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        <link:roleType roleURI="http://perma-fix.com/role/SubsequentEventsDetailsNarrative" id="SubsequentEventsDetailsNarrative">
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    <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
    <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
    <import namespace="http://xbrl.sec.gov/dei/2026" schemaLocation="https://xbrl.sec.gov/dei/2026/dei-2026.xsd" />
    <import namespace="http://fasb.org/us-gaap/2026" schemaLocation="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd" />
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    <import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd" />
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    <import namespace="http://fasb.org/srt-types/2026" schemaLocation="https://xbrl.fasb.org/srt/2026/elts/srt-types-2026.xsd" />
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    <element id="PESI_TimeAndMaterialsMember" name="TimeAndMaterialsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_TreatmentMember" name="TreatmentMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_FixedPriceMember" name="FixedPriceMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ServicesMember" name="ServicesMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DomesticGovernmentMember" name="DomesticGovernmentMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DomesticCommercialMember" name="DomesticCommercialMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ForeignGovernmentMember" name="ForeignGovernmentMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ForeignCommercialMember" name="ForeignCommercialMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_YearToDateChangesMember" name="YearToDateChangesMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SoftwareMember" name="SoftwareMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PermitsMember" name="PermitsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DirectorStockOptionsMember" name="DirectorStockOptionsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_EmployeeAndDirectorsMember" name="EmployeeAndDirectorsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_TwoThousandThreeOutsideDirectorsStockOptionPlanMember" name="TwoThousandThreeOutsideDirectorsStockOptionPlanMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PortionOfDirectorFeeEarnedInCommonStockMember" name="PortionOfDirectorFeeEarnedInCommonStockMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_StockOptionOutstandingOneMember" name="StockOptionOutstandingOneMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_StockOptionVestedTwoMember" name="StockOptionVestedTwoMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_StockOptionOutstandingThreeMember" name="StockOptionOutstandingThreeMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_RevolvingCreditMember" name="RevolvingCreditMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_TermLoanMember" name="TermLoanMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CapitalLoanMember" name="CapitalLoanMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_NotesPayableMember" name="NotesPayableMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_NotePayableMember" name="NotePayableMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PncLoanAgreementMember" name="PncLoanAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_LoanAgreementMember" name="LoanAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PNCBankMember" name="PNCBankMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_LenderMember" name="LenderMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PurchaseAndSalesAgreementMember" name="PurchaseAndSalesAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PermaFixNorthwestRichlandIncMember" name="PermaFixNorthwestRichlandIncMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_AmericanInternationalGroupIncMember" name="AmericanInternationalGroupIncMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_FiniteRiskSinkingFundsMember" name="FiniteRiskSinkingFundsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PayrollMember" name="PayrollMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_OtherMember" name="OtherMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_TotalSegmentMember" name="TotalSegmentMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_UnderwritingAgreementMember" name="UnderwritingAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_UnderwriterMember" name="UnderwriterMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_OfferingMember" name="OfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_HanfordTankWasteOperationsAndClosureLLCMember" name="HanfordTankWasteOperationsAndClosureLLCMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_VehiclesGross" name="VehiclesGross" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DisposalTransportationAccrual" name="DisposalTransportationAccrual" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_IncreaseDecreaseInUnbilledReceivable" name="IncreaseDecreaseInUnbilledReceivable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_IncreaseDecreaseInAccountsPayableAccruedExpensesAndUnearnedRevenue" name="IncreaseDecreaseInAccountsPayableAccruedExpensesAndUnearnedRevenue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PropertyAndEquipmentPurchaseSubjectToFinancing" name="PropertyAndEquipmentPurchaseSubjectToFinancing" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PropertyAndEquipmentPurchaseSubjectToFinanceLeases" name="PropertyAndEquipmentPurchaseSubjectToFinanceLeases" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PropertyAndEquipmentAdditionsIncludedInAccountsPayable" name="PropertyAndEquipmentAdditionsIncludedInAccountsPayable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_LesseeOperatingAndFinanceLeasesTextBlock" name="LesseeOperatingAndFinanceLeasesTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DisclosureSaleOfCommonStockAbstract" name="DisclosureSaleOfCommonStockAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SaleOfCommonStockTextBlock" name="SaleOfCommonStockTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_NewAccountingPronouncementsNotYetAdoptedPolicyTextBlock" name="NewAccountingPronouncementsNotYetAdoptedPolicyTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ScheduleOfWeightedAverageLeaseTableTextBlock" name="ScheduleOfWeightedAverageLeaseTableTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_OperatingLeaseAndFinanceLeaseLiabilityMaturityTableTextBlock" name="OperatingLeaseAndFinanceLeaseLiabilityMaturityTableTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ScheduleOfSupplementalCashFlowAndOtherInformationRelatedToLeasesTableTextBlock" name="ScheduleOfSupplementalCashFlowAndOtherInformationRelatedToLeasesTableTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ScheduleOfUnallocatedCorporateExpensesTableTextBlock" name="ScheduleOfUnallocatedCorporateExpensesTableTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DepreciationAndAmortizationTableTextBlock" name="DepreciationAndAmortizationTableTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_NetCashProvidedByUsedInOperatingActivitiesContinuingOperation" name="NetCashProvidedByUsedInOperatingActivitiesContinuingOperation" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ContractBalancesTable" name="ContractBalancesTable" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" />
    <element id="PESI_ContractBalancesLineItems" name="ContractBalancesLineItems" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ChangeInUnbilledReceivablesCurrentPercentage" name="ChangeInUnbilledReceivablesCurrentPercentage" nillable="true" xbrli:periodType="duration" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ChangesInDeferredRevenuePercentage" name="ChangesInDeferredRevenuePercentage" nillable="true" xbrli:periodType="duration" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ChangeInAccountsReceivablesPercentage" name="ChangeInAccountsReceivablesPercentage" nillable="true" xbrli:periodType="duration" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_FinanceLeaseCost" name="FinanceLeaseCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_LossPerCommonShareFromContinuingOperationsAbstract" name="LossPerCommonShareFromContinuingOperationsAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PromissoryNoteLineitems" name="PromissoryNoteLineitems" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ReductionInRevlovingBorrowingAvailability" name="ReductionInRevlovingBorrowingAvailability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_LiquidityValueUnderCreditFacility" name="LiquidityValueUnderCreditFacility" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CommitmentsAndContingenciesTable" name="CommitmentsAndContingenciesTable" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" />
    <element id="PESI_CommitmentsAndContingenciesLineItems" name="CommitmentsAndContingenciesLineItems" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SelfinsuredRetention" name="SelfinsuredRetention" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PeriodOfFiniteRiskInsurancePolicy" name="PeriodOfFiniteRiskInsurancePolicy" nillable="true" xbrli:periodType="duration" type="xbrli:durationItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_MaximumAllowableCoverageOfInsurancePolicy" name="MaximumAllowableCoverageOfInsurancePolicy" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CoverageAmountUnderPolicy" name="CoverageAmountUnderPolicy" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_InsurersObligationToEntityOnTerminationOfContract" name="InsurersObligationToEntityOnTerminationOfContract" nillable="true" xbrli:periodType="instant" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_BondOutstanding" name="BondOutstanding" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ReimbursementOfContributionsAndExpenses" name="ReimbursementOfContributionsAndExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DisposalGroupIncludingDiscontinuedOperationOtherAssetsCurrent" name="DisposalGroupIncludingDiscontinuedOperationOtherAssetsCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_DisposalGroupIncludingDiscontinuedOperationClosureNoncurrentLiabilities" name="DisposalGroupIncludingDiscontinuedOperationClosureNoncurrentLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CostPayrollAndBenefitsExpenses" name="CostPayrollAndBenefitsExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CostDisposalExpenses" name="CostDisposalExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CostTransportationExpenses" name="CostTransportationExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_CostSubcontractExpenses" name="CostSubcontractExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PayrollAndBenefits" name="PayrollAndBenefits" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_OperatingIncomeLossExcludesCorporateExpenses" name="OperatingIncomeLossExcludesCorporateExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_UnallocatedCorporateExpenses" name="UnallocatedCorporateExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_PayrollUnallocatedCorporateExpenses" name="PayrollUnallocatedCorporateExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_OtherUnallocatedCorporateExpenses" name="OtherUnallocatedCorporateExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SaleOfCommonStockAbstract" name="SaleOfCommonStockAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SaleOfCommonStockTable" name="SaleOfCommonStockTable" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" />
    <element id="PESI_TotalCashFeePercentage" name="TotalCashFeePercentage" nillable="true" xbrli:periodType="instant" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_ContractMetricsDescription" name="ContractMetricsDescription" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_EquipmentPurchaseSubjectToFinanceLease" name="EquipmentPurchaseSubjectToFinanceLease" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_EquipmentPurchaseSubjectToFinancing" name="EquipmentPurchaseSubjectToFinancing" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_SegmentsTotalMember" name="SegmentsTotalMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="PESI_UnderwriterExpenseReimbursement" name="UnderwriterExpenseReimbursement" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
</schema>
