Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 03/06/2026 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 4, 5, 7, and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamazaki (JPS6171899, refer attached English language machine translation for claim mapping), in view of Ennouri et al. (Bioresource Technology 214 (2016) 184–191).
Regarding claim 1, Yamazaki teaches a method for selectively removing micro-contaminants from sludge, said method comprising:
a) providing wastewater contaminated with micro-contaminants (refer page 2 – 1st paragraph),
b) subjecting said wastewater to a primary treatment step, thereby producing a first stream of primary sludge comprising a first part of micro-contaminants and a second stream of remaining wastewater comprising a second part of micro-contaminants (refer page 2 disclosing initial settling stage),
c) subjecting the second stream of remaining wastewater to a secondary treatment step, thereby producing biological sludge (refer page 2 – 4th paragraph disclosing supernatant from initial settling stage is subject to final settling/precipitation stage),
d) subjecting the first stream of primary sludge to an incineration step, thereby eliminating the primary sludge and the first part of micro-contaminants and producing ashes and heat (Refer page 2 -2nd and 3rd paragraph disclosing incineration of primary sludge), and
recovering the biological sludge for land application (refer page 3 – 6th paragraph disclosing secondary sludge being dehydrated and used as compost or fertilizer).
Yamazaki does not teach anaerobic digestion of the biological sludge, thereby producing methane and a solid product, and subjecting the biological sludge to a thermal conditioning step upstream or downstream of the anaerobic digestion step.
Ennouri teaches treatment of waste activated sludge, wherein the waste activated sludge is subject to thermal conditioning (refer thermal pre-treatment in graphical abstract), after the thermal preconditioning, the sludge is subject to anaerobic digestion to produce methane and solids (Refer ASBR reactor in graphical abstract). Ennouri discloses that thermal preconditioning improves digester performance (refer abstract).
It would have been obvious to one of ordinary skill in the art to modify the method of Yamazaki to include steps of anaerobic digestion of the biological sludge, thereby producing methane and a solid product, and subjecting the biological sludge to a thermal conditioning step upstream or downstream of the anaerobic digestion step to generate methane that can be used for heating or as electricity source as taught by Ennouri (Refer left column on page 185).
Yamazaki teaches heating the secondary sludge using heat from incineration of primary sludge (Refer fig. 1, paragraph 7 on page 2). Selecting where to use the heat produced from incineration step in the method of modified Yamazaki would have been an obvious matter of choice to one of ordinary skill in the art since Yamazaki discloses use of heat generated from incineration to other parts of process. Yamazaki establishes that heat produced in one step can be used in another step. One of ordinary skill in the art would realize that reusing heat would provide benefit of requiring less “new” heat.
Regarding claim 4, Yamazaki teaches limitations of claim 1 as set forth above. The limitations of claim 4 do not recite any additional step and rather recites results of the method steps of claim 1. Since Yamazaki teaches the all limitations of claim 1, the results of the method as claimed in claim 4 are inherent.
Regarding claim 5, modified Yamazaki teaches limitations of claim 1 as set forth above. Yamazaki teaches dehydrating second sludge to use it as compost or fuel or fertilizer (refer page 2). Ennouri also teaches that anaerobic sludge is found to be an effective organic fertilizer causing beneficial effects on plants growth and soil structure (Refer left column on page 185) suggesting use of nutrients of the sludge for plant growth and soil enrichment.
Regarding claim 7, modified Yamazaki teaches limitations of claim 1 as set forth above. Ennouri further teaches that the thermal conditioning step is thermal hydrolysis process (refer page 185 – left column), and that the anaerobic digestion is performed downstream of thermal hydrolysis (Refer graphical abstract) and produces methane and sludge.
Regarding claim 10, Yamazaki teaches limitations of claim 1 as set forth above. Yamazaki further teaches that the primary sludge is subject to anaerobic digestion prior to incineration (Refer 2nd paragraph on page 2).
Claim(s) 6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Yamazaki, in view of Ennouri as applied to claim 1 above, and further in view of Yu et al. (Applied Energy 229 (2018) 88–95).
Regarding claim 6, modified Yamazaki teaches limitations of claim 1 as set forth above. Ennouri teaches that the anaerobic digestion produces methane and solids (Refer abstract). Modified Yamazaki does not teach subjecting solids of anaerobic digestor to hydro thermal carbonization.
Yu teaches hydrothermal carbonization of anaerobic sludge to produce hydrochar and improve nutrient recovery (refer abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of modified Yamazuki to subject the anaerobic solids to hydrothermal carbonization to produce hydrochar and improve nutrient recovery as taught by Yu.
Regarding claim 9, modified Yamazaki teaches limitations of claim 6 as set forth above. Yu further teaches using solid fraction produced from HTC as fertilizer (refer abstract).
Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over Yamazaki, in view of Ennouri and Yu as applied to claim 6 above, and further in view of Tale (US 2017/0121197).
Regarding claim 8, modified Yamazaki teaches limitations of claim 6 as set forth above. Modified Yamazaki does not teach separating digestate of anaerobic digestion into liquid and solid fraction. However, such process is well known in the art. Tale teaches anaerobic digestion of secondary sludge (refer step 46) and dewatering the digestate by separating solids and liquid fraction (Refer liquid fraction 60 returned to the process). Selecting dewatering process would have been an obvious matter of design choice to one of ordinary skill in the art from known dewatering processes.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamazaki, in view of Ennouri as applied to claim 1 above, and further in view of Ju et. al. (US 2016/0090317).
Regarding claim 11, modified Yamazaki teaches limitations of claim 1 as set forth above. Yamazaki does not teach anaerobic digestion of the biological sludge, and oxidizing the secondary sludge before the step of anaerobic digestion.
Ju teaches treatment of waste activated sludge by anaerobic digestion (Refer fig. 2, step 30), wherein the waste activated sludge is oxidized (refer step 14) prior to anaerobic digestion.
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of Yamazaki to provide a step of anaerobic digestion to produce biogas and perform oxidizing prior to anaerobic digestion to allow growth of active microorganism as taught by Ju.
Claim(s) 1, 4, 5, and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Komline (US 3803806), in view of Ennouri et al. (Bioresource Technology 214 (2016) 184–191).
Regarding claim 1, Komline teaches a method for selectively removing contaminants from sludge, said method comprising:
a) providing wastewater contaminated with contaminants (refer fig. 1 disclosing raw sewage being supplied to primary tank 16),
b) subjecting said wastewater to a primary treatment step (refer fig. 1 disclosing raw sewage being supplied to primary tank 16), thereby producing a first stream of primary sludge comprising a first part of contaminants ( refer primary sludge taken out by conduit 18) and a second stream of remaining wastewater comprising a second part of contaminants (refer conduit 32),
c) subjecting the second stream of remaining wastewater to a secondary treatment step, thereby producing biological sludge (refer aeration tank 34 and secondary settling tank 42), and
d) subjecting the first stream of primary sludge to an incineration step (refer incinerator 28 connected to primary sludge), thereby eliminating the primary sludge and the first part of contaminants and producing ashes and heat (Refer fig. 1 indicating hot flue gases and ashes generated from incineration step).
Komline does not teach anaerobic digestion of the biological sludge, thereby producing methane and a solid product, and subjecting the biological sludge to a thermal conditioning step upstream or downstream of the anaerobic digestion step.
Ennouri teaches treatment of waste activated sludge, wherein the waste activated sludge is subject to thermal conditioning (refer thermal pre-treatment in graphical abstract), after the thermal preconditioning, the sludge is subject to anaerobic digestion to produce methane and solids (Refer ASBR reactor in graphical abstract). Ennouri discloses that thermal preconditioning improves digester performance (refer abstract).
It would have been obvious to one of ordinary skill in the art to modify the method of Komline to include steps of anaerobic digestion of the biological sludge, thereby producing methane and a solid product, and subjecting the biological sludge to a thermal conditioning step upstream or downstream of the anaerobic digestion step to generate methane that can be used for heating or as electricity source as taught by Ennouri (Refer left column on page 185).
Komline teaches using heat produced by the incinerator for treatment of the second stream of primary treatment (Refer fig. 1, hot flue gas is supplied to aeration tank). Selecting where to use the heat produced from incineration step in the method of modified Komline would have been an obvious matter of choice to one of ordinary skill in the art since Yamazaki discloses use of heat generated from incineration to other parts of process.
Regarding claim 4, modified Komline teaches limitations of claim 1 as set forth above. The limitations of claim 4 do not recite any additional step and rather recites results of the method steps of claim 1. Since modified Komline teaches the all limitations of claim 1, the results of the method as claimed in claim 4 are inherent.
Regarding claim 5, modified Komline teaches limitations of claim 1 as set forth above. Ennouri further teaches that anaerobic sludge is found to be an effective organic fertilizer causing beneficial effects on plants growth and soil structure (Refer left column on page 185) suggesting use of nutrients of the sludge for plant growth and soil enrichment.
Regarding claim 7, modified Komline teaches limitations of claim 1 as set forth above. Ennouri further teaches that the thermal conditioning step is thermal hydrolysis process (refer page 185 – left column), and that the anaerobic digestion is performed downstream of thermal hydrolysis (Refer graphical abstract) and produces methane and sludge.
Claim(s) 6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Komline, in view of Ennouri as applied to claim 1 above, and further in view of Yu et al. (Applied Energy 229 (2018) 88–95).
Regarding claim 6, modified Komline teaches limitations of claim 1 as set forth above. Ennouri teaches that the anaerobic digestion produces methane and solids (Refer abstract). Modified Yamazaki does not teach subjecting solids of anaerobic digestor to hydro thermal carbonization.
Yu teaches hydrothermal carbonization of anaerobic sludge to produce hydrochar and improve nutrient recovery (refer abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of modified Komline to subject the anaerobic solids to hydrothermal carbonization to produce hydrochar and improve nutrient recovery as taught by Yu.
Regarding claim 9, modified Komline teaches limitations of claim 6 as set forth above. Yu further teaches using solid fraction produced from HTC as fertilizer (refer abstract).
Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over Komline, in view of Ennouri and Yu as applied to claim 6 above, and further in view of Tale (US 2017/0121197).
Regarding claim 8, modified Komline teaches limitations of claim 6 as set forth above. Modified Komline does not teach separating digestate of anaerobic digestion into liquid and solid fraction. However, such process is well known in the art. Tale teaches anaerobic digestion of secondary sludge (refer step 46) and dewatering the digestate by separating solids and liquid fraction (Refer liquid fraction 60 returned to the process). Selecting dewatering process would have been an obvious matter of design choice to one of ordinary skill in the art from known dewatering processes.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Komline, in view of Ennouri as applied to claim 1 above, and further in view of Ju et. al. (US 2016/0090317).
Regarding claim 11, modified Komline teaches limitations of claim 1 as set forth above. Komline does not teach anaerobic digestion of the biological sludge, and oxidizing the secondary sludge before the step of anaerobic digestion.
Ju teaches treatment of waste activated sludge by anaerobic digestion (Refer fig. 2, step 30), wherein the waste activated sludge is oxidized (refer step 14) prior to anaerobic digestion.
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of Yamazaki to provide a step of anaerobic digestion to produce biogas and perform oxidizing prior to anaerobic digestion to allow growth of active microorganism as taught by Ju.
Response to Arguments
Applicant's arguments filed 01/28/2026 have been fully considered but they are not persuasive.
Regarding rejection of claims 1, 3-5, 7 and 10 under 35 USC 103(a) as being unpatentable over Yamazaki (JP S6171899), in view of Ennouri (Bioresource Technology 214 (2016) 184–191); and rejection of claims 1, 3, 4, and 7 under 35 U.S.C. 103 as being unpatentable over Komline (US 3803806), in view of Ennouri et al. (Bioresource Technology 214 (2016) 184–191), applicant argued:
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This is not found to be persuasive. It should be noted that claim recites “wherein the heat produced in step d) (which is incineration step) is provided to the thermal conditioning step”. Office action page 3 indicated that Yamazaki alone does not teach thermal conditioning step. Yamazaki teaches using heat produced in incineration to heat secondary sludge. Therefore, Yamazaki establishes that heat produced in one step can be used in another step. One of ordinary skill in the art would realize that reusing heat would provide benefit of requiring less “new” heat. Office action does not suggest that reuse of heat from incineration should be the only source of heat in thermal conditioning. Neither does the claim require that the only source of heat should come from reusing heat from step d. Similarly, reusing heat from incineration step of Komline in thermal conditioning would have been obvious to one of ordinary skill in the art.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant further argued:
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This is not found to be persuasive. Page 26 of the specification provides a table with a comparison between “invention” against incineration only, digestion only, and digestion+incineration. However, the table does not state whether the “invention” column includes reuse of heat or it is simply combination of digesion+incineration+thermal conditioning. Since a clear distinction is not provided in the specification, the argument of unexpected and synergistic results for reuse of heat is not found to be persuasive.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 4769149 teaches a recovery of energy from waste and residues, wherein solids are subjected to incineration in a furnace in order to produce thermal energy recovered in at least one heat recuperator, the respective two steps of bacterial digestion and of incineration being joined together so that at least one of the two steps uses at least partially the production of energy of the other step, enabling the conditions of operation of the receiving step to be optimized (Refer abstract, C1/L21-38).
US 2019/0144321 teaches a process for treating primary sludge in a wastewater treatment plant, and a method of improving the energy balance of a wastewater treatment plant, wherein the dewatered primary sludge cake obtained in the present process is burned to provide energy in the form of heat and/or electricity, which may be used within the plant or may be sold (refer abstract, [0041]).
US 2007/0217995 teaches a sewage treatment plant, there is installed a methane fermentation treatment apparatus for sewage or the like, and digestion gas (biogas) having methane as a principal component thereof is produced here. This biogas can be heated using heating means, and used as the reducing gas supplied into the high-temperature steam electrolysis apparatus, wherein the high-temperature steam can be manufactured from water using heating means using waste heat from a waste incineration plant that is, for example, adjacent to the sewage treatment plant. In this case, the waste heat from the waste incineration plant supplied may also be used as a heating source for the methane fermentation apparatus (refer [0181]-[0182]).
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/PRANAV N PATEL/Primary Examiner, Art Unit 1777