Dithiocarbamate Heavy Metal Agent for Stable Wastewater Flocculation
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Solution Overview
Problem
Conventional heavy metal treatment methods for wastewater and incinerated ash face inefficiencies in metal scavenging, floc formation, and stability issues, particularly with dithiocarbamates precipitating in mineral-containing water, leading to secondary pollution and high operational costs.
Innovation Solution
A heavy metal treatment agent comprising dithiocarbamates of amine compounds represented by specific formulae (I) to (III) and additional components (B) to (E), including bases, aminocarboxylic acids, mercaptans, aminophosphoric acids, dithiocarbamate of polyethyleneimine, and sulfur-containing compounds, enhancing stability and floc formation capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dithiocarbamates are used for heavy metal treatment, then heavy metal scavenging is achieved, but the agent precipitates in mineral-containing water leading to reduced stability and secondary pollution
Solution Approach 1:
The patent combines conventional dithiocarbamate with specific additives (polyethyleneimine, polyacrylamide, or inorganic flocculants) to create a composite treatment agent. This composite structure prevents precipitation in mineral-containing water while maintaining heavy metal scavenging effectiveness, thereby improving stability and preventing secondary pollution.
Solution Approach 2:
The patent introduces intermediary substances (polyethyleneimine, polyacrylamide, or inorganic flocculants) that mediate between the dithiocarbamate and mineral components in water. These intermediaries prevent direct harmful interactions that cause precipitation, while still allowing the dithiocarbamate to effectively scavenge heavy metals.
2Productivity
If neutralizing coagulation precipitation is used for metal removal, then metals are removed from wastewater, but significant quantity of metallic hydroxide sludge is generated requiring extensive processing
Solution Approach 1:
The patent extracts only the essential heavy metal components from wastewater using dithiocarbamate chelation, leaving behind the bulk water and minimizing sludge generation. This selective extraction approach removes metals without generating the large volumes of metallic hydroxide sludge associated with conventional precipitation methods.
Solution Approach 2:
The patent enables recovery of valuable heavy metals through selective chelation and concentration, allowing them to be discarded from the wastewater stream in a concentrated, manageable form rather than dispersed in large volumes of sludge. This facilitates both metal removal and potential resource recovery.
3Ease of manufacture
If conventional dithiocarbamates are used for incinerated ash treatment, then heavy metals are treated, but heavy metals can leak after landfilling due to rainwater elution
Solution Approach 1:
The patent creates a composite treatment system combining dithiocarbamate with flocculating agents that form stable complexes with heavy metals in incinerated ash. This composite structure prevents rainwater elution by creating a stable, non-leachable complex that remains fixed in the ash matrix after landfilling.
Solution Approach 2:
The patent applies dithiocarbamate treatment beforehand to incinerated ash to pre-stabilize heavy metals before landfilling. This prior cushioning prevents future elution by establishing stable chemical bonds between the dithiocarbamate and heavy metals, protecting against subsequent rainwater infiltration and environmental contamination.
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 agent effectively treats elements of groups 6 to 16 of the periodic table, maintains stability in mineral-containing water, and forms stable flocs, improving treatment efficiency and reducing metal elution from incinerated ash.
Implementation Method 1
an approach of collecting and removing the metals in wastewater using a metal scavenger such as an organic chelator has been widely used
Implementation Method 2
neutralizing coagulation precipitation presents challenges such as inadequate floc formation
Data Source
AI summary
Provided are: a novel heavy metal treatment agent having improved performance for treating elements of groups 6 to 16 of the periodic table or compounds thereof, including treatment of wastewater and incinerated ash and so forth; and a method for treating wastewater and incinerated ash using the heavy metal treatment agent. This heavy metal treatment agent of the present invention includes the component (A) and at least one species selected from the components (B) to (E) as defined in the following as: (A) at least one dithiocarbamate of one or more amine compounds represented by any of formulae (I) to (III): ; and wherein each of the n Xs independently represents a hydrogen atom or a 2-aminoethyl group, and at least one X is a 2-aminoethyl group; (B) a base; (C) at least one species selected from aminocarboxylic acids, mercaptans, and aminophosphoric acids; (D) a dithiocarbamate of polyethyleneimine; and (E) a sulfur-containing compound.