Solutions to renovate and restore "dead lands"

A craft village is a pollution hotspot

Established in the 1970s, Dong Mai has hundreds of households recycling lead batteries. All stages, from demolition, melting to metal separation, take place right in the yards, pond banks, and fields of households. From there, a large amount of smoke and lead dust is directly released into the environment, causing serious pollution of the soil, water, and air, turning this place into one of the most seriously polluted environmental spots in Hung Yen province.

Research results conducted by many organizations such as the Blacksmith Institute in 2013 and the General Department of Environment (now the Department of Environment) in 2019 all show serious heavy metal pollution in the soil here, many times exceeding the allowable standards, especially Lead (Pb), Copper (Cu) and Zinc (Zn) pollution.

Lead recycling activities in Chi Dao commune, Van Lam district, Hung Yen (now Lac Dao commune, Hung Yen province).

Pollution enters the soil, water, and air environment through the food chain, seriously affecting the health of local people, especially the elderly and children. Many reports have pointed out the sad consequences of serious environmental pollution, about 80% of villagers suffer from one of the following diseases: intestinal, duodenal, stomach, respiratory, and eye diseases. According to a survey by the Institute of Occupational Medicine and Environmental Hygiene ( Ministry of Health ), many cases have lead levels in the blood exceeding the safe threshold, and it is recommended that filtration be performed.

Find a way to save the land…

In recent years, this pollution hotspot has received special attention from local authorities as well as functional agencies. In 2010, the People's Committee of Hung Yen province decided to build the "Chi Dao Commune Industrial Cluster" to relocate production households out of Dong Mai village. Local authorities also coordinated with organizations and specialized agencies to implement many solutions to improve the quality of soil, water and air here. However, the pollution situation still continues and has not been completely resolved.

In order to help the locality improve the serious soil pollution situation, within the framework of the "Project integrating climate change resilience and environmental protection to develop green cities" of the Department of Environment, experts have piloted the remediation and restoration of polluted soil environment here.

The area of land contaminated with heavy metals was renovated and restored by the Project on integrating climate change resilience and environmental protection in green urban development.

With the characteristics of heavy metal pollution and long-term pollution, the group of experts proposed the method of washing soil with iron III alum (FeCl3) - a method proven to be effective in quickly reducing heavy metal content (Pb, Zn) in a short time.

After more than a year of implementation, monitoring results in the selected pilot area showed that the content of heavy metals (As, Cr, Cu, Pb, Cd, Zn) in the soil after treatment all decreased below the allowable threshold according to the provisions of the National Technical Regulation. In particular, the content of heavy metals with high pollution levels before treatment such as Lead, Copper, Zinc has decreased significantly, showing that the treatment method has promoted high treatment efficiency, significantly eliminating the amount of heavy metals accumulated for a long time in the soil.

After treatment, the previously polluted area was also renovated by experts by adding new soil, lime and organic microbial fertilizers, helping to improve soil fertility and pH balance, creating conditions for the flora to grow again. Thanks to that, the ecosystem was gradually restored, increasing vegetation cover, contributing to improving air quality and environmental landscape.

According to Mr. Duong Quynh Thai, the Project's expert in analyzing toxic chemicals that are difficult to decompose, although it is only a small-scale pilot project, the results of the Project open up the possibility of renovating and restoring areas of land contaminated with heavy metals. Compared with technologies of washing soil with chemical solutions or mixing soil with chemicals or biological treatment with plants and microorganisms, the method of washing soil with iron sulfate brings positive effects such as quickly reducing the content of heavy metals in the soil without destroying the soil, protecting the mineral clay in the soil, and having little impact on soil quality. The treated soil can be combined with lime and organic fertilizers for restoration and re-cultivation.

The polluted land area after renovation is used by people to grow vegetables.

According to the national environmental report for the period 2016-2020 of the General Department of Environment (now the Department of Environment), the soil environment in some areas around craft villages and industrial parks in our country is at high risk of heavy metal pollution. Some monitored areas such as Phu Ta Industrial Park (Binh Dinh), Lien Chieu Industrial Park (Da Nang), some communes of Lam Thao District (old) of Phu Tho Province, District 12 Industrial Park of Ho Chi Minh City, Dai Dang Industrial Park of Binh Duong (old) all have heavy metal content exceeding the permissible threshold.

Therefore, the results of the project are of great significance. The technology of treating heavy metals in soil with iron sulfate solution can be replicated in other areas that are also suffering from heavy metal pollution, especially in craft villages, landfills or old industrial zones.

WISDOM

Source: https://baotuyenquang.com.vn/xa-hoi/202509/giai-phap-cai-tao-hoi-phuc-nhung-vung-dat-chet-e534002/