阅读说明：本技术 一种基于水热炭肥的养分控释方法 (Nutrient controlled-release method based on hydrothermal carbon fertilizer ) 是由 钟磊 孙于茹 陈冠益 田静楠 武文竹 颜蓓蓓 马文超 宋英今 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种基于水热炭肥的养分控释方法。取水热炭肥与不同浓度的盐酸溶液混合振荡不同时间,结束后洗至中性过滤,烘干后可得到具有不同养分控释效果的水热炭肥,该方法可使得水热炭肥中的主要养分氮缓慢释放。同时,解析其控释原理,并且基于Matlab-2018b,将相关数据通过多项式模型拟合,建立了一个养分控释方程。该方法可以有效延缓水热炭肥中氮素的溶出速率,提高养分利用率；并且该方法操作简单,设备及工艺要求低,易于工业化生产,在生产中应用前景广阔；通过该方法得到的水热炭肥缓释效果好,一次性施用即可,可提升作物产量；并且该养分控释方程可根据不同作物的养分需求,预测最佳养分控释的处理条件。(The invention discloses a nutrient controlled release method based on a hydrothermal carbon fertilizer. Mixing the hydrothermal carbon fertilizer with hydrochloric acid solutions with different concentrations, oscillating for different times, washing to be neutral after finishing, filtering, and drying to obtain the hydrothermal carbon fertilizer with different nutrient controlled release effects. Meanwhile, the controlled release principle is analyzed, and based on Matlab-2018b, the related data are fitted through a polynomial model, so that a nutrient controlled release equation is established. The method can effectively delay the dissolution rate of nitrogen in the hydrothermal carbon fertilizer and improve the nutrient utilization rate; the method is simple to operate, low in equipment and process requirements, easy for industrial production and wide in application prospect in production; the hydrothermal carbon fertilizer obtained by the method has a good slow release effect, can be applied at one time, and can improve the crop yield; and the nutrient controlled release equation can predict the optimal nutrient controlled release treatment condition according to the nutrient requirements of different crops.)

1. A method for controlling and releasing nutrients based on a hydrothermal carbon fertilizer is characterized in that the hydrothermal carbon fertilizer is added into a hydrochloric acid solution with the concentration of 0.05-0.2mol/L, oscillated for 6-24 hours at 25 ℃ and under the condition of 200r/min with 120-.

2. The method as claimed in claim 1, wherein the solid-to-liquid ratio of the hydrothermal carbon fertilizer to the hydrochloric acid solution is 1:10-30 (g/mL).

3. The method of claim 1, wherein the hydrochloric acid solution has a concentration of 0.05 to 0.1 mol/L.

4. The method of claim 1, wherein the oscillation time is 8-18 h.

5. The method of claim 1, wherein independent variables are determined as acid treatment concentration (x, mol/L) and acid treatment time (Y, h), dependent variables are determined as accumulated water solubility (Y,%) of nitrogen in the treated hydrothermal carbon fertilizer after 7 days, and a relation between Y and x and Y is established by quadratic model fitting based on Matlab-2018b, and the relation is a nutrient controlled release equation:

Y＝A+B·x+C·y+D·x²+E·x·y+F·y²

A. b, C, D, E, F are constant coefficients in the relational expression, and the values of the coefficients can be automatically calculated by Matlab-2018b software.

Technical Field

The invention relates to a fertilizer slow-release and controlled-release method, in particular to a nutrient controlled-release method based on a hydrothermal carbon fertilizer.

Background

As a big agricultural country in China, the large-scale application of chemical fertilizers plays an important role in guaranteeing the food safety in China, and it is worth noting that the food yield in China increases by nearly 85% in three decades from 1980 to the present, but the application amount of the chemical fertilizers increases by 4.5 times. The excessive application of chemical fertilizers results in low utilization rate of fertilizers, the utilization rate of nitrogen fertilizers in China is about 20-35% and far lower than the international level, and simultaneously, huge ecological environment pollution is caused, and sustainable development of agriculture is threatened. More and more students think that the research on novel fertilizers, the reduction of production cost and the improvement of the utilization rate of the fertilizers are problems to be solved urgently in the current fertilizer research, so that a new thought is provided for the slow release fertilizers.

The utilization method of the traditional biochar material in the slow-release fertilizer is mature, but most biochar materials are used as controlled-release materials and improved materials to be matched with organic and/or inorganic fertilizers, and because most biochar materials have less nutrient elements reserved by the biochar materials, the biochar materials cannot be directly used for fertilizing. Chinese patent application CN 104876679A discloses a crude biochar slow-release fertilizer and a preparation method thereof, the method mixes biochar as a slow-release agent with urea, ammonium sulfate, a binder and other substances to achieve the purpose of regulating and controlling the release rate of the fertilizers such as urea and the like in soil, the biochar fertilizer obtained by the method is a mixed fertilizer, the preparation method is complex, the energy consumption is overlarge, the cost is higher, and the biochar fertilizer cannot fully play a role; chinese patent application CN 105272389A discloses a method for developing a pig manure carbon-based fertilizer based on soil improvement, the invention prepares pig manure carbon-based fertilizer by a hydrothermal carbonization method, the pig manure carbon-based fertilizer contains a large amount of nutrient elements required by plants, the nutrient elements can be directly added into soil in the form of fertilizer, but the fertilizer does not have the effect of nutrient slow release, and the nutrient loss can be caused by too fast nutrient release after the fertilizer is applied into the soil.

The hydrothermal carbon is a carbon-rich substance which is high in nutrient content and rich in oxygen-containing functional groups and is generated by low-temperature (150-340 ℃) pyrolysis of biomass in an anoxic environment by taking water as a reaction medium. Therefore, aiming at the hydrothermal carbon fertilizer with high nutrient content, a nutrient controlled-release method which is simple in operation method, does not cause secondary pollution to the environment and obviously improves the utilization rate of the fertilizer is urgently needed, and the method has important significance for developing matched controlled-release carbon fertilizer according to the nutrient requirement rule of different crops to improve the utilization rate of the fertilizer of the crops.

Disclosure of Invention

The invention aims to provide a nutrient controlled-release method based on a hydrothermal carbon fertilizer, so as to solve the problems. Abundant acidic oxygen-containing functional groups (such as carboxyl, lactone group and the like) can be introduced on the surface of the hydrothermal carbon fertilizer through acid treatment, and the functional groups can realize the limited-domain limited-speed release through coordination and chelation reaction; meanwhile, after the hydrothermal carbon fertilizer is subjected to acid treatment, a clear pore structure appears, most nutrient elements are stored in pores and passages, the pores and the passages are too small, water has surface tension, cannot rapidly permeate into the narrow hydrothermal carbon passages and can only slowly permeate through osmotic pressure, and the nutrient elements in the hydrothermal carbon can be slowly released.

A nutrient controlled release method based on a hydrothermal carbon fertilizer is characterized in that the hydrothermal carbon fertilizer is added into a hydrochloric acid solution with the concentration of 0.05-0.2mol/L, the solution is oscillated for 6-24 hours at room temperature under the condition of 200r/min and 120-;

in the step (1), the solid-to-liquid ratio of the hydrothermal carbon fertilizer to the hydrochloric acid solution is 1:10-30 (g/mL).

In the step (1), the concentration of the hydrochloric acid solution is 0.05-0.1 mol/L.

In the step (1), the shaking time of the shaking table is 8-18 h.

And (3) nutrient controlled release analysis:

establishing a relational expression, namely firstly determining the independent variables of the fertilizer as acid treatment concentration (x, mol/L) and acid treatment time (Y, h), determining the dependent variable as the accumulated water dissolution rate (Y,%) of nitrogen of the treated hydrothermal carbon fertilizer in 7 days, and establishing a relational expression between Y and x and Y through quadratic model fitting based on Matlab-2018b, wherein the relational expression is a nutrient controlled release equation: (polynomial model equation is suitable for analyzing and predicting the influence of acid treatment concentration and time on the controlled release behavior of the hydrothermal carbon fertilizer)

Y＝A+B·x+C·y+D·x²+E·x·y+F·y²

A. B, C, D, E, F are constant coefficients in the relational expression, and the values of the coefficients can be automatically calculated by Matlab-2018b software. .

The invention brings the following beneficial effects:

the nutrient controlled-release method provided by the invention utilizes the characteristic of high nutrient content of the hydrothermal carbon fertilizer, and combines an acid modification method to control the main nutrient nitrogen of the carbon fertilizer in a controlled-release manner, so as to form the hydrothermal carbon fertilizer controlled-release method capable of independently regulating and controlling the nutrient release rate. The method can effectively delay the dissolution rate of nitrogen in the hydrothermal carbon fertilizer, improve the nutrient utilization rate and prolong the fertilizer efficiency; the method has the advantages of simple process, easy operation, low production investment, low requirements on equipment and process, easy industrial production and wide application prospect in production; the hydrothermal carbon fertilizer obtained by the method has a good slow release effect, can be applied at one time, and can improve the crop yield. Meanwhile, a nutrient controlled-release equation established based on the method can predict the treatment condition of the matched controlled-release carbon fertilizer according to the nutrient requirement rules of different crops, so that the nutrient loss is reduced, and the fertilizer utilization rate is improved.

Drawings

FIG. 1 is a graph of the 24-hour cumulative water dissolution rate of nitrogen in a hydrothermal carbon fertilizer treated by the nutrient controlled-release method.

FIG. 2 is a graph showing the cumulative water solubility of nitrogen in the hydrothermal carbon fertilizer after being treated by the nutrient controlled-release method for 7 days.

Detailed Description

The invention is further illustrated by the following specific examples. The specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention.