001.docx
CHEMICAL ENGINEERING TRANSACTIONS
VOL. 83, 2021
A publication of
The Italian Association
of Chemical Engineering
Online at www.cetjournal.it
Guest Editors: Jeng Shiun Lim, Nor Alafiza Yunus, Jiří Jaromír Klemeš
Copyright © 2021, AIDIC Servizi S.r.l.
ISBN 978-88-95608-81-5; ISSN 2283-9216
The Influences of Internal Recycling Competencies and
External Environmental Conditions on Urban Residents'
Waste Classification and Recycling Behaviours: Based on the
Mediating Effects of Classification and Recycling Intentions
Xin Jina,*, Haoxin Guana, Jie Wangb, Jungang Shaoa, Songtao Wangc
aSchool of Economics & Management, Shanghai Maritime University, Shanghai 201306, China
bDepartment of Civil & Environmental Engineering, Center for Sustainable Development and Global Competitiveness,
Stanford University, Stanford, CA 94305-4020, USA
cSchool of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
jinxin@shmtu.edu.cn
Waste classification and recycling behaviours of urban residents are important for waste recovery, reduction,
and decontamination. Because residents’ waste classification and recycling behaviours are influenced by
several factors, this study developed a new waste classification and recycling influencing factor model. Based
on 424 questionnaires collected from Shanghai residents, the influences of internal recycling competencies
(i.e., waste classification skills and habits) and external environmental conditions (i.e., classification facilities
and systems, reward and penalty measures for classification, and failure to safeguard classification
achievements) on residents’ classification and recycling behaviours were empirically tested. It was found that
residents’ classification and recycling skills and habits as well as government reward and penalty measures
for classification had a significant positive effect on the residents’ classification and recycling
behaviours(0.159,p<0.01;0.241, p<0.01 and 0.141, p<0.01), and the failure to safeguard classification
achievements had a significant negative influence on their classification and recycling behaviours(-0.106,
p<0.05). Residents’ classification and recycling intentions were found to have a partial mediating effect on the
relationship between waste classification skills and classification and recycling behaviours(0.572, p<0.01); and
a complete mediating effect on that between reward and penalty measures for classification and classification
and recycling behaviours(0.577, p<0.01). This research contributes to previous research by offeringa new
waste classification and recycling influencing factor model with a new and comprehensive empirical research
result.
1. Introduction
While China’s rapid economic and social development has significantly raised living standards, it has also
resulted in a commensurate rise in urban household waste for consecutive years. The huge amount of waste
has exerted tremendous pressure on social environments(Pham Phu et al., 2020). Recent data indicate that
the proportion of wet waste in household food waste is over 50 %.Such waste turns into organic fertilizer after
fermentation, so if such a resource can be reused, it would reduce soil and underground water pollution and
add greatly to social wealth(Zou et al., 2019). Waste classification is closely linked to whether waste
decontamination, reduction, and recovery can be achieved (Sabki et al., 2019).
Research on the source separation of waste has gradually extended from the technical dimension to the
personal psychological dimension, with the aim of finding the inherent law to guide residents to actively
participate in household waste management activities. Most of the related studies conduct from the
perspective of either individual socioeconomic variables or external stakeholders. For example, Botetzagias et
al. (2015) found that gender, age, and education level significantly affect residents’ waste classification and
recycling intentions and that income has no influence on such intentions; Wang and Yang (2013) found that
DOI: 10.3303/CET2183066
Paper Received: 28/05/2020; Revised: 25/06/2020; Accepted: 30/06/2020
Please cite this article as: Jin X., Guan H., Wang J., Shao J., Wang S., 2021, The Influences of Internal Recycling Competencies and External
Environmental Conditions on Urban Residents' Waste Classification and Recycling Behaviours: Based on the Mediating Effects of Classification
and Recycling Intentions, Chemical Engineering Transactions, 83, 391-396 DOI:10.3303/CET2183066
391
environmental protection behaviours are by no means simply individual behaviours, but are also influenced by
surrounding stakeholders and the classification and recycling atmosphere in communities.
Research on the classification and recycling of residential waste has achieved certain results, but the research
on the influencing factors in waste classification still has the following inadequacies: (1)Past studies examine
the direct influencing factors of waste classification and recycling behaviours from a single dimension and lack
an examination of both internal recycling competencies and external environmental conditions dimensions.
(2)Most studies have failed to consider the path through which internal and external factors act on waste
classification and recycling behaviour by affecting residents’ waste classification and recycling intentions.
(3)Regarding the measurement of samples, as most studies measured variables using a single item, there
could easily be bias in the results. The following questions arise: what then are the internal and external
factors affecting residents’ waste classification and recycling behaviour?; which factors exert influence on
classification and recycling behaviours through affecting classification and recycling intentions? Based on
these questions, a new residents’ classification and recycling behaviour influencing factor model was
constructed to investigate how internal recycling competencies (i.e., waste classification skills and habit) and
external environmental conditions (i.e., classification facilities and systems, reward and penalty measures for
classification, and safeguarding classification achievements) exert an influence on classification and recycling
behaviours through affecting classification and recycling intentions.
2. Theoretical foundation and research hypotheses
2.1 Internal recycling competences and classification and recycling behaviour
Waste classification skills refer to the ability to identify common household waste and waste classification bins.
In general, people are unwilling to accept demands that are more difficult. If they can accurately identify
common household waste, waste classification becomes relatively simple, and they will be more inclined to
classify waste. This paper puts forward the following hypothesis:
H1a: Residents’ waste classification skills have a significant positive effect on their classification and recycling
behaviours.
With more serious levels of environmental pollution and waste classification pilot sites in place, knowledge of
waste classification and recycling has gradually spread among residents, resulting in a wider spread of waste
classification habits. Once a habit is formed, it has a lasting effect. The cultivation of waste classification habits
among residents will have a lasting influence on their own waste classification and recycling behaviours. The
following hypothesis proposes:
H1b: Residents’ waste classification habits have a significant positive effect on their classification and
recycling behaviours.
2.2 External environmental conditions and classification and recycling behaviours
Waste classification facilities are the foundation that allows residents to begin their classification and recycling
activities. The number of facilities and how easily the classification signs can be comprehended affect
residents’ waste classification and recycling intentions and behaviours. Bolderdijk et al. (2018)held that the
implementation of government-led environmental policies and systems is an important force in commencing
effective waste classification in cities. This leads to the following hypothesis:
H2a: Perfect waste classification facilities and systems have a significant positive effect on residents’
classification and recycling behaviours.
Waste classification and recycling activities will provide extra time and space costs. Economic and emotional
rewards will increase residents’ enthusiasm for participating in waste classification and recycling. Levying
extra fees on those who do not classify waste or recycle properly will have positive effects on residents’
classification and recycling behaviours. This paper proposes the following hypotheses:
H2b: Necessary reward and penalty measures for residents’ waste classification have a significant positive
effect on their classification and recycling behaviours.
The classification achievements that residents become aware of are derived primarily from the classification
and recycling behaviours of groups of neighbours and the waste-disposal behaviour of environmental
sanitation workers after they collect waste. The negative classification and recycling behaviours among
neighbours has unfavourable effects on residents’ classification and recycling. Otherwise, environmental
sanitation organizations mixing classified waste and transporting it will hurt the classification enthusiasm of
residents inclined to classify waste and recycle. The hypothesis puts forward:
H2c: Failure to safeguard residents’ waste classification achievements has a significant negative effect on
their classification and recycling behaviours.
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2.3 Mediating effects of classification and recycling intentions
The theory of planned behaviour states that personal attitudes, subjective norms, and perceived behavioural
control affect the behavioural intentions of individuals, whose ultimate behaviours are shaped through
influencing their behavioural intentions. Residents with greater internal recycling competencies, driven by their
classification and recycling intentions, engage more in classification and recycling. In light of the above, this
paper proposes the following hypotheses:
H3a: Classification and recycling intentions mediate the effects of waste classification skills on classification
and recycling behaviours.
H3b: Classification and recycling intentions mediate the effects of waste classification habit on classification
and recycling behaviours.
Whether residents adopt a certain behaviour depends on the strength of social pressure they feel in relation to
it. With the increasing level of damage to the environment, now the government calls for waste classification,
and residents gradually understand their individual classification and recycling habits can have a major impact,
encouraging them to engage more actively in waste classification and recycling. Classification and recycling
intentions play a bridging role in the relationship between the external environmental conditions and residents’
waste classification and recycling behaviours. This paper proposes the following hypothesis:
H3c: Classification and recycling intentions mediate the effects of classification facilities and system on
classification and recycling behaviours.
H3d: Classification and recycling intentions mediate the effects of reward and penalty measures on
classification and recycling behaviours.
H3e:Classification and recycling intentions mediate the effects of failure to safeguard classification
achievements on classification and recycling behaviours.
Figure 1: A conceptual model and research hypothesis
3. Research samples and measurement of variables
This study used a questionnaire survey to collect data through both online and offline means. The subjects
were Shanghai residents and the period lasted from March to May 2019. 424 valid ones were collected at last.
3.1 Measurement of variables
Independent Variables: The measurement scale for internal recycling competencies was derived primarily
from survey questions developed by Pakpour et al. (2014) and constructed a scale consisting of five survey
questions, with answers on a 5-point Likert scale. The five questions were about the residents’ degree of
knowledge of waste classification, ability to identify waste bins, time availability, waste classification habit, and
possession of classification tools. The measurement scale for the dimension of external environmental
conditions relied mainly on the question items developed by Chung and Poon (1999).A scale with seven
survey question items was formed, using a 7-point Likert scale. The selection of a 7-point scale was intended
to reduce common method biases in the questionnaires. The seven survey question items covered the
reasonableness of the number of waste bins available, installation of waste classification bins, implementation
Waste Classification
Skills
Waste Classification
Habits
Classification Facilities and
Systems
Reward and Penalty
Measures for Classification
Failure to Safeguard
Classification Achievements
Classification and
Recycling Intentions
Classification and
Recycling Behaviors
Internal Recycling Competences
External Environmental Conditions
H1a/H1b
H2a/H2b/H2c
H3a
H3b
H3c
H3d
H3e
393
of the classification system, penalty measures, implementation of rewards, neighbors’ classification situation,
and the backend classification process.
Mediating and Dependent Variables: The mediating variable was classification and recycling intentions. The
scale items developed by Tonglet et al. (2004), which contained two items: residents’ intention to accept the
waste classification system and their intention to participate actively in waste classification. The dependent
variable was classification and recycling behaviours, which developed by Ghani et al. (2013). For this variable,
respondents indicated their subjective ratings on the item “I can usually do waste classification”; in addition, a
reverse item, “I rarely perform waste classification” was included to identify and exclude invalid
questionnaires.5-point Likert scales were used for these variables.
Control Variables: The control variables included the respondents’ gender, age, education level, nature of their
residence (i.e., owned or rented) and personal monthly income.
3.2 Reliability and validity testsand test for common method biases
The overall alpha coefficient of the scale was 0.830. The removed alpha value of any indicator was lower than
the overall alpha value (0.830), which means that all indicators must be preserved. The scale had good
internal consistency and relatively good overall reliability. The correlation coefficient between waste
classification skills and habits was 0.529, smaller than the internal consistency of these two variables
measurements (0.762, 0.731) , which is an indicator of good validity; the correlation coefficient between the
three variables of classification facilities and system, reward and penalty measures for classification, and
failure to safeguard classification achievements (-0.362, 0.480, -0.364) was far smaller than the internal
consistency coefficient for each variable (0.788, 0.727, 0.723), also indicating validity.
The eigenvalue of the common factor with the greatest explanatory power was 4.142, which explained 34.516
% of the total variance. The problem of common factor biases were relatively small and could be ignored.
4. Empirical analysis
The correlation coefficient for each variable was smaller than 0.6, so the problem of multicollinearity did not
exist. Control variables, which are not the focus of this research, are omitted in the following data analysis.
The regression results are provided in Table 1. Residents’ waste classification skills had a significant positive
effect on such behaviours (α = 0.159; p < 0.01) and H1a is valid. Waste classification habits had a significant
positive effect on such behaviours(α = 0.241; p < 0.01), and H1b was confirmed. Classification facilities and
systems had no significant effect on such behaviours, so H2a was not confirmed. Reward and penalty
measures for classification had a significant positive effect on such behaviours (α = 0.141; p < 0.01), so H2b is
valid. H2c was confirmed because failure to safeguard classification achievements had a significant negative
effect on classification and recycling behaviours (α = -0.106; p < 0.05).
Table 1: Effects of internal and external factors on classification and recycling behaviours
Variables Classification and recycling behaviours
Internal Recycling
Competences
Waste classification skills 0.159***
Waste classification habits 0.241***
External Environmental
Conditions
Classification facilities and systems 0.018
Reward and penalty measures for
classification
0.141***
Failure to safeguard classification
achievements
-0.106**
R2 0.195
Adjusted R2 0.145
F value 3.867***
Notes: * p<0.1; ** p<0.05; *** p<0.01.
To test the mediating effect of classification and recycling intentions between internal recycling competencies
and classification and recycling behaviours, this research performed a test based on Baron and Kenny (1986)
criteria. First, Table 1 shows that waste classification skills and habits were significantly positively correlated
with classification and recycling behaviours, satisfying the first condition of the mediator test. Second, a test
was performed on the significant correlation between the independent variables and the mediating variable. A
regression analysis was conducted on the relationship between waste classification skills and habits and
classification and recycling intentions; the results are shown in Table 2. Waste classification skills and such
intentions were significantly positively correlated (α = 0.077; p < 0.05), meeting the conditions of the mediator
394
test. The relationship between waste classification habit and such intentions was not significant, and so the
test for a mediating effect was ended at this point; classification and recycling intentions had no mediating
effect between waste classification habit and such behaviours, and so H3b could not be verified. Third, when
tested the simultaneous regression of the independent and mediating variables, the effect of the mediating
variable was significant. As Table 3 shows, after bringing in the mediating variable of classification and
recycling intentions, the effect of waste classification and recycling skills on such behaviours decreased from
0.101 (p < 0.05) to 0.067 (p < 0.1), and the significance of classification and recycling intentions was 0.572 (p
< 0.01), indicating that these intentions had a partial mediating effect between classification and recycling
skills and such behaviours. H3a was verified.
A similar research process performed to test the mediating effect of classification and recycling intentions
between external environmental conditions and classification and recycling behaviour. First, as indicated in
Table 1, the effect of classification facilities and systems, on such behaviours was not significant, which failed
to satisfy the first condition of mediating effect, and H3c was not confirmed. Both reward and penalty
measures for classification and safeguarding classification achievements were significantly correlated with
such behaviours. Second, a regression analysis was performed on the relationship between reward and
penalty measures for classification and safeguarding classification achievements and such intentions; the
results are shown in Table 2. The relationship between failure to safeguard classification achievements and
such intentions was not significant, so the test for a mediating effect was ended at this point. It concluded that
such intentions had no mediating effect between failure to safeguard classification achievements and such
behaviours, so H3e could not be verified. Reward and penalty measures for classification did have a
significant positive effect on such intentions (α = 0.103; p< 0.01). Third, as shown in Table 3, after bringing in
the mediating variable of such intentions, the effect of reward and penalty measures for classification on such
behaviours changed from 0.075 (p< 0.1) to insignificant, and the significance of such intention was 0.577 (p<
0.01), indicating that such intentions had a complete mediating effect between reward and penalty measures
for classification and such behaviours. H3d was verified.
Table 2: Effects of internal and external factors on waste classification and recycling intentions
Variables Classification and recycling intentions
Internal Recycling
Competences
Waste classification skills 0.077**
Waste classification habits 0.047
External Environmental
Conditions
Classification facilities and systems -0.036
Reward and penalty measures for
classification
0.103***
Failure to safeguard classification
achievements
0.042
R2 0.132
Adjusted R2 0.078
F value 2.422***
Notes: * p<0.1; ** p<0.05; *** p<0.01.
Table 3: Test of the mediating effect of waste classification and recycling intentions
Variables
Dependent
Variables
Dependent
Variables
Dependent
Variables
Dependent
Variables
Independent variables
Waste classification skills 0.101** 0.067*
Reward and penalty measures for
classification
0.075* 0.029
Mediating variable
Classification and recycling
intentions
0.572*** 0.577***
R2 0.129 0.277 0.124 0.272
Adjusted R2 0.084 0.237 0.078 0.232
F value 2.835*** 6.970*** 2.702*** 6.824***
Notes: * p<0.1; ** p<0.05; *** p<0.01.
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5. Conclusions
This study started from the perspectives of internal recycling competences and the external environmental
conditions that affect residents’ waste classification and made a comprehensive analysis of the mediating
effects of residents’ waste classification and recycling intentions between the factors influencing classification
and recycling and such behaviours. Research conclusions are as follows: (1) Waste classification skills and
habit have a significant positive effect on classification and recycling behaviours. (2) Government reward and
penalty measures for classification have a significant positive effect on such behaviours. Failure to safeguard
residents’ classification achievements has a significant negative effect on such behaviours. Classification
facilities and systems have no significant effect on such behaviours, which might be owing to the improved
waste classification facilities in Shanghai so that their breakthrough effect is not significant. (3) Residents’
waste classification and recycling intentions have a partial mediating effect on the relationship between their
waste classification skills and such behaviours; and their such intention has a complete mediating effect on
the relationship between reward and penalty measures for waste classification and such behaviours. Starting
in 2019, all Chinese cities at the prefectural level and above initiated waste classification work. In this context,
residents’ source separation of household waste is an important link that affects such work. Based on these
results, this paper makes several theoretical and management contributions.
This study is still inadequate regarding a few aspects, which can be improved through follow-up research.
First, in the future, the sampling district should be enlarged to increase the generalizability of the research
results. Second, further research can be conducted on the changes in the influencing factors in classification
and recycling behaviors in different stages of development.
Acknowledgments
This research isfinancially supported by Science and Technology Commission of Shanghai Municipality (No.
18230743000, 16ZR1417400) and National Natural Science Foundation Council of China (No. 21808141).
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