Limnology

Introduction:

The adjoining point of Hoogly and Haldi river is one of the most significant place for the developing industrial township. The Hoogly river carries a lots of industrial wastes from industrial area of Kolkata and Howrah. Since Haldia is the fast growing city into a major industrial center of Eastern-India.

Major Industries :-

• Haldia Petrochemicals;
• Pteriphthalic acid project of Mitsubishi Chemical Corporation;
• Haldia Dock Complex under Calcutta Port Trust;
• Exide Industries Ltd. producing automotive batteries;
• Consolidated Fibers and Chemicals Ltd. producing acrylic staple fiber;
• Him Containers Ltd. producing marine containers;
• Hindusthan Lever Ltd. producing industrial phosphate;
• Indian Oil Corporation Ltd. having oil refinery complex;
• Petroleum Coke Chemicals Ltd. producing petrocarbons
•  Shaw Wallace & Co. producing organophosphate pesticides

General properties

Properties	Highest	Lowest
Ammonia-N(mg/l)	0.47	0.12
Bod(mg/l)	3	0.7
Fluoride(mg/l)	0.49	0.23
Phosphate-P(mg/l)	4.25	0.02
Potassium (mg/l)	67.1	28.87
Total Fixed Solids(TFS) (mg/l)	10388	118
Total Hardness as Caco3 (mg/l)	3450	150
Conductivity (µs/cm)	15936.80	265.20
Sodium (mg/l)	2416.23	1131.40
Sulphate (mg/l)	1021.28	20.39
Total Alkalinity (mg/l)	160	66
Total Dissolved solids(TDS) (mg/l)	12960	206
Total Kjeldahl Nitrogen (TKN) (mg/l)	–	–
Nitrate-N (mg/l)	4.76	1.19
Dissolved 02 (mg/l)	9.6	4.6
Fecal Coliform (MPN/100ml)	11000	`790
Fecal Streptococci (MPN/100ml)	200	100
pH	8.35	6.85
Magnesium (mg/l)	697.41	18
Phenolphthalein Alkanity (mg/l)	22	4
Total Suspended solids (TSS) (mg/l)	632	86
Turbidity (NTU)	933	18.60
COD (mg/l)	22.72	4.41
Temperature (˚c)	32	19
Total coliform (MPN/100ml)	160000	8000
Boron  (mg/l)	BDL	BDL
Calcium (mg/l)	232	30
Chloride (mg/l)	9996.90	942.27

 Biodiversity:

SL. No	Order	Family and scientific name	Vernacular name/Local name	Season of collection
	Perciformes	Goblidac
1		Gobiosoma hildebrandl	Balkiri mach	Monsoon
2		Glossogobius giurls	Tank goby/balkiri mach	Monsoon
3		Periophthalmus modestus	Shuttles hopp fish/danphar mach	Winter
		Scatophagidae
4		Scatophagu sargus	Spotted scat/Vaja chauli	Monsoon and Summer
		Sillaginidae
5		Sillago sihama	Silver sillago/Sila mach	Monsoon and Winter
		Terapontidae
6		Terapon jarbua	Tiger perch /Kunkuni mach	Summer and Winter
		Leiognathidae
7		Eubleekeria splendens	Splendid pony fish/Tekathi mach	Winter
		Eleotriae
8		Gobiomorus dormitory	Giant goby/Balkiri mach	Monsoon and Winter
		Latidae
9		Lates calcarifer	Silver grunt/Vetki mach	Monsoon and Winter
	Perciformes	Haemulidae
10		Pomadasys hasta	Silver grunt/Khurunda mach	Monsoon and Winter
	Clupeiformes	Clupeidae
11		Corica soborna	Gangas river sprat/Kagia mach	Winter
12		Anodontostoma chacunda	Chacunda gizzard shad/Khayera mach	Winter and Summer
	Mugiliformes	mugilidae
13		Mugil cephalus	Parse mach	Monsoon and Winter
	Siluriformes	Ariidae
14		Arius sp	Cat fish	Monsoon and Winter
15		Mystus sp	Tangra	Monsoon and Winter
16		Rita gogra	Nadi tangra
	Scorpaeniformis	Platycephalidae		Monsoon
17		Platycephalus indicus		Monsoon
	Beloniformes	Belonidae
18		Xenetodon cancila	Gar fish	Monsoon and Winter

Diversity of Phytoplankton

Spirogyra sp,Volvox sp, Chlamydomonus sp, Anabaena sp, Nostoc sp, Stigeoclonium sp,

Uronema sp.

Diversity of Zooplankton

Filinialongiseta, Brachionu ssp, Keratella sp, Lepadella ,Trichocerea ,Notholca sp , B. angulsaris,Trichocerea sp ,Mysids shrimp ,Daphnia sp ,Bosmina sp ,Cyclops sp ,Acartia clausi,Labidocera wollastoni ,Eurytemora hirundoides, Nauplius stage ,Mesocyclops sp.

Effects of heavy metals on fish

SL. No	Heavy  metals	Fish Tissues
		Gill (mg/kg)	Muscle (mg/kg)
01	Zinc (Zn)	21.05	9.81
02	Copper (Cu)	3.51	0.92
03	Cadmium (Cd)	0.51	0.26
04	Cromium (Cr)	0.23	0.09
05	Lead ((Pb)	4.01	2.72
06	Nickel (Ni)	0.21	0.08

Heavy metals cause changes in the body of fish. Several kinds of disease are found in the fishes due to the pollution are given bellow.

Histological manifestations in gill and liver of A. gagora and P. pama from Haldia.

A) Clubbing of gill filaments in A. gagora.

B) Degeneration of secondary gill filament in A. gagora.

C) Gill filament showing epithelial lifting and hypertrophy in P. pama.

D) Fusion of secondary gill filament in A. gagora.

E) Liver showing cytoplasmic degeneration in A. gagora.

F) Evacuolation of hepatic ~ells in liver of P. pama.

Histological manifestations in kidney of A. gagora and P. pama from Haldia (H & E)

G) Necrotic hemapoietic tissue in liver of A. gagora.

H) An enlarged glomerulus and degenerating renal tubules in kidney of A. gagora.

I) Kidney showing congregated epithelial cells in renal tubules and picnotic nucleus of P. pama.

J) Kidney showing thickening in the walls of renal tubules and degenerating hemopoietic tissue in P. pama.

What should we stop?

• Various industries discharges harmful chemicals consists of several harmful heavy metals.
• We have to stop the careless mentality about the releasing of untreated industrial wastes into the river.
• Hot water should be cooled before releasing.
• Use of excessive fertilizer should be avoided.

What should we do?

Type of remediation	Description
Adsorption	It is the process of solid holds molecules of liquid or solute as a thin film.
Chlorination	It is the most widely used disinfectant for the treatment of waste water.
Ion exchange	It is the process of demineralization.
Chemical extraction	Separation of various water solvent.
Membrane separation	Separation of various molecules through membrane, it depends on the pore size and molecular size.
Electrokinetics	It is a procedure of a low-voltage direct-current electric field is applied across a section of contaminated soil to move contaminants.
Bioleaching	Removes heavy metals.
Phytoremediation	Application of plants to remove wastes from water.

Chlorination

Flowchart

Ion exchange

References

1. West Bengal water pollution control board
2. Heavy metals in water of the rivers Hooghly and Haldi at Haldia and their impact on fish, Article  in  Journal of Environmental Biology · August 2005, Srikanta Samanta, Kadamvari Saha
3. An assessment of heavy metals in sediments from two tributaries of lower stretch of Hugli estuary in West Bengal , Bhupander Kumar1, Sanjay Kumar1, Meenu Mishra1, Dev Prakash1, S. K. Singh1, C. S. Sharma1 and D. P. Mukherjee2
4. Impact of Industrial Effluents on Aquatic Biota in the Mouth of Haldi River, West Bengal ,Authors: Maity, Riyanka, Mandal, Basudev Gupta, Ashis
5. Wastewater technology fact sheet, Chlorination
6. https://images.app.goo.gl/NGyLF8J4A8YeVeiC8
7. https://www.sciencedirect.com/science/article/pii/S2090447920301131#:~:text=organic%20pollutant%20removal.-,Phytoremediation%20technique%20is%20a%20branch%20of%20bioremediation%20that%20employs%20the,to%20absorb%20nutrients%20from%20wastewater.