Sludge Treatment Patent Landscape 2026
Sludge Treatment Patent Landscape in 2026
The sludge treatment patent field is in a mature phase, with 7,390 patent families on record and annual volume having eased from its 2020 peak. Japanese water-technology incumbents dominate, led by Kurita Water Industries, while China accounts for the largest share of filing jurisdictions and adjacent branches such as waste-to-fertiliser and incineration remain comparatively sparse.
Japanese incumbents lead a moderately concentrated field
Kurita Water Industries holds the top position with 467 patent families, ahead of Kubota Corporation at 424 and Ebara Research at 394, establishing a clear first tier of Japanese water-technology specialists.
The top five filers together account for 22% of the combined output of the hundred largest filers, indicating moderate concentration — meaningful incumbency advantages exist, but the field is not locked up by a single dominant player.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Kurita Water Industries Ltd. | 467 | |
| 2 | Kubota Corporation | 424 | |
| 3 | Ebara Research Co., Ltd. | 394 | |
| 4 | Toray Engineering Co., Ltd. | 267 | |
| 5 | Toshiba Corporation | 230 | |
| 6 | Evoqua Water Technologies LLC | 226 | |
| 7 | Hitachi, Ltd. | 208 | |
| 8 | Hitachi Plant Technologies, Ltd. | 207 | |
| 9 | Mitsubishi Electric Corporation | 191 | |
| 10 | VEOLIA WATER SOLUTIONS & TECHNOLOGIES SUPPORT SAS | 172 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Toray Industries, Inc. | 172 | |
| 12 | Mitsubishi Heavy Industries, Ltd. | 171 | |
| 13 | Mitsubishi Chemical Corporation | 161 | |
| 14 | Solvay SA | 151 | |
| 15 | Meidensha Corporation | 149 | |
| 16 | Nishihara Environment & Sanitation Research Corporation | 146 | |
| 17 | Organo Corporation | 138 | |
| 18 | Ebara Corporation | 137 | |
| 19 | Nippon Steel Corporation | 125 | |
| 20 | Saudi Arabian Oil Company (Aramco) | 109 |
The depth of the Japanese incumbent tier — with eight Japanese entities in the top twelve — suggests that core process IP (biological treatment, membrane separation, sludge digestion) is well covered by established players, raising the bar for undifferentiated entry.
Data for 2024–2025 reflect publication lag and likely undercount activity from those years; trend comparisons should be anchored to 2017–2023. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Activity plateaued post-2020; water treatment dominates but adjacent branches diversify the mix
Annual filing volume climbed to a 2020 peak of 1,019 patent families before easing; the technology mix is anchored by water and wastewater treatment (C02F) with a long tail of process-adjacent classes.
Annual filing trend
Filings rose steadily from 719 families in 2017 to a 2020 peak of 1,019, then moderated through 2023 at 896. The 2024 and 2025 bars are substantially under-counted due to publication lag and should not be read as a continued decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C02F (water and wastewater treatment) is the dominant class by a wide margin, followed by B01D (separation and filtration). Smaller but distinct clusters appear in fertiliser recovery (C05F), incineration (F23G), biological engineering (C12N), and drying (F26B), reflecting the breadth of end-of-life sludge routes.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Crude oil sludge treatment agent, crude oil sludge…
The crude oil sludge treatment agent is mixed with crude oil sludge and water and used for treatment of the crude oil sludge under alkali conditions. The crude oil sludge treatment agent contains green rust. The crude oil sludge treatment agent may further contain either or both a metal and a metal ferrite. The metal and the metal of the metal ferrite are… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | New and improved system for processing various che… | 852 |
| 2 | Method and apparatus for dielectrophoretic manipul… | 600 |
| 3 | Controlled natural purification system for advance… | 323 |
| 4 | Apparatus for treating activated sludge and method… | 285 |
| 5 | Thermophilic aerobic waste treatment system | 221 |
| 6 | Two phase anaerobic digestion | 196 |
| 7 | Method of back-washing submerged-type ceramic memb… | 191 |
| 8 | Controlling wastewater treatment by monitoring oxy… | 190 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the competitive structure means for R&D investment
Four structural observations — maturity stage, concentration, collaborative patterns, and geography — shape where incremental and disruptive R&D can gain traction.
Mature field with plateaued annual volume
Annual filing volume plateaued near the 2020 peak and has since eased, consistent with a mature technology lifecycle. Core biological and membrane-based treatment processes are densely patented. R&D investment is most defensible in differentiated sub-processes — resource recovery, advanced digestion, or process control — rather than incremental improvements to established unit operations.
Lifecycle: MaturityModerate concentration with a strong Japanese incumbent tier
The top five filers represent 22% of the hundred largest filers’ combined output, and eight of the top twelve are Japanese water-technology companies. This creates a dense IP thicket in biological treatment (C02F3) and membrane filtration (B01D65). New entrants or challengers from outside this tier should prioritise freedom-to-operate analysis before committing to process-core development.
Moderate concentrationEbara Research–Toray Engineering is the dominant co-filing pair
The most active co-filing relationship is between Ebara Research and Toray Engineering, with 173 joint patent families — far ahead of any other pair in the dataset. Secondary collaborations include Ebara Research with Ebara Corporation (26 families), Mitsubishi Heavy Industries with Kansai Electric Power (11), and Kurita Water Industries with Otsuka Chemical (9). These pairings suggest that membrane and biological treatment cross-licensing is a preferred route for capability extension among incumbents.
Partnership-driven IPChina is the primary filing jurisdiction; Japan and the US are close seconds
China leads in patent-record volume, followed by the United States and Japan in close proximity, with Europe (EPO) and WIPO (PCT) providing meaningful international coverage. Secondary jurisdictions including Canada, Australia, and South Korea indicate that commercially active players are seeking broad international protection. Filers targeting only domestic markets risk exposure in the major water-infrastructure build-out markets.
Global footprint requiredGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| Ebara Research Co., Ltd. | Toray Engineering Co., Ltd. | 173 |
| Ebara Research Co., Ltd. | Ebara Corporation | 26 |
| Mitsubishi Heavy Industries, Ltd. | Kansai Electric Power Co., Inc. | 11 |
| Kurita Water Industries Ltd. | Otsuka Chemical Co., Ltd. | 9 |
| Kubota Corporation | Kubota Environmental Service Co., Ltd. | 6 |
| Kubota Corporation | Ebara Corporation | 5 |
| Kubota Corporation | Unitika Ltd. | 5 |
| Ebara Corporation | Unitika Ltd. | 5 |
| Toray Industries, Inc. | Chiyoda Corporation | 5 |
| Kubota Corporation | Daicen Membrane-Systems Ltd. | 4 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Kurita and Kubota anchor a Japanese-dominated top tier
The leading applicants concentrate heavily in C02F water and wastewater treatment sub-classes, with some differentiation in membrane filtration. Momentum among established leaders has moderated recently.
Kurita Water Industries
Kurita Water Industries holds 467 patent families, the largest portfolio in scope. Its technology emphasis concentrates on C02F11 (sludge digestion and conditioning), C02F3 (biological treatment), and C02F1 (physical-chemical treatment), reflecting broad coverage of the sludge treatment process chain. Recent filing momentum has eased, with a –53% trend versus the prior three-year window, consistent with the field’s overall maturation.
467 patent familiesKubota Corporation
Kubota Corporation ranks second with 424 patent families and differentiates from Kurita through a stronger emphasis on membrane filtration (B01D65), alongside C02F3 and C02F1 coverage. This membrane focus positions Kubota in the submerged membrane bioreactor segment, where cited patents on back-washing of ceramic membranes signal established technical depth. Recent filing momentum reflects a –50% trend versus the prior three-year window, mirroring the sector-wide plateau.
424 patent families| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Kurita Water Industries Ltd. | 7 | ▼ -53% |
| Kubota Corporation | 6 | ▼ -50% |
| Evoqua Water Technologies LLC | 16 | ▼ -71% |
| Mitsubishi Heavy Industries, Ltd. | 2 | ▲ new entrant |
| Toray Industries, Inc. | 3 | ▲ new entrant |
Under-served branches adjacent to the sludge treatment core
Several IPC classes appear at lower relative share within this corpus, suggesting areas where patent density is thin relative to technical relevance. These are observations of relative sparsity, not validated commercial opportunities.
C05F · Organic & waste-derived fertilisers
C05F accounts for a 2% share among identified branches, despite sludge-to-fertiliser conversion being a well-recognised circular-economy route for nutrient recovery. The technical pathway — stabilised biosolids application to land — is plausible and aligns with tightening phosphorus-recovery regulations in multiple jurisdictions. Existing players in biological treatment (C02F3) would have a logical entry path through process extension, but the branch remains comparatively sparse in this corpus.
Search this in Eureka →C12N · Microorganisms & genetic engineering
C12N carries a 1% share in this corpus, indicating that engineered-microorganism approaches to sludge digestion — such as enhanced anaerobic consortia or genetically optimised dewatering organisms — are not yet a primary patenting focus among the dominant filers. Given the growing interest in biotechnology-enhanced wastewater treatment, this branch has plausible technical value for players with biological sciences capability. Entry would require both microbiology IP and integration with existing C02F process frameworks.
Search this in Eureka →How leading applicants differ by technology route
Strength of each leader across the main technology routes.
| Player | C02F 11 · Water & wastewater treatment | C02F 3 · Water & wastewater treatment | C02F 1 · Water & wastewater treatment | C02F 9 · Water & wastewater treatment | B01D 21 · Separation processes (filtration etc.) |
|---|---|---|---|---|---|
| Ebara Research Co., Ltd. | Strong · 135 | Strong · 216 | Strong · 142 | Moderate · 93 | Emerging · 41 |
| Kurita Water Industries Ltd. | Strong · 167 | Strong · 153 | Strong · 142 | Emerging · 30 | Moderate · 82 |
| Kubota Corporation | Moderate · 82 | Strong · 198 | Strong · 161 | Emerging · 25 | Absent |
| Toray Engineering Co., Ltd. | Strong · 93 | Strong · 137 | Strong · 84 | Moderate · 58 | Moderate · 30 |
| Ebara Corporation | Strong · 77 | Strong · 90 | Strong · 91 | Moderate · 26 | Absent |
| Evoqua Water Technologies LLC | Absent | Strong · 117 | Strong · 75 | Absent | Absent |
| Hitachi Plant Technologies, Ltd. | Strong · 69 | Strong · 115 | Absent | Absent | Absent |
Frequently asked questions
The corpus covers 7,390 patent families globally. Filing records span multiple jurisdictions and IPC classes; China, the United States, and Japan are the three largest individual filing destinations.
Kurita Water Industries holds the largest portfolio with 467 patent families, followed by Kubota Corporation at 424 and Ebara Research at 394. All three are Japanese water-technology specialists.
The field has reached maturity. Annual filings peaked at 1,019 patent families in 2020 and have eased since. The multi-year window still shows a substantial accumulated body of IP, but the pace of new filing has moderated. Data for 2024 and 2025 are affected by publication lag and undercount recent activity.
C02F (water and wastewater treatment) is by far the dominant class, reflecting that biological digestion, physical-chemical conditioning, and sludge dewatering are the core process steps. B01D (separation and filtration) is the second-largest cluster, driven by membrane bioreactor technology.
China leads in patent-record volume, followed closely by the United States and Japan. Europe (EPO) and WIPO (PCT) filings indicate that leading applicants pursue international protection. Canada and Australia are also significant secondary jurisdictions.
The most active co-filing pair is Ebara Research and Toray Engineering, with 173 joint patent families — substantially more than any other pair. Other notable pairings include Mitsubishi Heavy Industries with Kansai Electric Power (11 families) and Kurita Water Industries with Otsuka Chemical (9 families), reflecting a pattern of Japanese incumbents combining process and materials expertise through co-development.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. PatSnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.