Industrial Waste Diversion Methods and Their Results

Transforming Waste into Value: Recovering Nitrate & Fluoride Salts from Pickling Wastewater The stainless steel industry generates massive amounts of wastewater rich in valuable salts—but what if we could recover and reuse them instead of discarding them? In our latest publication (#OA open access), we demonstrate how Flow-Electrode Capacitive Deionization (FCDI) can effectively recover nitrate and fluoride salts from stainless steel pickling baths. This not only reduces industrial waste but also creates a closed-loop recycling system that saves resources and cuts costs. 🔹 Key Insights from Our Research: ✅ Turning wastewater into a resource—recovering valuable salts instead of losing them ✅ A cost-effective and energy-efficient alternative to conventional acid recovery methods ✅ Membrane technology breakthroughs that enhance salt separation and recycling ✅ Industrial applications that could make stainless steel production more sustainable 🔗 Read the full paper here: [https://lnkd.in/eQU_Dni6] #SustainableIndustry #WaterRecycling #Desalination #FCDI #StainlessSteel #CircularEconomy #Innovation

Industrial Opportunities from Scrubber Water in Phosphate Fertilizer Plants Scrubber systems used in single or triple superphosphate fertilizer production generate process water rich in compounds such as fluoride (F⁻) and silica derivatives (SiF₄, H₂SiF₆). Rather than treating this water solely as waste, it can be processed and transformed into valuable industrial products, aligning with circular economy principles. 1. Production of Sodium Fluorosilicate (Na₂SiF₆) Scrubber water commonly contains fluorosilicic acid (H₂SiF₆), formed from the hydrolysis of silicon tetrafluoride (SiF₄). Sodium fluorosilicate is made by neutralizing fluorosilicic acid with sodium salt. H2[SiF6] + 2 NaCl → Na2[SiF6] + 2 HCl It is used in some countries as additives for water fluoridation, opal glass raw material, ore refining, or other fluoride chemical (like sodium fluoride, magnesium silicofluoride, cryolite, aluminum fluoride) production. 2. Silica Gel Manufacturing Silica can be precipitated after fluoride removal by pH adjustment and acid neutralization. The resulting silica gel is widely used in moisture control applications across electronics, pharmaceuticals, and food preservation. 3. Compound Fertilizer with Fluorosilicates There is potential to integrate treated fluoride and silica compounds into phosphate fertilizers to create specialized blends. However, toxicological and agronomic studies are essential prior to any agricultural application. 4. Use of Solid Residues in Ceramic or Refractory Materials Precipitated silica and fluoride-based solids can be incorporated into ceramic tiles, refractory bricks, or insulation materials, improving heat resistance and structural integrity. --- References: Müller, U. Industrial Inorganic Chemistry, Wiley-VCH. Walsh, R. (2000). Fluorine Chemistry at the Millennium, Elsevier. US Patent No. 5641543A: Method for silica gel production from waste solution. United States Environmental Protection Agency (EPA): Guidelines on Fluoride Recovery in Phosphate Plants.

Landfills can be a gateway example of Circularity in action - let me explain! Last week as part of the California Foundation on the Environment and the Economy (CFEE)delegation, I had the privilege to visit the Hartland Landfill in British Columbia. Thanks to a comprehensive approach to waste management, including strong EPR policies that emphasize diversion and environmental protection, the Hartland Landfill is projected to last at least 75 years. Whereas Landfills can be a "money maker" in some places, Hartland embodied an "landfilling as a last resort" ethos. The key to their strategy is Extended Producer Responsibility (EPR) and rigorous source separation. Instead of just a hole in the ground, Hartland acts as a hub for dozens of different recycling streams, from electronics to used oil and antifreeze. We even got a unique look at the bottom of the landfill, which is built to last. Here's what I learned, in numbers: 🟢 Nearly half of all materials received at the landfill in 2022 could have been diverted through existing recycling programs. 🟢 The disposal rate for organic waste has decreased since a 2015 organics landfilling ban, now making up 16.7% of landfilled waste, down from 21% in 2016. 🟢 It's cheaper to divert! The price for general refuse is $155 per tonne, while clean wood, which is diverted, is charged at $80 per tonne, creating a financial incentive for proper sorting. 🟢 The facility's recycling programs for tires, oil, and antifreeze boast high diversion rates, with 90% of tire-related fees going to processors and haulers, and 100% of used antifreeze being re-refined and recycled into new products. This multi-pronged approach has two major benefits: 🟡 Methane Capture --> The landfill has a $25MM electricity generating station that captures methane gas produced from decomposing waste. This is crucial because methane is a potent greenhouse gas, and its capture significantly reduces the landfill's carbon footprint. 🟡 Strategic Diversion --> The facility actively diverts a wide range of materials, including wood, asphalt shingles, and organic waste, from the main landfill stream. By making landfill disposal considerably more expensive than dropping off separated recyclable materials, the landfill creates a clear economic incentive for residents and businesses to sort their waste properly. I loved seeing this ethos come from a landfiller: get everything out of the landfill that can be recycled, reused, or converted into energy. As a result, the lifespan of the landfill is extended, while our precious natural resources are conserved and protected. #CircularEconomy #EPR #WasteManagement #Sustainability #HartlandLandfill

Refuse-derived fuel (RDF) is a high-calorific fuel produced by processing non-recyclable waste materials like household and commercial waste into a fuel that can be used in energy-from-waste facilities. The process involves sorting waste to remove non-combustible items such as metals and glass, followed by shredding and drying the remaining combustible materials to create a consistent fuel. RDF serves as an alternative to landfilling, reduces reliance on fossil fuels, and produces heat, power, and steam for various industrial processes and electricity generation. What is the purpose of Refuse-Derived Fuel (RDF)? Waste management: RDF diverts waste from landfills, reducing the pressure on landfill sites and helping to meet zero-waste-to-landfill goals. Energy recovery: It converts waste materials into a usable energy source, generating heat, power, and steam. Fossil fuel reduction: Using RDF helps decrease the demand for fossil fuels, contributing to lower carbon emissions and greater energy independence. How is RDF produced? The production of RDF typically involves several steps: Waste collection: Combustible materials from municipal solid waste (MSW) and commercial waste streams are collected. Sorting and separation: Non-combustible items like metals (using magnets) and glass (using screening) are removed. The sorted waste is shredded into a consistent size, and the moisture content may be reduced. The final product can be a loose mixture or compressed into forms like pellets, briquettes, or logs for storage and transport. Tyre derived fuel (TDF) is created from shredded end-of-life tires, a waste product that is then used as a fuel source in industries like cement manufacturing, power plants, and pulp and paper mills, substituting for fossil fuels such as coal. TDF offers a high calorific value, providing comparable or greater energy than other fuels, while also reducing landfill waste and potentially lowering emissions. How it's made: Shredding: Used and end-of-life tires are mechanically shredded into smaller chips or crumb-like materials. Fuel blending: These shredded tires are then blended with other fuels or used as a direct substitute. Combustion: The mixture is burned in industrial kilns and boilers to generate energy, steam, or electricity. Where it's used: Cement and lime kilns: The high heat required for cement production makes TDF an ideal fuel source. Power plants: Used as a substitute for coal to generate electricity. Pulp and paper mills: Used as a supplemental fuel in industrial boilers. Benefits of TDF: Waste diversion: Keeps millions of used tires out of landfills. High energy content: TDF has a high calorific value, producing more energy than coal. Reduced emissions: Can lead to reduced emissions of sulfur and nitrogen compared to some fossil fuels. Lower ash content: TDF has a lower ash content than coal, making it a more efficient fuel in some industries.