Introduction

The leather industry across Asia is undergoing rapid transformation driven by stricter environmental regulations, rising export standards, and the need to optimize operating costs. At the center of this transformation is a group of essential auxiliary chemicals that support both production efficiency and environmental compliance. Among these, polyaluminium chloride (often abbreviated as PAC) has become a critical coagulant and process aid for tanneries, especially in the field of wastewater and sludge treatment. For buyers, technical managers, and procurement teams in the leather chemicals sector, understanding how PAC fits into modern tannery operations is increasingly important.

Asia dominates global leather production and processing. Major manufacturing hubs such as China, India, Pakistan, Bangladesh, Vietnam, and Indonesia collectively account for a significant share of global hides and skins processing, finished leather exports, and leather goods manufacturing. This scale generates substantial volumes of high-load wastewater, rich in chromium, sulfides, fats, dyes, and organic matter. To meet tightening discharge norms and customer-driven sustainability requirements, Asian tanneries rely on robust primary and secondary treatment systems, where polyaluminium chloride is widely applied as a high-performance inorganic coagulant.

Suppliers like chemtradeasia connect producers of PAC with leather chemicals buyers across Asia, ensuring consistent quality, reliable logistics, and technical support. This article provides a structured overview of PAC as a product, its role in leather chemicals applications, key performance benefits, and relevant market insights for buyers in the region. It is intended to support informed sourcing and application decisions within the leather value chain.
 

Understanding Polyaluminium Chloride and Its Key Properties

Polyaluminium chloride is an inorganic polymer coagulant derived from aluminum salts. It is typically produced by the controlled reaction of aluminum hydroxide, aluminum metal, or aluminum trihydrate with hydrochloric acid, resulting in a polymerized aluminum complex with varying basicity levels. Unlike traditional coagulants such as aluminum sulfate (alum), PAC contains pre-hydrolyzed aluminum species, which provide faster and more efficient coagulation performance in many industrial and municipal water treatment applications.

Commercial PAC is available in both liquid and solid forms. Liquid grades are commonly supplied as yellowish solutions with an Al2O3 content in the range of 8–18%, while solid or powder grades may offer Al2O3 contents of 28–31% or higher. Basicity (the degree of hydroxylation of the aluminum species) typically ranges from 40–90%, depending on the manufacturing route and intended application. For leather industry wastewater, medium to high basicity PAC is often preferred, as it tends to perform well over a wider pH range and generates denser flocs, leading to improved clarification.

Key properties that make polyaluminium chloride attractive to leather chemicals buyers include its high charge density, rapid coagulation kinetics, and relatively low sludge production compared with some conventional coagulants. PAC is effective across a broad pH spectrum, often between pH 5–9, which suits the variable conditions in tannery effluent streams. Additionally, PAC solutions are relatively stable when stored under appropriate conditions, making them suitable for bulk handling by medium and large tanneries. Reliable distributors such as chemtradeasia typically offer PAC grades with controlled impurity levels (e.g., low heavy metals and low insoluble content) to meet environmental and industrial standards.
 

Role of Polyaluminium Chloride in Leather Chemicals and Tannery Operations

Within the leather value chain, polyaluminium chloride is not a primary tanning or retanning agent, but rather a crucial auxiliary chemical that supports process water management and compliance. Tannery operations generate wastewater at almost every stage: soaking, liming, deliming, pickling, tanning (including chrome tanning), dyeing, and fatliquoring. Each stage contributes different contaminants such as suspended solids, colloids, fats, surfactants, chromium, and color. Effective coagulation and flocculation are necessary to remove a large portion of these pollutants before biological treatment or discharge, and PAC is widely used in this first line of treatment.

In primary treatment systems, PAC is dosed into equalization tanks, coagulation tanks, or rapid mixing chambers, where it destabilizes colloidal particles and facilitates the formation of larger flocs. These flocs capture suspended solids, emulsified fats, oils, and some dissolved organic color bodies. In many Asian tanneries, PAC is used in combination with anionic or non-ionic polymeric flocculants to optimize settling in primary clarifiers or dissolved air flotation (DAF) units. The result is clearer supernatant water and reduced organic load (COD/BOD) entering secondary treatment stages, which can significantly improve the performance and stability of biological treatment systems.

Beyond wastewater, PAC can also be applied in certain process-water recycling and clarification steps, particularly in integrated leather complexes and large industrial clusters that operate centralized effluent treatment plants (CETPs). Here, consistent and efficient coagulation is essential to handle variable loads from multiple tanneries. For procurement teams in the leather chemicals sector, ensuring a reliable supply of well-specified PAC often sourced from regional distributors like chemtradeasia is essential to maintaining continuous operations and meeting regulatory discharge limits in countries such as India, Bangladesh, and Pakistan, where environmental norms are tightening.
 

Applications of Polyaluminium Chloride in Tannery Effluent Treatment

The most critical application of polyaluminium chloride in the leather industry is the treatment of tannery effluent. Tannery wastewater is typically characterized by high chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), sulfides, chlorides, and often chromium from chrome tanning. In Asia, regulatory authorities and export markets are increasingly enforcing strict discharge standards, prompting tanneries to upgrade from basic sedimentation systems to more advanced treatment lines that rely on efficient coagulants like PAC.

In a typical tannery effluent treatment plant, PAC is injected at the coagulation stage following preliminary screening and equalization. Dosage ranges can vary widely depending on wastewater characteristics, but many industrial references report PAC doses in the range of 50–300 mg/L for tannery wastewater, often optimized through jar testing. When combined with appropriate pH adjustment (commonly around pH 6.5–7.5) and a selected flocculant, PAC can achieve significant removal of TSS, turbidity, and color. Studies and field data from Asian tanneries have shown that PAC-based coagulation can reduce COD by 30–60% and achieve TSS reductions exceeding 80% in primary treatment, thereby easing the load on biological reactors.

Another important application is sludge conditioning. The sludge generated from primary and secondary treatment in tanneries is often high in moisture and difficult to dewater. PAC, sometimes used in combination with other inorganic coagulants or polymers, can improve sludge floc structure and enhance dewatering performance in filter presses, belt presses, or centrifuges. This translates into lower sludge disposal volumes and reduced handling costs. For CETPs serving multiple tanneries, these improvements can be significant at scale. Buyers sourcing PAC through channels such as chemtradeasia often consider not only the price per ton, but also the total treatment cost per cubic meter of wastewater treated, including sludge management savings.
 

Market Insights, Buyers, and Supply Dynamics in Asia

Asia is both a major producer and consumer of polyaluminium chloride. China is one of the largest manufacturing bases for PAC globally, supplying domestic water treatment markets as well as exporting to neighboring countries. India, Indonesia, and other Southeast Asian nations also have local PAC production capacities, though many leather industry buyers still rely on imports for specialized or higher-basicity grades. The growth of municipal water treatment, industrial wastewater treatment, and stricter environmental enforcement has supported steady demand for PAC across the region, with the leather sector representing an important industrial segment.

Leather chemicals buyers in Asia typically fall into several categories: individual tanneries (small, medium, and large), integrated leather parks, centralized effluent treatment plants, and specialized leather chemical formulators who incorporate PAC into treatment packages. Procurement decisions are influenced by product quality (Al2O3 content, basicity, impurities), consistency between batches, delivery reliability, and technical service. International and regional distributors such as chemtradeasia play a key role by aggregating demand, offering multiple PAC grades, and providing cross-border logistics solutions that help stabilize supply for buyers in markets with fluctuating local production.

Market trends show a clear movement toward higher-performance and more sustainable treatment solutions. Many Asian tanneries are upgrading from traditional alum or iron salts to PAC due to lower overall dosage requirements, reduced sludge generation, and better color removal. At the same time, buyers are increasingly sensitive to total cost of ownership, including chemical consumption, energy use, and sludge disposal. This is driving demand for technical support services such as jar testing, on-site optimization, and customized dosing strategies, areas where experienced suppliers like chemtradeasia can add value. As leather-exporting countries in Asia continue to align with international environmental and social governance (ESG) standards, the role of PAC in reliable and efficient wastewater treatment is expected to remain strong.
 

Conclusion

Polyaluminium chloride has established itself as a key auxiliary chemical for the leather industry in Asia, particularly in the fields of wastewater treatment and sludge management. Its pre-hydrolyzed aluminum species, broad operating pH range, and efficient coagulation performance make it well suited to handle the complex, variable effluent streams generated by tanneries. By integrating PAC into their effluent treatment plants, leather manufacturers and CETPs can achieve better removal of suspended solids, color, and organic load, thereby improving compliance with increasingly strict environmental regulations and enhancing the overall sustainability profile of their operations.

For buyers and technical teams in the leather chemicals sector, selecting the right grade and supplier of polyaluminium chloride is essential. Factors such as Al2O3 content, basicity, impurity profile, physical form, and supply reliability all influence treatment performance and cost. Regional distributors and solution providers like chemtradeasia can support tanneries and leather clusters by offering tailored PAC options, consistent quality, and application guidance based on local operating conditions. As Asia’s leather industry continues to evolve under the pressure of global market expectations and regulatory requirements, PAC will remain an important component in the toolkit of leather chemicals that enable both productivity and environmental responsibility. To discuss sourcing options, technical specifications, or application support for polyaluminium chloride in leather industry wastewater treatment, contact the Chemtradeasia team.

This article is intended solely for informational and market insight purposes and does not constitute technical, safety, design, or professional advice. Users should independently verify all information with qualified experts, consult official documentation such as MSDS/SDS for polyaluminium chloride and related leather chemicals, and contact appropriate technical specialists or our team for guidance on specific applications, dosing, and compliance requirements.