Introduction
Treating landfill leachate is one of the most challenging tasks in wastewater management. High concentrations of organic matter, heavy metals, ammonia, and suspended solids often render conventional chemical treatments ineffective. When a leachate treatment facility struggled with poor flocculation and high chemical costs, our technical team stepped in. By switching to our high-performance Polyaluminum Chloride (PAC) and Polyacrylamide (PAM), we achieved remarkable clarification and solid‑liquid separation.
This case study demonstrates how the right chemical selection and on‑site optimization can dramatically improve leachate treatment efficiency.
The Challenge: Ineffective Chemical Dosing
The facility was treating approximately 200 m³/day of mature landfill leachate (characteristics: COD ~8,000 mg/L, TSS ~1,500 mg/L, pH 7.8). The existing coagulant (alum) and flocculant (low‑MW anionic PAM) produced:
Small, loose flocs that settled slowly
High residual turbidity after sedimentation
Frequent clogging of downstream filters
Excessive polymer consumption (overdosing required)
The operators had already tried adjusting dosages and mixing conditions, but the results remained unsatisfactory. High effluent solids were causing permit violations and extra disposal costs.
Based on a bench‑scale jar test analysis performed by our field technician, we recommended:
Coagulant: Polyaluminum Chloride (PAC) with 60% basicity – PAC provides stronger charge neutralization than alum, forming dense flocs over a wider pH range.
Flocculant: High‑molecular‑weight Cationic Polyacrylamide (PAM) – selected for optimum bridging effect with PAC‑generated flocs.
Within 24 hours of switching to our PAC and PAM, the plant achieved:
| Parameter | Before (alum + old PAM) | After (our PAC + PAM) | Improvement |
|---|---|---|---|
| Effluent turbidity (NTU) | 85 | 12 | 86% reduction |
| TSS (mg/L) | 210 | 28 | 87% reduction |
| COD removal | 58% | 79% | +21% |
| Floc settling rate (cm/min) | 3.5 | 9.2 | 2.6× faster |
| Chemical cost ($/m³) | $0.42 | $0.31 | 26% savings |
Visual observation: The flocs formed were large, compact, and settled rapidly, leaving crystal‑clear supernatant. No residual polymer carryover was detected.
Long‑term operation (30 days) confirmed stable performance, with reduced sludge volume (35% less). Downstream equipment cleaning frequency dropped from weekly to once a month.
On-site demonstration of flocculation effect and sludge pressing effect
Why This Matters for Your Leachate Facility
This case highlights two critical factors for successful landfill leachate flocculation:
Product quality matters – Our PAC has optimized aluminum speciation for high‑strength wastewater. Off‑the‑shelf coagulants often fail with variable leachate composition.
On‑site technical support is essential – Dosing, mixing intensity, and point of addition must be tailored. Without our technician’s adjustments, even good chemicals might underperform.
Are you facing similar issues?
– Slow settling flocs in your leachate treatment?
– High polymer consumption with poor turbidity removal?
– Frequent filter blockages?
--The sludge has a high moisture content, and the pressed sludge does not take on a definite shape？
Our technical team offers free jar tests and on‑site commissioning for PAC and PAM products designed specifically for landfill leachate and industrial wastewater.
Contact our water treatment specialists for a free consultation – we’ll help you select the right PAC and PAM, run jar tests, and even visit your site for optimization.
WhatsApp:+8615138699676
Tel/WeChat: +8618236921808
E-mail：vanzon@vanzonwater.com VanzonWater@outlook.com
