Risk Analysis and Optimization of Fishing Port Waste Water Treatment Plant Using Fault Tree Analysis Method

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1 J. Appl. Environ. Biol. Sci., 7(2) , , TextRoad Publication ISSN: Journal of Applied Environmental and Biological Sciences Risk Analysis and Optimization of Fishing Port Waste Water Treatment Plant Using Fault Tree Analysis Method Diki I. Perdana* and Nieke Karnaningroem Department of Environmental Engineering, Faculty of Civil Engineering and Planning, Institut Teknologi Sepuluh Nopember (ITS) Surabaya, 60111, Indonesia ABSTRACT Received: October 23, 2016 Accepted: January 1, 2017 This research will analyze the potential risks that will jeopardize the performance of fishing port Waste Water Treatment Plant (WWTP) and propose an optimization strategy. The variables of the analysis are human resource capacity, machinery and tools, and wastewater treatment process. The operations of WWTP will be analyzed using Failure Mode Effect Analysis (FMEA) to discover the factors of potential risks. The risks will then be scrutinized to find out the true causes of the problems using Fault Tree Analysis (FTA) method and be calculated on the value of probability and its consequences to determine into which category in the risk matrix that they will fall. Pursuant to the risk matrix, an optimization will be strategized by mitigating the risks. Optimization priority will be given to those with the category of Severe and High. The major causes of decremental effluent quality reside on the factor of machinery and tools i.e. defective flow meter and hydroextractor; the factor of wastewater treatment process i.e. the value of BOD loading, recirculation ratio, airflow, and the substandard efficiency of the aeration tank; and the factor of human resource i.e. the inadequate capacity of the technicians due to absence of training on wastewater treatment and WWTP operations. KEYWORDS: Risk Analysis, Failure Mode Effect Analysis, Fault Tree Analysis, Wastewater Treatment Plant (WWTP), Optimization. INTRODUCTION Pelabuhan Perikanan Samudera Nizam Zachman Jakarta is the largest fishing port in Indonesia of which industrial zone is packed with small- to large-scale fish processing business entities. Their wastewater contains high organic matter [1], and the level of pollution very much depends on the type of processing and of the processed raw material [2]. The fishing port Wastewater Treatment Plant (WWTP) applies biological treatment using activated sludge technology, with the maximum treatment capacity of m 3 /day, the wastewater contains maximum BOD 500 mg/l and TSS of 500 mg/l [3]. Data of periodical inspection on the quality of the WWTP effluent from 2013 to 2015 demonstrate that 87% of the effluent do not meet the standard quality. A number of factors have caused the failure and measures have been taken to address the issue, however they have yet to increase the WWTP performance as targeted. Therefore, methods for risk identification and analysis are needed. Some of the commonly used ones are Failure Mode Effect Analysis (FMEA) and Fault Tree Analysis (FTA). Both can be used as an instrument to develop a process, product, or service [4]. To obtain an optimum condition, the identified risk will be analyzed to determine and measure, as well as assess each of the elements of problem-causing factors [5]. Fault Tree Analysis has ability to analyze system failure and to determine risk-causing factors from the smallest element [5], [6], [7], [8] and [9]. The risk factors will be measured and assessed by considering their probability and consequences. Risk assessment is important in determining risk category based on risk matrix [10]. The objectives of this research are evaluating the WWTP operations and identifying factors that have caused the failure; and analyzing risk category and determining priority for optimization in order to optimize the WWTP treatment and operation performances. If the WWTP operations and treatment performances are optimum, the effluent quality will meet the standard quality and reduce the level of pollution in the receiving waters. MATERIALS AND METHODS In this research, the risk analysis and performances optimization are carried out using descriptive quantitative method. Research activities include field observation on the WWTP operations, effluent sample testing, questionnaire and interview, evaluation of the WWTP performances, and data analysis and interpretation. The data collected for risk identification and determination are: *Corresponding author: Diki Indra Perdana, Department of Environmental Engineering, Faculty of Civil Engineering and Planning, Institut Teknologi Sepuluh Nopember (ITS), Surabaya, 60111, Indonesia. dikiindraperdana@gmail.com 134

2 Perdana and Karnaningroem, WWTP Planning/Design documents. 2. WWTP Standard Operating Procedure or Operation and Maintenance Manual. 3. Sampling and effluent quality testing according to standard quality [11]. 4. Daily operation report of the operator and technician (malfunction and troubleshooting). 5. Maintenance, repair, and replacement of WWTP machinery and tools. 6. Personnel Data, Job Description and Personnel Workload Analysis. 7. WWTP operation and maintenance budget. The risk identification steps using FMEA method are: a. reviewing every unit of process in WWTP, b.composing Fishbone Diagram for the reviewed aspects, c. identifying risk by taking into account affecting factors, and d. validating and determining risk as top event. Next, risk analysis is conducted using Fault Tree Analysis method which comprise of two steps: a. quantitative analysis i.e. composing Fault Tree diagram and b. quantitative analysis which includes value of Probability, Likelihood and Consequence. Table 1. Criteria of Probability or Likelihood Value Category Description Value Range Rare The performed activities rarely cause risk to the environment <10% Unlikely The performed activities may cause risk to the environment 11 30% Moderate The performed activities will possibly cause risk to the environment 31 60% Likely The performed activities will probably cause risk to the environment 61 80% Almost Certain The performed activities will cause risk to the environment >81% Source: [10] Table 2. Criteria of Consequences Value Category Description Value Range Negligible Risk consequences to the environment are insignificant <10% Low Risk consequences expose minor negative impact to the environment but, in order to reduce 11 30% possible risk, necessary actions such as on-site troubleshooting are needed Medium Risk consequences expose intermediate negative impact to the environment, thus management 31 60% based on normal procedure is needed High Risk consequences expose major negative impact to the environment, thus intensive 61 80% management measures are needed to tackle the issue Extreme Risk consequences are very destructive to the environment >81% Source: [10] The obtained risk value will be evaluated based on the category of risk level [9] and cross-checked in the risk map. Risk of highest level will be given priority for optimization. RESULTS AND DISCUSSION A. Risk Identification The purpose of risk identification is to recognize any possible risks so that the system can be optimized by preventing or minimizing the event. Based on data, interview, and observation, it can be identified that risk factors are human resource, machinery and tools, and wastewater treatment process. The benchmark for WWTP performance failure is the decremental effluent quality which goes below the standard quality [11]. In each of the risk factors, there are several risk subfactors that influence the value of risk factor. Figure 1. Fishbone Diagram of WWTP Decremental Effluent Quality 135

3 J. Appl. Environ. Biol. Sci., 7(2) , 2017 B. Risk Analysis and Evaluation Determining Probability and Likelihood The probability calculation is done by plugging the value of frequency of event and frequency of process that have been determined from each of the components of root events into the following formula: where: P : Probability Fp : Frequency of Process Fk : Frequency of Event The result of the probability calculation on each factor and subfactor will then be plugged into a mathematical formula which is an expression of quantitative logic of Fault Tree qualitative analysis to have the value of likelihood. Mathematical formula for factor of human resource (HR) is as follows: P HR = P quantity + P quality + P job description + P guidance & supervision = {P operator + P technician + P analyst} + {P education + P expert + P operation} + {P SOP + P unfeasible of SOP + P implementation of SOP} + {P person in charge + P work report + P assestment of performance} = {P operator + P technician + P analyst} + {P education + P expert + (P training x P literature)}+ {P SOP+ (P tools x P method) + P implementation of SOP} + {P person in charge + P work report + (P evaluation+ P sanction)} Figure 2. Fault Tree Diagram of Factor of Human Resource Figure 3. Fault Tree Diagram of Factor of Machinery and Tools 136

4 Perdana and Karnaningroem,2017 The following is the mathematical formula for the factor of machinery and tools: P Machinery &Tools = P manhole pump + P flowmeter + P blower + P diffuser + P lift pump + P sludge circulation pump + P hydroextractor = {P condition/function+ P spare part+ P lifetime + P maintenance} + {P condition/function + P spare part + P repair} + {P condition/function + P capacity + P spare part + P lifetime + P maintenance} + {P condition/function + P placement + P maintenance} + {P condition/function + P spare part + P lifetime + P maintenance} + {P condition/function + P spare part + P lifetime + P maintenance} + {P condition/function + P spare part + P repair} = {P condition/function + P spare part + P lifetime + P maintenance} + {(P jammed x P out of order) + P spare part + P repair} + {P condition/function + P capacity + P spare part + P lifetime + P maintenance} + {(P clogged x P out of order) + P placement + P maintenance} + {P condition/function + P spare part + P lifetime + P maintenance} + {P condition/function + P spare part + P lifetime + P maintenance} + {(P nonoperational x P out of order) + P spare part + P repair} Figure 4. Fault Tree Diagram of Factor of Treatment Process Mathematical formula for the factor of treatment process is as shown below: P process = P buffer tank + P aeration tank + P sedimentation tank = {P td} + {P BOD loading + P air required + P aeration time + P RAS + P efficiency} + {P td + P efficiency} = {P Q x P volume} + {P BOD loading + P air required + P aeration time + P RAS+ P efficiency} + {P td + P efficiency} Determination of Consequence Consequence is an effect/impact of an event that is usually expressed as a loss caused by that event. The value of Consequence is obtained from the calculation of each of the factors in the Fault Tree Diagram. The result will then be categorized according to the range of value attained from the value of Consequence/the largest impact with the category of Extreme observed in the factor of Machinery and Tools (Flowmeter and Hydroextractor components) and factor of Treatment Process (Aeration Tank components). Risk Mapping The results of the calculation of Likelihood and Consequence are plotted into a matrix of risk level category with Consequence on the X-axis and Likelihood on the Y-axis. The plotting will then become the risk map which will serve as the basis for designing strategy for optimization action. 137

5 J. Appl. Environ. Biol. Sci., 7(2) , 2017 Risk Factor Human Resource Machinery and Tools Process Subfactor Level 1 Quantity Quality Job Description Guidance & Supervision Inlet Pump (Manhole Pump) Flowmeter Blower Diffuser Lift Pump Sludge Recirculation Pump Hydroextractor Buffer Tank Aeration Tank Sedimentation Tank (Clarifier) Table 3. Recapitulation of Risks Assessment Subfactor Level 2 Subfactor Level 3 Category of Probability Category of Consequence Category of Risk WWTP Operator Likely Medium Major Mechanic and Likely Medium Major Electrician Laboratory Analyst Almost Certain Medium High Education Level Likely High High Expert Moderate High Major Comprehension Training Almost Certain High Severe on WWTP Reference/ Likely High High Operations Literature Set of SOP Likely Medium Major Unfeasible SOP Tools Almost Certain Medium High Methods Likely Medium Major Implementation of Almost Certain Medium High SOP Person in Charge Likely Medium Major Work Report Likely Medium Major Assessment of Evaluation Likely Medium Major Performance Sanction Almost Certain Medium High Condition/ Likely Low Significant Function Spare Parts Likely Low Significant Pump Lifetime Moderate Low Moderate Maintenance Likely Low Significant Condition/ Jammed Unlikely Extreme Major Function Out of Order Almost Certain Extreme Severe Spare Parts Almost Certain Extreme Severe Repair Almost Certain Extreme Severe Condition/ Likely Low Significant Function Capacity Likely Low Significant Spare Parts Likely Low Significant Blower Lifetime Moderate Low Significant Maintenance Likely Low Significant Condition/ Clogged Likely Low Significant Function Out of Order Moderate Low Moderate Placement Moderate Low Moderate Maintenance Moderate Low Moderate Condition/ Likely Low Significant Function Spare Parts Likely Low Significant Pump Lifetime Moderate Low Moderate Maintenance Likely Low Significant Condition/ Moderate Low Moderate Function Spare Parts Moderate Low Moderate Pump Lifetime Moderate Low Moderate Maintenance Moderate Low Moderate Condition/ Non Operational Almost Certain Extreme Severe Function Out of Order Unlikely Extreme Major Spare Parts Almost Certain Extreme Severe Repair Almost Certain Extreme Severe Influent Moderate Negligible Trivial Detention Time Discharge Tank Volume Unlikely Negligible Trivial BOD Loading Almost Certain Extreme Severe Air Intake Likely Extreme Severe Aeration Time Moderate Extreme High Circulation Ratio Almost Certain Extreme Severe Efficiency Likely Extreme Severe Detention Time Almost Certain Negligible Trivial Efficiency Likely Negligible Trivial 138

6 Perdana and Karnaningroem,2017 Likelihood Human Resource Almost Certain Likely Moderate Unlike Rare Table 4. Map of Risk Category Consequence Extreme High Medium Low Negligible Severe Severe High Major Trivial Out of Order, Spare Training Laboratory Parts & Repair Analyst Tools (Flowmeter) Implementation of Non Operational SOP (Hydroextractor) Sanction BOD Loading Sludge Circulation Ratio Severe High Major Significant Trivial Air Required Efficiency (Aeration Tank) Education Level Reference/ Literature STP Operator Mechanic & Electrician Set of SOP Method Person in Charge Work Report Evaluation Condition/Function, Spare Parts & Maintenance (Inlet Pump) Condition/Function, Spare Parts & Maintenance (Blower) Clogged (Diffuser) Condition/Function, Spare Parts & Maintenance (Lift Pump) Efficiency (Clarifier) High Major Significant Moderate Trivial Aeration Time Expert Lifetime (Inlet Pump) Lifetime (Blower) Out of Order, Placement & Maintenance (Diffuser) Lifetime (Lift Pump) Condition/Function, Spare Parts, Lifetime & Maintenance (Sludge Circulation Pump) Effluent Discharge Major Significant Moderate Low Trivial Jammed (Flowmeter) Out of Order (Hydroextractor) Tank Volume (Buffer Tank) Significant Moderate Low Trivial Trivial C. Optimization Action The method that will be used for optimization is risk mitigation. Risk mitigation is risk management with the strategy to reduce the frequency of risk events and prevent the emergence of other risks. The optimization is focused more on the last level of subfactor (minimal cut set), or on the problem-causing root as identified with FTA method. Mitigation strategy is carried out by taking into account the scale of priority. The recommendations are actualized starting from the highest risk criterion (Severe) which imposes the largest potential in decrementing the WWTP performances. Next, the optimization is performed gradually for risks with the category of High and Major by of course considering availability of budget. Table 5. Recommendation and Estimation of Optimization Cost (Risk Category of Severe and High) Risk Category Severe Recommended Mitigation Plan Requisite/Investment Cost (IDR) Outcome Routinely sending relevant personnel to technical training of WWTP operations Replacing Flowmeter with the one needed and specifically designed to endure the WWTP environment Supplying fast-moving spare parts of the Flowmeter Conducting periodical maintenance and repair of Flowmeter every month - Training of Wastewater Treatment and WWTP 30,000,000 Operations (6 once/year) - Courses for Mechanic and Electrician (6 15,000,000 once/year) - Sewage Hi-Flowmeters (1 unit for reserve) 30,000,000 - Flowmeter maintenance (quarterly) 600,000 Increased proficiency and skill of the personnel which will result in better performance Known effluent intake so that WWTP treatment load is assessable 139

7 J. Appl. Environ. Biol. Sci., 7(2) , 2017 High Proposing the reactivation of hydroextractor operation Supplying fast-moving spare parts Conducting periodical maintenance every month Routinely monitoring and assessing BOD load intake and soliciting industry to pretreat their effluent Replacing DO meter monitoring device for out-of-order DO meter, ORP & ph meter and monitoring the performance of the blower & hyper rater Controlling, monitoring and daily registering the process of active sludge recirculation (20-40%) Monitoring and maintaining processes criteria at designed criteria by conducting periodical assessment/calibration and registration Employing a Laboratorium Analyst Replacing and/or hiring more operators based on evaluation of performance & competence Enriching references/literature relevant to WWTP processes and operations Procuring necessary tools as mentioned in the SOP Conducting regular monitoring and supervision to WWTP operators Imposing sanction based on applicable personnel regulations - Filter Press machine repair 250,000,000 - Spare Parts of machinery and electrical tools 30,000,000 - Machinery and tools maintenance (12 IDR ,-) 60,000,000 - Portable COD meter 8,500,000 - Tools/sensor of DO meter, ORP and ph meter including monitor 25,000,000 - Automatic sensor and timer of sludge circulation pump 500,000 - Recruiting personnel (1 person, 13 months of salary) 43,550,000 Hydroextractor being able to treat sludge, by-product of biological process, which is usually dumped and pollutes the waters Known intake load to WWTP to prevent shock loading of the process Managed work of the blower to keep oxygen transfer at desirable rate Maintained number of microorganisms in aeration, extended sludge lifetime, and better process efficiency WWTP treatment performance in desired target and consistently maintained effluent quality More frequent and routine analysis of effluent quality - Hired personnel having the needed competence and skills - Mechanical and electrical working tools 30,000,000 - Monthly Meeting of Coordination and Evaluation (meeting consumption for 15 people x IDR ,-) 9,000,000 Monitoring and assuring that effluent intake does not exceed the WWTP capacity (1000 m3/day) and filling out logbook on daily basis Total Cost 532,150,000 Increased knowledge and understanding of the operators and technicians Better performances of the operators and technicians that will increase their productivity Evaluated performance, discussion and problem solving, and maintained communications and relations among personnel Increased work discipline and compliance of the operators Available data of daily effluent discharge and status of WWTP treatment capacity CONCLUSION Risk factors which influence the operations of WWTP are human resource, machinery and tools, and treatment process. Risk with the category of Severe can be observed in the following subfactors: absence of training for personnel, damaged Flowmeter without further repair and availability of spare parts, nonoperational and unmaintained hydroextractor, BOD loading exceeding WWTP capacity, unqualified air required and sludge circulation ratio, and low processing efficiency of aeration tank. Optimization action is prioritized for risk with the category of Severe and High with estimate cost of IDR ,-. 140

8 Perdana and Karnaningroem,2017 ACKNOWLEDGMENTS The authors would like to express their gratitude to the Ministry of Marine and Fisheries of the Republic of Indonesia, for granting the scholarship and fund for this research. REFERENCES [1] Gonzalez Wastewater Treatment in Fisheries Industry. FAO Fishery Technical Paper 335. Rome. [2] Ibrahim, B Review Active-Sludge Wastewater Biological Treatment System in Fishing Industry. Bulletin of Technology of Fishery Products. Vol. VIII, No. 1, pp [3] Pacific Consultants International Final Completion Report Jakarta Fishing Port Phase IV. Directorate General of Capture Fisheries. Ministry of Marine Affairs and Fisheries - Government of Indonesia. Jakarta. [4] Perdana R., dan Yuliawati E Integration of FMEA Method and Topsis to Analyze Risk of Accident on the process of Frame and Fork Welding. Journal of Industry Spectrum. Vol. 12, No. 1, pp [5] Apsari, M.N Risk Analysis and Optimization of Quality of Water Produced by Ngagel I Water Processing Installation. Thesis Department of Environmental Engineering, Faculty of Civil Engineering and Planning, Institut Teknologi Sepuluh Nopember. [6] Clemens, P.L Fault Tree Analysis 4th edition. [7] Occupational Safety and Health Administration (OSHA) Job Hazard Analysis. U.S. Department of Labor. [8] Syaifudin, M., Sugiono., dan Yuniarti, R Risk Analysis on the Workshop Division of PT. XYZ Branch Office Malang. Journal Purification Department of Industrial Engineering. Universitas Brawijaya. [9] Wulandari, T Analysis of Failure of System with Fault Tree. Essay. Mathematical Study Program. Faculty of Mathematics and Natural Sciences. Universitas Indonesia. [10] Government of Western Australia Guidelines for Managing Risk In The Western Australian Public Sectors. [11] The Regulation of the Minister of the Environment of the Republic of Indonesia No. 5 of 2014 concerning Standard Quality of Effluent. Ministry of the Environment and Forestry of the Republic of Indonesia. Attachment XIV.C Standard Quality of Effluent in Fishery Industrial Zone with Off-site Wastewater Treatment. 141

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