Introduction

The construction industry is one of the largest producers of air and water pollution by using clay bricks that are made in coal fired bricks. The brick kilns are found in the suburban areas of all major cities of South Asia. Often found in clusters, these brick kilns are poorly regulated that produces a number of toxic air pollutants affecting human health and agricultural production. A single brick kiln factory operates round the year and can produce up to 800,000 bricks monthly depending upon the demand. These brick kilns mostly use used engine oil, rubber tyres and other domestic wastes along with poor quality of coal. In Pakistan, more than 50% of the coal is used by brick kiln factories 1,2. Along with other air pollutants, it emits hydrogen fluoride (HF) that is toxic to plants ecosystem 2,3. The construction industry regularly strives for sustainable materials to lower the environmental pollution and enhanced the brick quality. This traditional brick making also affects the soil degradation, depletion and contributes to carbon emission by expediting climate change. The incorporation of agricultural by-products as additives in brick manufacturing has gained traction as a sustainable practice. For instance, using locally sourced agricultural residues in brick kilns reduced energy consumption and greenhouse gas emissions by up to 20%, promoting environmental sustainability and supporting the circular economy by creating economic opportunities in rural areas 4. These additives, such as sawdust, wood chips, and more recently, renewable by-products like rice husks and seed husks, combust during the firing process, releasing additional energy within the brick and reducing the energy demands of industrial furnaces 5. This shift towards eco-friendly materials aligns with stringent environmental regulations, driving demand for clay bricks with improved insulation properties and lower embodied energy. This transition to using eco-friendly materials for reprocessing and energy conservation marks a critical area of ongoing research in the brick and ceramic industries. Moreover, environmental regulations are driving the demand for clay bricks with improved insulation properties.

A promising candidate for such applications is Parthenium hysterophorus L., an invasive weed from the Asteraceae family, prevalent across Asia (including Bangladesh, India, Pakistan, Nepal, and others), Africa, Australia, and Pacific regions 6. Parthenium hysterophorus poses significant challenges as it causes severe human and animal health issues, leads to agricultural losses, and creates serious environmental problems 7. Surprisingly, its ability to persist in hot and arid regions in the southern districts indicates that it can thrive in even harsher conditions than previously-believed 8. Parthenium hysterophorus L. exhibits remarkable adaptability, capable of germinating and thriving year-round under warm temperatures and adequate rainfall 9. This weed boasts a rapid germination rate, surpassing many other weed species 10. Parthenium plant can achieve the height of around one meter that have well-developed leaves supported by a strong stem 11. The maize crops have been significantly affected (50% decrease) when Parthenium (20 plants/m2) is left unchecked in the same plot according to the study conducted bin Pakistan 12.

It also affects the sorghum grain production from 40 to 97% in Ethiopia, almost destroying the sorghum crop entirely with three plant/m2 can reduce the sorghum yield by 69% 9. The control of Parthenium weed can be controlled efficiently by employing its native predators, e.g. snails, fungi, slugs, nematodes and other competitive plants that are resistant 13. However, these methods are relatively expensive and time consuming. The study pioneers the use of Parthenium biomass as additives in clay bricks to achieve low density and increased porosity without compromising mechanical strength. Additionally, it sought to reduce energy consumption and provide policy recommendations for integrating weed biomass into brick production. To carry out a targeted survey for brick kiln owners to determine their awareness of the benefits of using Parthenium biomass and to identify barriers to adoption, which promote UN SDGs to foster green and circular economy principles. Notably, this was the very first study in Pakistan to explore the use of invasive Parthenium weed biomass, which lacks recycling mechanisms, for sustainable brick manufacturing.

Methodology

Several toxic air pollutants are emitted by brick kilns depending upon the clay and fuel type. These pollutants are particulate matter (PM), CO, SO2 and HF. Le et al., 14 reported that a brick kiln producing 800,000 bricks/batch capacity consuming 60 tonns of coal as a fuel can produce 5.9, 12.3 and 1.4 kg/1000 brick/batch of SO2, Co and PM, respectively (Table 1).

Table 1 Emissions of pollutants (SO2, CO and PM) from typical brick kiln 14.
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It was important to assess the concentration of fluoride in the clay soil of the samples as it is the second most phyto-toxic pollutant after ozone (O3). For this study, Parthenium plants were identified by Shahen Shah, an expert from the Department of Agronomy, University of Agriculture, Peshawar, with permission/license from the department. The identification was conducted by comparing the plants with reference specimens in the department’s plant library that is open to the public.10 samples were taken from the brick kiln field near Ring Road area of Peshawar city through provincial agriculture extension workers with the permission of Director Research, Agriculture Research Institute, Peshawar. The soil samples were also collected and analyzed for their total fluoride content from the same site by using alkali fusion method before and after firing in the furnace 15,16.

This study involved preparing clay bricks by incorporating varying percentages (5%, 10%, 15%, 20%, 30%, 40%, and 50% by weight) of coal and Parthenium biomass separately into the initial ingredients. The whole Parthenium plant was dried in the sun and were then cut into smaller pieces with the help of a chopper, which were then added to the clay bricks in the quantified proportions mentioned above. The brick samples were made by molding pressing and shaping with the help of stainless steel molds that gave out the dimensions of 20 mm × 15 mm × 10 mm in a rectangular shape. The shaping procedure was conducted on a small scale in the laboratory of The University of Agriculture, Peshawar that was based on industrial replication followed by drying and firing of the subjected samples. The newly formed bricks were kept under sunlight for drying up to 3 days and then were directly transferred to the furnace and subjected to sintering, by raising the temperature at 10 °C per minute until the temperature reaches 950 °C.

The samples were kept for 1 h at this temperature and were then left to cool down. The chemical composition of the samples was examined by a wavelength dispersive X-ray fluorescence (XRF) spectrometer (Bruker AXS GmbH-S4 Pioneer, Germany) at The University of Agriculture in Peshawar. The spectrometer included a high-power X-ray tube, which contained a rhodium anode and a 75 μm beryllium window that produced around 4 kW of power. Additionally, it was equipped with 8 diffracting crystals that allowed accurate analysis due to distinct d-spacings. The mechanical strength of the brick was analyzed using a 100–500 kN Universal Testing Machine (UTM) manufactured by Testometric Co. Ltd., UK. The thermal diffusivity (α) and conductivity (κ) of the samples were determined by a transient plane source (TPS) technique 17. The measurements were made with the help of a calibrated Pt-100 thermometer.

The water absorption, apparent porosity, and mechanical strength were measured to determine the quality of the coal and Parthenium biomass additives bricks compared to the ordinary clay bricks. Archimedes method was used for the water absorption and apparent porosity of the samples 18. The samples were first dried at a 105 °C temperature until a stable weight was obtained. After measuring the dried samples (W1) they were subsequently boiled in water for 5 h, and then were cooled weighed while submerged in water (W2). Finally, the samples were weighed again in the saturated wet state in the air (W3). The apparent porosity and water absorption of the samples were calculated using Eqs. (1) and (2):

$$\% {\text{Apparent porosity }} = {\text{ W}}_{{3}} - {\text{W}}_{{1}} /{\text{ W}}_{{3}} - {\text{W}}_{{2}} \times {1}00$$
(1)
$$\% {\text{Water absorption }} = {\text{ W}}_{{3}} - {\text{W}}_{{1}} /{\text{ W}}_{{1}} \times {1}00$$
(2)

A conversation with around 50 brick kiln owners took place in the vicinity of Peshawar ring road area, where most of the brick kiln fields are operating to assess their awareness of the financial benefits of using Parthenium biomass as brick clay additive and to the environment in general, and to identify barriers to adoption. The following questions were asked from the owners of the brick kiln during the conversation;

  1. 1.

    How much are you aware of the environmental pollution from brick kilns using current methods of brick making?

  2. 2.

    Are you familiar of using Parthenium biomass as a clay brick additive in brick production?

  3. 3.

    How much reluctant you are about the benefits or drawbacks of using Parthenium biomass additive into your brick production process?

  4. 4.

    Can Parthenium biomass as an additive will improve the quality and sustainability of your products?

  5. 5.

    What aspects of producing bricks using Parthenium biomass would you consider important that can influence your decision?

  6. 6.

    What kind of support you would need in terms of technical, financial, informational to adopt this new method?

  7. 7.

    How will the market react to brick made from Parthenium biomass in terms of possible acceptance?

  8. 8.

    By adopting this method, do you think it will lower the cost of production?

Results and discussions

Total fluoride content of the soil

The total fluoride content in the pre-fired brick samples ranged from 180 to 241 µg/kg, which reduced to 75 to 106 µg/kg after firing at temperatures above 900 °C. The soil samples used for brick manufacturing revealed that over 70% of the total fluoride was emitted during the firing process, as illustrated in Fig. 1.

Fig. 1
figure 1

Total Fluoride content of soil before and after firing of brick. Standard errors are the mean of 10 samples.

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The natural fluoride content of soil varies between 500 and 1000 µg/g, depending on the clay raw material and more than 50% of the fluoride is released when the temperature inside the kiln exceeds 900 °C 19. In this study, the fluoride content in the soil used for brick manufacturing was notably lower. However, the continuous operation of brick kilns has been associated with fluoride damage to vegetation 2,20. They assessed the effects of air pollutants emitted from brick kilns, reporting a hydrogen fluoride (HF) concentration of 0.3 µg/m3 (Fig. 2), which, while low, is still significantly high enough to affect vegetation in Peshawar, particularly local fruit orchards and crops (Fig. 3).

Fig. 2
figure 2

The air concentration of hydrogen fluoride (HF) measured at the ARI and BKF sites was reported by Ahmad et al. 2. The findings indicated HF levels were below the detection limit of 0.1 mg/m3, denoted as ‘bdl’ (below detection limit). This data highlights the effectiveness of measures implemented to control HF emissions in these areas during the specified period.

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Fig. 3
figure 3

Typical fluoride foliar injury seen in the selected area: (a) Necrosis in form of severe injury to leaf margins and tip burn to apricot at brick kilns kiln site; (b), (c) lower apricot foliar injury at control sites; (d) Shrinkage of plum fruit prematurely at brick kiln site 2.

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Chemical composition of coal and Parthenuim biomass

The primary raw materials used in the brick industry, notably clay and coal, comprise silica, alumina, calcium oxide, and iron oxide. The specific composition of these materials in this study is detailed in Table 2. Oxides such as Fe2O3, CaO, K2O, and Na2O serve as effective fluxes, enhancing the desirable properties of fired bricks.

Table 2 Shows the chemical composition (% weight) of locally available clays and coal used in the present study.
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Clay is classified as calcareous if it contains over 6 wt.% CaO. Additionally, if the combined content of K2O, Fe2O3, CaO, MgO, and TiO2 exceeds 9 wt.%, the clay is considered low refractory. In contrast, if the total concentration of these oxides is below 9 wt.%, the clay is deemed highly refractory. Based on these criteria, the raw materials typically used in the brick industry are categorized as calcareous with low refractory properties. Parthenium biomass, utilized as a pore-forming additive or insulation material in brick manufacturing, contains cellulose fiber, enhancing its suitability for these purposes. The chemical composition of Parthenium biomass is outlined in Table 3.

Table 3 Chemical compositions (% weight) of biomass material (Parthenuim weed).
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Water absorption

The water absorption of plain clay bricks typically ranges from 8 to 21%, primarily due to minor variations in raw materials and production methods 21. However, for high-quality bricks, the water absorption should not exceed 20% of their dry weight after being submerged in water for 24 h 22. In this study, the water absorption of clay bricks with additives, fired at 1000 °C, varied from 10 to 35% with coal addition and 11–36% with Parthenium biomass addition, as depicted in Fig. 4. It was observed that the additions of more than 15% led to water absorption levels surpassing the threshold limit of 20%. The water absorption of bricks is directly linked to their apparent porosity, which is crucial for preventing water intrusion by ensuring a dense internal structure. To enhance density and reduce water absorption, the firing temperature must be increased. Consequently, the porosity in fired specimens was a result of the combustion of additives during firing.

Fig. 4
figure 4

Effect of additives on the water absorption of the samples.

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Apparent porosity

Porosity refers to the ratio of the volume of voids or pores in a porous solid to its total volume. The material’s properties are affected by various factors, including its mineral composition, internal structure, and geometric arrangement. The firing of these clay bricks products produces a liquid phase above 900 °C temperature, which results in removing the empty spaces and pores by filling the spaces between and within the additives. Based on the amount of coal and Parthenium biomass additives used in the clay bricks, the porosity varied significantly. The porosity of the fired test bricks was mainly analyzed by the quantity of the additive that underwent combustion during the firing of the bricks, which resulted in the observed empty spaces. However, these voids and empty spaces may contain air but also works as an insulator that reduces thermal conductivity as the amount of coal and Parthenium biomass increases. The highest porosity was 64% with 50% Parthenium biomass addition, while the lowest porosity was approximately 12% with 5% coal addition as shown in Fig. 5. The elevated porosity and water absorption contributed to higher thermal resistance 23.

Fig. 5
figure 5

Variation of % porosity with the additives.

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Mechanical strength

The results of this study showed that the strength of the test specimens was influenced by the quantity of additives. Specifically, the compressive strength of the test specimens fired at 1000 °C decreased as the amount of coal and wheat husk increased. The compressive strength decreased from 25 to 11 MPa with an increase in coal content from 5 to 50 wt.%, and from 24 to 10 MPa with an increase in Parthenium biomass content from 5 to 50 wt.% as shown in Fig. 6. It is generally observed that in clay-based ceramic systems, strength tends to decrease as porosity increases.

Fig. 6
figure 6

Variation in mechanical strength with the additives.

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The aim of the study was to obtain a highly porous brick with low density and cost effective. Excessive addition of additives to brick clay is discouraged due to its negative impact on the physical properties of the sintered bricks. This is primarily because the poor contact among different ingredients within the brick body hampers their mutual reaction, leading to undesirable outcomes. It’s crucial to control the quantity of additives to prevent adverse effects. Typically, locally made clay bricks without additives exhibit an average compressive strength of around 25 MPa. The densification characteristics of some samples aligned well with the standards set by the British Standard Institution for good quality bricks, which specify a compressive strength of 15 MPa 24. The current study revealed that by increasing the percentage of either coal and Parthenium biomass material in brick can also hinder its porosity and mechanical strength that is imperative for a quality brick making. However, the additives of up to around 20% coal and Parthenium biomass will give the mechanical strength that will not exceed from 20 MPa, which is well under the permissible limit of 25 MPa for a good brick quality. Hence, we can add around 15–20% of coal and Parthenium biomass in brick making. The average weight of a single brick is around 3–3.5 kg in South Asia, which means that around 200–600gm of Parthenium biomass material can be added in a single brick making. The brick specimen are shown in Fig. 7.

Fig. 7
figure 7

The brick specimen having different % of Parthenium biomass are shown in each picture.

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Conversation with brick kiln owners

The conversation with brick kiln owners is presented here in verbatim for authenticity in local Urdu language with English translation.

Question 1: How much are you aware of the environmental pollution from brick kilns using current methods of brick making?

آپ موجودہ طریقوں سے اینٹیں بنانے والے بھٹوں سے ہونے والی ماحولیاتی آلودگی سے کس حد تک واقف ہیں؟

Answer:

ہم اس بات سے بخوبی واقف ہیں کہ اینٹوں کے زیادہ تر بھٹے اپنے موجودہ نظام کی وجہ سے ماحولیاتی” ”آلودگی میں نمایاں کردار ادا کر رہے ہیں.

(We are fully aware that most brick kilns contribute significantly to environmental pollution due to their current operating systems).

Question 2: Are you familiar of using Parthenium biomass as a clay brick additive in brick production?

کیا آپ اینٹوں کی تیاری میں مٹی کی اینٹوں میں پارٹینیم (Parthenium) بائیوماس کو بطور اضافی جزو استعمال کرنے سے واقف ہیں؟

Answer: “ہم اینٹوں کے بھٹوں میں زرعی فضلے کے کسی بھی اضافی جزو، بشمول پارٹینیم بائیوماس کے استعمال سے بالکل ناواقف ہیں۔".

(We are unaware of any agricultural waste additives, including Parthenium biomass, used in brick kiln production at all).

Question 3: How much reluctant you are about the benefits or drawbacks of using Parthenium biomass additive into your brick production process?

آپ اپنی اینٹوں کی تیاری کے عمل میں پارتھینیم بائیوماس کو بطور اضافی جزو استعمال کرنے کے فوائد یا نقصانات کے بارے میں کتنے ہچکچاتے ہیں؟

Answer: “ہم اینٹوں کی تیاری کے لیے پارتھینیم بائیوماس کے اضافی اجزاء کے استعمال میں اعتماد کی کمی محسوس کرتے ہیں، کیونکہ ہمیں اپنے کاروبار کے لیے اس کے ممکنہ فوائد کے بارے میں غیر یقینی ہے۔".

(We lack confidence in using Parthenium biomass additives for brick production, as we are uncertain about its potential benefits for our business).

Question 4: Can Parthenium biomass as an additive will improve the quality and sustainability of your products?

کیا پارتھینیم بائیوماس بطور اضافی جزو آپ کی مصنوعات کے معیار اور پائیداری کو بہتر بنا سکتا ہے؟

Answer: “میں فی الحال اس طریقہ کار سے ناواقف ہوں، لیکن اگر یہ ہمارے کاروبار کے لیے فائدہ مند ثابت ہوا تو میں اسے نافذ کرنے پر غور کروں گا۔".

(I am currently unaware of this method, but if it proves beneficial for our business, i will consider implementing it).

Question 5: What aspects of producing bricks using Parthenium biomass would you consider important that can influence your decision?

پارتھینیم بائیوماس کا استعمال کرتے ہوئے اینٹیں بنانے کے کونسے پہلو آپ اہم سمجھیں گے جو آپ کے فیصلے پر اثر انداز ہو سکتے ہیں؟

Answer: “اگر یہ طریقہ اینٹوں کی پیداواری لاگت کو کم کر سکتا ہے تو مجھے اس میں گہری دلچسپی ہوگی؛ میں اسے تب ہی اپناؤں گا۔".

(I will be highly interested if this method can reduce the cost of brick production; only then will I adopt it).

Question 6: What kind of support you would need in terms of technical, financial, informational to adopt this new method?

اس نئے طریقہ کار کو اپنانے کے لیے آپ کو تکنیکی، مالی، اور معلوماتی لحاظ سے کس قسم کی مدد درکار ہوگی؟

Answer: “اس طریقہ کار کو مؤثر طریقے سے نافذ کرنے کے لیے، مجھے اپنے ملازمین کو تکنیک کو بہتر اور مکمل کرنے کے لیے ورکشاپ ٹریننگ فراہم کرنے کی ضرورت ہوگی۔".

(To implement this method effectively, I will need to provide workshop training for my employees to refine and perfect the technique).

Question 7: How will the market react to brick made from Parthenium biomass in terms of possible acceptance?

پارتھینیم بائیوماس سے بنی اینٹوں کو مارکیٹ ممکنہ قبولیت کے لحاظ سے کیسے رد عمل دے گی؟

Answer: “اگر پروڈکٹ روایتی اینٹوں کے مقابلے میں زیادہ پائیداری کا مظاہرہ کرتی ہے تو مارکیٹ کا ردعمل مثبت ہونے کا امکان ہے۔ اس مقصد کے لیے، حکومت کے مالی تعاون سے چلنے والا ایک پائلٹ پروجیکٹ ایک اہم قدم ہوگا۔".

(The market will likely respond positively if the product demonstrates greater durability than conventional bricks. To this end, a government-funded pilot project will be a critical step).

Question 8: By adopting this method, do you think it will lower the cost of production?

اس طریقے کو اپنانے سے، کیا آپ کے خیال میں پیداواری لاگت کم ہوگی؟

Answer: “اس کا اطلاق صرف پائلٹ پراجیکٹ کی کامیاب تکمیل پر ہوگا۔ ”.

(This will occur only upon the successful completion of the pilot project).

From the above survey discussion, the majority of brick kiln owners possess knowledge regarding the environmental pollution resulting from their current operational techniques. They frequently employ substandard fuel to minimize the expenses associated with brick production. Interestingly, none of them were acquainted with the notion of incorporating agricultural waste additives into clay bricks, and they opted to adhere to their conventional techniques. At first, over 50% of the owners were reluctant to utilize Parthenium as an additive because they were worried about the bricks’ quality. Nevertheless, their viewpoints underwent a positive change when they were provided with evidence showcasing the sustainable advantages of the altered bricks, such as increased longevity and eco-friendly. Although the brick owners have developed a recent interest, they have expressed apprehensions regarding the necessity of providing training to their employees on this novel approach. The brick owners were off the view to conduct workshops and trainings to brought awareness about the environmental pollution and providing sufficient trainings to the employees to successfully incorporate the new method, which can show the importance of using Parthenium biomass and its advantages, such as decreased energy consumption and reduced emissions from clay brick during manufacturing. The owners were highly excited about the prospect of reducing their cost of production due to high fuel price.

The brick owners further suggested to start pilot projects few brick kilns to authenticate the current method, which will function a solid base a benchmark for broader acceptance to showcase the advantages and practices offered by the new method. Moreover, they requested the government to provide financial benefit by providing subsidies and tax incentives for the equipment used, buying the agricultural waste bi-products on reduces rates. Furthermore, there should be a proper mechanism through which farmers can bring their agricultural waste to a single point for onward distribution to the brick kilns as a fuel. According to the brick owners, the positive feedback from the pilot projects will depend on how much the new method can reduce the fuel cost and the overall expenses significantly, which will pave the way for its adoption widely due to its ecological sustainability as well. In addition, they also emphasized on providing certification/recognition for brick kiln owners who initiate or embrace such eco-friendly practices. This will inspire other brick kiln owners to adopt this new method to reduce environmental pollution and contribute to the green economy.

The present study aligns with existing literature, which identifies the disposal of agricultural crop waste e.g. sugarcane bagasse, wheat straw, coconut, and rice husks, as a significant challenge in developing countries 25. For instance, approximately 600 million metric tonnes of agricultural waste have been reported in India alone 26, with projections indicating an increase in the coming years due to intensified agricultural practices 27. Conventional disposal methods, including landfilling, composting, and incineration, exacerbate environmental pollution 28. However, the incorporation of agricultural waste and its by-products into construction materials, either partially or entirely, presents a viable solution to these challenges 28. Utilizing agro-waste not only mitigates pollution from conventional construction materials, such as cement, but also reduces the environmental impact associated with landfill disposal 28.

For example, incorporating agricultural residues, such as rice straw, rice husks, coconut shells, and peanut shells, as a partial substitute for sand in cement block production yielded blocks that met ASTM standards for compressive strength and durability 29. Similarly, soil stabilization using barley and wheat straw fibers produced reinforced bricks with superior structural and thermal properties 30. Furthermore, constructing buildings with straw bales and soil resulted in sustainable structures characterized by low embodied energy and excellent thermal performance 31. These findings underscore the potential of agro-waste in construction materials to enhance sustainability while minimizing pollution and environmental degradation.

However, the current study diverges from prior research that has used other agricultural wastes by incorporating Parthenium hysterophorus, an invasive weed prevalent in South Asia with no known environmental or economic benefits, unlike the agricultural residues used in previous studies, which have alternative applications, such as fuel or livestock feed. By utilizing Parthenium weed in brick production, this research offers a novel approach to managing an ecologically harmful species while addressing sustainability challenges in construction. Consequently, integrating this invasive weed into brick manufacturing not only mitigates its environmental impact but also provides a sustainable alternative to conventional materials.

But agri waste additive bricks, although a sustainable construction material, are best suited for smaller structures and may not be optimal for large-scale projects for its load bearing capacity. The production of bio bricks can be labor-intensive, and inadequate compaction may lead to structurally unstable outcomes 32. Therefore, proper training is required for the construction workers as mentioned by the brick kiln owners in the survey. The study was conducted on a smaller scale and at a single point. It will be better to carried out such study for a longer duration at multiple points for clearer outcomes.

The current research contributes to the United Nations Sustainable Development Goals (SDGs), namely SDG 11,12 and 13 as it has a significant positive impact to the advancement of sustainable cities and communities by utilizing the use of agricultural waste materials and production methods in the brick making factories and opening ways for the adoption of responsible consumption and production practices, while at the same time addressing key issues of climate change via the application of energy-efficient methods and the use of sustainable materials. This alignment not only highlights the environmental significance of the research but also underlines its broader impact on overall sustainability initiatives globally. The current study makes a substantial contribution to ecological sustainability and resilience to climate by integrating Parthenium biomass as additive into the clay bricks manufacturing, which also significantly lowers the amount of clay used in the brick making process, which interns reduces of toxic gases like SO2, HF and O3 during the brick making process. The current research not only boost the use of cleaner brick making techniques but also backs efforts to lower the environmental damage and improve sustainable practices by reducing SO2, HF and O3 emissions.

Brick kilns, commonly located on agricultural lands to take advantage of affordable land leases and clay availability, release these noxious gases that can have adverse effects on crop yields. The detrimental impact of HF on fruit orchards and cash crops 2, highlighting the necessity for environmentally friendly alternatives in brick production. In addition, the government should initiate friendly policies that offer incentives to the farmers e.g. encouraging them to harvest Parthenium and providing them to the brick kiln owners free of charge for the purpose of integrating it into the production of bricks. Furthermore, it is important to promote an awareness drive, which emphasizes the harmful effect of Parthenium on the ecosystem and public health. This campaign drive should target to educate all stockholders and promote the adoption of sustainable practices and circular economy.

Conclusion

  • The study confirms that incorporating Parthenium hysterophorus biomass and coal as additives improves clay brick quality, achieving up to 64% porosity and 15–20 MPa compressive strength with 15–20% biomass by weight.

  • Substituting coal with Parthenium biomass significantly reduces hydrogen fluoride (HF) and sulfur dioxide (SO2) emissions by over 50%, mitigating atmospheric pollution.

  • Utilizing Parthenium biomass, an invasive weed, as an additive promotes a circular green economy by reducing waste and enhancing resource efficiency in brick production.

  • This approach minimizes environmental degradation, improves public health, and supports community well-being by reducing harmful emissions from brick kilns.

  • The integration of agro-industrial by-products like Parthenium weed fosters economic and social benefits, including potential production cost reductions of 10–15%.

  • Local governments, in collaboration with provincial environmental protection agencies, should formulate policies to eradicate Parthenium weeds and provide economic incentives, such as subsidies and training, to farmers and brick kiln operators.

  • These sustainable practices align with UN Sustainable Development Goals (SDGs) 11 (Sustainable Cities), 12 (Responsible Consumption), and 13 (Climate Action).

  • Future research should prioritize scaling these practices and exploring their adaptability across diverse regions and manufacturing sectors to maximize global impact.