Unravelling the effects of complexation of transition metal ions on the hydroxylation of catechol over the whole pH region

Catechol pollutants (CATPs) serving as chelating agents could coordinate with many metal ions to form various CATPs-metal complexes. Little information is available on the effects of complexation of metal ions on CATPs degradation. This work presents a systematical study of •OH-mediated degradation of catechol and catechol-metal complexes over the whole pH range in advanced oxidation processes (AOPs). Results show that the pH-dependent complexation of metal ions (Zn²⁺, Cu²⁺, Ti⁴⁺ and Fe³⁺) promotes the deprotonation of catechol under neutral and even acidic conditions. The radical adduct formation (RAF) reactions are both thermodynamically and kinetically favorable for all dissociation and complexation species, and OH/O⁻ group-containing C positions are more vulnerable to •OH attack. The kinetic results show that the complexation of the four metal ions offers a wide pH range of effectiveness for catechol degradation. At pH 7, the apparent rate constant (k_app) values for different systems follow the order of catechol+Ti⁴⁺ ≈ catechol+Zn²⁺ > catechol+Cu²⁺ > catechol+Fe³⁺ > catechol. The mechanistic and kinetic results would greatly improve our understanding of the degradation of CATPs-metal and other organics-metal complexes in AOPs. The toxicity assessment indicates that the •OH-based AOPs have the ability for decreasing the toxicity and increasing the biodegradability during the processes of catechol degradation.     

基于不同原理的低浓度二氧化硫分析仪性能研究

为掌握非色散红外吸收光谱法(NDIR)、紫外差分吸收光谱法(DOAS)、非色散紫外吸收光谱法(NDUV)、红外激光吸收光谱法(OFCEAS)测定烟气中低浓度二氧化硫的差异,通过方法比对实验,对基于不同原理二氧化硫分析仪的响应时间、重复性、线性误差、干扰因素等进行研究。结果表明,不同原理的低浓度二氧化硫分析仪在响应时间、线性误差、重复性、漂移等基本性能上均能满足《HJ/T 76—2007》的要求,但不同原理之间性能指标差异也很明显。不同露点温度对基于NDIR和NDUV法的二氧化硫分析仪有正干扰,CO不干扰二氧化硫的测定,CH4对基于NDIR和OFCEAS法的二氧化硫分析仪有正干扰,NH3和HCl对基于DOAS法的二氧化硫分析仪有正干扰。     

加强土壤污染防治 保障土壤环境安全——《江苏省土壤污染防治工作方案》解读

简述了江苏省土壤污染防治现状,对《江苏省土壤污染防治工作方案》进行了解读。该方案从全局和战略的高度对江苏省土壤污染防治工作进行了顶层设计和谋划,提出了当前和今后一个时期土壤污染防治工作的目标与主要任务。指出,土壤污染的形成非一朝一夕,问题的解决也不可能一蹴而就,要充分认识土壤污染防治工作的紧迫性、长期性、艰巨性、复杂性,既要打好攻坚战,也要做好打持久战的准备。     

Highly promoted phytoremediation with endophyte inoculation in multi-contaminated soil: plant biochemical and rhizosphere soil ecological functioning behavior

Environmental Science and Pollution Research - Rhizosphere soil ecological functioning behavior is of critical importance for regulating phytoremediation efficiency during microbial-assisted...     

复合填料一维冻胀量数值模拟分析

复合填料是以废铸砂、粉煤灰、聚苯乙烯颗粒(EPS)、水泥和水为原料,拌合后形成的一种轻质填筑材料。其中,EPS颗粒含量适当时,能减少或消除复合填料的冻胀和融沉,可作为季节性冻土区的路基填料。假设复合填料中除EPS颗粒外的骨料颗粒、孔隙冰为刚性介质,同时考虑EPS颗粒变形和填料孔隙变形对复合填料冻结过程的影响,在已有的冻土水热耦合分离冰模型的基础上,得到考虑EPS颗粒变形影响的饱和填料一维冻结水热耦合控制方程,进而预测填料的冻胀量。与室内模型试验结果对比表明,本文模型可用于该种具有弹性颗粒复合填料的冻胀量模拟,为工程中冻胀量预测提供依据。     

Carbon emission reduction potential and its influencing factors in China’s coal-fired power industry: a cost optimization and decomposition analysis

Environment, Development and Sustainability - China has become the world’s most carbon-emitting country, and the coal-fired power industry (CFPI) dominates China’s carbon emissions....     

氟乐灵在土壤中的结合残留及其对作物的影响

介绍了除草剂氟乐灵在两种土壤中可提部分的消失动态,研究了土壤组分、水分状况及微生物活性对~(14)C-氟乐灵结合残留形成的影响,以及土壤中结合残留物对小麦、黑麦草的有效性.结果表明,有机质含量高的黑土能结合较多的~(14)C-残留物.对含结合残留物的土壤进行高温馏出处理,馏出物的GC检定结果显示除少量母体结构外,氟乐灵主要是通过其代谢物与土壤结合的.盆栽试验表明,氟乐灵结合残留对农作物的生长有明显抑制.     

Seed priming with brassinosteroids alleviates aluminum toxicity in rice via improving antioxidant defense system and suppressing aluminum uptake

Environmental Science and Pollution Research - Brassinosteroids (BRs) are growth-promoting hormones that exhibit high biological activities across various plant species. BRs shield plants against...