College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
Environ Sci Pollut Res Int. 2022 Oct;29(50):76446-76455. doi: 10.1007/s11356-022-21243-5. Epub 2022 Jun 7.
Phosphate-solubilizing fungi (PSF) can enhance P release from phosphate minerals to immobilize heavy metals. However, this promotion substantially depends on their survival in highly polluted soils. The aim of this study was to investigate the survival of PSF after addition of phosphogypsum (PG) and bioorganic fertilizer (BF) in the soil with coexistence of multiple heavy metals, e.g., Pb, As, Cd, Sb, etc. Addition of typical PSF (Aspergillus niger) did not promote the formation of pyromorphite (the most stable form of Pb), possibly due to the buffering effect of the soil (the secreted oxalic acid was neutralized) and limited P supply. Meanwhile, despite that A. niger has high tolerance to heavy metal stress, its survival was significantly declined due to the deficiency of available P. It was also shown that PG, as the major by-product in phoschemical industry, still has relatively high available P compared with common natural soils. PG addition dramatically increased available P (up to 93.87 mg/kg) and the subsequent fungal growth. However, sole PG did not promote the formation of pyromorphite, probably as the abundant Fe and Mn prevented the contact between PO and Pbin the soil system. The enhanced soil respiration after addition of BF and PG confirmed the promoted microbial activity (elevated to 3465.58 μg C kg h). This study showed PG's potential as P source for both microbial growth and heavy metal remediation in soil system. A combination of PG, A. niger, and BF can hence achieve long-term bioremediation of heavy metals.
解磷真菌（PSF）可以促进磷酸盐矿物中磷的释放，从而固定重金属。然而，这种促进作用在很大程度上取决于它们在高度污染土壤中的生存能力。本研究旨在研究在共存多种重金属（如 Pb、As、Cd、Sb 等）的土壤中添加磷石膏（PG）和生物有机肥料（BF）后，PSF 的生存能力。添加典型的 PSF（黑曲霉）并没有促进磷铅矿（Pb 最稳定的形式）的形成，这可能是由于土壤的缓冲作用（分泌的草酸被中和）和有限的 P 供应。同时，尽管 A. niger 对重金属胁迫具有较高的耐受性，但由于可利用 P 的缺乏，其生存能力显著下降。研究还表明，PG 作为磷化工行业的主要副产物，与常见的天然土壤相比，仍具有较高的有效 P。PG 的添加显著增加了有效 P（高达 93.87mg/kg）和随后的真菌生长。然而，单独的 PG 并没有促进磷铅矿的形成，这可能是因为丰富的 Fe 和 Mn 阻止了土壤系统中 PO 和 Pb 之间的接触。添加 BF 和 PG 后土壤呼吸的增强证实了微生物活性的增强（提高到 3465.58μg C kg h）。本研究表明 PG 作为微生物生长和土壤系统中重金属修复的 P 源具有潜力。PG、黑曲霉和 BF 的结合可以实现重金属的长期生物修复。
