Environmental risk assessment method for engineered nanoparticles in industrial wastewater

Abstract

The present invention provides an environmental risk assessment method for engineered nanoparticles in industrial wastewater, comprising the following steps: screening out a first nanoparticle and a first heavy metal ion from a nanoparticle group and a heavy metal ion group to form a first pollutant system having the strongest cytotoxicity to the detected microorganism. Determining a first mapping relationship between the concentration of the first nanoparticle and the cytotoxicity produced on the detected microorganism in a ternary system. Obtaining morphological data produced by the detected microorganism and physicochemical data produced by the first nanoparticle and the first heavy metal ion in a reaction system under the first reaction conditions of the ternary system. Evaluating the environmental risk of the engineered nanoparticles in the industrial wastewater based on the morphological data and the physicochemical data. This environmental risk assessment method comprehensively considers the changes in the physicochemical properties of the nanoparticles and heavy metal ions as well as the changes in the morphological data of the microorganisms, so that the assessment is comprehensive and the assessment results are accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological environment protection, and in particular to an environmental risk assessment method for nanoparticles in industrial wastewater. Background Art

[0002] The widespread use of engineered nanomaterials has led to the release of nanoparticles into water bodies, impacting ecological safety and causing toxic effects on the environment. Nanoparticles in industrial wastewater often exist in various mixed forms with other pollutants, and multi-component mixtures may exhibit different ecotoxicities than single-component mixtures. Traditional research on the combined toxicity of engineered nanoparticles has primarily focused on interactions between binary pollutants, such as superposition, synergy, and antagonism, and how these interactions alter the toxic potential of nanoparticles. Consequently, traditional environmental risk assessment methods are incomplete, impacting assessment results. Summary of the Invention

[0003] The main purpose of the present invention is to provide an environmental risk assessment method for engineered nanoparticles in industrial wastewater to solve the technical problem that traditional environmental risk assessment methods are incomplete and affect the assessment results.

[0004] To achieve the above objectives, the present invention provides a method for environmental risk assessment of engineered nanoparticles in industrial wastewater, comprising the following steps:

[0005] S101: Selecting a first nanoparticle and a first heavy metal ion from a nanoparticle group and a heavy metal ion group to form a first pollutant system having the strongest cytotoxicity to the detection microorganism. The nanoparticle group is a collection of at least some types of engineered nanoparticles found in industrial wastewater, and the heavy metal ion group is a collection of at least some types of heavy metal ions found in industrial wastewater. The detection microorganism is a microorganism that has a biological effect on at least some types of the heavy metal ion group.

[0006] S102: Determine a first mapping relationship between the concentration of the first nanoparticle and the cytotoxicity produced on the detection microorganism in the ternary system. The ternary system includes the first pollutant system and the detection microorganism.

[0007] S103: Selecting a first reaction condition according to the first mapping relationship, obtaining a ternary system in a reaction system under the first reaction condition, and detecting morphological data generated by microorganisms.

[0008] S104: Obtaining physical and chemical data generated by the first nanoparticle and the first heavy metal ion in the reaction system of the ternary system under the first reaction conditions.

[0009] S105: Assess the environmental risks of engineered nanoparticles in industrial wastewater based on morphological and physicochemical data.

[0010] According to some embodiments of the present application, the step of selecting the first nanoparticle and the first heavy metal ion from the nanoparticle group and the heavy metal ion group to form the first pollutant system having the strongest cytotoxicity to the detected microorganism in step S101 includes:

[0011] A first growth inhibition rate of each single nanoparticle in the nanoparticle group on the growth of the detected microorganism is obtained.

[0012] A second growth inhibition rate is generated by obtaining a combination of two of the various nanoparticles in the nanoparticle group on the growth of the detected microorganism.

[0013] The first biological action inhibition rate of each single nanoparticle in the nanoparticle group on the biological action of the detected microorganism is obtained.

[0014] Obtain the second biological action inhibition rate of each of the two combinations of various nanoparticles in the nanoparticle group on the biological action of the detected microorganism.

[0015] The first nanoparticles and the first heavy metal ions are determined based on at least one of the first growth inhibition rate and the second growth inhibition rate, and at least one of the first biological action inhibition rate and the second biological action inhibition rate to form a first pollutant system.

[0016] According to some embodiments of the present application, the biological effect is a detoxification effect.

[0017] According to some embodiments of the present application, the morphological data in step S103 is first morphological data generated by detecting microorganisms.

[0018] According to some embodiments of the present application, the environmental risk assessment method further includes:

[0019] Second morphological data generated by the detection microorganism in a reaction system of the first nanoparticle and the detection microorganism under the first reaction condition is obtained.

[0020] Acquire third morphological data generated by the detection microorganism in a reaction system where the first heavy metal ion and the detection microorganism are under the first reaction condition.

[0021] The interaction mechanism among the first nanoparticle, the first heavy metal ion and the detection microorganism is determined based on the first morphology data, the second morphology data and the third morphology data.

[0022] According to some embodiments of the present application, the physicochemical data includes the ion concentration of the ionic species produced by the first nanoparticles and various oxidation states produced by the first heavy metal ions.

[0023] Step S104 includes:

[0024] The ion concentration of the ion form produced by the first nanoparticle in the reaction system of the ternary system under the first reaction conditions is obtained.

[0025] Various oxidation states of the first heavy metal ion produced in the reaction system of the ternary system under the first reaction conditions are obtained.

[0026] According to some embodiments of the present application, step S105 includes:

[0027] The environmental risk of the engineered nanoparticles in industrial wastewater is assessed based on the ionic concentrations of the ionic species produced by the first nanoparticles and the various oxidation states produced by the first heavy metal ions.

[0028] According to some embodiments of the present application, step S102 further includes:

[0029] A third growth inhibition rate of the first pollutant system on the growth of the detection microorganism and a fourth biological action inhibition rate of the first pollutant system on the biological action of the detection microorganism are obtained.

[0030] Step S105 includes:

[0031] The dissolution rate of the first nanoparticles is determined based on the ion concentration of the ionic species generated by the first nanoparticles.

[0032] If at least one of the first nanoparticle dissolution rate, the third growth inhibition rate, and the fourth biological action inhibition rate is greater than 10%, the environmental risk of the engineered nanoparticles in the industrial wastewater is high.

[0033] If the first nanoparticle dissolution rate, the third growth inhibition rate, and the fourth biological action inhibition rate are all less than 10%, the environmental risk of the engineered nanoparticles in industrial wastewater is low.

[0034] According to some embodiments of the present application, the first nanoparticles are ZnO nanoparticles, the first heavy metal ions are Cr 6+ ion.

[0035] According to some embodiments of the present application, the detection microorganism is Pannonibacterphragmitetus BB.

[0036] The environmental risk assessment method for engineered nanoparticles in industrial wastewater constructs a ternary toxicological system encompassing nanoparticles, heavy metal ions, and microorganisms to assess their impact on microorganisms. This method comprehensively considers the changes in the physical and chemical properties of nanoparticles and heavy metal ions under the action of microorganisms, explores the mechanisms of interaction between microorganisms, nanoparticles, and heavy metal ions, and identifies the potential toxicity of nanoparticles and heavy metal ions in the natural environment, ultimately establishing an environmental risk assessment methodology. This environmental risk assessment method comprehensively considers changes in the physical and chemical properties of nanoparticles and heavy metal ions, as well as changes in microbial morphological data, resulting in a comprehensive and accurate assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0038] Figure 1 is a flow chart of a method for environmental risk assessment of engineered nanoparticles in industrial wastewater in one embodiment of the present application;

[0039] Figure 2 : is a graph showing the effect of metal oxide nanoparticles on bacterial growth and Cr(VI) reduction in one embodiment of the present application; wherein, Figure 2 a is the effect of metal oxide nanoparticles on bacterial growth; Figure 2 b is the effect of metal oxide nanoparticles on bacterial reduction of Cr(VI);

[0040] Figure 3 is the morphological change of bacteria exposed to ZnO nanoparticles and / or Cr(VI) in one embodiment of the present application; wherein, Figure 3 a is the SEM image of BB bacteria; Figure 3 b is the TEM image of BB bacteria; Figure 3 c is the SEM image of BB bacteria in the first system; Figure 3 d is the SEM image of BB bacteria in the first system; Figure 3 e is the SEM image of BB bacteria in the second system; Figure 3 f is the SEM image of BB bacteria in the second system; Figure 3 g is the SEM image of BB bacteria in the third system; Figure 3 h is the SEM image of BB bacteria in the third system;

[0041] Figure 4 is a characterization diagram of the physical and chemical properties of ZnO nanoparticles in one embodiment of the present application; wherein, Figure 4 a is the XRD pattern of pure ZnO nanoparticles (bottom figure), ZnO nanoparticles in the first system (middle figure), and ZnO nanoparticles in the second system (top figure); Figure 4 b is the dissolution diagram of ZnO nanoparticles.

[0042] Figure 5 This is an XPS graph of heavy metal Cr in one embodiment of the present application.

[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0044] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of these features.

[0047] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] The present invention provides a method for environmental risk assessment of engineered nanoparticles in industrial wastewater, see Figure 1 , including the following steps:

[0049] S101: Selecting a first nanoparticle and a first heavy metal ion from a nanoparticle group and a heavy metal ion group to form a first pollutant system having the strongest cytotoxicity to the detection microorganism. The nanoparticle group is a collection of at least some types of engineered nanoparticles included in industrial wastewater, and the heavy metal ion group is a collection of at least some types of heavy metal ions included in industrial wastewater. The detection microorganism is a detection microorganism that has a biological effect on at least some types of the heavy metal ion group.

[0050] In industrial wastewater environments, nanoparticles (also known as industrial nanoparticles, as they are often used in industrial production) always coexist with metal ions in various forms. Industrial wastewater contains a variety of nanoparticles. Among them, some types of nanoparticles are widely present in industrial wastewater due to their wide application (such as metal oxide nanoparticles, CuO, ZnO, Al2O3, Fe2O3, and TiO2). These types of nanoparticles are collectively referred to as the nanoparticle group. Similarly, the various heavy metal ions with high content in industrial wastewater environments are collectively referred to as the heavy metal ion group.

[0051] The impact evaluation on the detection microorganism mainly includes growth amount and biological action index. Among them, the detection microorganism can be screened from microorganisms that have biological effects (for example, dissolution, oxidation, reduction, and fixation) on at least some types of heavy metal ions. Preferably, the detection microorganism exists in the industrial wastewater environment to be evaluated. Among them, the toxicity of some heavy metal ions is reduced after reduction by the detection microorganism. Therefore, the reduction effect of the detection microorganism can also be called detoxification, and the corresponding biological action index can be called detoxification rate. The following description is based on the detoxification rate as an example.

[0052] Based on this, the effects of individual nanoparticles or any combination of nanoparticles in the nanoparticle group on the test microorganisms can be evaluated. For example, their effects on the growth of the test microorganisms, i.e., their growth inhibition rates, can be examined. A nanoparticle with a high growth inhibition rate, i.e., a significant impact on the growth of the test microorganism, exhibits a strong cytotoxic effect on the test microorganism. In this way, the nanoparticle group is screened for the nanoparticle with the strongest cytotoxicity towards the test microorganism.

[0053] Similarly, the effects of single / any two-by-two mixed heavy metal ions in the heavy metal ion group on the detection microorganisms can be evaluated, such as the effects on the detoxification rate of the detection microorganisms can be investigated separately. A large effect on the detoxification rate of the detection microorganism can also be referred to as having a strong cytotoxicity to the detection microorganism. On this basis, the first heavy metal ion with the strongest cytotoxicity to the detection microorganism is screened out from the heavy metal ion group. Usually, the combination of the first nanoparticle and the first heavy metal ion screened by the above method is the first pollutant system with the strongest cytotoxicity to the detection microorganism. It should be noted that the strongest cytotoxicity here is the strongest in the pollutant system formed by each heavy metal ion and each nanoparticle in the industrial wastewater to be evaluated.

[0054] S102: Determine a first mapping relationship between the concentration of the first nanoparticle and the cytotoxicity produced on the detection microorganism in the ternary system. The ternary system includes the first pollutant system and the detection microorganism.

[0055] Based on the effect of the nanoparticles on the test microorganisms obtained in step S101, the binary pollutant system with the strongest cytotoxic effect on the test microorganisms (i.e., the first pollutant system) is identified. By varying the concentration of the nanoparticles, the concentration dependence of the combined toxicity of the nanoparticles and heavy metal ions on the test microorganisms is analyzed. The first mapping relationship is the corresponding relationship between the concentration of the first nanoparticles and the cytotoxicity produced by the test microorganisms.

[0056] S103: Selecting a first reaction condition according to the first mapping relationship, obtaining a ternary system in a reaction system under the first reaction condition, and detecting morphological data generated by microorganisms.

[0057] A specific reaction condition is selected from the first mapping relationship as the first reaction condition, such as the reaction condition corresponding to the maximum cytotoxicity produced by the test microorganism. The reaction conditions include the concentration of the first nanoparticle, the concentration of the first heavy metal ion, and may also include the amount of the test microorganism added. The effects of the nanoparticles and / or heavy metal ions on the test microorganism under these conditions are analyzed. The morphology of the test microorganism exposed to the first nanoparticle and / or the first heavy metal ion is characterized using SEM and TEM to observe changes in bacterial morphology.

[0058] S104: Obtaining physical and chemical data generated by the first nanoparticle and the first heavy metal ion in the reaction system of the ternary system under the first reaction conditions.

[0059] Detecting microbial effects on the first nanoparticle and the first heavy metal ion also involves analyzing changes in the physical and chemical properties of the nanoparticles and heavy metal ions in the ternary system under the first reaction conditions. For example, XRD, XPS, and ICP-MS can be used to study the crystal structure, oxidation state, and ion dissolution of the nanoparticles in the ternary system. Another example is using XPS to study changes in the valence state of the heavy metal ions.

[0060] S105: Assess the environmental risks of engineered nanoparticles in industrial wastewater based on morphological and physicochemical data.

[0061] According to the change patterns of each component before and after the reaction of the ternary system of the detection microorganism, the first nanoparticle and the first heavy metal ion in steps S103 and S104, the interaction mechanism of the three components is elucidated, and a new ecotoxicological evaluation scheme for the detection microorganism of binary pollutants including nanoparticles in the environment is proposed.

[0062] The environmental risk assessment method for engineered nanoparticles in industrial wastewater constructs a ternary toxicological system consisting of nanoparticles, heavy metal ions, and test microorganisms. This system evaluates the impact of nanoparticles and heavy metal ions on the test microorganisms, comprehensively considers the changes in the physical and chemical properties of nanoparticles and heavy metal ions under the action of the test microorganisms, explores the interaction mechanisms between the test microorganisms and nanoparticles and heavy metal ions, clarifies the potential toxicity of nanoparticles and heavy metal ions in the natural environment, and establishes an environmental risk assessment method. This environmental risk assessment method comprehensively considers the changes in the physical and chemical properties of nanoparticles and heavy metal ions, as well as the changes in the morphological data of the test microorganisms, resulting in a comprehensive and accurate assessment.

[0063] In some embodiments, the step of selecting the first nanoparticles and the first heavy metal ions from the nanoparticle group and the heavy metal ion group in step S101 to form a first pollutant system having the strongest cytotoxicity to the detected microorganisms comprises:

[0064] A first growth inhibition rate of each single nanoparticle in the nanoparticle group on the growth of the detected microorganism is obtained.

[0065] A second growth inhibition rate is generated by obtaining a combination of two of the various nanoparticles in the nanoparticle group on the growth of the detected microorganism.

[0066] The first biological action inhibition rate of each single nanoparticle in the nanoparticle group on the biological action of the detected microorganism is obtained.

[0067] Obtain the second biological action inhibition rate of each of the two combinations of various nanoparticles in the nanoparticle group on the biological action of the detected microorganism.

[0068] The first nanoparticles and the first heavy metal ions are determined based on at least one of the first growth inhibition rate and the second growth inhibition rate, and at least one of the first biological action inhibition rate and the second biological action inhibition rate to form a first pollutant system.

[0069] In this embodiment, the first nanoparticles are screened. For example, the effect of each single nanoparticle on the growth inhibition rate of the test microorganism and the effect of the biological action of the test microorganism are considered, and then the single nanoparticle with the greatest effect on the test microorganism is determined by combining the two.

[0070] Next, the effects of each pairwise combination of nanoparticles on the growth inhibition rate of the test microorganism and the effects of the biological action of the test microorganism are considered. The two effects are then combined to determine the nanoparticle combination that has the greatest effect on the test microorganism. In some embodiments, the single nanoparticle that has the greatest effect on the test microorganism is one of the nanoparticles in the nanoparticle combination that has the greatest effect on the test microorganism. Thus, the single nanoparticle that has the greatest effect on the test microorganism is typically the first nanoparticle.

[0071] In some embodiments, the biological effect is a detoxification effect.

[0072] In some embodiments, the morphological data in step S103 is first morphological data generated by the detected microorganisms. The morphological data can be used to more intuitively and accurately determine the growth of the detected microorganisms, such as the survival of the microorganisms, and the biological interaction or influence of the first nanoparticles and the first heavy metal ions.

[0073] In some embodiments, the environmental risk assessment method further comprises:

[0074] Second morphological data generated by the detection microorganism in a reaction system of the first nanoparticle and the detection microorganism under the first reaction condition is obtained.

[0075] Acquire third morphological data generated by the detection microorganism in a reaction system where the first heavy metal ion and the detection microorganism are under the first reaction condition.

[0076] The interaction mechanism among the first nanoparticle, the first heavy metal ion and the detection microorganism is determined based on the first morphology data, the second morphology data and the third morphology data.

[0077] In this embodiment, by comparing the morphological data of the detected microorganisms under different conditions, the growth of the detected microorganisms and the biological interaction or influence of the first nanoparticles and the first heavy metal ions can be judged more accurately and intuitively.

[0078] In some embodiments, the physicochemical data includes ionic concentrations of ionic species produced by the first nanoparticles and various oxidation states produced by the first heavy metal ions.

[0079] Step S104 includes:

[0080] The ion concentration of the ion form produced by the first nanoparticle in the reaction system of the ternary system under the first reaction conditions is obtained.

[0081] Various oxidation states of the first heavy metal ion produced in the reaction system of the ternary system under the first reaction conditions are obtained.

[0082] In this way, it is possible to determine whether the first nanoparticles and the first heavy metal ions have undergone changes in physical and chemical properties under the action of the detection microorganisms, and then determine whether they have been affected by the action of the detection microorganisms and determine the extent of the impact.

[0083] In some embodiments, step S105 includes:

[0084] The environmental risk of engineered nanoparticles in industrial wastewater is assessed based on the ion concentration of the ionic form produced by the first nanoparticle and the various oxidation states produced by the first heavy metal ion. This assessment method is more comprehensive and accurate.

[0085] In some embodiments, step S102 further includes:

[0086] A third growth inhibition rate of the first pollutant system on the growth of the detection microorganism and a fourth biological action inhibition rate of the first pollutant system on the biological action of the detection microorganism are obtained.

[0087] Step S105 includes:

[0088] The dissolution rate of the first nanoparticles is determined based on the ion concentration of the ionic species generated by the first nanoparticles.

[0089] If at least one of the first nanoparticle dissolution rate, the third growth inhibition rate, and the fourth biological action inhibition rate is greater than 10%, the environmental risk of the engineered nanoparticles in the industrial wastewater is high.

[0090] If the first nanoparticle dissolution rate, the third growth inhibition rate, and the fourth biological action inhibition rate are all less than 10%, the environmental risk of the engineered nanoparticles in industrial wastewater is low.

[0091] In some embodiments, the first nanoparticles are ZnO nanoparticles, and the first heavy metal ion is Cr 6+ ion.

[0092] Papermaking, electroplating, leather and other industries will produce Cr (VI) waste. Therefore, there will be hexavalent chromium pollution in industrial wastewater. The first heavy metal ion was identified as Cr 6+ ion.

[0093] In some embodiments, the detection microorganism is Pannonibacterphragmitetus BB, because Pannonibacterphragmitetus interacts with Cr(VI) and is commonly found in industrial wastewater.

[0094] The present invention is described in detail below using a ternary system of ZnO nanoparticles (ZnO NPs), Cr(VI), and Pannonibacterphragmitetus BB (hereinafter referred to as BB), which has strong Cr(VI) reduction and detoxification capabilities. The system comprises the following steps:

[0095] S1. Select the five most widely used metal oxide nanoparticles: CuO, ZnO, Al2O3, Fe2O3, and TiO2 (the nanoparticle group). Select Cr(VI) as the heavy metal ion group and as the first heavy metal ion. Because BB bacteria interact with Cr(VI) and are commonly found in industrial wastewater, BB bacteria were chosen as the detection microorganism.

[0096] like Figure 2 As shown, single ZnO, CuO, Al2O3, Fe2O3, and TiO2 nanoparticles were observed to inhibit bacterial growth (BB bacteria, hereinafter referred to as BB bacteria) by 47.6%, 6.5%, 9.4%, 22%, and 13.3%, respectively. Furthermore, binary mixtures of ZnO NPs with CuO, Al2O3, Fe2O3, and TiO2 nanoparticles also inhibited bacterial growth, with inhibition rates ranging from 29% to 31.3%, significantly higher than any binary nanoparticle mixtures without ZnO NPs. Furthermore, single ZnO NPs exhibited an inhibition rate of up to 86.5% on bacterial Cr(VI) reduction, while mixtures of ZnO NPs with CuO, Al2O3, Fe2O3, and TiO2 nanoparticles exhibited inhibition rates of 75% to 78.1%. However, single nanoparticles other than ZnO NPs or their binary mixtures showed little to no inhibitory effect on Cr(VI) reduction (less than 1%). These results indicate that in the ternary system of nanoparticles, Cr(VI), and Cr(VI)-reducing bacteria, the coexistence of ZnO NPs and Cr(VI) exhibits significant cytotoxicity to bacteria.

[0097] S2. Based on the effect of the nanoparticles on the detected microorganisms determined in step S1, the binary pollutant system with the strongest cytotoxic effect on the detected microorganisms (i.e., the first pollutant system, including ZnO NPs (first nanoparticles) and Cr(VI) (first heavy metal ion)) is identified. The concentration of the nanoparticles (ZnO NPs, hereinafter referred to as ZnO NPs) is changed to analyze the concentration dependence of the combined toxicity of the nanoparticles and heavy metal ions (Cr(VI), hereinafter referred to as Cr(VI)) on the detected microorganisms. In the embodiment of the present invention, the toxic effects of different concentrations of ZnO NPs on bacterial cells (i.e., the first mapping relationship) are studied, as shown in FIG. Figure 2 As shown, the inhibition of bacterial growth and the reduction of Cr(VI) reduction ability were proportional to the concentration, and exposure to 100 ppm and 200 ppm of ZnO NPs severely inhibited the bacterial reduction of Cr(VI).

[0098] S3. The morphologies of BB bacteria in the first system composed of BB bacteria, ZnO NPs and BB bacteria, BB bacteria in the second system composed of Cr(VI) and BB bacteria, and BB bacteria in the third system (i.e., ternary system) composed of ZnO NPs, Cr(VI) and BB bacteria were characterized by SEM and TEM, respectively. The results are shown in Figure 3. Figure 3 shown.

[0099] like Figure 3 As shown in a, c, e, and g, no significant changes were found in the bacterial morphology of BB under different conditions, indicating that ZnO NPs and / or Cr(VI) had no significant negative impact on the cell ultrastructure. TEM analysis of the bacteria exposed to ZnO NPs (the first system) was performed, as shown in Figure 3 As shown in Figure d, a small amount of tiny particles were found inside and outside the cells, indicating that some nanoparticles entered the cells. Figure 3 f shows that under Cr(VI) exposure (second system), obvious particles can be observed inside and outside the cells, which are presumably Cr(III) precipitates. The number of intracellular particles is significantly less than that of extracellular particles, indicating that a large amount of Cr(VI) reduction products are squeezed out of the cells, thereby reducing the damage of intracellular Cr(III) to proteins and DNA. Figure 3 h It can be seen that a large number of particle aggregations can be observed inside and outside the cells co-exposed to Cr(VI) and ZnO NPs (the third system), and these particles may be a mixture of ZnO NPs and Cr(III) precipitates.

[0100] It should be noted that the first reaction conditions for the third system were: BB bacteria at 10% (v / v); Cr(VI) at 250 ppm; and ZnO NPs at 100 ppm. The reaction conditions for the first and second systems corresponded to those for the first reaction, i.e., except for the excluded components, the concentrations or addition amounts of the remaining components were the same.

[0101] S4. In the present invention, the physical and chemical properties of ZnO NPs are closely related to their toxicity. The crystal structure of ZnONPs in the ternary system and the 2+ dissolution, such as Figure 4 The XRD peaks of ZnO NPs correspond to those in JCPDS NO.01-079-2205, which indicates that the crystal structure is zincite, and the crystal structure of ZnO NPs does not change before and after the treatment. 2+ The concentration test found that after 24h, the Zn 2+ Continue to dissolve to 39.08 mg L -1 , which is much higher than that of BB+ZnONPs or Cr(VI)+ZnO NPs binary system. It can be seen that the coexistence of ZnO NPs, Cr(VI) and BB promotes the 2+ This may be related to the fact that Cr(VI) stimulates bacteria to produce metabolites. XPS was further used to study the changes in the oxidation state of Cr, such as Figure 5 As shown, the Cr 2p spectrum shows that Cr 2p 3 / 2 and Cr 2p 1 / 2 The peaks are located at 576.17 / 577.87eV and 584.23 / 586.79eV, respectively, indicating the presence of CrO4 in the system. 2- , Cr(OH)3 and organic Cr(III), confirming that ZnO NPs restricted the complete reduction of Cr(VI).

[0102] S5. According to the change rules of each component before and after the reaction of the ternary system of detection microorganisms, nanoparticles and heavy metal ions in steps S3 and S4, the interaction mechanism of the three components is clarified, and a new ecotoxicological evaluation scheme for binary pollutants including nanoparticles in the environment on detection microorganisms is proposed. The changes in ZnONPs and Cr(VI) in the ternary system involved in BB in the embodiment of the present invention are significantly different from those in their respective binary systems, which is mainly due to the interaction between the detection microorganisms and ZnO NPs and Cr(VI). ZnO NPs have a toxic effect on BB, inhibiting the reduction of Cr(VI), but have no significant effect on bacterial activity. The metabolites produced by BB under the induction of Cr(VI) prompt ZnO NPs to dissolve Zn inside and outside the cells. 2+ Dissolved Zn 2 +The detoxification process of bacteria reducing Cr(VI) to Cr(III) is restricted. 2+ The dissolved concentration was 39.08 mg / L. Since the initial concentration of ZnO NPs was 100 mg / L, the dissolution rate of ZnO NPs was 39.08%. Therefore, the environmental risk of engineered nanoparticles in industrial wastewater can be assessed as high.

[0103] This paper proposes an ecotoxicological assessment scheme for binary pollutants, including nanoparticles, in the environment. The interaction between microorganisms, nanoparticles, and heavy metal ions truly reflects the ecotoxicity of nanoparticles in the presence of other pollutants.

[0104] The above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for environmental risk assessment of engineered nanoparticles in industrial wastewater, characterized in that: The following steps are involved: S101: selecting a first nanoparticle and a first heavy metal ion from a nanoparticle group and a heavy metal ion group to form a first pollutant system having the strongest cytotoxicity to the detection microorganism; wherein the nanoparticle group is a collection of at least some types of engineered nanoparticles included in the industrial wastewater, the heavy metal ion group is a collection of at least some types of heavy metal ions included in the industrial wastewater; and the detection microorganism is a microorganism that has a biological effect on at least some types of the heavy metal ion group; S102: Determine a first mapping relationship between the concentration of the first nanoparticle and the cytotoxicity produced on the detection microorganism in a ternary system; the ternary system includes the first pollutant system and the detection microorganism; S103: selecting a first reaction condition according to the first mapping relationship, and obtaining morphological data generated by the detected microorganism in the reaction system of the ternary system under the first reaction condition; S104: Acquiring physical and chemical data generated by the first nanoparticles and the first heavy metal ions in the reaction system of the ternary system under the first reaction conditions; S105: Assessing the environmental risk of the engineered nanoparticles in the industrial wastewater based on the morphological data and the physicochemical data; The morphological data in step S103 is the first morphological data generated by the detected microorganism; The environmental risk assessment method further includes: acquiring second morphological data generated by the detection microorganism in a reaction system of the first nanoparticles and the detection microorganism under the first reaction conditions; acquiring third morphological data generated by the detection microorganism in a reaction system of the first heavy metal ion and the detection microorganism under the first reaction condition; determining an interaction mechanism among the first nanoparticle, the first heavy metal ion, and the detection microorganism based on the first topography data, the second topography data, and the third topography data; The physicochemical data includes ion concentrations of ionic species produced by the first nanoparticles and various oxidation states produced by the first heavy metal ions; The step S104 includes: Obtaining an ion concentration of an ion form produced by the first nanoparticle in a reaction system of the ternary system under the first reaction conditions; obtaining various oxidation states of the first heavy metal ion in the reaction system of the ternary system under the first reaction conditions; The step S105 includes: The environmental risk of the engineered nanoparticles in the industrial wastewater is assessed based on the ion concentration of the ionic species produced by the first nanoparticles and the various oxidation states produced by the first heavy metal ions.

2. The environmental risk assessment method according to claim 1, characterized in that: The step of selecting the first nanoparticles and the first heavy metal ions from the nanoparticle group and the heavy metal ion group to form a first pollutant system having the strongest cytotoxicity to the detected microorganisms in step S101 includes: Obtaining a first growth inhibition rate of each single nanoparticle in the nanoparticle group on the growth of the detection microorganism; obtaining a second growth inhibition rate of the detection microorganism produced by a combination of two of the various nanoparticles in the nanoparticle group; Obtaining a first biological action inhibition rate of each single nanoparticle in the nanoparticle group on the biological action of the detection microorganism; Obtaining a second biological action inhibition rate of each of the nanoparticles in the nanoparticle group in combination with each other on the biological action of the detection microorganism; First nanoparticles and first heavy metal ions are determined based on at least one of the first growth inhibition rate and the second growth inhibition rate, and at least one of the first biological action inhibition rate and the second biological action inhibition rate to form the first pollutant system.

3. The environmental risk assessment method according to claim 1 or 2, characterized in that: The biological effect is a detoxification effect.

4. The environmental risk assessment method according to claim 1, characterized in that: The step S102 further includes: Obtaining a third growth inhibition rate produced by the first pollutant system on the growth of the detection microorganism, and a fourth biological action inhibition rate produced by the first pollutant system on the biological action of the detection microorganism; The step S105 includes: determining a dissolution rate of the first nanoparticles based on an ion concentration of the ionic form produced by the first nanoparticles; If at least one of the dissolution rate of the first nanoparticles, the third growth inhibition rate, and the fourth biological action inhibition rate is greater than 10%, the environmental risk of the engineered nanoparticles in the industrial wastewater is high; If the dissolution rate of the first nanoparticles, the third growth inhibition rate, and the fourth biological action inhibition rate are all less than 10%, the environmental risk of the engineered nanoparticles in the industrial wastewater is low.

5. The environmental risk assessment method according to claim 1, characterized in that: The first nanoparticles are ZnO nanoparticles, and the first heavy metal ions are Cr 6+ ion.

6. The environmental risk assessment method according to claim 1, characterized in that: The detection microorganism is Lactobacillum panloniae Pannonibacter phragmitetus BB.

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