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<!-- Modified on: 8/8/2022 7:45:43 PM --> |
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| | <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis_1" xlink:title="us-gaap_IncomeStatementLocationAxis_1"/> |
| | <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain_1" xlink:title="us-gaap_IncomeStatementLocationDomain_1"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_SwingLineLoanMember" xlink:label="hdsn_SwingLineLoanMember"/> |
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| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LetterOfCreditMember" xlink:label="us-gaap_LetterOfCreditMember"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_RevolvingCreditFacilityAmendmentMember" xlink:label="hdsn_RevolvingCreditFacilityAmendmentMember"/> |
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| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FederalFundsPurchasedMember" xlink:label="us-gaap_FederalFundsPurchasedMember"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_ApplicableLeverageRationMember" xlink:label="hdsn_ApplicableLeverageRationMember"/> |
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| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:label="us-gaap_ShortTermDebtTypeAxis"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_FCCRMember" xlink:label="hdsn_FCCRMember"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="1" xlink:from="us-gaap_ShortTermDebtTypeDomain" xlink:to="hdsn_FCCRMember" use="optional"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_PaycheckProtectionProgramMember" xlink:label="hdsn_PaycheckProtectionProgramMember"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_CaresActLoanMember" xlink:label="hdsn_CaresActLoanMember"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_FirstInLastOutTrancheMember" xlink:label="hdsn_FirstInLastOutTrancheMember"/> |
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| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_PeriodForFixedChargeCoverageRatio" xlink:label="hdsn_PeriodForFixedChargeCoverageRatio"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="9" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_PeriodForFixedChargeCoverageRatio" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="10" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="11" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredOfferingCosts" xlink:label="us-gaap_DeferredOfferingCosts"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="12" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DeferredOfferingCosts" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnsecuredDebt" xlink:label="us-gaap_UnsecuredDebt"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="13" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_UnsecuredDebt" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtTerm" xlink:label="us-gaap_LongTermDebtTerm"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="14" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LongTermDebtTerm" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtInstrumentInterestDeferralTerm" xlink:label="hdsn_DebtInstrumentInterestDeferralTerm"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="15" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtInstrumentInterestDeferralTerm" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityExpirationPeriod" xlink:label="us-gaap_LineOfCreditFacilityExpirationPeriod"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="16" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LineOfCreditFacilityExpirationPeriod" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtPrepaymentPremiumPercentageYearOne" xlink:label="hdsn_DebtPrepaymentPremiumPercentageYearOne"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="17" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtPrepaymentPremiumPercentageYearOne" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtPrepaymentPremiumPercentageYearTwo" xlink:label="hdsn_DebtPrepaymentPremiumPercentageYearTwo"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="18" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtPrepaymentPremiumPercentageYearTwo" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtPrepaymentPremiumPercentageYearThree" xlink:label="hdsn_DebtPrepaymentPremiumPercentageYearThree"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="19" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtPrepaymentPremiumPercentageYearThree" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtPrepaymentPremiumPercentageYearFourAndThereafter" xlink:label="hdsn_DebtPrepaymentPremiumPercentageYearFourAndThereafter"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="20" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtPrepaymentPremiumPercentageYearFourAndThereafter" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_PaymentsProtectionProgramForgiveness" xlink:label="hdsn_PaymentsProtectionProgramForgiveness"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="21" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_PaymentsProtectionProgramForgiveness" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="us-gaap_ProceedsFromLinesOfCredit"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="22" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromLinesOfCredit" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_PrincipalPaymentAsPercentageOfOriginalPrincipalAmountOfOutstandingTermLoanPerAnnum" xlink:label="hdsn_PrincipalPaymentAsPercentageOfOriginalPrincipalAmountOfOutstandingTermLoanPerAnnum"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="23" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_PrincipalPaymentAsPercentageOfOriginalPrincipalAmountOfOutstandingTermLoanPerAnnum" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="24" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="hdsn-20220630.xsd#hdsn_DebtInstrumentPaymentExcessCashFlowAmount" xlink:label="hdsn_DebtInstrumentPaymentExcessCashFlowAmount"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="25" xlink:from="us-gaap_StatementLineItems" xlink:to="hdsn_DebtInstrumentPaymentExcessCashFlowAmount" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts" xlink:label="us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="26" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="27" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DeferredFinanceCostsNet" priority="1" use="optional"/> |
| | <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityPeriodicPaymentInterest" xlink:label="us-gaap_LineOfCreditFacilityPeriodicPaymentInterest"/> |
| | <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" order="28" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LineOfCreditFacilityPeriodicPaymentInterest" priority="1" use="optional"/> |
| | </definitionLink> |
| </link:linkbase> |