Abstract

CPG’s wastewater from phosphate ore processing was characterized and its phytotoxicity before and after physicochemical treatment inside washing units was investigated for the first time. Mineralogical, spectral, physicochemical and microbiological characterizations showed that these wastewaters are relatively alkaline due to the high calcium and phosphorus contents. In fact, numerous minerals mainly fluorapatite, clinoptilolite and gypse were identified. In addition to its high salinity (EC = 9890 µS cm⁻¹), the BOD₅/COD ratio is equal to 0.949, which allows for the estimation that this effluent is potentially biodegradable. The microbiological characterization revealed the presence of revivable aerobic bacteria as; total coliforms (TC), fecal coliforms (FC), Pseudomonas, anaerobic sulfite bacteria (ASR), and fungi (F), whereas a complete absence of Salmonella, Vibrio cholera (CV), and Helminth egg (HE) was noted. In the second part, the influence of varying concentrations of phosphate wastewater was studied on radish, lentil, wheat and fenugreek seeds. Phosphate effluents were provided at 10%, 25%, 50%, 75% and 100%. Results were compared with a control group of the same seeds, irrigated with tap water. Based on several germination tests, plant irrigated with treated or untreated effluent exhibited a prominent reduction in growth traits at all four harvests. Except plant treated with treated effluent at 25% which generally induced no significant phytotoxicity to all species and which can play a fertilizer role. The adverse effects occurred with effluent-dose dependent manner. The high toxicity of untreated effluent compared to the treated effluent was inferred from the results. Nevertheless, the treated ffluent is still toxic, except at very low concentrations acting as a fertilizer.

摘要

首次对CPG磷矿石加工废水进行表征，并首次研究其在洗选装置内理化处理前后的植物毒性。矿物学、光谱、物理化学和微生物学特征表明，由于钙和磷含量较高，这些废水呈相对碱性。事实上，已鉴定出许多矿物，主要是氟磷灰石、斜发沸石和石膏。除了其高盐度（EC = 9890 µS cm ^-1）之外，BOD ₅ /COD 比率等于 0.949，这使得可以估计该废水具有潜在的可生物降解性。微生物学特征揭示了可复活需氧细菌的存在：总大肠菌群 (TC)、粪大肠菌群 (FC)、假单胞菌、厌氧亚硫酸盐细菌 (ASR) 和真菌 (F)，而完全不存在沙门氏菌、霍乱弧菌 (CV)、并注意到蠕虫卵（HE）。第二部分研究了不同浓度磷酸盐废水对萝卜、扁豆、小麦和胡芦巴种子的影响。提供10%、25%、50%、75%和100%的磷酸盐废水。将结果与用自来水灌溉的相同种子的对照组进行比较。根据多项发芽测试，用经过处理或未经处理的废水灌溉的植物在所有四次收获中都表现出生长性状的显着下降。除用25%处理后的废水处理的植物外，一般对所有物种均不产生明显的植物毒性，且可起到肥料作用。不利影响以流出物剂量依赖性方式发生。从结果推断，与处理过的废水相比，未经处理的废水具有较高的毒性。尽管如此，