3.3 EHC技术原理 Principle of EHC Technologies

“一种注入式含水土壤,地下水和底泥污染的修复产品”

EHC: 此技术是由德拉门德技术演变而成的一个“就地”污染修复产品系列。它包含整合控制释放的食用碳和零价铁(ZVI),一定比例的营养和食用有机物。常于地下水和饱和土壤层的土质修复。所针对的污染物有重金属,防腐剂如氯化物,杀虫剂,和能源物质等。

此技术是结合物理,化学,及生物处理机制于一体来达到使污染的迅速沉淀和吸附。

直接铁(ZVI)效应 (下图中黑色部位)

间接铁(ZVI)效应(黄色):

生物刺激作用(兰色):

提升的热动力条件(红色):

 

以上作用共同导致极度低的氧化还原潜力形成(-500 mV),从而加速治理的完成,并无新陈代谢中间产物的积累。控制释放的有机碳和零价铁延长了产品的使用寿命 (1-5年) 并扩大了影响的范围。

它可以干粉直接用于挖开的现场(倾倒和混合),也可以泥浆注入地下。

 

EHC: The technology is a modification of our DARAMEND?technology and a family of remediation products used for the in situ treatment of groundwater and saturated soil impacted by heavy metals and persistent organic compounds such as chlorinated solvents, pesticides and energetic. It include a controlled-release, integrated carbon and ZVI source, Major/ minor/micronutrients and Food grade organic component

A number of physical, chemical and microbiologic processes combine to stimulate rapid and complete precipitate and absorption:

• Direct iron effects (black color in above figure)

• Indirect iron effects

• Biostimulation

• Enhanced Thermodynamic condition

 

It can either be injected into the subsurface as slurry or applied directly into open excavations or trenches as a dry powder.

 

EHC-M: 是一个特殊的配方,通过加强的沉淀和吸附反应来控制和稳固溶解性的重金属污染,使可渗漏的重金属减少到低于 TCLP标准 (参看第10章的达标标准)。

在图中,氧化还原潜能(Eh) 与pH的关系展示了在有溶解性铁和硫的情况下砷的化合物种族的形成。当pH值升高时这些种族的氧化还原势能下降,当Eh降到一定范围,一种较活跃的物质就转化为另一种更稳定的物质。最后形成最稳定的不溶性沉淀。因为这个从活跃到中间状态再到稳定的过程使砷的消除过程有吸附和沉淀两种机制的存在。(Manning et al., 2002; Craw et al., 2003)

EHC-M: is specially formulated for in situ immobilization of soluble metals via enhanced precipitation and adsorption reactions to reduce the amount of leachable metals to below the TCLP standard (see Chapter 10, the strandard).

In the figures, the relationship between redox potential Eh and pH: shows Arsenic Speciation in the presence of dissolved Fe and S. During the process, relatively reactive species becomes relatively stable species when Eh decreases and pH increases, and finally becoming solid sediments.Both precipitation and adsorption mechanisms occur in the treatment phase. (Manning et al., 2002; Craw et al., 2003)

 

EHC-A: 是一个冷水溶性配方,特别设计用来从现有的井或液压注入网注入来处理大范围的地下水污染。产品主要由控制释放的食用有机碳和溶解性的铁构成。它的应用可大大提高难分解混合物的就地还原,如有机氯农药和能量物质。

EHC-A? is a cold-water soluble formulation of EHC that is specially designed for injection via existing wells or hydraulic injection networks for the treatment of a wide range of groundwater contaminants. It is composed of primarily controlled-release food-grade organic carbon and dissolved iron. Application of EHC-A will greatly enhance the in situ reduction of persistent compounds such as chlorinated solvents, chlorinated pesticides, and energetics through a combination of biostimulation and chemical reduction resulting in very low redox levels.

EHC-O: 通过控制释放的氧和营养来激发有氧生物降解。适宜于石化碳氢化合物,轻多环芳烃和苯系物的整治。本产品有高氧释放率和低价的优势。

This product is stimulation of aerobic biodegradation to Petroleum Hydrocarbons Light PAHs, and BTEX through controlled-release oxygen and nutrient delivery. Significant cost savings realized through the use of EHC-O due to its higher oxygen release rate and lower price.