Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture; College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
Department of Soil and Environmental Science, Ghazi University, Dera Ghazi Khan, Pakistan.
Environ Sci Pollut Res Int. 2021 Nov;28(41):57769-57780. doi: 10.1007/s11356-021-14611-0. Epub 2021 Jun 7.
Contamination of soils by nickel (Ni) has become a serious environmental problem throughout the world, and this substance wields dangerous effects on the ecosystem and food chain. A pot experiment was conducted to examine the effect of rice straw (RS), rice straw biochar (BI), and calcite (CC) at 1% and 2% application rates in a Ni-contaminated soil. The objective was to potentially stabilize Ni and reduce its bioavailability to spinach (Spinacia Oleracea L.). Spinach plants were grown in a Ni-contaminated Ultisol (commonly known as a red clay soil). Plant growth parameter results indicated that a BI 2% application rate significantly increased the root and shoots dry biomass increased by 1.7- and 6.3-fold, respectively, while essential nutrients were enhanced in the spinach plant compared to those in the untreated soil (CK). Moreover, adding amendments significantly decreased CaCl extractable Ni by 62.5% 94.1%, and 87.2%, while the toxicity characteristics leaching procedure (TCLP) fell by 26.7%, 47.8%, and 41.7% when using RS, BI, and CC, respectively, at 2% compared to CK. The Ni concentrations in the spinach roots declined by 51.6%, 73.3%, and 68.9%, and in the shoots reduced by 54.1%, 76.7%, and 70.8% for RS, BI, and CC, at a 2% application rate, respectively. Bio-concentration factor (BCF) and translocation factor (TF) dropped significantly by as much as 72.7% and 20%, respectively, for BI 2% application rate. Results of the present study clearly indicated that biochar potential soil amendments for Ni stabilization, thereby reducing its bioavailability in the Ni-contaminated soil. This process enhanced the safety of food to be consumed and mitigated security risks.
镍（Ni）污染土壤已成为全球严重的环境问题，该物质对生态系统和食物链具有危险影响。本试验采用盆栽实验，研究了在镍污染土壤中添加 1%和 2%的稻草（RS）、稻草生物炭（BI）和方解石（CC）对土壤中镍的稳定作用及其降低蔬菜可食性的影响。供试土壤为镍污染的赤红壤（俗称红壤），蔬菜选用菠菜（Spinacia Oleracea L.）。结果表明，与对照相比，BI 处理显著增加了菠菜根和地上部干生物量，分别提高了 1.7 倍和 6.3 倍，同时提高了植物的必需营养元素。此外，添加改良剂使 CaCl2 可提取态镍降低了 62.5%-94.1%和 87.2%，毒性特征浸出程序（TCLP）降低了 26.7%-47.8%和 41.7%，RS、BI 和 CC 处理在 2%添加率下分别比对照降低了 62.5%-94.1%和 87.2%，而 TCLP 降低了 26.7%-47.8%和 41.7%。当添加率为 2%时，RS、BI 和 CC 处理使菠菜根部镍浓度分别降低了 51.6%、73.3%和 68.9%，地上部镍浓度分别降低了 54.1%、76.7%和 70.8%。生物浓缩因子（BCF）和转运因子（TF）分别降低了 72.7%和 20%。结果表明，生物炭作为土壤改良剂可有效稳定土壤中的镍，降低其生物有效性，提高蔬菜食用安全性，降低安全风险。
