4@SiO2-NH2磁性复合纳米材料和阿拉善黏土岩为吸附剂,采用静态批量法进行U(Ⅵ)吸附实验,并通过吸附动力学模型和吸附等温模型对实验数据进行拟合,分析吸附机理,研究了磁性复合纳米材料和阿拉善黏土岩分别在不同条件下对U(Ⅵ)的吸附性能.结果 表明,固液比为1:200、温度为35℃、吸附平衡时间为2 h、pH为5的条件下,复合材料对U(Ⅵ)的吸附效果最佳,为73％左右,说明该材料在特定水相环境中对核素U(Ⅵ)也能表现出较好的吸附性能.阿拉善黏土岩对U(Ⅵ)的吸附研究发现:固液比为1:200、温度为35℃、吸附平衡时间为24 h、pH为8的条件下对U(Ⅵ)的吸附率为35％左右.吸附实验表明:在特定水相环境中,制备的Fe3 O4@SiO2-NH2复合粒子比阿拉善黏土岩具有更好的吸附性能和更大的吸附容量.

以内蒙古阿拉善粘土岩为原料,采用静态吸附的方法,研究了不同因素对吸附铀(Ⅵ)效果的影响,通过吸附量和吸附率对结果进行分析.结果 表明,粘土岩对铀(Ⅵ)的吸附效果较好,10 h就达到了平衡;在铀(Ⅵ)的最佳初始浓度为40 μg· mL-1时,吸附率达到最大;不同离子的影响不同,阳离子中,Mg2+的影响最大,Na+和K+几乎没影响,阴离子中,CO32--和HCO3-的影响最大,其次是SO42-,而NO3-基本没有影响;最佳固液比为1∶40;吸附率和吸附量都随腐殖酸浓度的升高而减小;pH对吸附的影响较大,最佳pH值为6;吸附率和吸附量都随温度的升高而增大.Freundlich等温吸附模型较Langmuir能更好的拟合吸附过程.

以铝皂石胶体为原料,用静态吸附的方法,通过计算吸附量和吸附率,探讨铝皂石胶体吸附Cs+时,吸附时间、胶体溶液pH值、溶液中的离子浓度、腐殖酸(HA)的投加量以及吸附时的温度对吸附效果的影响.结果表明:1 mL 300μg/mL的Cs+溶液加入9 mL饱和铝皂石胶体溶液,吸附时间为20 min、溶液pH值为7,腐殖酸(HA)的投加量为3 mg,温度为45℃时,铝皂石胶体对Cs+的吸附效果最好.溶液中阴阳离子对吸附的抑制作用顺序分别为:CO32->HCO3->NO3->SO42-,Ca2+>Mg2+>K+.铝皂石胶体对Cs+的吸附过程符合准二级动力学方程和Langmuir热力学模型,是一个自发吸热的过程.

该文分别设置不同反应温度(120、150、180、210、240℃)和不同反应停留时间(0.5、1.0、2.0、4.0、8.0h),采用控制变量法对污泥进行水热处理.研究水热处理对污泥中氮、磷、钾含量及重金属形态分布的影响,且对重金属进行风险评估.结果表明,随着水热处理温度升高和时间延长,滤液的pH值逐渐降低,溶解性COD(SCOD)浓度逐渐升高.此外,液相中总氮(TN)、氨氮(NH4+-N)、总磷(TP)、磷酸盐(PO43-)浓度呈现递增趋势,而固相中总氮和钾呈现递减趋势.固相产物中OP向IP转化,NAIP向AP转化,TP、IP和AP含量升高,OP和NAIP含量下降.水热处理对Cu、Ni、Zn、Pb4种重金属具有稳定化作用,Zn由极高污染风险等级降为高污染风险等级,Cu由中度污染风险降为低污染风险,Ni和Pb的风险值都有所下降.总体来说,水热温度对污泥的影响效果比水热时间更显著.

以伊利石为吸附剂,通过吸附实验探究U(Ⅵ)在伊利石上的吸附特征,分别考查了接触时间、吸附剂用量、U(Ⅵ)初始浓度、pH值及温度对吸附的影响.用 FT‐IR和SEM 对吸附前后的伊利石进行表征,研究了U(Ⅵ)在伊利石上吸附的动力学和热力学过程.结果表明:吸附过程在10 h后达到动态平衡;在U(Ⅵ)初始浓度为50 mg/L时,吸附效果最好;最佳吸附剂用量为0.03 g;pH值对伊利石吸附铀的影响显著,最佳pH 值为 5～6;升高温度有利于U(Ⅵ)在伊利石上的吸附;准二级动力学模型和Langmuir等温吸附模型对U(Ⅵ)在伊利石上的吸附过程拟合效果较好,吸附过程主要为表面络合作用,属于单层吸附.

[Background] Kaolin is one of clay rocks that can be used to adsorb uranium (VI), but performance has hardly studied. [Purpose] This study aims at the effects of adsorption time, initial U(VI) concentration, adsorption quality, pH value, ion species and humic acid quality on kaolin adsorption U(VI). [Methods] Kaolin 200 mesh, drying reserve, and formation of U(VI) solution with 1 g?L?1 mass concentration by U3O8 were prepared. Analytically pure reagents of known content were used to config deionized water and ionic solution with different pH values. Then, experimental method of static adsorption was used for the study. [Results] Kaolin has good adsorption performance for U(VI), and it reaches equilibrium at 6 h. The optimum concentration of U(VI) is 60 μg?mL?1. The best adsorbent mass is 0.01 g. When the pH value increases, the adsorption effect of kaolin on U(VI) increases first and then decreases, when pH=5, the adsorption effect is the greatest. In the solution, K+, NO3?, Na+and SO42?have little effect on the adsorption of U(VI). Mg2+, CO32?and HCO3?have an inhibitory effect on the adsorption of U(VI), which is not conducive to adsorption. Increasing the quality of the humic acid in the solution inhibits the U(VI) adsorption of the kaolin. [Conclusions] The quasi-secondary kinetic model can better describe the adsorption of U (VI) on kaolin than the quasi-first-order kinetic model. This experiment provides a theoretical basis for kaolin as a backfill material for radioactive nuclear waste.

[Background] The research of radionuclide adsorped by colloids can provide understanding data and vital technical reference for the mechanism of clay colloid nuclide migration in the safety assessment of high-level radioactive waste repository. [Purpose] This study aims to provide basic data and technical basis for the study of nuclide migration mechanism in clay mineral colloid processing system. [Methods] The structure and adsorption mechanism of saponite colloid were investigated by means of infrared spectrum (FT-IR), X-ray fluorescence spectrum (XRF) and scanning electron microscope (SEM) of laser granulator Zeta potentiometer. The contacting time, pH, particles and humic acid concentration were studied by static adsorption experiments. [Results] Experimental results showed that different types of particles in the solution have a huge influence on the adsorption. Best adsorption efficiency was achieved when the adsorption equilibrium time was 20 min, pH=6, humic acid was 2 mg. [Conclusions] The saponite colloid has excellent adsorption properties and is expected to be an adsorbent material capable of effectively treating uranium-containing wastewater.

以伊利石为吸附剂,采用静态实验方法探究了接触时间、吸附剂质量、U(Ⅵ)初始浓度、pH、阴阳离子及腐植酸对U(Ⅵ)在伊利石上吸附的影响.实验结果表明,伊利石与U(Ⅵ)接触10 h后反应基本达到平衡,当U(Ⅵ)初始浓度为30 μg/mL、溶液pH为5～6、吸附剂质量为0.03 g时,伊利石对U(Ⅵ)的吸附效果最好.阴阳离子对伊利石吸附U(Ⅵ)影响显著,阳离子中Ca2+对吸附有超强的抑制作用,而K+有一定的促进作用;阴离子中CO32-、HCO3-对吸附的抑制作用较强.腐植酸的加入也促进了伊利石对U(Ⅵ)的吸附,且吸附效果与腐植酸浓度成正相关.对吸附前后的伊利石进行表征,探讨U(Ⅵ)在伊利石上的吸附动力学规律,结果表明,准二级动力学模型可以更好地描述U(Ⅵ)在伊利石上的吸附过程,相关系数达0.998,吸附机理主要为离子交换和表面络合作用.

采用化学共沉淀法制备Fe3O4磁性纳米粒子,利用正硅酸乙酯的水解在其表面包裹SiO2,以3-氨丙基三乙氧基硅烷(APTES)对复合粒子进行表面氨基化制备出Fe3O4@SiO2-NH2;采用红外(FT-IR)、扫描电镜(SEM)、磁滞回线等手段对复合粒子进行了表征.结果显示,制备的复合粒子呈微球形,粒径相对均匀,大约在200 nm.并采用静态吸附的方法进行批量实验,研究了该复合纳米材料作为吸附剂在不同条件下对U(Ⅵ)的吸附性能.实验结果表明,固液比1∶200、温度35℃、吸附平衡时间30 min、pH 5的条件下,复合粒子对U(Ⅵ)的吸附效果最佳,为95％左右.准二级动力学模型能更好地描述粒子对U(Ⅵ)的吸附动力学过程;吸附可用Freundich等温模型较好地描述,说明为多分子层吸附.实验表明所制备的氨基化磁性复合纳米粒子对溶液中U(Ⅵ)具有优良的吸附性能,有望成为一种能够有效处理含铀废水的吸附材料.

以伊利石和高岭石为吸附剂,通过静态吸附法研究了其对U(Ⅵ)的吸附特性.考察了接触时间、初始浓度、吸附剂质量、pH、温度、离子种类、腐殖酸等对其吸附效果的影响;采用红外光谱(FTIR)对伊利石和高岭石的结构进行了表征.研究结果表明:伊利石和高岭石对U(Ⅵ)具有很强的吸附能力,在10 h、铀初始质量浓度为30 mg/L、吸附剂质量为0.04 g、pH=5的条件下,伊利石对U(Ⅵ)的吸附效果最好;在12 h、铀初始质量浓度为30 mg/L、吸附剂质量为0.01 g、pH=5的条件下,高岭石对U(Ⅵ)的吸附效果最好;随着温度的升高,伊利石和高岭石对U(Ⅵ)的吸附能力不断增强,尤其是伊利石;溶液中Mg2+、CO2-3、HCO-3显著降低了伊利石和高岭石对U(Ⅵ)的吸附效果;随着腐殖酸浓度的增加,伊利石对U(Ⅵ)的吸附能力提高,高岭石对U(Ⅵ)的吸附能力降低.