75 results about "In situ adsorption" patented technology

In general, the purpose of the probe system is to provide improved rapid field methods using re-designed direct push technology (DPT) and “push-pull testing” concepts to evaluate in situ chemical, biochemical, surfactant, adsorptive media, and leaching and fixation remediation technologies for hazardous subsurface contaminant(s). The probe system and methods described here when applied to a hazardous waste site being considered for in situ remediation of contaminants (organic or inorganic) by the listed treatment technologies will yield information that greatly reduces the uncertainty with regards to treatment effectiveness for the in situ soil, groundwater, and contaminant(s) conditions affecting dosage requirements and reaction rate(s) for various reactants. The probe system described here is multi-purpose in that it was designed: 1) to measure the relative permeability of the subsurface soil and groundwater to a liquid or gas ejectant, 2) to recover soil gas, soil, or groundwater samples for contaminant analyses, 3) to measure the chemical dosage and reaction, dissolution, adsorption, desorption, leaching, or fixation rate of a reactant such as a chemical or biochemical oxidant, metallic or bimetallic dehalogenating agent, surfactant or emulsifier solution, adsorbent media regenerant, leaching or fixation reagent that is injected into the matrix and withdrawn during a push-pull test, 4) to perform combinations of the above, 5) to measure the in situ adsorption capacity of adsorbent media and subsequently measure the effectiveness of regenerant(s) for the adsorbent media, and (6) to measure the effectiveness of a treated soil column for inorganic contaminant(s) leaching or fixation. In addition to being an in situ remedial alternatives evaluation tool, the probe system can be used as a reactant(s) delivery device after the specific remedial technology has been selected.

The invention relates to a novel method for preparing a polyaniline composite conductive fabric. The novel method for preparing a polyaniline composite conductive fabric is characterized in that a conductive fabric with good conductive properties is prepared from a chemical fiber fabric as a matrix material and polyaniline as a conductive material through an in-situ polymerization method (also known as an in-situ adsorption polymerization method). The novel method for preparing a polyaniline composite conductive fabric adopts an ultrasonic dipping treatment process as an auxiliary process of a base fabric dipping process adopting aniline. Therefore, the novel method for preparing a polyaniline composite conductive fabric has good surface modification effects on a base fabric, is beneficial for depositing a conductive material on fiber surfaces of the base fabric in polymerization and enabling the conductive material to permeate into fibers of the base fabric, and improves conductivity and conductive stability. A conductive fabric prepared by the novel method has high conductivity and good environmental stability, is easy for synthesis, and keeps physical and mechanical properties belonging to fabrics on the basis of acquirement of conductive properties, wherein surface resistance R of the conductive fabric is reduced to a value of 1 to 5 kilo-ohm.

The invention belongs to the field of equipment related to carbon capture technologies, and discloses a continuous circulation carbon dioxide capture system on the basis of in-situ adsorption/desorption modes.The continuous circulation carbon dioxide capture system comprises a flue gas purification module, a pressurization module, an isothermal circulation carbon capture reactor group, a gas outlet condensation device, a negative-pressure module and the like which are sequentially connected with one another.The designed isothermal circulation carbon capture reactor group comprises a carbonization reactor and a regeneration reactor which cling to each other to transfer heat, and functions of the carbonization reactor and the regeneration reactor can be switched over after reaction is carried out for a certain time; the carbonization reactor is provided with the pressurization module, the regeneration reactor (42) is provided with the negative-pressure module, and an appropriate quantity of water vapor can be continuously supplied for the regeneration reactor (42).The continuous circulation carbon dioxide capture system has the advantages that the integral reaction efficiency can be obviously improved as compared with existing continuous carbon capture modes, abrasion of solid adsorbent particles due to collision can be eliminated, temperature difference between adsorption and desorption can be reduced to a great extent, the continuous circulation carbon dioxide capture system is economical and environmentally friendly, and the like.

The invention discloses a process method for preparing hydrogen by strengthening chemical chain reforming in a continuous catalytic adsorption manner via a moving bed. The process method is characterized by adopting a reformer, a regenerator, a condenser, a cyclone separator and a lifting pipe, wherein glycerinum which is a biodiesel byproduct serves as a raw material for preparing the hydrogen. According to the method, the oxygen transfer performance of the oxidation reduction of an NiO/AI2O3 catalyst is utilized fully, so that in-situ adsorption intensification of CO2 for hydrogen preparation is carried out by taking CaO as an adsorbent; the water vapor serves as a carrier gas of the reformer, so that the water vapor and the hydrogen of a product are separated conveniently; and the catalyst reduced in the reformer and an adsorbent mixture adsorbing the CO2 are simultaneously oxidated and regenerated in the regenerator. According to the process method, the partial oxidation, the water vapor reforming, the water-vapor transformation and the CO2 adsorption are carried out in the regenerator in a highly coupling manner; and the continuous movement, reaction and regeneration of the catalyst and the adsorbent are carried out by using the moving bed, so that an approximately fresh state is maintained always. Therefore, the hydrogen with high purity is continuously and stably produced at the low temperature under the normal pressure. As a result, the hydrogen preparing process is simplified; the hydrogen preparing cost is saved greatly; and the CO2 is continuously desorbed by the regenerator, which is favorable for CO2 reclamation.

The invention belongs to a coupling device and a coupling technology for in situ extraction of succinic acid by an expanded bed and fermentation and separation of the succinic acid, in particular relates to a technology for producing the succinic acid by the fermentation method, a technology for separating the succinic acid by the expanded bed and a fermentation and separation coupling process. The device is to couple a chromatography column of the expanded bed and a succinic acid bioreactor, so as to extract the succinic acid in situ. The device utilizes the characteristic of the chromatography column of the expanded bed that microbial zymotic liquid provided with solid materials is allowed to directly enter the chromatography column, avoids the blockage problem of a chromatography column of a fixed bed due to direct coupling of the fixed bed and the bioreactor in the prior art, saves an additional membrane separator between the bioreactor and the chromatography column of the expanded bed, realizes direct coupling of the chromatography column of the expanded bed and the bioreactor, and performs in situ extraction of target substances and does not cause blockage of the chromatography column of the expanded bed. Moreover, a coupling system for in situ extraction of the succinic acid by the expanded bed and the fermentation and the separation of the succinic acid is established to meet the requirements of sterilization and pollution-free operation.

The invention relates to a self-cleaning cloth with decontamination and anti-bacteria functions in the sun and a manufacturing method thereof. The manufacturing method comprises the following steps of: forming a layer of photocatalytic complex coating on the surface of a cloth, adding a stabilizing agent and organic amines to a titanium dioxide collosol, jointly stirring, refluxing and reacting to obtain a stable modified titanium dioxide collosol, for a cleaned cloth, loading the modified titanium dioxide collosol to the surface of the cotton by adopting a multi-step circulative soaking-rolling method, soon afterwards, carrying out stabilizing treatment and washing by adopting a hot water bath method, then sequentially immersing the cloth in a solution of silver compound and halide, and obtaining a silver compound composite coating by adopting an in-situ adsorption-reaction-sedimentation method. Compared with the prior art, the manufacturing method provided by the invention is simpleand appropriate in cost; and the prepared self-cleaning cloth has the self-cleaning functions of decontamination and anti-bacteria in the sun, in cloudy days, stray lights or under the condition of indoor natural lights.

The invention provides a preparation method of a TEM sample. According to the preparation method, low-current L-shape or U-shape cutting is firstly carried out on a target structure in a suspended film structure at the top of an MEMS sample by the use of a low-energy ion beam; then, the target structure is cut off from the suspended film structure through adhering by a probe of a nano-manipulation instrument; and finally, the target structure is transferred onto a copper bracket by an in situ adsorption mode to undergo fine-polishing and thinning. According to the invention, damage to the target structure is reduced to the maximum and integrity of a sample is guaranteed to the maximum during the whole sample preparation process; consistency of angle of the target structure when taken out with angle of the target structure in the suspended film structure is guaranteed, and observation result accuracy of the target structure is greatly enhanced; and in comparison with an existing TEM sample preparation process of MEMS by firstly transferring a suspended film onto a Si sheet and then preparing a sample, the method provided by the invention is simple and easy to operate so as to save preparation time of samples.

The invention discloses in-situ adsorption-microelectrolysis-catalytic oxidation sewage treatment equipment and method, belonging to the technical field of sewage treatment in environment engineering. The in-situ adsorption-microelectrolysis-catalytic oxidation sewage treatment equipment is characterized in that adsorption equipment, electrolysis equipment and catalytic oxidation equipment are integrated so as to gather enable pollutants to be gathered from a low-concentration water phase onto an adsorbent; by using the favorable electric conductivity, the adsorbent is used as a complexly polarized three-dimensional electrode to form countless micro electrolytic baths, so that the organic pollutants are electrolyzed while organic matters are adsorbed, and adsorption active sites are continuously regenerated; and by utilizing an electric insulation material, the three-dimensional electrode is complexly polarized and has a high-class oxidation catalyst function at the same time, so that a gas oxidant dissolved in water and an oxidant generated by side reaction of the electrode form a high-class oxidant to efficiently remove the organic pollutants. According to the equipment and the method, the problems of slow reaction speed, low space-time efficiency, low current efficiency and low pollutant degradation efficiency in the conventional electrolytic reactors are solved, and an excellent market prospect is provided.

The invention discloses a biomass grading gasification hydrogen production method. The biomass grading gasification hydrogen production method comprises the steps of subjecting biomass sequentially tohigh-temperature water vapour catalytic gasification, middle-temperature adsorption-enhanced water vapour reforming and low-temperature water-gas shift reaction and CO2 adsorption to produce high-purity H2; the temperature of the high-temperature water vapour catalytic gasification process is higher than or equal to 700 DEG C; the temperature of the middle-temperature adsorption-enhanced water vapour reforming process is 600-700 DEG C; and the temperature of the low-temperature water-gas shift reaction and CO2 adsorption reaction process is 300-500 DEG C. According to the biomass grading gasification hydrogen production method, catalysis and CO2 in-situ adsorption are organically combined, so that a biomass gasification hydrogen production process is significantly enhanced; and meanwhile,by controlling the temperature of the various grades of reaction, hydrogen production key reaction processes of biomass water vapour gasification, WGS reaction, CO2 adsorption and the like are conducted in optimized reaction temperature ranges, so that the biomass grading gasification hydrogen production method benefits a high H2 concentration and yield.

The invention relates to a magnetic solid chelating adsorption material and a preparation method thereof. The preparation method comprises the following steps: firstly, polymerizing epoxy chloropropane and triethylene tetramine in the presence of a ferroferric oxide microsphere to form a linear polymer chain, and performing in situ adsorption and winding on the surface of the ferroferric oxide microsphere; then, performing dispersion in toluene, and adding glutaraldehyde to enable the polymer chain to be further crosslinked so as to be stably covered on the surface of the ferroferric oxide microsphere; and in an aqueous solution, enabling carbon disulfide to react with an active amino group or imino group on the polymer chain under the catalysis of sodium hydroxide to modify a dithio-formyl group on the surface of the ferroferric oxide to generate the magnetic solid chelating adsorption material. The magnetic solid chelating adsorption material and the preparation method thereof provided by the invention have the advantages that active groups such as the ditho-formyl group, the amino group, the imino group and a hydroxyl group are effectively modified on the surface of the ferroferric oxide microsphere, capture and adsorption capabilities to heavy metals are greatly enhanced, the magnetic separation performance is excellent, the subsequent separation is convenient, continuous operation of adsorption and separation can be realized, and industrial application and popularization are facilitated.

The invention relates to the field of remediation for heavy metal pollution of soil and specifically discloses an in-situ remediation method for removing farmland soil arsenic. The in-situ remediation method comprises the following steps: applying iron passivator into soil and then forming an indissolvable matter with the arsenic in soil through complexation and coprecipitation; utilizing a stirring function of a rotary cultivator to suspend arsenic-iron compound particle in water; and utilizing a magnetic adsorption plate connected with the rotary cultivator to absorb the arsenic-iron compound, thereby achieving the purpose of removing the arsenic from farmland soil. According to the invention, the method has the effectiveness in reducing arsenic from soil; the magnetic adsorption plate is loaded on the rotary cultivator generally existing in village; the in-situ adsorption for the arsenic-iron compound can be realized following the advancing and movement of the rotary cultivator in the farmland; the arsenic is thoroughly removed from soil; the soil does not need to be dug; the planting function of the soil is not damaged.

The embodiment of the invention provides an in-situ adsorption testing device for rock core gas and a working method of the in-situ adsorption testing device. The device comprises a constant-temperature tank for providing a required testing temperature, wherein a sample tank, a first pressure transmitter and a pressure loader are arranged in the constant-temperature tank, a gas adding device and a stress loading device are arranged outside the constant-temperature tank, and the sample tank is used for containing a to-be-tested rock core sample; the gas adding device is used for injecting testing gas into the sample tank until the pressure in the sample tank reaches a preset testing pressure value; the first pressure transmitter is used for acquiring the pressure and temperature data of the sample tank; the stress loading device is used for supplying pressure to the stress loading device; the pressure loader is used for converting the pressure supplied by the stress loading device into confining pressure and axial pressure which are supplied to the rock core sample in the sample tank. According to the embodiment, the confining pressure and the axial pressure are increased when the temperature and the gas pressure are considered, the test conditions are accordant with in-situ adsorption states of coal rock and shale, so that the accuracy of an adsorption test measuring result is increased.

The invention discloses an embattling treatment method of environment polluted by toxic heavy metals, inorganic matters and organic matters. The embattling treatment method is an in-situ adsorption method, namely a method for adsorbing and removing the toxic heavy metals, the inorganic matters and the organic matters. The embattling treatment method comprises the following steps: A, an embattling stage, namely, carrying out analysis preparation before an adsorbate is put; B, an adsorption stage, namely, putting the adsorbate; C, a removing stage, namely, removing toxic elements through the adsorbate; D, a recovery stage, namely, resolving out the toxic elements for reusing or embedding so as to avoid secondary pollution; and E, a reusing stage. The embattling treatment method disclosed by the invention has the advantages that soil environment is treated, soil and water resources can be reused, and heavy metals are turned into wealth, the treatment effect is good, and the like.

The invention relates to a filtering sorbent material, a preparation method and an application, concretely relates to a filtering sorbent material obtained by taking a filter aid material as a main raw material for modifying, which belongs to the filtering aid technical field. According to the invention, the filter aid materials such as diatomite and the like are subjected to an acid-base surface modification, washed, dried and crushed to obtain the final product. The filtering adsorbent are used for modifying the filtering ingredients in the prior art without requiring situ adsorption or chemical combination on the filtering ingredients by using silicate like silica gel as an adsorbent, the component usage enables strong controllability and the operation is simple. The part for realizing filtering function and the part for realizing adsorption function are congenitally combined together, thereby the practicality and stability are substantially enhanced.

The invention provides a process for producing hydrogen by combining biomass combustion gasification and furnace internal calcium spraying in a circulating fluidized bed with H2 in-situ adsorption enhanced water vapor transformation. The process comprises the following steps: gradually enlarging a conical circulating fluidized bed of a hearth, and enabling biomass to carry out partial air combustion at the bottom of the circulating fluidized bed; releasing heat for water vapor gasification of most biomass raw materials; moreover, spraying quicklime into the furnace for catalytic synergism, enabling synergic gas generated by the circulating fluidized bed to enter a moving-bed reactor, and carrying out H2 in-situ adsorption enhanced water vapor transformation reaction to produce hydrogen at the temperature of 250 to 350DEG C; at the same time, adsorbing produced hydrogen and storing the adsorbed hydrogen in a hydrogen absorption material; separating the hydrogen absorption material for regenerating to release pure hydrogen; arranging a water vapor transformation moving bed reactor, a solid separator, a regenerator and a solid mixer for H2 adsorption enhanced water vapor transformation, and enabling a water vapor transformation catalyst and the hydrogen absorption material for adsorbing H2 to continuously and simultaneously move, react and regenerate, so as to obtain pure hydrogen with the content of 100 percent.

The invention relates to a treatment method of water containing organic arsenic, and discloses a method for removing organic arsenic in water through synchronous oxidation and in-situ adsorption. According to the method, organic arsenic pollutants in water are solved; particularly, a problem that organic arsenic in water source water of a large-scale drinking water arsenic removal water plant cannot be synchronously oxidized and adsorbed and removed in situ is solved. The method comprises the following steps: adding a divalent iron salt and persulfate into water containing organic arsenic to realize synchronous oxidative degradation and in-situ adsorption removal of organic arsenic in water, and the molar ratio of the divalent iron salt to the persulfate is 1:(0.8-4). The method disclosedby the invention is simple in process operation, wide in applicable water quality condition, capable of efficiently removing representative organic arsenic that is p-arsanilic acid contained in water,and particularly suitable for removing organic arsenic in water source water of large-scale drinking water arsenic removal water plants. The method is applied to the field of arsenic removal.

The invention discloses a preparation method and application of a composite material constructed from a halogen perovskite material ABX3 and a metal complex M complex. The composite material is synthesized by two methods comprising the following steps: 1) adding a pre-synthesized halogen perovskite material ABX3 into a solution of a metal complex functionalized by groups such as carboxyl, amino orphosphate, and forming the composite material under a certain condition by utilizing coordination between the functional groups of the metal complex and the halogen perovskite material; and 2) addingthe functionalized metal complex into the preparation process of the halogen perovskite material, and performing in-situ adsorption on the complex on the surface of the halogen perovskite so as to form the composite material. The synthetic method disclosed by the invention is convenient, excellent in reproducibility and operable at a normal temperature; and meanwhile, the prepared composite material can be applied to photocatalytic CO2 reduction and can be further applied to the fields such as hydrogen production by photocatalysis, organic matter degradation and photocatalysis/photoelectrocatalysis.

The invention discloses a method for preparing a NaX-type molecular sieve from fly ash and application of the molecular sieve. The fly ash is adopted as a main raw material and subjected to pretreatment, and sodium hydroxide is added for a melting reaction. Deionized water is added into a melting product, and NaX-type molecular sieve raw powder is obtained through a hydrothermal crystallization method. Octadecanoic acid is added to generate an esterification reaction with the NaX-type molecular sieve raw powder, and a NaX-type molecular sieve adsorption material is obtained. The NaX-type molecular sieve adsorption material is placed in crude oil or an oil-water mixture, and in-situ oil removing treatment on spilled oil pollution is achieved by utilizing the in-situ adsorption and purification capacity of the NaX-type molecular sieve adsorption material on spilled oil. According to the method, the environmental problems caused by fly ash solid waste and spilled oil pollution are simultaneously solved, and not only is the comprehensive utilization performance of the fly ash improved, but also cyclic utilization of the fly ash and recycling of oil products in the spilled oil are achieved, and the secondary pollution problem cannot be generated; in addition, the product cost of the molecular sieve is reduced by taking the fly ash as the raw material to prepare the NaX-type molecular sieve adsorption material.

The invention discloses a device suitable for sewer harmful gas in situ control and an adsorbent preparation method, the device includes a filter screen, and an upper cover arranged on the filter screen, and an adsorbent for sewer harmful gas adsorption is filled in the filter screen. The steps of the adsorbent preparation method are as follows: putting silica gel into an alkaline solution for full immersion, taking out the silica gel, washing and drying; and the prepared adsorbent is used for accommodating into the filter screen of the device. The device can be very convenient to install and fix under a sewer well cover, and the prepared adsorbent is contained in the device, and can be effective in in-situ adsorption of ammonia and hydrogen sulfide gas in a sewer. The device is simple and clear in structure, the adsorbent preparation method is simple and practical, and the device and the adsorbent have good prospects in urban sewage odor treatment.

The invention belongs to the technical field of electrochemical engineering, and relates to a method of one-step hydrogenation esterification between ketone and carboxylic acid in an electrochemical hydrogen pump reactor. In an electrochemical hydrogen pump reactor, when electrical power is applied, an electrochemical window with extremely low hydrogen is utilized to dissociate hydrogen in the anode, then hydrogen is delivered to the catalysis layer of the cathode to generate in-situ adsorption hydrogen, in-situ adsorption hydrogen and ketone in the cathode circulation liquid carry out hydrogenation reactions directly, the generated alcohols further carry out esterification reactions with carboxylic acids in the cathode circulation liquid; hydrogenation and esterification are carried out in one reactor under a normal pressure, and a synergistic effect is generated.

The invention belongs to the technical field of electrochemical engineering, and relates to a H2/CO2 separation and CO2 hydrogenation self-coupling method. In an electrochemical hydrogen pump, H2/CO2mixed gas is fed from an anode, anode outlet gas is introduced into a cathode to serve as a raw material, and cathode CO2 hydrogenation is achieved. When electric energy is externally added at normaltemperature and normal pressure, high selectivity and controllable dissociation of the hydrogen at the anode are realized by utilizing an extremely low electrochemical window of hydrogen, and generated hydrogen protons are transferred to a cathode catalyst layer to generate in-situ adsorption hydrogen to participate in cathode CO2 hydrogenation. CO2 in the anode outlet mixed gas is enriched through hydrogen transmembrane transmission and is directly used as cathode feed, so that cathode CO2 catalytic hydrogenation is realized. According to the invention, hydrogen separation and CO2 hydrogenation of the same strand of H2/CO2 feed gas are synchronously carried out in the same reactor, and synergistic interaction is realized, so that the process and the device are simplified, and the utilization rate of the H2/CO2 feed gas is improved.

The invention belongs to the technical field of cello-oligosaccharide preparation, and discloses a method for preparing cello-oligosaccharide through directional two-stage hydrolysis of cellulose. The method includes the following steps of reaction stock solution preparation, temperature and pH value setting, substrate in-situ adsorption, solid-liquid separation treatment, first-time hydrolysis treatment, second-time hydrolysis treatment and cello-oligosaccharide purification. According to the method for preparing cello-oligosaccharide through directional two-stage hydrolysis of cellulose, the steps are simple and reasonable, a liquid phase containing cello-oligosaccharide is obtained by hydrolyzing xylo-oligosaccharide production residues through cellulase containing low beta-glucosidase, cello-oligosaccharide is obtained through solid-liquid separation and purification, the feedback inhibition of the product on the enzyme in the hydrolysis process can be effectively relieved by adopting the two-stage hydrolysis mode for hydrolysis, and the production yield of cello-oligosaccharide is greatly increased as the cello-oligosaccharide yield is higher than that in a non-staged hydrolysis mode. The method is simple, low in cost, high in resource utilization rate and capable of achieving industrial production of cello-oligosaccharide.

The invention discloses a preparation method and application of a PtIr alloy and TiO2 coated graphene composite material, and relates to the field of nano material synthesis and electrochemical catalysis. The PtIr alloy and TiO2 coated graphene composite material comprises graphene, a PtIr alloy and TiO2. The method comprises the following steps: uniformly coating TiO2 on the surface of graphene by adopting a sol ultrasonic coating-gel roasting method, and then continuously reducing by utilizing an ultrasonic wave and hydrothermal chemical reduction method to obtain PtIr alloy nanoparticles with uniform particle size, wherein the size distribution of the nanoparticles is 2-5nm; and then carrying out dynamic in-situ adsorption on the PtIr/TiO2/GN to form the uniformly distributed PtIr/TiO2/GN catalyst. The composite material can be used as an ethanol electrooxidation catalyst, the use amount of Pt can be greatly reduced, and the catalytic stability and conversion efficiency of ethanol oxidation are improved.

The invention discloses an adsorption-low-temperature thermal catalyst for removing volatile organic compounds. A method includes: using cerium nitrate, potassium permanganate and diatomite to prepareDt/Mn2Ce1 powder through a hydrothermal synthesis method in an acidic condition, and performing granulating, drying and calcining to obtain catalyst spherical particles capable of adsorbing and catalytically degrading methylbenzene VOCs. In a catalytic material prepared by the method, diatomite has high VOCs adsorptivity and is combined with Mn-Ce to provide catalytic active sites, and in-situ adsorption-catalytic oxidation is realized; so that the catalytic material shows efficient methylbenzene degradability, 90% degradation temperature is lowered to 300 DEG C, and 100% degradation temperature is lowered to 340 DEG C.

The invention relates to a solidified heavy metal remover and a preparation method. The solidified heavy metal remover comprises the following components in percentage by mass: 10-30% of an adsorbentactive material, 0.5-5% of a pore forming agent, and 69.5-89.5% of a coagulant. A pore forming agent solution of the pore forming agent is added to mixed powder of the adsorbent active material and the coagulant according to the mass percentage, the mixture is kneaded and extruded into granules, and the granules are solidified to obtain a common solidified heavy metal remover; and the obtained common solidified heavy metalremover is ultrasonically treated in an acid solution, washed and dried to obtain an acidified solidified heavy metal remover. The soil heavy metal remover has relatively high mechanical strength and good adsorption effect, can be recycled, belongs to in-situ repair and has little influence on soil; and the heavy metal remover can adsorb heavy metals in soil in situ, andcan also be applied to the removal of heavy metals in sewer sludge, river, pond and lake sediments and wastewater.