Gao Fei, Xiao Liwen, Zhang Hongzhou
Department of Civil, Structural and Environmental Engineering,Trinity College Dublin,Dublin,Ireland.
CRANN, School of Physics, Trinity College Dublin,Dublin,Ireland.
J Dairy Res. 2018 Aug;85(3):375-378. doi: 10.1017/S0022029918000560. Epub 2018 Aug 13.
The studies described in the Research Communication aimed to describe the feasibility of using coal fly ash to synthesize nano-zeolite, and the ammonium and phosphate adsorption efficiencies of the nanomaterial in dairy wastewater. Chemical treatment of coal fly ash was conducted and changes observed. Samples treated with NaOH had an increased cation exchange capacity and P sorption index compared to the initial fly ash, due to particle modification from smooth surface to plate- and rod-shape crystals, referred to as nano-zeolite. Batch experiments were conducted by mixing coal fly ash and nano-zeolite with synthesized wastewater to study the effect of sorption time, pH values and dosage of nano-zeolite on ammonium and phosphate removal efficiency. The adsorption process reached equilibrium in a very short time (less than 60 min), which suggests a potential for fast immobilization of pollutants. The concentration of ammonium decreased from 118 to 35 mg/l (71% removal) while the concentration of phosphate decreased from 52 to 45 mg/l. The removal efficiency of ammonium was 36·6, 51·8 and 70·9% at pH 3, 7 and 10, respectively whilst that of phosphate increased dramatically with decreased slurry pH (92·1, 47·3 and 12·3% at pH 3, 7 and 10, respectively). Nano-zeolite could be a potential absorbent for fast immobilization of ammonium but not phosphate. Surface modification of nano-zeolite could be introduced in order to enhance the pollutants removal efficiency.
《研究通讯》中描述的研究旨在探讨利用粉煤灰合成纳米沸石的可行性，以及该纳米材料对乳品废水中铵和磷酸盐的吸附效率。对粉煤灰进行了化学处理并观察其变化。与初始粉煤灰相比，用氢氧化钠处理的样品阳离子交换容量和磷吸附指数有所增加，这是由于颗粒从光滑表面转变为板状和棒状晶体，即纳米沸石。通过将粉煤灰和纳米沸石与合成废水混合进行批次实验，以研究吸附时间、pH值和纳米沸石用量对铵和磷酸盐去除效率的影响。吸附过程在很短时间内（不到60分钟）达到平衡，这表明具有快速固定污染物的潜力。铵浓度从118毫克/升降至35毫克/升（去除率71%），而磷酸盐浓度从52毫克/升降至45毫克/升。在pH值为3、7和10时，铵的去除效率分别为36.6%、51.8%和70.9%，而磷酸盐的去除效率随着浆料pH值的降低而显著增加（在pH值为3、7和10时分别为92.1%、47.3%和12.3%）。纳米沸石可能是快速固定铵而非磷酸盐的潜在吸附剂。可以引入纳米沸石的表面改性以提高污染物去除效率。
