Guangdong Institute of Eco-Environmental Science & Technology

Guangdong Institute of Eco-Environment and Soil Sciences

Guangdong Institute of Eco-Environmental China Science & Technology

Guangdong Inst. of Eco-Environmental Science&tech

University of Science and Technology Beijing

Chuanping Liu

Li Wang

Fangbai Li

Ping Wu

Jianghu Cui

Xianghua Xu

Xiangqin Wang

Chengshuai Liu

Qing Chun Li

Tongxu Liu

Huimin Li

Jiangtao Qiao

Lige Tong

Shaowu Yin

The present invention discloses a method for safe production of rice on soil mildly and moderately polluted by heavy metals. The method includes applying a passivator before transplanting rice seedlings to reduce activity of heavy metals in soil, and then spraying a foliar barrier from the peak tillering stage to the booting stage of rice and at the filling stage of rice; the passivator includes bentonite, gypsum powder, lime, a biochar, an iron-based biochar, a slow-release iron-based biochar, an iron-sulfur-silicon composite biochar, a heavy metal cadmium passivator and a cadmium-arsenic synchronous passivator for activating sulfur reducing bacteria in paddy soil; and the foliar barrier includes an acid silica sol, a selenium-silicon composite sol, a cerium composite silica sol, a ferrous modified selenium sol. The method can also include applying a nitrate nitrogen fertilizer at the seedling stage of rice, and/or applying a phosphorus potassium fertilizer at the tillering stage of rice.

Method for safe production of rice soil mildly and moderately polluted by heavy metals

A ferrous modified selenium sol for inhibiting accumulation of cadmium and arsenic in rice and the preparation method and application thereof are disclosed. The method includes: dissolving an iron-containing compound and a selenium-containing compound into water; adding a reductant to the solution, and stirring until no more precipitation is generated, then adding carbonate, continuing to stir until no more precipitation is generated, and then filtering, taking the precipitation, and washing to obtain the precipitation of the selenium element and ferrous carbonate; adding an emulsifier to a citric acid buffer solution to obtain an emulsified citric acid buffer solution; adding the precipitation of the selenium element and ferrous carbonate to the emulsified citric acid buffer solution to obtain a sol system; and evaporating to concentrate the sol system, and adjusting the pH to 4.5-8.5 to obtain a ferrous modified selenium sol for inhibiting the accumulation of cadmium and arsenic in rice.

Ferrous modified selenium sol for inhibiting accumulation of cadmium and arsenic in rice and preparation method and application thereof

The invention discloses a method for the preparation and use of a slow-release iron-based biochar soil heavy metal passivator. The slow-release iron-based biochar soil heavy metal passivator of the present invention is prepared by an one-step method, wherein iron-based biochar, kaolin and a biological starch are mixed into a core material in a specific ratio; an acidic silica sol and a chitosan solution are prepared, under the effects of an alkaline catalyst and an emulsifier, as a chitosan and silica-sol composite material as a coating, and the iron-based biochar is coated with the alkaline coating material, with the core material and the coating material being controlled at a certain volume ratio. The passivator has a wide raw material source, a simple and convenient preparation process, easy industrialized production, and can passivate the heavy metal arsenic and cadmium efficiently and inhibit the absorption and accumulation of arsenic and cadmium. The passivator prepared by the present invention can last for 4 growing seasons and has a higher passivation efficiency and a longer action time than common iron-based biochar passivators. The passivator can be widely used in the control of arsenic and cadmium pollution farmland.

Preparation and use of slow-release iron-based biochar soil heavy metal passivator

The present invention relates to the field of environmental protection, and in particular to a leaf surface barrier for accurately controlling cadmium absorption and transport related gene expression in rice, and an application thereof. The present invention comprises: reducing a raw material, i.e., selenious acid or selenite, by using ascorbic acid to generate a nanogel, and then emulsifying the nanogel for peptization to obtain a leaf surface barrier for accurately controlling cadmium absorption and transport related gene expression in rice; and then mixing the leaf surface barrier with a silica sol to obtain a composite selenium and silica sol leaf surface barrier. The present invention also provides a leaf surface barricading method for accurately controlling cadmium absorption and transport related gene expression in rice. By applying the leaf surface barrier, the silica sol or the composite selenium and silica sol leaf surface barrier having a particular atomization degree and a particular concentration by means of foliar spray during a particular growth period of rice and within a particular time, the cadmium accumulation in rice can be effectively reduced. Applying the present invention to a moderately or lightly polluted field can enable cadmium content in rice to satisfy the food hygiene standards, and therefore is significant for achieving the safe use of the large area of field polluted by heavy metal cadmium in China.

Foliage blocking agent for precise regulation of expression of cadmium absorption and transportation-related gene in rice and application thereof

A heavy metal cadmium deactivator for activating the activity of sulfur-reducing bacteria in rice field soil, and an application thereof. The deactivator is constituted by electron shuttles alone or electron shuttles and electron donors, but cannot be constituted by electron donors alone. The mass ratio of the electron donors to the electron shuttles is (1:3)-(1:8). Also, a heavy metal cadmium deactivating method for activating the activity of microorganisms in rice field soil, such as sulfur-reducing bacteria. By applying the functional deactivator to rice field soil, the activity of microorganisms, such as sulfur-reducing bacteria, can be activated, thereby accelerating the reduction process of sulfur and iron in soil to facilitate the fixation of cadmium; cadmium adsorption and accumulation in rice is reduced to achieve secure production in fields moderately or lightly polluted by cadmium.

Heavy metal cadmium deactivator for activating activity of sulfur-reducing bacteria in rice field soil, and application thereof

A method for preparing the iron-based biochar material, the iron-based biochar material prepared there from and a method for controlling the heavy metal pollution in soil using the iron-based biochar material. For the iron-based biochar material of the present invention, by using a method of high-temperature carbonization, a biomass is used as a raw material and an iron-containing compound is add in the process of preparing biochar, wherein iron is incorporated in a specific ratio, to form the iron-based biochar material with a special structure and function. The material has a simple preparation process, low cost and a short production period; the prepared iron-based biochar material has an unique effect on the arsenic-cadmium combined pollution soil remediation, can effectively reduce the bioavailability of arsenic and cadmium in the soil, significantly reduces the arsenic and cadmium contents in the agricultural products planted in the arsenic-cadmium combined pollution soil, and has no toxic and side effects on the crops, is safe to apply and can be applied to the control of arsenic-cadmium combined pollution soil in a large scale.

Iron-based biochar material, preparation therefor and use thereof in soil pollution control

A method for preparing an iron silicon sulfur multi-element composite biochar soil heavy metal conditioner, including: adding silicate to agricultural wastes and roasting with air isolated to enable silicate to enter structural pores of biochar; enabling iron-containing slats to gather on kaolinite with a given proportion; enabling sulfate to gather on bentonite with a given proportion; mixing the above three materials evenly according to a given proportion; and adding diatomite and starch to the mixture, and pelleting to prepare the iron silicon sulfur multi-element composite biochar soil heavy metal conditioner. The conditioner can be widely applied in soil heavy metal pollution abatement of rice fields, and it is able to synchronously passivate composite pollutants in acid or alkaline soils to reduce the amount of pollutants absorbed by and accumulated in rice, thereby achieving safe utilization of polluted farmland.

Method for preparing iron silicon sulfur multi-element composite biochar soil heavy metal conditioner

The present invention discloses a selenium-doped nano-silica sol capable of both inhibiting the absorption and accumulation of heavy metal in rice and producing a selenium-rich rice, and a preparation method thereof. The selenium-doped nano-silica sol of the present invention is prepared mainly by using a nano-silica sol as a carrier, sodium selenite and the like as a raw material, vitamin C and the like as a reducing agent, and polyvinylpyrrolidone and the like as an emulsifier, and doping and dispersing selenium in a specific ratio in a silica sol so as to form a selenium-doped nano-silica sol with a special structure and function. The selenium-doped nano-silica sol prepared according to the invention has high stability and high concentration, and is uniform and transparent, and has a silica content of up to 20% or more, a selenium content of up to 1% or more, and low impurity content. The selenium-doped nano-silica sol of the present invention has a pH close to neutral, wherein selenium, in a nano particle form, is dispersed in colloidal silica, with a particle size of less than 50 nm; and after the foliar application, it can significantly promote the growth of crops, inhibit the absorption and accumulation of arsenic and cadmium in crops, and increase the selenium content in crops, and has no toxic and side effects on crops, and is safe to application.

Selenium-doped nano silica sol used for producing selenium-enriched rice and capable of suppressing absorption and accumulation of heavy metals in paddy rice and preparation method therefor

The present invention is related to the field of environmental protection, more specifically, to a foliage silicon fertilizer and a method for production of the fertilizer, which is a molybdenum-silica compound sol used for reducing heavy metal and nitrates in vegetables. The fertilizer, which is a molybdenum-silica compound sol, comprises 10-25 wt % silica, 0.05-5.5 wt % molybdenum ions. More preferably, the fertilize, which is a rare earth-molybdenum-silica compound sol, comprises 10-25 wt % silica, 0.05-5.5 wt % molybdenum ions and 0.1-7.5 wt % rare earth ions. By the combination of silica with molybdenum in the present invention, it is effective for preventing the absorption/accumulation of nitrates in vegetables. In addition, by the further combination with rare earth element, the prevention ability of the fertilizer from absorbing heavy metal and nitrates into vegetables is even enhanced. With a preparation method with normal pressure and relatively, low temperature, that is, with mild condition, simple process and high operability, large scale production of the present invention may be readily executed.

Growing community of inventors

Guangzhou, China

Chuanping Liu