WASTE TREATMENT
Zeolites are hydrated aluminosilicates in crystal structure, capable of absorbing many different types of gases, odors, moisture, petrochemicals, ammonia, heavy metals, low-level radioactive elements and a multitude of various solutions.
Zeolite's highly porous structure provides large surface areas on which chemical reactions and cation exchanges can take place. The cavities and channels inside zeolites occupy up to 50% of its volume, which enables them to capture particulate contamination down to 4 microns in size.
The main principle of Zeolite (clinoptilolite) is Ion Exchange. It has a natural negative charge which gives it a high cation exchange capacity.
Thanks to its eco-friendly structure and low cost, zeolite (clinoptilolite) has a wide range of applications:
BIOGAS PLANTS
The high amount of ammonium in the feces can decrease the efficiency of biogas plants. Zeolite application increase the energy production of the biogas facilities by absorbing excess ammonia. It creates a suitable environment for the beneficial bacteria and microorganisms responsible for proper functioning of biogas plant.
Moreover, Clinoptilolite possess unique adsorption properties for simultaneous biogas purification (H2S removal) and upgrading of methane. Improves and expands habitats for process-relevant bacteria.
The 10% clinoptilolite (v/v) addition was the balanced amount which presented the optimal efficiencies enhancement for biogas generation. Clinoptilolite could not only inhibit the acidification of digestion liquid, but also could enhance the organic acids destruction.
WASTE WATER TREATMENT
Industrial waste waters contain toxic heavy metal ions such as lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), copper
(Cu), and zinc (Zn). Municipal waste waters contain high amounts of ammonium. These toxic elements must be removed from aqueous solutions before disposal; otherwise they can cause serious environmental problems. They can contaminate water sources.
The ion-exchange process is the most attractive, simple and cost effective method to remove the toxic elements in waste water. Natural zeolite mineralcontains exchangeable cations, such as Na+, K+, Ca2+, and Mg2+, in its structural framework. Ammonium and heavy metal ions in wastewater is replaced by these cations during ion exchange. Absorbents like clinoptilolite is the future in environmental applications.
Sources of Heavy Metals & Contaminants
LANDFILL LEACHATE TREATMENT
Sanitary landfilling is the most widely used method for management of municipal solid waste. The major problems caused by landfilling are related to the generation of highly contaminated leachates that pose long-term environmental problems. Leachate containing various hazardous pollutants
is produced in large quantities by landfills. Among these pollutants, ammonium is found high concentrations.
Zeolite is an influential and a low-cost alternative adsorbent for the removal of NH4- N and heavy metals:
Hazardous Pollutants Inside Municipal Solid Waste
INDUSTRIAL / SEWAGE SLUDGE and ORGANIC SOLID WASTE SOLIDIFICATION & COMPOSTING
The elimination of sewage sludge from wastewater treatment plants is a significant problem. Composting is one of the most common treatments of
sewage sludge; however toxic compounds and heavy metal concentrations are usually high and the sludge is not suitable for disposal or for application to the land.
Another problem during sludge composting is the release of ammonia due to the decomposition of nitrogenous material (proteins
and amino acids). There is frequently ammonia emission during composting at the thermophilic process.
The addition of zeolites into sludge provide several benefits during the composting process:
AIR TREATMENT & GAS SEPARATION
Carbon dioxide, sulphuric compositions, acetylene, ammonia can be discharged to the air through flue gases. Even dioxins and furans, volatile heavy metals and toxins can be present in these gases. Natural zeolite has exceptional characteristics making it the right choice for air treatment applications:
RADIOACTIVE WASTE TREATMENT
Cesium (Cs) is a very hazardous nuclide which is highly present in low level radioactive waste and in waste repositories. Clinoptilolite's pore size is close to the diameter of hydrated Cesium. Therefore, it has a high selectivity for Cs and similar hydrated cations like Uranium and Strontium. It has the ability to retain radioactive fission products
Zeolite was widely used at Chernobyl and lately at Fukushima nuclear disasters to trap the active radioactive elements into the cage structure of zeolite. They are used as a reactive barrier at the waste repositories and at nuclear plants.
OIL & CHEMICAL SPILLS
Zeolite has a very large surface area and absorbing capacity. It is safely used as an absorbent grit at industrial accidents, oil spills, chemicals leaks and leachates.
