Concrete Washout Waste Treatment System with CO2 pH Control
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Solution Overview
Problem
Construction sites generate significant urban runoff pollution due to improper handling of concrete washout waste, with existing methods like temporary washout areas, dumpsters, and evaporation ponds being inefficient and environmentally hazardous.
Innovation Solution
A truck-mounted liquid concrete waste vacuum system with a storage tank is used in conjunction with a watertight concrete washout bin to collect and transport waste to a treatment facility, where the waste is processed through multiple tanks for settling, pH reduction using CO2 injection, filtration, and precipitation of heavy metals, allowing for safe recycling or reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temporary washout areas with berms, haybales, linings and catchment systems are used, then washout waste can be contained at construction sites, but these areas are prone to leaking or flooding during rains and require significant space
Solution Approach 1:
The patent replaces mechanical containment structures (berms, haybales, linings) with a chemical treatment system that neutralizes the harmful properties of washout waste. By adding neutralizing agents to lower pH and prevent leaching, the system eliminates the need for complex physical containment structures that are prone to failing during rain events.
Solution Approach 2:
The patent changes the chemical parameters of the washout waste by adding neutralizing agents that reduce pH and prevent leaching. This parameter change transforms the waste from a hazardous, leaking-prone substance into a stable, non-leaching material that does not require robust physical containment structures.
2Loss of substance
If evaporation or leaching is used to remove liquid waste, then waste volume is reduced, but this method is not environmentally safe
Solution Approach 1:
The patent converts the harmful high-pH, leaching-prone washout waste into a beneficial neutralized material. By adding neutralizing agents, the system transforms the waste's chemical properties so that it can be safely applied to soil for dust control or used in concrete mixing, turning a environmental hazard into a useful resource.
Solution Approach 2:
The patent introduces neutralizing agents as intermediary substances that facilitate the transformation of washout waste from a hazardous state to a safe, usable state. These agents mediate the chemical reaction that lowers pH and prevents leaching, enabling safe environmental disposal or reuse without harmful effects.
3Reliability
If dumpsters and sludge boxes are used to contain washout waste, then waste can be collected, but they are prone to leaking during use or during transport
Solution Approach 1:
The patent changes the chemical parameters of the washout waste by neutralizing the high pH and preventing leaching. This transformation creates a stable, non-leaching material that can be safely contained in simple, lightweight containers without the risk of leakage during transport or storage.
4Reliability
If individual plastic bags are used to contain washout waste, then waste can be contained at construction sites, but they are time consuming to use and require two persons to handle
Solution Approach 1:
The patent merges the waste containment and treatment functions into a single integrated system. By neutralizing the waste on-site and allowing it to set into a solid, non-leaching material, the system eliminates the need for multiple handling operations and heavy-duty containment equipment, enabling single-person operation with simpler tools.
5Reliability
If reclaimer systems are used on concrete trucks, then washout waste can be stored temporarily and returned to batch plant, but these systems require valuable operator time and ongoing maintenance
Solution Approach 1:
The patent enables the washout waste to be self-contained and self-stabilizing through the addition of neutralizing agents. The waste neutralizes itself and sets into a solid material that requires no active management, monitoring, or maintenance during storage and transport, eliminating the need for operator intervention and complex mechanical reclaimer systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively treats and recycles concrete washout waste, reducing environmental impact by removing suspended solids and heavy metals, and meeting EPA drinking water standards for pH and turbidity.
Implementation Method 1
a CO2 injector hydraulically coupled to the third tank, where the CO2 injector is adapted to reduce pH by injecting CO2 into liquid circulated from the third tank
Implementation Method 2
a first tank configured to receive liquid concrete waste, where the first tank is configured to settle suspended solids
Implementation Method 3
a second tank configured to receive liquid from the first tank, where the second tank is configured to settle suspended solids
Implementation Method 4
a filter positioned in the discharge line, the filter adapted to remove suspended particles from liquid flowing through the discharge line from the third tank
Data Source
AI summary
Solid and liquid concrete waste is collected from a construction site and safely off-loaded at a treatment site. Solid waste is separated and sent to a crusher to be made into road bed aggregate. Liquid waste is put in a first tank to settle the solids, then moved to a second tank to settle remaining fine solids, and moved to a third tank coupled to a circulation pump with CO2 gas injection to lower the pH. The liquid in the third tank is then filtered before discharging for recycle, irrigation or dust control. A precipitate agent is preferable added to the liquid in the third tank to remove heavy metals and the precipitate is periodically backwashed from the filter into the first tank. The sludge created in the settling and filtering process is periodically dewatered in the first tank and mixed with the solid concrete waste sent to the crusher.