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过磷酸钙对氨气的吸附解吸特性研究   总被引:4,自引:0,他引:4       下载免费PDF全文
禽畜粪便堆肥过程中氨气挥发既导致肥料养分下降又使周边环境出现恶臭,常用的化学磷肥过磷酸钙,由于其含有的游离酸可与氨反应,是潜在的堆肥挥发氨气回收固定的吸附剂.本研究以氨水挥发出来的氨气来模拟堆肥过程中的氨挥发,以过磷酸钙含氮量表征其对氨的吸附,分析过磷酸钙对氨气的吸附解吸特性及其pH的变化.结果表明:过磷酸钙对氨气吸附达到饱和后,含氮量可达干重的12%左右,pH升高到11.5,呈现较强的碱性;氨吸附饱和过磷酸钙在不同方式放置时,会逐渐解吸,pH也会随之下降,其中在空气中自然放置时,吸附氨氮含量最终降低到4%左右,pH值为6.21;密封保存时降低到6%左右,pH值为7.54;与氨同时挥发的水蒸汽也可被过磷酸钙大量吸附,并对氨的吸附具有影响.过磷酸钙吸附氨饱和后呈强碱性,施用土壤不利于作物吸收,且在保存过程中会再次损失氨,实际应用时应避免;而使吸附氨氮含量维持在4%~6%,pH则处于较易被植物吸收利用的中性范围,固定的氨也比较稳定.  相似文献
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In order to test whether the long-term application of calcium superphosphate leads to an increase of the soil rare earth element contents, superphosphate fertilized soils were sampled and compared with superphosphate-free soils. Spectrophlame inductively coupled argon plasma atomic emission spectrophotometer (ICP-AES) was applied to quantify the rare earth elements (REEs). The total rare earth element contents in calcium superphosphate from Zhijin County, west part of Guizhou Province, China (produced by the sulphuric acid treatment of the apatites) are about 2.54 mg/g. Between 38 and 189 gREEs/hm^2 per year (available for plants, estimated by 2% citric acid) will be introduced into the soil solution when applying 320 kg superphosphate/hm^2 per year. The long-term application of the latter will increase the REE content by about 18% in the soil surface layer in these areas. A statistically significant increase of the content of the rare earths in some cultivated soils should not be neglected.  相似文献
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 利用木浆造纸黑液活化磷矿矿浆,降低矿浆流动起点水分,既简化普钙生产流程,降低普钙生产成本,又能消除造纸黑液污染。试验结果表明:木浆造纸黑液活化磷矿矿浆最佳黑液投入量为0.027mL/g矿粉,当矿浆含水率控制在26%~28%之间时,矿浆粘度可降至0.70Pa·s以下,所生产的鲜钙能满足质量要求。为造纸黑液活化磷矿矿浆生产普钙提供了理论和技术依据  相似文献
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Mercury (Hg) contents in ten chemical fertilizers were determined, and the e ect of calcium superphosphate (CSP) on the uptake and translocation of Hg in corn seedlings was investigated by pot experiments. CSP was applied at the levels of 0, 66.7, and 133.4 mg P2O5/kg to Hg-treated (2 mg/kg) and untreated soils. CSP had the highest Hg content (5.1 mg/kg), followed by the NPK compound fertilizer 15-5-5 (15% N, 5% P2O5, 5% K2O) (1.2 mg/kg), then by nitrogen fertilizers (except for ammonia sulfate) and potassium fertilizers. Application of CSP did not obviously influence the biomass of corn roots, but it significantly increased the biomass of corn shoots in Hg-treated soil. Application of CSP at the levels of 66.7 and 133.4 mg P2O5/kg did not obviously influence the uptake of Hg by corn seedlings on soils without Hg treatment, but it decreased the Hg uptake of corn seedlings significantly on Hg-treated soils. The transfer coe cient of Hg in corn seedlings improved slightly on soils without Hg treatment, but decreased slightly on Hg-treated soils with the application of CSP. These results implied that CSP could ameliorate Hg toxicity to corn seedlings by inhibiting the uptake and the translocation of Hg in plants on Hg-polluted soils.  相似文献
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Mercury(Hg)contents in ten chemical fertilizers were determined,and the effect of calcium superphosphate(CSP)on the uptake and translocation of Hg in corn seedlings was investigated by pot experiments.CSP was applied at the levels of 0,66.7,and 133.4 mg P2O5/kg to Hg-treated(2 mg/kg)and untreated soils.CSP had the highest Hg content(5.1 mg/kg),followed by the NPK compound fertilizer 15-5-5(15% N,5% P2O5,5% K2O)(1.2 mg/kg),then by nitrogen fertilizers(except for ammonia sulfate)and potassium fertilizers.Application of CSP did not obviously influence the biomass of corn roots,but it significantly increased the biomass of corn shoots in Hg-treated soil Application of CSP at the levels of 66.7 and 133.4 mg P2O5/kg did not obviously influence the uptake of Hg by corn seedlings on soils without Hg treatment,but it decreased the Hg uptake of corn seedlings significantly on Hg-treated soils.The transfer coefficient of Hg in corn seedlings improved slightly on soils without Hg treatment,but decreased slightly on Hg-treated soils with the application of CSP.These results implied that CSP could ameliorate Hg toxicity to corn seedlings by inhibiting the uptake and the translocation of Hg in plants on Hg-polluted soils.  相似文献
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