Can a Farm Use UASB?
Yes, a farm can use a UASB, but only on the liquid fraction after solids separation; whole manure slurry at 8-12% total solids is too thick and gritty for the granular blanket, so the UASB treats the separated liquor while a CSTR or USR digests the solids. In practice the UASB is the polishing and biogas-recovery stage for the liquid stream, not the primary manure digester.
1. What a UASB Needs
A UASB (upflow anaerobic sludge blanket) keeps dense granules in suspension by upward flow and lets them settle back at 0.5-1.2 m/h. It works on soluble, warm, high-strength streams with COD above about 1,500-2,000 mg/L and very little suspended solids. Whole manure fails all three: solids blind the bed, grit erodes it, and the separator is the gatekeeper.
2. The Farm Split-Train
| Stream | What it is | Reactor |
| Solids | Bedding, grit, fibers | CSTR or USR |
| Liquid | Separated liquor, soluble COD | UASB + AOAO |
| Biogas | From both streams | Buffer + use |
3. Why It Pairs, Not Replaces
At 5-15 kg COD/m3-day the UASB removes 80-90% of the soluble load and recovers biogas at 0.30-0.45 m3 per kg COD. But it cannot swallow the solids, which still need a mixed or upflow solids reactor. Farms that try to push whole manure through a UASB wash the blanket out within weeks. The CSTR or USR keeps the solids; the UASB cleans the water.
Project Case Study
Beijing 5S Pig Farm Wastewater Treatment Project. A 580 m3/day on-site plant using UASB + AOAO, cutting COD from 10,000 to 200 mg/L and ammonia from 1,000 to 80 mg/L - a delivered example of UASB applied on a farm's separated liquid stream rather than on raw manure.
| Project | Beijing 5S Pig Farm Wastewater Treatment Project |
| Location | Beijing, China |
| Industry | Livestock / Pig Farm |
| Application | Farm UASB - separated liquid |
| Product | GFS process tanks |
| Effluent | COD 10,000 to 200, NH3-N 1,000 to 80 mg/L |
| Status | Delivered 2020 |
About Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel)
Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel) supplies the product technology for the split-train: bolted GFS reactor and buffer tanks fuse glass to steel at 820-930 C for an inert, impermeable barrier against corrosive, H2S-bearing liquor. Because the tanks ship flat-pack and assemble fast, the UASB and the CSTR/USR share one delivered, corrosion-resistant package on the farm.
Comparison: UASB vs CSTR on a Farm
| Criterion | UASB (liquid) | CSTR (solids) |
| Feed TS | Low, soluble | 8-12% TS |
| HRT | Hours | 20-40 days |
| OLR | 5-15 kg COD/m3-day | 1-4 kg VS/m3-day |
| Role | Liquid polish | Solids digestion |
Use UASB on the farm's separated liquid, not on raw manure; keep a CSTR or USR for the solids. Separate first, then send the liquor to the UASB at 35-38 C. Send your manure split and we will size the GFS reactor train for both streams.
Frequently Asked Questions (FAQ)
Q1: Can a farm run a UASB?
A: Yes, on the liquid fraction after solids separation; raw manure is too thick for the blanket.
Q2: What COD can a farm UASB treat?
A: Soluble streams above 1,500-2,000 mg/L, removing 80-90% at 5-15 kg COD/m3-day.
Q3: Does UASB replace CSTR on farms?
A: No; it pairs with CSTR or USR, which digest the solids the UASB cannot.
Q4: What temperature does the UASB need?
A: Mesophilic 35-38 C for stable granule activity.
Q5: What tank capacity is available?
A: GFS tanks from 200 m3 to 60,000 m3.
Q6: What standards apply?
A: GFS tanks follow ISO 28765 and AWWA D103; ISO 9001 quality system.
Suggested CTA
Send your manure stream split and flow. We will size the GFS UASB and CSTR/USR train for the farm.