Characteristics of diatomite-alginate-Fe3O4 composite as a phosphate adsorbent

Technological approaches to the use of diatomaceous earth as a raw material for the creation of composite adsorbents for wastewater treatment from phosphate ions are analysed. It is shown that the developed surface of diatomite can be used to create a granular adsorbent, and iron (III) oxides (magnetite, goethite, lepidocrocite, ferrihydrite, hematite and goethite) are environmentally safe, cheap, economically feasible modifiers. Emphasis is placed on the possibility of obtaining magnetic granules due to the formation of magnetite. The use of the deposition method for the formation of the applied granular adsorbent is proposed. The influence of diatomite concentration on the static strength of granules was established. It is determined that the diameter of the nozzle is also an important factor. The selected technical solutions are aimed at solving the problems of granule hardening and ensuring high adsorption activity. Experimental studies of the synthesis and granulation of the composite adsorbent alginate - diatomaceous earth - magnetite have shown that an increase in the content of diatomaceous earth leads to a natural increase in the size of the granules. When increasing the diameter of the nozzle from 1.5 mm to 3.5 mm, for example, the size of the granules 1.5-4.0 (dc = 1.5 mm), 2.0-5.0 mm (dc = 3.0 mm) and 2.5-5.0 mm (dc = 3.5 mm). The diatomaceous earth content of more than 20% does not allow to carry out high-quality granulation on the experimental installation due to the increase in the viscosity of the suspension. The relationship between the size of gel granules and dried. The process of application of the active magnetic phase of the adsorbent is investigated. The dependence of the quality of the granulation process on the solid phase content is established. The measured static strength of the adsorbent granules is in the range of 17 - 25 kPa. It is established that the composite adsorbent with the applied layer of magnetite has magnetic properties. The adsorption of PO43- anions from aqueous solutions was studied. For the adsorbent alginate - diatomite and alginate - diatomite - Fe3O4 - the adsorption capacity is 4 and 9 mg PO43- / g, respectively. The obtained composite adsorbents have a set of functional properties that are promising for use in modern water purification and purification systems.

Laboratory methods for producing of effective adsorbents on the basis of diatomite for purification of water from impurities of well-soluble organic compounds

Today there is the problem of fine water purification during its consumption and disposal in industry from impurities of water-soluble organic compounds that enter it with pharmaceutical, cosmetic preparations, food waste, waste from the textile and chemical industries. Diatomite is a good raw material for the production of these adsorbents. It is found that diatomite is the mesoporous sorbent. The permeability of diatomite can be increased by granulating of the rock. It is found that heat treatment is necessary to obtain more durable granules from diatomite: when the increasing in the temperature of heat treatment of granules the compressive strength of granules increases too. At the same time, when the temperature of the heat treatment is increasing, the equilibrium adsorption of methylene blue on diatomite granules is decreasing. The optimum temperature for the heat treatment of granules is 550 °C. It is found that the heat treatment and granulation of diatomite do not have a significant impact on the adsorptive-structural properties of the rock: up to 70 % of the pore volume of granules is the volume of mesopores. The powdered adsorbent from diatomite which can be obtained by the developed laboratory method can be used in industrial water purification schemes where static adsorption is used for fine water purification. Using the developed laboratory method for producing granular adsorbent from diatomite, it is possible to produce an adsorbent for water purification under dynamic adsorption conditions, where a high value of the sorbent permeability is important.

COD AND AMMONIA REMOVAL FROM LANDFILL LEACHATE USING MIXED GRANULAR ADSORBENT MEDIA

Landfills generate leachate that contains elevated concentration of contaminants and is hazardous to human health and the ecosystem. In this study, the mixture of granular feldspar and cockle shells was investigated for remediation of COD and ammonia from landfill leachate. All adsorbent media were sieved to a particle size between 2.00 and 3.35 mm. The results revealed that the optimum mixing ratio of feldspar and cockle shells was 20:20, shaking speed was 150 rpm, pH level was 6, shaking time was 120 min, and dosage was 30 g. The adsorption isotherm analysis reveals that the Langmuir isotherm yielded the best fit to experimental data as compared to the Freundlich isotherm. The media produce encouraging results and can potentially be used as a good and sustainable adsorbent.

Preparation of macroscopic spherical porous carbons@carboxymethylcellulose sodium gel beads and application for removal of tetracycline

We report a new convenient macroscopic granular adsorbent for the removal of tetracycline from water by immobilizing porous carbons into carboxymethylcellulose sodium gel beads.

Lead adsorption from aqueous solutions by a granular adsorbent prepared from phoenix tree leaves

In this study, a granular adsorbent was prepared from phoenix tree leaf powder with bentonite as the binder. The adsorption kinetics and isotherms of Pb2+ removal by the 500 °C-calcined granular adsorbent were studied by various models.