FeCl3 was found to be generally superior to the other two coagulants in removing all the parameters like color TSS COD

source : http://civil.eng.usm.my/awam07/sample%20paper.doc

Three types of coagulants were examined using standard jar test apparatus, i.e., aluminum sulphate (alum), ferric chloride (FeCl₃) and ferrous sulphate (FeSO₄). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were exermined. At 300 rpm of rapid mixing and 50 rpm of slow mixing and 60 minutes settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl₃ was found to be superior compared with other coagulants. At pH 4 and 12, fair removal of suspended solids was observed at reasonably lower amount of coagulant, i.e., 600 mg/L. However, about 2500 mg/L of coagulant was required to achieve good removals at pH 6. Better removals were achieved at higher temperature.

The coagulation-flocculation process was employed for the treatment of reactive dye wastewaters, with ferric chloride hexahydrate employed as the coagulant. The process was found to be very effective with a more than 99.5% colour removal. Typical representatives of monochlorotriazine reactive dyes, with azo and anthraquinone chromophores, were CI Reactive Red 45 and CI Reactive Green 8, which were chosen as the model dyes. In order to determine the optimum pH range and coagulant concentration, a series of jar tests was done. Further experiments were conducted using a square flocculation tank with turbine impeller applying rapid and slow mix operations. The optimisation of initial rapid mixing, which has an important role in the overall coagulation process efficiency, was carried out. The optimum combination of velocity gradient and time of rapid mix was suggested for reactive dye wastewater treatment. Sedimentation curves for both model dyes were also obtained.

.

FeCl₃ was found to be generally superior to the other two coagulants in removing all the parameters.

FeCl₃ at pH 4 (at a coagulant dosage of 600 mg/L) and pH 6 (at a coagulant dosage of 2500 mg/L).

exhibited better performance with 90% and 97% removals, respectively.

 

Table 2:Removal of suspended solids, colour and COD at different pH values and dosages of coagulants.

pH	Results	Suspended Solids			Colour			COD
		Alum	FeCl3	FeSO4	Alum	FeCl3	FeSO4	Alum	FeCl3	FeSO4
4	Optimum/ economical dosage (mg/L)	600	600	600	600	600	600	600	600	600
	Initial* concentration	1106	1106	1068	6450	6460	7275	2660	2565	3320
	Final** concentration	282	59	582	2554	626	5485	1862	1472	1291
	% Removal	74.5	94.7	45.5	60.4	90.3	24.6	30	42.6	61.1
6	Optimum/ economical dosage (mg/L)	2500	2500	2500	2500	2500	2500	2500	2500	2500
	Initial* concentration	983	786	878	7005	7100	7003	3015	2980	3066
	Final** concentration	291	8	506	3159	249	5953	2204	1648	2422
	% Removal	70.4	99	42.4	54.9	96.5	15	26.9	44.7	21
12	Optimum/ economical dosage (mg/L)	600	600	600	600	600	600	600	600	600
	Initial* concentration	1106	932	1068	6460	6658	7270	3210	3565	3320
	Final** concentration	90	52	197	2558	1738	2690	2793	2777	2825
	% Removal	91.9	94.4	81.6	60.4	73.9	63	13	22.1	14.9

 

 

 

COD removal efficiency of poly-silicate-aluminium-ferric chloride (PSAFC) and polyferric chloride (PFC) coagulant increased with increasing dose of coagulants, and that the performance of PSAFC and PFC coagulants was superior to PAC coagulant. This difference in efficiency may also be attributed to the copolymers of Si(IV), Al(III) and Fe(III). However, compared with PFC, PSAFC can easily reach high COD removal efficiency below coagulant dose 0.3 g/L. Thus, from the economic point of view, PSAFC is more suitable for treatment of wastewater effluent from dye manufacturing

 

 

Source :http://civil.eng.usm.my/awam07/sample%20paper.doc

Re: WINDROW COMPOSTING

On Tue, Aug 28, 2007 at 3:33 PM, saleem asraf syed imdaadullah <saleemasraf@gmail.com> wrote:

 

The Sanitary landfill sites are fast disappearing. Dumping Waste into Landfill sites in not the solution of Municipal Solid Waste Management. Composting provides a way out not only to reduce the amount of waste that needs to be disposed off but also converts garbage into a product that is useful for gardening, landscaping or house plants.

What can be Composted

: Good things you can compost are vegetable peelings, fruit waste, tea bags , plant prunings, grass cuttings etc.

What cant be used

: Certain things should never be placed in your bin. Keep away COOKED vegetables, Meat, Dairy Products, Diseased Plants,. Ideally wet garbage should not be put into the bin.

THE FIRST STEP: Segregate the garbage before handing it to the sweepers who come to your homes. DRY & WET waste need to be separated at the household level. Two storage bin of different color should be provided at homes for the purpose.

 

 

THE SECOND STEP: The sweeper store the kitchen waste like food leftovers, vegetables, meat refuse, egg shells at the compost making site. They take the dry waste away.

Third Step: COMPOST MAKING: Adding falling leaves from the road side completes the preparation for making compost. The wet garbage is moved and a new layer of waste is spread over it daily.. Water should be sprinkled daily on it and a fresh stock of compost is ready every three weeks.

Fourth Step: Marketing and selling of compost. This will not creat a problem if it is sold as a brand name or as organic manure. All the tea gardens will be happy to take it. Also all health conscious people will stop using chemical fertilizers in their kitchen garden.

 

THE 22 MT COMPOSTING PROJECT

ANNEXURE-I Key Personnel details

S No

Category of personnel	Name	Qualification	Present designation	Experience in relevant field	Remarks
1	Team Leader (Solid waste Engineer with 10 Years experience)
2	Municipal Engineering Specialist
3	Medical and Health Specialist
4	Finance Specialist
5	Management specialist

 

 

 

 

 

 

 

 

 

ANNEXURE-II NORMS FOR GENERATION OF GARBAGE

Category of garbage	Quantity generated
Domestic household (1) Population range upto 1 lakh (2) Population range 1 to 5 lakh (3) Population range 5 to 10 lakh (4) Population range 10 to 20 lakh	0.21 Kg per person per day 0.21 Kg per person per day 0.25 Kg per person per day 0.27 Kg per person per day
Street sweepings and drain silt	0.10 Kg per person per day
Slaughter House: (1) Small slaughter house (2) Medium slaughter house (3) Large slaughter house	0.5 to 1.0 ton per day 2 to 6 ton per day 6 to 7 ton per day
Domestic waste from Hospitals / Clinics etc.	1.1 Kg per bed per day

 

ANNEXURE-III

What constitutes Biodegradable Waste – Components

1. Kitchen / canteen waste – unused vegetable cuttings, fruit peel-off, tea / coffee powder, coconut fiber, egg shells, non-vegetable waste, stale / leftover / rotten food etc.
2. Flowers / garlands
3. Hair / cut nails
4. Excreta of the pet animals, cow dung etc.
5. Horticulture waste like dried leaves, grass, cut trees, uprooted wheat.

Segregation at Source:

• Encouraging residents / producers to segregate
• Separation of Bio-degradable and non-biodegradable at source.
• Involve Rag pickers in segregation at source.
• Involve Self-help Groups in segregation, if required.
• Introduction of TWO BIN system.

WINDROW COMPOSTING

:

In areas/regions were higher ambient temperatures are available,composting in open windrows is to be preferred. In this method, refuse is delivered on a paved/unpaved open space but levelled and well drained land in

about 20 windrows with each windrow 3m long x 2m wide x 1.5m high, with a total volume not exceeding 9.0 cu.m.Each windrow would be turned on 6th& 11thdays outside to the centre to destroy insects larvae and to provide aeration. On 16thday, windrow would be broken down and passed through manually operated rotary screens of about 25mm square mesh to remove the oversize contrary material. The screened compost is stored for about 30 days in heaps about 2m wide x 1.5m high and up to 20m long to ensure stabilization before sale.

 

However, the composting mass should have a certain minimum moisture content in it for the organisms to survive. The optimum moisture content is known to be between 50 to 60 % . Higher moisture content may be required while composting straw and strong fibrous material which soften the fibre and fills the large pore spaces.

The C/N ratio considers the available carbon as well as the available nitrogenwhile the available carbon and nitrogen in the MSW may vary from sample to sample. Whenever the C/N ratio is less than the optimum, carbon source such as straw, sawdust, paper are added while if the ratio is too high, the sewage sludge, slaughter house waste, blood etc. are added as a source of nitrogen.

During the decomposition, the oxygen gets depleted and has to be continuously replenished. This can be achieved either by turning of windrows . During the turning, it is necessary to bring inner mass to the outer surface and to transfer the outer waste to the inner portion. In Indian conditions the decomposition is commonly carried out in open windrows. Studies at NEERI have shown that the optimum turning interval which will reduce the cost and simultaneously maintain aerobic conditions is 5 days.

The windrows should be located over impervious surface so that the surface water from the windrows which can go to Effluent Treatment Plant.

THE FINAL COMPOST CHARACTERISTICS

:

The compost prepared from MSW should be black brown or at least black in colour. It should be crumbly in nature with an earthy odour. The pH should be neutral though slightly acidic or alkaline pH within the range of 6.5 to 7.5 can be tolerated.The compost should neither be completely dry nor it be lumpy and water should not come out of the mass when squeezed.

The Nitrogen, Phosphorous and Potassium (NPK) contents should be more than one percent each. The Nitrogen should be in the form of Nitrates for proper utilisation by the plants. The C/N ratio should be between 15 to 20.In order to ensure safe application of compost,

As the compost plantoperates at a constant rate, a balancing storage has to be provided to absorb the fluctuations in the waste input to the plant. This is provided in a storage hopper of 8 to 24 hours storage capacity, the exact value depending upon the schedule of incoming trucks, the number of shifts and the number of days the plant and solid waste collection system works.

. These windrows are turned every 5 days to ensure aerobic decomposition. Various types of equipment such as front end loaders/windrows reshifters are used for turning of windrows.At the end of the 3 to 4 weeks period, the material is known as green or fresh compost wherein the cellulose has not been fully stabilised. It is hence stored in large sized windrows for 1-2 months either at the plant or the farms. At the end of the storage period, it is known as ripe compost.

 

POINTS TO BE NOTED

:

:-• Large storage hoppers are not needed.

• Covering of windrow area is not required as the plants are normally shut down during monsoon for annual repairs.

• Artificial aeration under Indian conditions is not required

• It is preferable to first stabilise the raw material and then subject it to picking and size reduction. This will require same windrow area, and improve efficiency of picking and size reduction

• Composting should not be considered as a commercial venture but should be treated as a processing method to reduce the MSW content to be dumped at landfill sites..

• On such days when the waste cannot be accepted at the compost plant or if shutdown occurs for extended period due to rains/cold climate/major breakdown or annual maintenance, the waste should be diverted to a properly designed and operated MSW landfill.

•. The height of stockpiled waste should not exceed 3 metres and the storage area must have provision for odour control, litter control, fire control and birds control.

The areas where compost is to be supplied should be near the site and should be easily accessible. A site for disposal of non compostables should be available near the compost plant site.Trees planted along the periphery of the site will serve partly as a barrier against the noise and odour from the plant and also help in litter control byreducing the wind speed . The trees will also protect the plant from dust and pollutants due to the highway.

GO FOR A PILOT PLANT STUDY FIRST

:

The design and construction of a full scale compost plant needs at least 1.5 to 2 years. Before the plant becomes operational, pilot scale studies be carried out using a small quantity of the raw waste that will be used in the final plant. The raw waste as well as finished compost should also be analysed for heavy metal content. The output of the plant should be widely advertised to the consumers. The pilot studies will help determine the proportion of non-compostables that need disposal, the compost output per tonne of input and its nutrient contents.

 

NORTH EAST INDIA

:

In the North East Indian states, to protect the windrows from heavy rainfall, the windrow area will have to be covered.

EFFLUENT TREATMENT PLANT

:

• All uncovered windrow areas should be provided with an impermeable base.Such a base may be made of concrete or of compacted clay, 50 centimetres thick, having permeability less than 10 centimetres/second. The base must be provided with 1 to 2 percent slope and must be encircled by lined drains for collection of leachate/surface water runoff. All lined drains should beconnected to a lined settling pond, where tests for quality of waste-water are to be performed on a weekly basis. A treatment unit will be provided to ensure that the waste-water is discharged to open drains only after it meets the regulatory standards.

--
http://www.saleemindia.blogspot.com

Re: WINDROW COMPOSTING

On Tue, Aug 28, 2007 at 3:33 PM, saleem asraf syed imdaadullah <saleemasraf@gmail.com> wrote:

 

The Sanitary landfill sites are fast disappearing. Dumping Waste into Landfill sites in not the solution of Municipal Solid Waste Management. Composting provides a way out not only to reduce the amount of waste that needs to be disposed off but also converts garbage into a product that is useful for gardening, landscaping or house plants.

What can be Composted

: Good things you can compost are vegetable peelings, fruit waste, tea bags , plant prunings, grass cuttings etc.

What cant be used

: Certain things should never be placed in your bin. Keep away COOKED vegetables, Meat, Dairy Products, Diseased Plants,. Ideally wet garbage should not be put into the bin.

THE FIRST STEP: Segregate the garbage before handing it to the sweepers who come to your homes. DRY & WET waste need to be separated at the household level. Two storage bin of different color should be provided at homes for the purpose.

 

 

THE SECOND STEP: The sweeper store the kitchen waste like food leftovers, vegetables, meat refuse, egg shells at the compost making site. They take the dry waste away.

Third Step: COMPOST MAKING: Adding falling leaves from the road side completes the preparation for making compost. The wet garbage is moved and a new layer of waste is spread over it daily.. Water should be sprinkled daily on it and a fresh stock of compost is ready every three weeks.

Fourth Step: Marketing and selling of compost. This will not creat a problem if it is sold as a brand name or as organic manure. All the tea gardens will be happy to take it. Also all health conscious people will stop using chemical fertilizers in their kitchen garden.

 

THE 22 MT COMPOSTING PROJECT

ANNEXURE-I Key Personnel details

S No

Category of personnel	Name	Qualification	Present designation	Experience in relevant field	Remarks
1	Team Leader (Solid waste Engineer with 10 Years experience)
2	Municipal Engineering Specialist
3	Medical and Health Specialist
4	Finance Specialist
5	Management specialist

 

 

 

 

 

 

 

 

 

ANNEXURE-II NORMS FOR GENERATION OF GARBAGE

Category of garbage	Quantity generated
Domestic household (1) Population range upto 1 lakh (2) Population range 1 to 5 lakh (3) Population range 5 to 10 lakh (4) Population range 10 to 20 lakh	0.21 Kg per person per day 0.21 Kg per person per day 0.25 Kg per person per day 0.27 Kg per person per day
Street sweepings and drain silt	0.10 Kg per person per day
Slaughter House: (1) Small slaughter house (2) Medium slaughter house (3) Large slaughter house	0.5 to 1.0 ton per day 2 to 6 ton per day 6 to 7 ton per day
Domestic waste from Hospitals / Clinics etc.	1.1 Kg per bed per day

 

ANNEXURE-III

What constitutes Biodegradable Waste – Components

1. Kitchen / canteen waste – unused vegetable cuttings, fruit peel-off, tea / coffee powder, coconut fiber, egg shells, non-vegetable waste, stale / leftover / rotten food etc.
2. Flowers / garlands
3. Hair / cut nails
4. Excreta of the pet animals, cow dung etc.
5. Horticulture waste like dried leaves, grass, cut trees, uprooted wheat.

Segregation at Source:

• Encouraging residents / producers to segregate
• Separation of Bio-degradable and non-biodegradable at source.
• Involve Rag pickers in segregation at source.
• Involve Self-help Groups in segregation, if required.
• Introduction of TWO BIN system.

WINDROW COMPOSTING

:

In areas/regions were higher ambient temperatures are available,composting in open windrows is to be preferred. In this method, refuse is delivered on a paved/unpaved open space but levelled and well drained land in

about 20 windrows with each windrow 3m long x 2m wide x 1.5m high, with a total volume not exceeding 9.0 cu.m.Each windrow would be turned on 6th& 11thdays outside to the centre to destroy insects larvae and to provide aeration. On 16thday, windrow would be broken down and passed through manually operated rotary screens of about 25mm square mesh to remove the oversize contrary material. The screened compost is stored for about 30 days in heaps about 2m wide x 1.5m high and up to 20m long to ensure stabilization before sale. 

However, the composting mass should have a certain minimum moisture content in it for the organisms to survive. The optimum moisture content is known to be between 50 to 60 % . Higher moisture content may be required while composting straw and strong fibrous material which soften the fibre and fills the large pore spaces.

The C/N ratio considers the available carbon as well as the available nitrogenwhile the available carbon and nitrogen in the MSW may vary from sample to sample. Whenever the C/N ratio is less than the optimum, carbon source such as straw, sawdust, paper are added while if the ratio is too high, the sewage sludge, slaughter house waste, blood etc. are added as a source of nitrogen.

During the decomposition, the oxygen gets depleted and has to be continuously replenished. This can be achieved either by turning of windrows . During the turning, it is necessary to bring inner mass to the outer surface and to transfer the outer waste to the inner portion. In Indian conditions the decomposition is commonly carried out in open windrows. Studies at NEERI have shown that the optimum turning interval which will reduce the cost and simultaneously maintain aerobic conditions is 5 days.

The windrows should be located over impervious surface so that the surface water from the windrows which can go to Effluent Treatment Plant.

THE FINAL COMPOST CHARACTERISTICS

:

The compost prepared from MSW should be black brown or at least black in colour. It should be crumbly in nature with an earthy odour. The pH should be neutral though slightly acidic or alkaline pH within the range of 6.5 to 7.5 can be tolerated.The compost should neither be completely dry nor it be lumpy and water should not come out of the mass when squeezed.

The Nitrogen, Phosphorous and Potassium (NPK) contents should be more than one percent each. The Nitrogen should be in the form of Nitrates for proper utilisation by the plants. The C/N ratio should be between 15 to 20.In order to ensure safe application of compost,

As the compost plantoperates at a constant rate, a balancing storage has to be provided to absorb the fluctuations in the waste input to the plant. This is provided in a storage hopper of 8 to 24 hours storage capacity, the exact value depending upon the schedule of incoming trucks, the number of shifts and the number of days the plant and solid waste collection system works.

. These windrows are turned every 5 days to ensure aerobic decomposition. Various types of equipment such as front end loaders/windrows reshifters are used for turning of windrows.At the end of the 3 to 4 weeks period, the material is known as green or fresh compost wherein the cellulose has not been fully stabilised. It is hence stored in large sized windrows for 1-2 months either at the plant or the farms. At the end of the storage period, it is known as ripe compost.

 

POINTS TO BE NOTED

:

:-• Large storage hoppers are not needed.

• Covering of windrow area is not required as the plants are normally shut down during monsoon for annual repairs.

• Artificial aeration under Indian conditions is not required

• It is preferable to first stabilise the raw material and then subject it to picking and size reduction. This will require same windrow area, and improve efficiency of picking and size reduction

• Composting should not be considered as a commercial venture but should be treated as a processing method to reduce the MSW content to be dumped at landfill sites..

• On such days when the waste cannot be accepted at the compost plant or if shutdown occurs for extended period due to rains/cold climate/major breakdown or annual maintenance, the waste should be diverted to a properly designed and operated MSW landfill.

•. The height of stockpiled waste should not exceed 3 metres and the storage area must have provision for odour control, litter control, fire control and birds control.

The areas where compost is to be supplied should be near the site and should be easily accessible. A site for disposal of non compostables should be available near the compost plant site.Trees planted along the periphery of the site will serve partly as a barrier against the noise and odour from the plant and also help in litter control byreducing the wind speed . The trees will also protect the plant from dust and pollutants due to the highway.

GO FOR A PILOT PLANT STUDY FIRST

:

The design and construction of a full scale compost plant needs at least 1.5 to 2 years. Before the plant becomes operational, pilot scale studies be carried out using a small quantity of the raw waste that will be used in the final plant. The raw waste as well as finished compost should also be analysed for heavy metal content. The output of the plant should be widely advertised to the consumers. The pilot studies will help determine the proportion of non-compostables that need disposal, the compost output per tonne of input and its nutrient contents.

 

NORTH EAST INDIA

:

In the North East Indian states, to protect the windrows from heavy rainfall, the windrow area will have to be covered.

EFFLUENT TREATMENT PLANT

:

• All uncovered windrow areas should be provided with an impermeable base.Such a base may be made of concrete or of compacted clay, 50 centimetres thick, having permeability less than 10 centimetres/second. The base must be provided with 1 to 2 percent slope and must be encircled by lined drains for collection of leachate/surface water runoff. All lined drains should beconnected to a lined settling pond, where tests for quality of waste-water are to be performed on a weekly basis. A treatment unit will be provided to ensure that the waste-water is discharged to open drains only after it meets the regulatory standards.

--
http://www.saleemindia.blogspot.com