REPORT TREATABILITY STUDIES, FEASIBILITY REPORT FOR TREATMENT OF WASTE WATER FOR. M/s DEEPAK NITRITE LTD., MIDC Taloja

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1 REPORT ON TREATABILITY STUDIES, FEASIBILITY REPORT FOR TREATMENT OF WASTE WATER FOR M/s DEEPAK NITRITE LTD., MIDC Taloja January PREPARED BY Goldfinch Engineering Systems Private Limited Plot No. A -288, Road No. 16 Z, Thane Industrial Area, MIDC (Wagle Estate) Thane Maharashtra, India TEL FAX Website :

2 I N D E X SR. NO. C O N T E N T S PAGE NO. 1. INTRODUCTION 1 2. WASTE WATER TREATABILITY STUDIES TREATMENT SCHEME 7 12

3 1. INTRODUCTION M/s. DEEPAK NITRITE LTD. (DNL) is a leading supplier of organic, inorganic and fine chemicals to global chemical majors. The DNL is a multi-division and multi-product company with manufacturing facilities at Nandesari and Dahej in Gujarat, Taloja and Roha in Maharashtra, and at Hyderabad in Andhra Pradesh. Wastewater is mainly generated due to production related activities. DNL already have existing ETP comprising of Primary, Secondary & Tertiary Treatment to treat the waste water generated from the existing manufacturing activities. DNL is changing their product mix due to which there is a change in the inlet characteristics of waste water. Hence DNL appointed M/s Goldfinch Engineering Systems Private Limited (Goldfinch), leading consultants in the field of environmental engineering to carry out the treatability studies and devise a suitable treatment process with its budgetary capital and operating cost estimates. To achieve this task DNL provided the samples of waste water to Goldfinch. Goldfinch carried out the treatability studies on these samples and arrived at the optimum treatment process, which is versatile in operation. Based on these studies Goldfinch prepared the report on treatability studies and its optimum treatment process. This report is organized as follows: Section 2 deals with the characterization of waste water samples. Section 3 details the treatability studies and optimization of design parameters. Section 4 mentions the treatment process along with the units and equipments required with budgetary capital and operating cost estimates. 1

4 2. WASTE WATER CHARACTERISTICS The waste water streams are generated from the manufacturing processes which are concentrated streams in terms of organic and TDS. These samples from the manufacturing plant were collected by DNL and sent to Goldfinch laboratory for studies. These samples were characterized individually. These samples were characterized for ph, COD, BOD C, chlorides and total dissolved solids (TDS). The average results are mentioned below Table 2.1: Characterization of Streams Sample No 1 2 Names Toulidines (Ortho, Meta, Para) Xylidines(2,3/2,4/2,5/2,6/3,5 )OR Xylidiene Derivatives as Xylenols(2,3/2,4/2,5/2,6) Flow CMD ph COD (mg/lt) BOD (mg/lt) TSS (mg/lt) TDS (mg/lt) Cumidines (Ortho, Para) Amino Benzo Trifluoride (3-ABTF) Benzhydrol OR Cyclohexenylethylamine (CHEA) OR Homoveratrylamine (HVA) OR (2-Methoxyethyl) Phenol.(4 MEP) Boiler & Cooling Tower Total The 4 Litres composite sample was prepared by mixing above samples in proportion of proposed flow rates which were shared by M/s DNL. The Quantity of the samples are as mentioned in below table. 2

5 Table: 2.3Details of volumes for preparing Composite Stream Sr No. Sample Name ML of Sample taken 1 Toulidines (Ortho, Meta, Para) Xylidines(2,3/2,4/2,5/2,6/3,5)OR Xylidiene Derivatives as Xylenols(2,3/2,4/2,5/2,6) Cumidines (Ortho, Para) Amino Benzo Trifluoride (3-ABTF) 90 5 Benzhydrol OR Cyclohexenylethylamine (CHEA) OR Homoveratrylamine (HVA) OR (2-Methoxyethyl) Phenol (4 MEP) Boiler & Cooling Tower 1515 Total 4000 Characteristics of Composite Sr. No. Parameter Unit Value 1 ph Chemical Oxygen Demand mg/l BOD, 27 o C for 3 days mg/l Total Dissolved Solids mg/l Total Suspended Solids mg/l 61 6 Oil & Grease mg/l 18 3

6 3. TREATABILITY STUDIES This study was undertaken to study the treatability of the effluent collectively and study the suitability of the existing treatment process to meet the standards prescribed by MPCB of the old ETP and new ETP individually including the adequacy of existing units and equipment, mainly for controlling the ph, COD, BOD3 days, TDS & TSS values below the prescribed standard Based on the characteristics of raw waste water, following treatment processes were considered for the treatability: Primary treatment comprising of neutralization and coagulation Secondary treatment with Aerobic biological oxidation Tertiary treatment with Activated carbon adsorption For this Goldfinch tried physicochemical, biological unit processes at laboratory scale. In physicochemical process, removal or conversion of contaminants to precipitate was brought about by dosing coagulative chemicals. Aerobic biological oxidation was studied on primarily treated sample to remove biodegradable organics while tertiary treatment was tried to remove refractory organics if any. From the analysis of large number of samples collected, the BOD to COD ratio of raw waste water was found to be about 50%. As BOD analysis requires three days while COD can be analyzed within 3 hours, COD was used as control parameter and the index of reduction in organic content during the treatability study. 3.1 Primary Treatment Coagulation: Determination of optimum ph and determination of optimum dose. Coagulation is always highly effective only at particular ph with particular Alum dosage. Hence, studies were carried out to determine optimum ph and dose. Methodology observed was as follows. 4

7 Determination of Optimum ph: 100 ml volume of wastewater samples were taken in 4 cylinders. Alum dose of 100 mg/lt was given to all the samples. The ph was adjusted to 7.0, 7.5, 8.0 and 8.5 respectively, by using 6N NaOH. After allowing for reaction time and settling, the supernatant COD was checked. Satisfactory settling with best COD reduction was observed at 7.5 PH. The results are presented in Table 3.1. Table 3.1 Determination of Optimum ph (Initial COD: 5103 mg/lit) ph COD, mg/lt % Reduction in COD On the basis of the above results, the optimum ph seems to be 7.5 Determination of Optimum Alum dose: 100 ml volume of wastewater samples were taken in 4 cylinders. Alum dose of 250, 500, 750 and 1000 mg/lt were given to respective wastewater samples. The ph was adjusted to 7.5 (optimum ph). After allowing for reaction time and settling, supernatant COD was checked. Satisfactory settling with good COD reduction was observed for 500 mg/l alum dose i.e. optimum dose. The results are presented in Table 3.2. Table 3.2 Determination of Optimum Alum Dose (Initial COD: 5103 mg/lit) Alum Dose, mg/lt COD, mg/lt % Reduction in COD Note: Accordingly the optimum ph and optimum dose were decided as 7.5 and 500 mg/lit respectively. After primary treatment by alum supernant was analyzed for ph, COD, BOD 3, TSS & TDS. Results are tabulated below 5

8 Table 3.3 Characterization of low TDS wastewater after primary Treatment Sr. No. Parameter Unit Value 1 ph Chemical Oxygen Demand mg/l BOD, 27 o C for 3 days mg/l Total Dissolved Solids mg/l Total Suspended Solids mg/l 18 6 Oil & Grease mg/l < Secondary Treatment: Bio degradation Study After mixing properly mixture was subjected to biodegradation for secondary treatment ml mixture sample was taken. MLSS was developed by adding 500 ml Bio sludge from efficiently operated ETP and it was washed 3 to 4 times with tap water. This washed sludge was filtered, filtrate was discarded and the sludge was added to the primarily treated composite sample. It was mixed well and aerated for min and the initial sample was taken for COD. COD of the bioreactor sample was checked and results are shown in table below. Initially the biomass was allowed to acclimatize with the effluent. The effluent was diluted and fed to the bio-reactor. The studies were started with 20% concentrated feed, which was steadily and subsequently increased by 40%, 60%, 80% and finally to 100%. Mixing and aeration were achieved through diffused aeration system. Small quantity of sample were withdrawn and allowed to settle for approximately 30min. Clear supernant was analyzed. Everyday loss of water due to evaporation was made up with tap water. Constant stirring was achieved throughout the experiment by aeration. After 100% feed was achieved studies were formalized. Percent settlement of sludge was observed after every 24 hrs. Also, COD was analyzed after every 24 hrs. After giving alum dose of 250 ppm at ph 7.5 to bioreactor sample. Result of Bio-degradation study is summarized in the following table

9 Table 3.5 Bio-degradation Study Date Hrs COD mg/lt Initial 0 hrs /01/ hrs /01/ hrs /01/ hrs /01/ hrs /01/ hrs /01/ hrs /01/ hrs 472 Note: 1. Lush brown healthy bio sludge was observed throughout the study. Settling of bio-sludge was good and texture was characteristics. From the above results it is seen that biodegradation was very good. Table 3.6 Analysis of Bio-Degradable Sample Sr. No. Parameter Unit Value 1 ph Chemical Oxygen Demand mg/l BOD, 27 o C for 3 days mg/l 78 4 Total Dissolved Solids mg/l Total Suspended Solids mg/l 18 7 Oil & Grease mg/l < Tertiary Treatment (Activated Carbon Treatment) Biodegraded sample was filtered and taken in 3 Nos. different beakers. A dose of activated charcoal was given as 250, 500 and 750 mg/lt respectively. ph was maintained at 7.5 Initial COD of the sample was 520 mg/l. All these mixtures were stirred for one hour. After the reaction the mass was filtered and analyzed for COD. The results are mentioned below. Table 3.7: Optimization of Charcoal Dose (Initial COD -472 mg/l) Charcoal Dose, mg/lt COD mg/l % reduction

10 Conclusion: COD is getting adsorbed on Charcoal. The optimum dose is 500 ppm. Table 3.8: Analysis of Tertiary Treated Sample Sr. No. Parameter Unit Value 1 PH TSS mg/l 15 3 COD mg/l BOD3,270C mg/l 75 5 TDS mg/l Recommended Treatment Process The waste water from process along with blow downs of cooling tower and boiler will be collected in the equalization tank neutralized and will then pumped to Primary Settling Tank for settling the precipitated solids. Alum will be dosed to settle the coagulated solids. The overflow of Primary Settling Tank will be collected in the collection tank from where it pumped to secondary treatment. The secondary treated wastewater will then be pumped for the tertiary treatment. The outlet of the tertiary treatment will be pumped to CETP drain. 8

11 4. TREATMENT SCHEME Primary Treatment The streams will be collected in collection tank from where it pumped to neutralization tank where provision of acid/ alkali dosing for neutralization of effluent will be made. The neutralizing agents will be dosed from the respective dosing tanks. The content of equalization tank is mixed with help of coarse diffused aeration system. The equalized and neutralized effluent will be then passed to flash mixer for primary clarification. Alum will be dosed as coagulant in the flash mixer provided with agitator. The coagulated mass will flow to primary settling tank for settlement of solids. The primary settling tank will be constructed with the hopper bottom for effective removal of solids. The settled solids will be drained to the sludge collection tank. The sludge from sludge tank is then pumped to the filter press for dewatering. Secondary (Aerobic) Treatment: The biological treatment will consist of following units; The mixture from the tank will flow to the aeration tanks one after the other for the aerobic treatment. Activated sludge treatment works on the principle of development of microbial culture in the aeration tank. Each bacterium is constituted of C, H, N, O and P. Bacteria assimilate all carbonaceous matter. The oxygen required for the bacterial growth will be supplied through the diffused aeration system. This system is energy saving and effective as compared to surface aerator. The mixed liquor suspended solids (MLSS) will continue to grow. The mixed liquor from the bioreactors will overflow to the respective secondary settling tanks where the sludge will settle down and will be recycled to the respective bioreactor to maintain the MLSS concentration. The clean treated effluent will overflow to the intermediate sump. TERTIARY TREATMENT Tertiary treatment include following units; The biologically treated effluent will flow to intermediate sump from where it is pumped to pressure sand filter for removing any fine solids which have escaped settlement. The Filtered water will be passed through the Activate charcoal Filter for polishing and removing any refractory organics. The tertiary treated effluent will be fed to CETP drain. Sludge Handling: Primary sludge, excess biomass from the secondary treatment and backwash water from PSF will be collected in the sludge sump. From the sludge sump the sludge will be pumped to the Filterpress for dewatering. The solid cake from the Filterpress will be sent for disposal to Hazardous waste disposal site. The filtrate from the Filterpress will be drained to the collection tank. 9

12 DESIGN PARAMETERS A) ETP: After Primary After Secondary After Tertiary Parameters Unit Raw Stream treatment Treatment Treatment Quantity M 3 /day ph COD mg/l BOD 3, 27 0 C mg/l <100 TSS mg/l <20 <20 <20 TDS mg/l Oil & Grease mg/l <20 <10 <10 <10 10

13 UNITS AND EQUIPMENTS REQUIRED FOR EFFLUENT TREATMENT PLANT A) ETP: Sr. No Description A) Civil Units & M.S Units List Actual Volume Size / Capacity Existing Volume Additional Volume Qty. MOC Remarks 1. Collection Tank No AR RCC Existing 2. Equalization tank 15 m No AR RCC Existing 3. Primary Settling Tank m 3 -- Existing 10 1 No FRP (hopper bottom) 4. Bioreactor No RCC Existing 5. Secondary Settling Tank -- Existing No RCC (hopper bottom) 6. Intermediate Tank -- 1 No HDPE Existing 7. Final Treated Water Tank No RCC Existing 8. Sludge Drying Beds Nos. RCC Existing 9. Shed for Sludge Drying Beds -- 1 No. MS-GI Existing 10. Equipment Foundations Lot RCC Existing B) MS Fabricated, Mechanical & Bought out Equipment List 1. Coarse bubble Diffusers for -- Existing 1 Lot PVC equalization Tank 2. Primary Settling Tank Feed 8 m 3 /hr 9 m 3 -- Existing /hr 2 Nos. CI pumps 3. Air Blower for Bioreactor m 3 /hr -- 2 Nos. CI Existing 4. Air Blower for Equalization 620m 3 /hr 5. Fine bubble diffuser no -- Silicon Existing 6. Alum dosing tank for -- Existing lit 1 No. HDPE Secondary 7. Sludge recirculation pump 8 m 3 /hr 10 m 3 /hr -- 2 Nos. CI Existing -- Inst: suitable Existing 8. Piping: Instrumentation, piping and Suitable Suitable Lot MS/HDPE Electrical Electrical: suitable 19. PSF Feed pump 8 m 3 /hr 9 m 3 /hr -- 2 Nos. CI Existing 20 Pressure sand filter (PSF) No. MS-Epoxy Existing 21 Activated Carbon filter (ACF) No. MS-Epoxy Existing 22 Instrumentation, piping and Electrical Suitable Suitable -- Lot Inst: suitable Piping: MS/HDPE Electrical: suitable Existing 11

14 All other mechanical equipment s such as pumps, blowers and other attended units exist with adequate capacities. Conclusion: From the treatability studies treatment process scheme was derived from existing ETP which is operative. Based on the parameters the required sizes of units were worked and were compared with existing units. It is observed that existing units and equipment s are quiet adequate. 12

15 ETP flow Diagram 13