New Technology in Civil Engineering

Introduction

It is easy to think of roads or buildings when thinking of civil engineering, but environmental engineering is quickly becoming an important aspect of this growing field. Scientists, politicians, and ultimately the public have become increasingly interested in working toward a cleaner environment.

That being said, a technological development whose goal is to assist in creating safer soil and water is nano-scale zero valent iron (NZVI). This nano-particle works with removing contaminants, such as PCBs and heavy metals, from ground water.   

Background

A large part of understanding a new technology is understanding how the new research works at achieving its goal. Therefore, I will now describe some reasons why NZVI is beneficial and how it works.

First of all, NZVI is a particle that is suspended in a liquid, such as water. As contaminants pass through a permeable wall that has NZVI particles, the NZVI cleans the ground water. The image (www.arstechnologies.com )depicts a scene where groundwater remediation occurs, showing how the pollutant passes through the NZVI wall.

 

Research

Researchers that study NZVI consider what substance the particle should be coated with, because this affects how effectively the reaction to remove the pollutant occurs. (It’s all quite chemical, but if you want to learn more about the chemistry follow this link: http://www.sciencedirect.com) The following image shows how the chemical reaction occurs.

Overall, some starches that can coat the NZVI include, but are not limited to, tapioca and wheat. The goal is to keep the nano-particle suspended in the liquid, so it can react with the most amount of contaminant. For example consider orange juice that has pulp. If you shake it, more pulp is distributed throughout the juice (therefore the pulp has more surface area exposed to the liquid). Once the pulp settles, there is less surface area, because the pulp touches other pulp pieces, not the liquid.

 

It is similar with NZVI. Because of this, the goal is for the NZVI particles to stay suspended as long as possible, so that the most amount of pollution can be removed from the ground water. If there is less surface area exposed for each particle, the remediation (or cleaning) process is less efficient.

Effect on Society

So why is NZVI so important to everyone and not just researchers or civil engineers? It is very important, because pollution happens on a daily basis. Once the contaminant enters the soil, it follows voids and enters the ground water. This now polluted water can flow into fields and forests, affecting the cleanliness of the environment, which is why this is an environmental engineering concern.

Almost anything we eat has something to do with the land, such as vegetables, wheat products, and fruit, so it is especially important to keep this soil and the water that feeds these fields uncontaminated. People definitely don’t want to eat anything that could cause them to get sick, because the food was from a polluted field.

Similarly, pollution can cause plant life found in parks and other recreation areas to die. Who really wants to walk their dog in a park with dead trees and no flowers? Probably not many people. 

Environmental engineering, such as nano-scale zero valent iron, affects people every day. Even if you don’t notice the individual advances it makes in research, you certainly are affected by how it helps create cleaner products and environments every day.