海绵铁在焦化废水预处理中的应用研究

采用静态和动态实验研究海绵铁预处理焦化废水。静态实验在海绵铁粒径、投加量、废水pH值和反应时间4个方面研究对处理效果的影响,结果表明,海绵铁处理焦化废水最适条件:粒径为0.5~1 mm、投加量为20 g,pH为6,反应时间为60 min。动态实验研究海绵铁在不同水力负荷下对废水色度、氨氮、COD的去除率,结果表明:水力负荷越小,出水水质越好,且明显改善焦化废水的可生化性,从原水的0.19提高到出水的0.38。海绵铁可作为焦化废水的一种有效的预处理方法。     

催化湿式氧化工艺中负载型催化剂的研制

研究了过渡金属氧化物和稀土金属氧化物对乳化液废水催化湿式氧化工艺中的催化活性，得出：CuO的活性高于MnO2,Co3O4未表现出催化活性。CeO2、Nd2O3、Sm2O3均表现一定活性：制备了CuO／γAl2O3，Mn／γAl2O3负载型催化剂及其复合负载型催化剂，并对它们各自的催化活性和稳定性进行了研究。发现：Cu／γAl2O3负载型催化剂用于乳化液废水处理，200℃反应2h，CODCr去除率为88．4％，达到均相催化效果，比非催化提高13.0％，Mn／γAl2O3表现出负催化作用．复合负载型催化剂的活性低于Cu／γAl2O3。     

混凝——吸附法处理油墨废水工艺研究

采用不同无机混凝剂及氧化还原剂对打印机生产中的油墨废水的混凝及脱色效果进行试验比较,确定了实验室工艺条件及各种混凝剂最佳用量及次序。结果表明,该工艺脱色率达１００％,ＣＯＤｃｒ去除率达５１％。     

聚多巴胺/蒙脱土复合材料对SO2的吸附性能

采用原位插层聚合制备聚多巴胺改性蒙脱土复合材料并研究其SO2吸附性能。对复合材料进行元素分析、红外分析、热稳定性和X射线衍射表征,结果证实,聚多巴胺大分子链不仅在蒙脱土表面包覆改性,同时插层进入蒙脱土层间,增大蒙脱土层间距。讨论SO2起始质量分数、吸附剂用量和吸附温度对单位吸附容量的影响,结果表明,聚多巴胺改性蒙脱土的SO2吸附性能显著提高。在SO2起始质量分数为0.5、吸附剂用量为8 g、吸附温度为125℃时,聚多巴胺改性蒙脱土复合材料的单位吸附容量为1.225 g/g。     

烟秸杆生物碳对铬(Ⅵ)废水的吸附动力学和热力学

以农业废弃物烟秸杆为原料,以KH2PO4为活化剂,制备了烟秸杆生物碳(简称TSC500),通过静态吸附实验研究了TSC500对含Cr(Ⅵ)废水的吸附性能。采用比表面积分析仪对TSC500进行了测试,实验考察了pH值、吸附剂用量、吸附时间、Cr(Ⅵ)初始浓度和温度对Cr(Ⅵ)吸附的影响,深入研究了TSC500对Cr(Ⅵ)的吸附行为。结果表明,在pH=3、温度313 K条件下,0.2 g TSC500吸附100 mg/L Cr(Ⅵ),去除率和吸附容量分别达到91.32%和45.66 mg/g,Langmuir和Freundlich比Temkin等温模型更好地拟合吸附实验数据;准一级和准二级动力学模型均能较好地描述该吸附行为,相关系数高达0.99;计算得到热力学参数ΔGθ、ΔHθ和ΔSθ值表明该吸附过程为自发吸热过程。     

Relationship between e-waste recycling and human health risk in India: a critical review

Informal recycling of waste (including e-waste) is an emerging source of environmental pollution in India. Polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDEs), and heavy metals, among other substances, are a major health concern for workers engaged in waste disposal and processing, and for residents living near these facilities, and are also a detriment to the natural environment. The main objective of this review article was to evaluate the status of these impacts. The review found that, huge quantity of e-waste/waste generated, only a small amount is treated formally; the remainder is processed through the informal sector. We also evaluated the exposure pathways, both direct and indirect, and the human body load markers (e.g., serum, blood, breast milk, urine, and hair), and assessed the evidence for the association between these markers and e-waste exposure. Our results indicated that the open dumping and informal e-waste recycling systems should be replaced by the best available technology and environmental practices, with proper monitoring and regular awareness programs for workers and residents. Further and more detailed investigation in this area is also recommended.     

利用高炉瓦斯泥-H2O2处理硝基苯废水

以高炉瓦斯泥为铁源,通过其在酸性条件下与H2O2 形成Fenton/类Fenton反应体系来处理硝基苯废水,考察了pH、H2O2用量、高炉瓦斯泥用量及反应时间对硝基苯降解率的影响,并对降解机理进行了分析表征。实验结果表明,在pH为3、高炉瓦斯泥用量为0.5 g/L、H2O2用量为10 mL/L、反应时间为60 min的条件下,100 mg/L的硝基苯溶液中硝基苯的降解率达87.88%;硝基苯先被氧化生成硝基苯酚、硝基苯二酚、对苯醌等中间产物,然后再进一步氧化生成二氧化碳和水达到降解的目的。     

Insight into soil nitrogen and phosphorus availability and agricultural sustainability by plant growth-promoting rhizobacteria

Environmental Science and Pollution Research - Nitrogen and phosphorus are critical for the vegetation ecosystem and two of the most insufficient nutrients in the soil. In agriculture practice,...     

Simultaneous nitrification and denitrification by Pseudomonas sp. Y-5 in a high nitrogen environment

Pseudomonas sp. Y-5, a strain with simultaneous nitrification and denitrification (SND) capacity, was isolated from the Wuhan Municipal Sewage Treatment Plant. This strain could rapidly remove high concentrations of inorganic nitrogen. Specifically, Pseudomonas sp. Y-5 removed 103 mg/L of NH₄⁺-N in 24 h without nitrate or nitrite accumulation when NH₄⁺-N was its sole nitrogen source. The NH₄⁺-N removal efficiency (RE) was 97.26%, and the average removal rate (RR) was 4.30 mg/L/h. Strain Y-5 also removed NO₃^?-N and NO₂^?-N even in aerobic conditions, with average RRs of 4.39 and 4.23 mg/L/h, respectively, and REs of up to 99.34% and 95.81% within 24 h. When cultured in SND medium (SNDM-1), strain Y-5 achieved an NH₄⁺-N RE of up to 97.80% and a total nitrogen (TN) RE of 93.01%, whereas NO₃^?-N was fully depleted in 48 h. Interestingly, high nitrite concentrations did not inhibit the nitrification capacity of Y-5 when grown in SNDM-2, the RE of NH₄⁺-N and TN reached 96.29% and 94.26%, respectively, and nitrite was consumed completely. Strain Y-5 also adapted well to high concentrations of ammonia (~401.68 mg NH₄⁺-N/L) or organic nitrogen (~315.12 mg TN/L). Our results suggested that Pseudomonas sp. Y-5 achieved efficient simultaneous nitrification and denitrification, thus demonstrating its potential applicability in the treatment of nitrogen-polluted wastewater.

     

Plant responses to metals stress: microRNAs in focus

Environmental Science and Pollution Research - Metal toxicity can largely affect the growth and yield of numerous plant species. Plants have developed specific mechanisms to withstand the varying...