Lingamurthy Dinesha Bettathavarekere, Hiregoudar Sharanagouda, Nidoni Udaykumar, Ganachari Sharanabasava V, Patil Veerabhadragouda B, Hiremath Vijayakumar
Centre for Nanotechnology, College of Agricultural Engineering, University of Agricultural Sciences, Raichur, 584 104, India.
Department of Processing and Food Engineering, College of Agricultural Engineering, University of Agricultural Sciences, Raichur, 584 104, India.
Environ Sci Pollut Res Int. 2023 Feb;30(9):24101-24119. doi: 10.1007/s11356-022-23854-4. Epub 2022 Nov 5.
Milk-processing industry effluent (MPIE) poses severe problems for aquatic and environmental systems, especially in the South Asian region. Therefore, its treatment is of great interest. This study deals with the investigation of chitosan titanium dioxide nanoadsorbent (CTiO) coated onto sand particles via calcination that are used to remove the emerging pollutants. The adsorptive properties of these developed adsorbents are compared with those of the nascent sand without coating as well as with the chitosan titanium dioxide nanoadsorbent coated sand (CTiO-CS). Batch adsorption experiments were performed to investigate the percent reduction efficiency (%RE) of organic pollutants in terms of biological oxygen demand (BOD) and chemical oxygen demand (COD) from synthetic and real effluents. The maximum %RE of BOD (96.76) and COD (98.91) was achieved at 1.5 M dose of CTiO-CS, 120 min of contact time, pH 6.5, an initial BOD concentration of 900 mg/L, and an agitation speed of 400 rpm. Similarly, the %RE of COD was found to be 86.75 for synthetic effluent and 90.97 for real effluent at initial COD concentrations of 8000 mg/L. Pseudo-second-order and Langmuir models are found to be the best fits for BOD and COD adsorption. The diffusion model suggests that surface adsorption as well as intraparticle diffusion contribute to the actual adsorption process. Regeneration experiments were performed for four cycles, and CTiO-CS was found to be the most regenerable adsorbent material. The performance of the adsorbent was compared with previous studies, and it was found to have excellent adsorption capacity. As a result, the developed filter bed could be used as a promising superadsorbent for the removal of organic load in MPIE.
牛奶加工行业废水（MPIE）给水生和环境系统带来了严重问题，尤其是在南亚地区。因此，对其进行处理备受关注。本研究探讨了通过煅烧将壳聚糖二氧化钛纳米吸附剂（CTiO）包覆在砂粒上，用于去除新出现的污染物。将这些制备的吸附剂的吸附性能与未包覆的原始砂以及壳聚糖二氧化钛纳米吸附剂包覆砂（CTiO-CS）的吸附性能进行了比较。进行了批量吸附实验，以研究合成废水和实际废水中有机污染物在生物需氧量（BOD）和化学需氧量（COD）方面的去除率（%RE）。在CTiO-CS剂量为1.5 M、接触时间为120分钟、pH值为6.5、初始BOD浓度为900 mg/L以及搅拌速度为400 rpm的条件下，BOD的最大去除率（96.76）和COD的最大去除率（98.91）得以实现。同样，在初始COD浓度为8000 mg/L时，合成废水的COD去除率为86.75，实际废水的COD去除率为90.97。发现伪二级和朗缪尔模型最适合BOD和COD的吸附。扩散模型表明，表面吸附以及颗粒内扩散对实际吸附过程都有贡献。进行了四个循环的再生实验，发现CTiO-CS是最可再生的吸附材料。将该吸附剂的性能与先前的研究进行了比较，发现其具有优异的吸附能力。因此，所开发的滤床可作为一种有前景的超级吸附剂，用于去除MPIE中的有机负荷。
