Study on Pollution Countermeasures of Microplastics of Sewage

Plant in China

Xueqin Wang

Institute of Intelligent Manufacturing Engineering, Chongqing College of Architecture and Technology,

Chongqing, 400044, China

Keywords: Microplastic Pollution, Sewage Plant, Microplastic Pollution Control.

Abstract: Microplastics refers to plastic particles with a diameter of less than 5mm. Due to their characteristics of

large dosage, small particle size, easy to absorb pollutants, large surface area, weak hydrolysis capacity,

difficult degradation, easy transmission in the food chain, microplastics has become a persistent organic

pollutant that poses a major threat to human health and ecosystem. Although the existing sewage treatment

plants in China have a relatively high removal rate of microplastics, they just simply transfers microplastics

from sewage to sludge, and do not really degrade microplastics. So the sewage plant is an important source

of microplastics into the environment. Based on the summary of the microplastics pollution and treatment of

the sewage plant, this paper proposes the targeted countermeasures for the pollution control of microplastics

and the depth treatment of microplastics in the sewage plant. It provides the basis for the pollution control

and the depth treatment of microplastics in sewage plants.

1 INTRODUCTION

Microplastics are plastic particles less than 5mm in

diameter through various ways into the ecological

environment. (

Eerkes-Medrano, 2015; Reecm,

2014)

Studies has shown that microplastics are

widely found in water ecosystems, soils and

sediments and even in drinking water, human feces

and polar environments. Microplastics have the

characteristics of large dosage, small particle size,

large specific surface area, easy to adsorbed

pollutants, weak photolysis capacity, difficult

degradation, and are a potential persistent organic

pollutant. Moreover, microplastics are easily eaten

by organisms of different nutritional levels in the

environment, so that they are transmitted and

enriched in the food chain. Microplastics enter into

the body primarily through the respiratory tract,

digestive tract and skin, and are toxic to the

corresponding tissues and organs through particle

internalization or migration. Microplastics through

physical damage, causing intestinal flora imbalance,

change enzyme activity, activation of immune cells,

cause oxidative stress and interference with

endogenous hormones on the body's digestive,

nerve, respiratory, immune, reproductive endocrine

system toxic effects, and even may even lead to

genetic lesions, cancer and other acute and chronic

diseases. Therefore, microplastics have more serious

impact on human health and ecosystem than large

plastics. (

Barnes, 2009)

It is a widely distributed,

environmental toxicity and biotoxic pollutant.

2 CURRENT STATUS OF

MICROPLASTIC POLLUTION

AND TREATMENT IN

SEWAGE PLANT

2.1 Current Pollution Status of

Microplastics in The Sewage Plant

The microplastics detected in sewage treatment

plants in different regions and cities in China show

different types and rules, but the main components

of the microplastics are polyester, polystyrene,

polypropylene, polypolyethylene, polyamide,

polyester, etc., and the shape composition is mainly

fiber, rod, film, thin sheet and other. (Long, 2019)

Li et al. studied 28 sewage treatment plants in

China, and found that the content of sludge

276

Wang, X.

Study on Pollution Countermeasures of Microplastics of Sewage Plant in China.

DOI: 10.5220/0011734700003607

In Proceedings of the 1st International Conference on Public Management, Digital Economy and Internet Technology (ICPDI 2022), pages 276-279

ISBN: 978-989-758-620-0

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

microplastics was 1.6 × 10

-56.4 × 10

/ (kg dry

sludge), and the average content of microplastics

was 22.7 × 10

/ (kg dry sludge). (Li, 2018)

In terms of source, the microplastics in the

sewage plants mainly include primary microplastics

and secondary microplastics. The primary

microplastics in urban sewage mainly come from

personal hygiene washing products (such as facial

washing milk, shower gel and other products),

chemical fiber clothing, car tires, etc. The

Secondary microplastics are plastics used in

production and human life and released into the

environment or are produced by continuous

decomposition and crushing during sewage

treatment. The world produces more than 3 00

million tons of plastic every year, and China's

plastics production exceeded 75 million tons in

2017. (

China Plastic Processing Industry

Association, 2018)

Due to the low reuse rate of

plastic products, the production of plastic waste

increases rapidly. This also leads to the increasing

amount of secondary microplastics in the

environment.

2.2 Current Treatment of

Microplastics in Sewage Plant

First, the relevant regulations and control standards

of microplastics are not in place. Up to now, China

has issued the Notice on The Restricted Production

and Sale of The Use of Plastic Shopping Bags,

Regulations on the Prevention and Control of

Pollution in the Processing and Utilization of Waste

Plastics, Implementation Plan for banning the Entry

of Foreign Waste and Promoting the Reform of the

Solid Waste Import Management System and

Express Packaging Supplies and other regulations

and standards. This provides some guarantee for the

management, recycling and disposal of waste

plastics, but the relevant regulations and standards

of microplastics are still very lacking, resulting in a

large number of primary microplastics and

secondary microplastics to eventually enter the

sewage plant.

Secondly, the whole process management of

microplastics is not in place. In the production

process of some products, the unlimited addition of

plastic micro beads leads to the large use and

discharge of microplastics at the source.

Microplastics are not properly treated in trade, use,

recycling and disposal, and some microplastics are

released into the environment and eventually

entered into the sewage plant. For example, in 2017,

the General Office of the State Council issued the

Implementation Plan for Banning the Entry of

Foreign Waste into the Reform and Promoting the

Import of Solid Waste. According to the plan, China

before the end of 2017 banned the import of waste

plastics from domestic sources. (Kou, 2018;

Xinhua

News Agency, 2018)

This will play a positive role

in controlling the plastic waste pollution in China,

and will also help the world strengthen the treatment

and recycling of plastic waste and reduce plastic

waste production; (

Verena, 2018)

but the cross-

border transfer of plastic waste can not be fully

controlled.

Finally, the existing sewage plants in China do

not have a special microplastics treatment

technology. Although the sewage treatment process

has a high removal effect on microplastics, reaching

more than 90%, which is of great significance for

reducing the discharge of microplastics into natural

water bodies with water discharge. However, due to

the large amount of domestic sewage discharge, a

large number of microplastics are still discharged

into the water through the sewage treatment plant.

Sewage plant is an important source of microplastics

into the environment. (

Ziajahromi, 2016)

At the

same time, the existing sewage plants remove

microplastics by settlement, adsorption, trap,

interception, etc. These removal methods only make

microplastics simply transfer from wastewater to

sludge, (

Nizzetto, 2016)

making the sludge of the

municipal sewage plant enrich about 90%-98% of

microplastics. (

Fendall, 2009)

If the microplastics

in sewage plants and sludge are not treated in depth,

it will lead to microplastics to enter the environment

again, causing secondary pollution of microplastics.

3 POLLUTION

COUNTERMEASURES OF

MICROPLASTICS IN THE

SEWAGE PLANT

3.1 Source Control to Reduce

Microplastic Emissions

Like many other pollutants, once formed, its

treatment difficulty and disposal cost will improve,

and the treatment efficiency will also be limited by

the technology. Therefore, we can formulate

industry standards through the relevant departments,

so as to greatly reduce the use and emissions of

microplastics. For example, the implementation of

more dense filter for the drainage of washing

machines, use plastic substitutes and other methods

Study on Pollution Countermeasures of Microplastics of Sewage Plant in China

277

as far as possible to gradually reduce the use of

plastic daily necessities, gradually control the total

amount of micro plastics into the environment,

Expanding public participation and promoting the

public to consciously reduce the use of plastic

materials and microplastics. This is also the current

source control method for some European and

American countries to reduce plastic pollution.

It is also very important to raise the whole social

awareness of the pollution hazards of microplastics

to consciously reduce the use of plastic materials

and microplastics. At present, China's attention to

micro plastic pollution and its ecological effects is

still limited to the scientific research level, and the

public has little or not realize the possible ecological

harm caused by microplastics. Therefore, various

forms of environmental science popularization and

publicity and education activities should be widely

carried out in schools, public places, enterprises and

institutions and government departments, improve

public awareness, further enhance the green lifestyle

of people use plastic as little as possible, improve

the recycling rate of plastic garbage, and form an

atmosphere to reduce the use of native micro

plastics in the whole society.

3.2 Developing Treatment Techniques

of Sewage and Sludge for

Microplastics

First, strengthen the research on the water

environment microplastics, to understand the

migration and transformation mechanism. New

environmental materials for treating microplastics

are studied to achieve the removal of microplastics

in each water environment. Study new adsorption,

filtration and other materials to reduce the amount

of entry into the sewage treatment plant.

Secondly, develop a sewage treatment

technology for microplastics. At present, China's

sewage treatment plants have not specialized

pollution treatment technology for microplastics,

the microplastic removal rate of ordinary sewage

plants is not high enough, and the existing sewage

treatment process is simply to transfer microplastic

to sludge, and there is no real degradation of

microplastics. Specialized removal microplastic

technology suitable for China's national conditions

and water quality still needs to be further studied

and developed to reduce the concentration of

microplastics in the Reduce the concentration of

microplastics in the effluent of plant.

Finally, a sludge treatment process for

microplastics is developed. The microplastics in the

sewage will eventually go to the sludge. Sludge

treatment technology of biodegradable microplastics

will need to be developed to avoid improper

disposal of sludge leading to microplastics again

entering the environment.

3.3 Improving The Relevant Laws and

Standards for The Prevention and

Control of Microplastic Pollution

The existing laws and regulations and standards in

microplastics control cannot meet the requirements

of microplastics pollution control. On the basis of

the existing laws and regulations, we should

establish and improve the laws and regulations as

soon as possible, and strengthen the enforceability

and timeliness of the laws and regulations and

relevant standards.

First, formulate and improve laws, regulations

and standards for the prevention and control of

primary microplastics, and formulate laws,

regulations and standards related to the production,

import and use of washing and protective products

containing microplastics. Secondly, improve the

laws and regulations on the prevention and control

of plastic waste pollution, and formulate regulations

and standards on the recycling and treatment of

plastic waste. Clarify the responsibilities of all

government departments in the production, use,

recycling and treatment of plastics, and avoid

secondary microplastics into the environment.

Finally, the pollution discharge standards of

industrial sewage and microplastics in the sewage

treatment plants should be formulated, and the

detailed rules for illegal acts and corresponding

economic and administrative punishment measures

should be clearly stipulated to control the discharge

of microplastics to cause secondary pollution to the

environment.

3.4 Strengthen The Whole Process

Management of Microplastic

Pollution

The prevention and control of microplastic pollution

is a whole process of supervision process. We need

to control microplastic pollution from the whole

process of production, trade, use, recycling and

disposal.

In the process of production, on the one hand,

we should reduce the use of plastic and plastic beads

as raw materials, vigorously support the research

and development of biodegradable plastics, and

encourage the use of environmentally friendly

ICPDI 2022 - International Conference on Public Management, Digital Economy and Internet Technology

278

materials instead of traditional plastics. Improve the

role of tax and other economic means to reduce the

production of microplastics. In international trade,

the cross-border transfer of plastic waste should be

controlled. At present, only the import of waste

plastic in domestic sources is prohibited in China. It

is recommended to increase the scope of the

prohibited import list and include waste plastic other

than domestic sources in the prohibited import list;

and the transfer of plastic waste from China should

also be prohibited to other countries. On the other

hand, the waste produced in the production process

is properly treated to avoid the microplastics from

entering the natural environment with the waste

water and waste residue. Prevent the leakage of

plastic and plastic waste during the transportation

process. During the sales process, the products sold

by the seller shall meet the relevant standards. In the

process of use, encourage the recycling of waste

plastics, promote the classification, recycling and

disposal of plastic waste, and gradually reduce the

landfill amount of plastic waste.

4 CONCLUSION

At present, due to the inadequate microplastics

related regulations and control standards, the lack of

whole-process management of microplastics

pollution, and the existing sewage plant has no

treatment process or technology specifically for

microplastics. So, the sewage plant becomes an

important discharge source of microplastics. To

effectively control the microplastics pollution and

the depth treatment of the microplastics, this paper

proposes four control countermeasures of

microplastics, including source control, reducing

microplastic discharge, developing sewage

treatment technology for microplastics, improving

relevant regulations and standards for microplastic

pollution prevention and control, and strengthening

the whole process management of microplastic

pollution.

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