Author: ArifAnwar

প্র্যাকটিস ডাউনলোড

দ্বিভাষিক PDF ওয়ার্কশিট প্রিন্ট করে বা সম্পাদনাযোগ্য এক্সেলের সঙ্গে ব্যবহার করুন। উদাহরণগুলো শেখার জন্য; সাইটের অনুমোদিত প্রসিডিউর ও প্রয়োজন অনুযায়ী রেকর্ড সাজান।

• অপারেশন, ইনস্পেকশন ও হ্যান্ডওভার ওয়ার্কশিট (PDF · English / বাংলা)

হোমপেজে ফিরুন · প্র্যাকটিস রিসোর্স

বাংলা সংস্করণ পড়ুন

A high COD result and a darker outlet can point to different treatment problems. Trace the change upstream and compare tests made on the same basis before adjusting a dose.

Find what is driving the COD result

At ET-01, total outlet COD increases from 84 to 155 mg/L and total suspended solids (TSS) rise from 24 to 78 mg/L. Filtered COD changes from 60 to 63 mg/L. That pattern supports solids carryover as an important contributor to the total COD rise. Verify sample comparability, then check settling and the solids path.

Use a jar test to compare color treatment

For a color shift, check the production batch, EQ timing, pH, mixing, and actual chemical delivery. A supervised jar test compares a representative sample with an untreated control and approved trials under matched conditions. Record the method, pH, residual color, settling behavior, and sludge produced. The clearest-looking jar is one observation. A decision also uses measured quality, sludge handling, and the site’s approved operating procedure. The animation shows an illustrative comparison of jars after settling.

Further reading · IFC textile wastewater guidance

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Practice downloads

Use the bilingual PDF worksheets in print or alongside the editable Excel files. Examples are for learning; adapt the records to the approved procedures and requirements at your site.

• Operations, inspection and handover worksheets (PDF · English / বাংলা)

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বাংলা সংস্করণ পড়ুন

A lab result is useful when you can trace it back to the right water, at the right time, by the required method. Give the sample an identity before it leaves the sampling point.

Match the sample to the decision

A grab sample describes a particular time and point. A composite sample combines increments over a time or flow period and can help estimate an internal load where the method and analyte allow it. For regulated discharge testing, follow the applicable requirements and the site’s approved plan. Schedule 12 of Bangladesh’s Environment Conservation Rules, 2023 specifies grab sampling for the applicable discharge testing described there.

Use approved safe access. Follow the laboratory instructions for the bottle, field readings, preservation, transport, and holding time. Record the collector, sample point and ID, date and time, process conditions, and each handoff. Check the lab report for the same ID, method, units, and a reporting limit suitable for the decision.

Follow one sample

ET-01 records O-16 as a grab sample taken at SP-301 at 16:00. The handover shows the result as pending. When the lab report arrives, match it to O-16, check the method and units, and compare it with the applicable criterion. Use the site’s escalation and release procedure if the result or sample record calls for action.

Further reading · Bangladesh Gazette, Environment Conservation Rules, 2023

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Practice downloads

Use the bilingual PDF worksheets in print or alongside the editable Excel files. Examples are for learning; adapt the records to the approved procedures and requirements at your site.

• Operations, inspection and handover worksheets (PDF · English / বাংলা)

Effluent Sampling, Monitoring and Laboratory QA/QC

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প্র্যাকটিস ডাউনলোড

দ্বিভাষিক PDF ওয়ার্কশিট প্রিন্ট করে বা সম্পাদনাযোগ্য এক্সেলের সঙ্গে ব্যবহার করুন। উদাহরণগুলো শেখার জন্য; সাইটের অনুমোদিত প্রসিডিউর ও প্রয়োজন অনুযায়ী রেকর্ড সাজান।

• প্লান্ট সেফটি, HIRA ও ইমার্জেন্সি ওয়ার্কশিট (PDF · English / বাংলা)
• অপারেশন, ইনস্পেকশন ও হ্যান্ডওভার ওয়ার্কশিট (PDF · English / বাংলা)

ETP, STP ও WTP-তে হেলথ অ্যান্ড সেফটি · ওয়াটার ও ওয়েস্টওয়াটার ট্রিটমেন্ট প্লান্টের HIRA

হোমপেজে ফিরুন · প্র্যাকটিস রিসোর্স

বাংলা সংস্করণ পড়ুন

A standby pump can show a run signal and still deliver too little water. The repair is ready for handover when it can meet its duty under a controlled test and the site’s protections are available.

Follow the site work sequence

1. Coordinate. Operations and maintenance agree on the outage, treatment continuity, permit, and responsible people.
2. Isolate and verify. Authorized staff apply the site’s hazardous-energy procedure and verify isolation and stored-energy control. A stop command provides only operating status. Treat tank and pit access under the site’s confined-space program.
3. Restore and test. Authorized staff clear the work area, restore safeguards, and follow the approved return-to-service test. Record the before and after readings and the operations handover.

One pump, two readings

ET-01’s example test band is 76–84 m³/h at approximately 22 m head. Pump P-102B gives 52 m³/h at 22 m before the work, so it is recorded as unavailable for that duty. After an authorized correction to a suction restriction, it gives 79 m³/h at the same head. That meets the example flow criterion. The team verifies the remaining conditions and protections before the responsible person signs off.

Further reading · OSHA technical reference on hazardous-energy control

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Practice downloads

Use the bilingual PDF worksheets in print or alongside the editable Excel files. Examples are for learning; adapt the records to the approved procedures and requirements at your site.

• Plant safety, HIRA and emergency worksheet (PDF · English / বাংলা)
• Operations, inspection and handover worksheets (PDF · English / বাংলা)

Health and Safety in ETP, STP and WTP · HIRA for Water and Wastewater Treatment Plants

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বাংলা সংস্করণ পড়ুন

Chemical oxygen demand (COD) is a measure of the oxygen equivalent of material oxidized by a specified test. COD concentration tells you how strong the wastewater is. The load tells you how much reaches the plant during a stated period.

Turn concentration into load

COD mass (kg) = volume (m³) × representative COD (mg/L) ÷ 1,000. Match the concentration and volume to the same interval. A grab sample during a batch dump describes that moment. A suitable representative sample supports the interval estimate.

• Shift A. 600 m³ × 700 mg/L ÷ 1,000 = 420 kg in 8 h.
• Shift B. 760 m³ × 900 mg/L ÷ 1,000 = 684 kg in 8 h.
• Both shifts. 1,104 kg in 1,360 m³ gives a flow-weighted COD of about 812 mg/L over 16 h.

Use EQ to read the next few hours

EQ can spread a production shock over time when capacity and mixing are available. At ET-01, 180 m³ of operating liquid volume at a steady 75 m³/h gives a nominal retention time of 2.4 h. Actual retention depends on the flow pattern and changing levels. To estimate how much extra water the tank can receive, check the free usable volume and the net filling rate. That is a separate calculation from retention time. A conversation with production before a large discharge gives the operator time to use the available buffer.

Further reading · IFC textile wastewater guidance

‹ Previous lesson · Chapter contents · Next lesson ›

Practice downloads

Use the bilingual PDF worksheets in print or alongside the editable Excel files. Examples are for learning; adapt the records to the approved procedures and requirements at your site.

• Operations, inspection and handover worksheets (PDF · English / বাংলা)

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বাংলা সংস্করণ পড়ুন

A useful shift log lets the next operator reconstruct what happened without guessing. Begin with the previous handover, then walk the approved route from the inlet to the outlet. Ask production about upcoming batches or cleaning discharges that could change the load.

Read the plant in three moments

• Start. Confirm the active train, duty and standby equipment, EQ level, open alarms, isolations, and pending tests.
• During the shift. Log the time, point or asset ID, units, and what changed. Compare meter readings at the same point. Verify an unexpected reading before acting on it.
• Handover. State what the team did, what remains open, who owns it, and when to check again. Keep the status of any hold or release decision explicit.

A shift at ET-01

The inlet totalizer moves from 10,000 to 10,760 m³ between 08:00 and 16:00. That is 760 m³ over 8 hours, or 95 m³/h on average. A separate final-outlet meter has its own record. At 15:20, the EQ high-level alarm appears. The operator records the alarm, verifies the available buffer through the site procedure, and alerts the shift lead. The outlet sample result is still pending at handover. Those two facts belong on separate lines so the next shift can follow each one.

‹ Previous lesson · Chapter contents · Next lesson ›

Practice downloads

Use the bilingual PDF worksheets in print or alongside the editable Excel files. Examples are for learning; adapt the records to the approved procedures and requirements at your site.

• Operations, inspection and handover worksheets (PDF · English / বাংলা)

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