The present study explores the utilization of very acidic (pH 1.46) and high fluoride (F-) containing (9290 ppm) phosphatic fertilizer industry (Paradeep, Odisha, India) pond wastewater (PW) generated from phosphogypsum (PG) stacks by using Crassostrea Sp. molluscan shell (MS) as an adsorbent. F- chemisorption batch experiments on molluscan shells (MS) powder (212 - 500 micron) varying 6 different MS (Solid-S) to PW (Liquid-L) i.e. S/L ratios (1: 8 to 1: 30), time (0.08 to 48 hours) and fluoride concentration (4645 – 8361 ppm) as diluted PW. Chemisorption of F- peaked with 1: 20 S/L ratio at 24 hrs and its concentration in the supernatant reduced by 99.9 %. XRF, FTIR and XRD analysis of MS and its chemisorbed residues confirmes the role of relatively high calcium containing MS (72 % CaO) towards formation of Fluorapatite (FA) [Ca5(PO4)3F]. Desorption experiments of FA residue for 24 hrs, highlights the stability of F- chemisorption process on MS, which is confirmed by presence of FA in desorbed residue through XRD analysis. The research findings establish prospects of F- recovery from PW through chemisorption process utilizing selected MS.

中文翻译：

---

利用沿海软体动物壳（Crassostrea Sp。）从磷肥池废水（奥里萨邦Paradeep）中对氟化物进行预期的化学吸附

本研究探讨了使用Crassostrea利用高酸性（pH 1.46）和高氟化物（F-）（9290 ppm）磷肥工业（印度奥里萨邦的Paraadeep）从磷石膏（PG）烟囱中产生的池塘废水（PW）的利用Sp。软体动物壳（MS）作为吸附剂。软体动物壳粉（212）至500微米的F-化学吸附分批实验，变化6种不同的MS（Solid-S）与PW（Liquid-L），即S / L比（1：8至1:30），时间（0.08至48小时）和稀释后的PW氟化物浓度（4645 – 8361 ppm）。F-的化学吸附在24小时达到1:20 S / L的峰值，其在上清液中的浓度降低了99.9％。MS及其化学吸附残留物的XRF，FTIR和XRD分析证实了含钙相对较高的MS（72％CaO）对氟磷灰石（FA）[Ca5（PO4）3F]形成的作用。FA残留物的脱附实验24小时，突出了F-化学吸附过程在MS上的稳定性，这通过XRD分析通过在脱附的残留物中存在FA来证实。研究结果为利用选定的质谱通过化学吸附过程从PW中回收F建立了前景。