锆改性沸石活性覆盖控制重污染河道底泥氮磷释放研究

通过实验考察了锆改性沸石对水中磷酸盐和铵的吸附去除作用,并考察了锆改性沸石活性覆盖控制底泥溶解性磷酸盐和铵释放的效率。锆改性沸石对水中磷酸盐的吸附能力随pH值的增加而降低：当pH值由4增加到5时,锆改性沸石对水中铵的吸附能力增加;当pH值 5~8时,对铵的吸附能力较高;当pH值由8增加到10时,对铵的吸附能力下降。锆改性沸石对水中磷酸盐和铵的吸附动力学满足准二级动力学模型,并且对磷酸盐和铵的吸附速率比较快。Langmuir和Freundlich等温吸附模型可以用于描述锆改性沸石对水中磷酸盐和铵的吸附平衡数据,根据Langmuir模型计算得到的锆改性沸石对水中磷酸盐和铵的最大吸附量分别为7.75 mg·g-1和9.59 mg·g-1（pH 7和25 °C）。锆改性沸石对水中磷酸盐和铵的去除率随锆改性沸石投加量的增加而增加,其吸附水中磷酸盐的主要机制是配位体交换,吸附水中铵的主要机制是阳离子交换。被锆改性沸石所吸附的磷酸盐大部分（82.5%）以较为稳定形态磷（NaOH-P）存在,低溶解氧条件下不容易重新被释放出来。吸附磷酸盐后锆改性沸石中水溶性磷（WSP）、易解吸磷（RDP）和NaHCO3可提取态磷（Olsen-P）含量非常低,藻类可利用磷（AAP）含量仅占总磷含量的29%左右。低溶解氧条件下,重污染河道底泥会释放出大量的溶解性磷酸盐和铵,锆改性沸石活性覆盖则不仅可以使上覆水中的溶解性磷酸盐浓度控制到很低的水平,而且可以明显降低铵由底泥向上覆水迁移的速率。上述实验结果表明,锆改性沸石适合作为一种活性覆盖材料用于控制底泥溶解性磷酸盐和铵的释放。     

四氧化三铁-沸石复合材料去除水中铵和磷酸盐研究

通过实验考察了四氧化三铁-沸石复合材料对水中铵和磷酸盐的吸附-解吸性能。结果表明,四氧化三铁-沸石复合材料对水中铵和磷酸盐的去除率随吸附剂投加量的增加而增加。当溶液pH为4~9时,四氧化-三铁 沸石复合材料对水中铵的吸附能力较高;当溶液pH由9增加到11时,铵的吸附能力明显下降。四氧化三铁 沸石复合材料对水中磷酸盐的吸附能力随溶液pH的增加而降低。四氧化三铁-沸石复合材料对水中铵和磷酸盐的吸附动力学过程较好地满足准二级动力学模型。四氧化三铁 沸石复合材料对水中铵的吸附平衡数据较好地满足Langmuir等温吸附模型,对水中磷酸盐的吸附平衡数据可以采用Langmuir、Freundlich和Dubinin Radushkevich等温吸附模型加以描述。溶液共存的Ca²⁺、Na⁺和K⁺会抑制四氧化三铁-沸石复合材料对水中铵的吸附。溶液共存的Cl^-、SO₄^2-和NO₃^-会略微促进四氧化三铁 沸石复合材料对水中磷酸盐的吸附,而共存的HCO₃^-则会略微抑制对水中磷酸盐的吸附。采用0.1 mol/L NaCl溶液可以使吸附到四氧化三铁-沸石复合材料上的铵全部解吸下来。采用0.1 mol/L NaOH溶液可以使大部分吸附到四氧化三铁-沸石复合材料上的磷酸盐解吸下来。     

Fertility and Mineralogy of an Aridisol Soil under Agroecological Management

ABSTRACT

Salinity is one of the most limiting environmental factors of crop production in the world. The objective of this study was to evaluate the relationships between soil agroecological management, mineralogy and fertility of an Aridisol soil in Atacama Desert. Studies were conducted in field and controlled conditions. Four zones were selected for the study. Zone 1. Alfalfa (Medicago sativa L.) silvopastoral system and organic fertilizers for 3 years. Zone 2. Integrated soil recovery system, subsoiling, organic fertilizers, and crop rotation for 8 years. Zone 3. Permanent cultivation of artichoke (Cinara sculemus L.) 3 years of management. Four experiments were realized in semi-controlled conditions, randomized block design. The experiment 1: 8 treatments and 5 replications, zeolite levels and combinations with organic fertilizers. Experiment 2 with zeolite levels, using a soil with established alfalfa for 3 years, 4 treatments and 5 replications. Experiments 3 and 4 were with non-saline sodic soil. The experiment 3 was established with levels of gypsum and experiment 4 with Zeolite levels, both with 4 treatments and 4 replicates. The alfalfa/organic matter/zeolite combinations produced changes in the soil from slightly sodic to non-sodic. Gypsum reduced the Exchangeable Sodium Percentage (ESP) and pH of non-saline sodic soils.     

NH4+-K+ co-loaded clinoptilolite as a binary fertilizer

ABSTRACT

Understanding the potential of clinoptilolite (CLI) for adsorption of NH₄⁺ and K⁺, providing appropriate fertilizer formula, and evaluation of the produced zeolitic nutrient sources (ZNSs) to meet the plant need are the main objectives of this study. Three ZNSs (NH₄⁺-saturated, K⁺-saturated and dual-purpose NH₄⁺-K⁺ saturated CLI) were produced, assessed, and compared with commercial N and K fertilizers (CFs) on corn growth in a greenhouse. The results indicated that CLI can potentially adsorb both NH₄⁺ and K⁺ to the maximum values of 25.00 mg-NH₄⁺ g^?1 and 47.61 mg-K g^?1, respectively, and chemisorptions mainly followed the process of adsorption. Saturation of zeolite by NH₄⁺ and K⁺ occurred after 10 and 15 d which lead to ZNSs with 2% and 5% of N and K, respectively. NH₄⁺-K⁺ saturated CLI contained 1% N and 1% K. The greenhouse experiment showed no significant difference between ZNSs and CFs on plant growth. However, the application of both N and K in the form of zeolitic sources significantly increased the uptake of N by the plant. The highest uptake of K (2.05 g pot^?1) occurred in plants supplied with both natural zeolite and CFs. The present results may benefit the future utilization of ZNSs in environmental friendly farming practices.     

改性生物炭的吸附作用及其对土壤硝态氮和有效磷淋失的影响

在实验室通过生物炭与FeCl3的不同配比确定了生物炭的最佳改性条件,并利用土柱模拟试验,研究改性生物炭对土壤硝态氮和有效磷淋失的影响。结果表明,Fe3+与生物炭质量比为0.7是最佳改性条件,改性作用大大增强了生物炭吸附硝态氮和有效磷的能力。在含N量为50mg.L-1的KNO3和含P量为50mg.L-1的KH2PO4溶液中,最佳改性炭的吸附量分别比改性前提高了12倍和66倍,氮和磷的理论最大吸附量分别为2.47mg.g-1和16.58mg.g-1。土壤中添加最佳改性炭能够延缓并减少硝态氮和有效磷的淋失,添加量为2.5%、5%和10%与不添加任何物质的对照相比,硝态氮的淋失量分别显著降低20%、43%和59%(P<0.05),有效磷的淋失量分别显著降低45%、59%和75%(P<0.05),表明土壤中添加改性生物炭能够有效降低土壤硝态氮和有效磷的淋失风险。     

Amount and speciation of N leached from a sandy soil fertilized with urea,liquid digestate,struvite and NH4-enriched chabazite zeolite-tuff

The large use and the bad management of fertilizers that are applied to soil for improving crop production have dramatically impaired soil, water, and air quality. To meet the requirements to reduce nitrogen (N) losses and all the related negative impacts on the environment and food production, it is mandatory to substitute or at least partially substitute the use of inefficient and unsustainable fertilizers with more efficient alternatives. The aim of this paper was to address the amount and speciation of the N released by a sandy soil fertilized with “slow-release fertilizers” and traditional fertilizers (urea and liquid digestate) by means of a series of column leaching experiments. The slow-release alternatives were represented by NH₄-enriched zeolitic tuff and struvite, both obtained by recovering the N from liquid digestate. The treatments consisted of sandy soil fertilized with (i) urea (U) (ii) liquid digestate (LD), (iii) NH₄-enriched zeolitic tuff (N-CHA) and (iv) struvite (STRV). Eight different flushing events were performed over 38 days, leachates were collected and analysed for total Kjeldahl N, organic-N, NH₄⁺-N, NO₃⁻-N, NO₂⁻-N and pH. U and LD lost the majority of N within the first 2 flushing events as organic N and NH₄⁺-N, respectively. On the other hand, STRV and N-CHA lost less N over the whole course of the experiment and with more balanced speciation. The mass balance outlined that after the experiment, native soil N was mined in U and LD treatments while in N-CHA and STRV a fraction of N from the fertilizers was still present. The results showed a slow release of N which can be used more efficiently in agricultural applications, minimizing the N losses.     

SYNTHETIC SOIL AGGREGATES AS A POTTING MEDIUM FOR ORNAMENTAL PLANT PRODUCTION

Synthetic aggregates (SA) were developed as alternative potting media for ornamental plant production. Four different types of SA were developed from low productive acidic soil and paper waste with adding different types of compost amendments. Compost amendments used in the experiment were cattle manure compost, chicken manure compost, and leaf manure compost. Popular ornamental plant french marigold (Tagetes patula) was used in this experiment. SA with different compost amendments gave considerable physical and chemical parameters compared to commercial zeolite media. Moreover, plant grown in SA media showed better growth and nutritional parameters compared to plant grown in zeolite media. The plant height, number of flowers per plant, shoot fresh weight, shoot dry weight, root length, root fresh weight and root dry weight obtained from three different compost based SA were increased by in the ranges of 8.14--14.41%, 5.66--9.46%, 25.52--31.47%, 9.44--16.13%, 6.14--9.23%, 2.40--8.47% and 8.85--17.05%, respectively, compared to zeolite control.     

ZEOLITE AS SLOW RELEASE FERTILIZER ON SPINACH YIELDS AND QUALITY IN A GREENHOUSE TEST

There has been a great need to reduce the non-point source pollution due to pesticide and fertilizer applications. With a high surface area and large cation exchange capacity, zeolite was proposed to use as carriers to control ammonium and potassium release. A greenhouse test was conducted to evaluate spinach growth and spinach quality after application of zeolite pre-load with ammonium (NH₄ ⁺) and potassium (Eco-zeolite). An increase in spinach yield with comparable vitamin C content was achieved using the Eco-zeolite. However, elevated oxalate content was unexpected, possible due to the presence of NH₄ ⁺ as the exchangeable cations after modification.     

Effects of Zeolite on Soil Nutrients and Growth of Barley Following Irrigation with Saline Water

ABSTRACT

Soil salinity is a major abiotic factor limiting crop production but an amendment with synthetic zeolite may mitigate effects of salinity stress on plants. The objective of the study was to determine the effects of zeolite on soil properties and growth of barley irrigated with diluted seawater. Barley was raised on a sand dune soil treated with calcium type zeolite at the rate of 1 and 5% and irrigated every alternate day with seawater diluted to electrical conductivity (EC) levels of 3 and 16 dS m^?1. Irrigation with 16 dS m^?1 saline water significantly suppressed plant height by 25%, leaf area by 44% and dry weight by 60%. However, a substantial increase in plant biomass of salt stressed barley was observed in zeolite-amended treatments. The application of zeolite also enhanced water and salt holding capacity of soil. Post-harvest soil analysis showed high concentrations of calcium (Ca^{2 +}), magnesium (Mg^{2 +}), sodium (Na⁺), and potassium (K⁺) due to saline water especially in the upper soil layer but concentrations were lower in soils treated with zeolite. Zeolite application at 5% increased Ca^{2 +} concentration in salt stressed plants; concentrations of trace elements were also increased by 19% for iron (Fe^{2 +}) and 10% for manganese (Mn^{2 +}). The overall results indicated that soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil.     

品种修饰与修饰品种简议

简要介绍了品种修饰概念的来源和内容等。修饰型品种随分子育种等现代育种技术的广泛应用而可能增加,建议将经过个别性状改进而获得的品种统归为修饰品种,并在区试审定和产权保护等方面予以参考,以此进一步推动我国作物育种自主创新水平的提高。