Journal of Scientific & Industri al Research Vo1.59, May 2000, pp 350-361

Impact of Industrial Effluents on Soil Health and Agriculture - Indian Experience: Part I - Distillery and Paper Mill Effluents

P.K. Chhonkar l*, S.P. Datta l, H.C. loshi2 and H. Pathak2

'Division of Soil Science and Agricultural Chemistry, 2Division of E nvironmenta l Sciences

Indian Agricultural Research In s titute, New Delhi , 110012, India

The disposal of industri al eftluents is a problem of increasing importance throughout the world. In Indi a, a huge amount of waste water generated from distillery and paper industri es is discharged on land or into the running water. Di stillery waste water is characterized by low pH, hi gh BOD and COD values and contains a high percentage of organic and inorganic material s. This waste water also contains considerable amounts of elements like N, P, K, Ca and S. The paper mill effluents are character­

ized by high values of BOD, COD and wide range of pH, depending upon the source of origin. The N, P and K contents are lower as compared to those in distillery waste waters. Impact of use of these effl uents on soi l, plant and waterbodies is discussed . Use of distillery effluents indicates a significant increase in elec trical conductivity (EC), organic carbon, exchangeable Na as well as avail ab le N, P and K in soil s. Similarly, pH, organic carbon, cation-exc hange capacity, avai lable N, P, K and micronut rient contents of soils irrigated with paper fac tory effluents are reported to be increased. Besides, the use of th is waste water increases the exchangeable Na content of soils. Some of the field crops show positive response to post-methanation eftluent applicat ion with irrigation water. Paper mill effluents are found to adversely affec t the seed germination and seedling growth of various crops, whereas, these aspec ts of crops are stimul ated due to the application of these eftl uents after proper dilution. Increase in organic load, depletion of oxygen content and destruction of aquatic li fe in water course are some of the major problems created due to disposal of these effluents in river. Met hods of control and treatment of these effluents are indi cated . Manuria l potential , strategies and constraints o f utilization of these industri al ertluents in agricu lture are mentioned.

Introduction In recent years, considerable attention has been paid

to industrial wastes which are usually discharged on land or into sources of water. It is anticipated that the indus­trial activities will accelerate with the pace of develop­ment. Thi s would have adverse impact on agriculture and would cause environmental degradation . On the other hand, a huge amount of waste W3.ter generated from dis­tillery and paper industries has em important role to play in the context of scarcity of fresh water resources for irrigating agricultural land . Besides being a useful source of plant nutrients (N, P, K, S, etc .), these effluents often contain high amounts of various organic and inorganic materials as well as toxic trace e lements. These may ac­cumulate in so ils in excessive quantities in long-term use. Subsequently, these toxic e lements may cause physi­cal problems to human beings and animal s by entering the food chains. However, industrial waste water could be used safely and effectively with proper precautions to increase the soi l productivity. The utili zation of in-

* Author for correspondence. **Part II appears in June 2000 issue of this journal

dustrial wastes for agricultural purposes could also pro­vide a solution to the disposal problems.

Soil health is a state defi ned by the delicate bal­ance of various physical , chemical and biological prop­erties of so il and its relationship with overall environ­ment of which it is a part. From the crop production point of view, a healthy soil may be defined as one that pro­duces good crops suitable for human and animal con­sumption and has the ability to recuperate to sustain production. Therefore, the present paper (Part 1)** attempts to review the available literature in Indi an con­tex t on a broad range of topics coveri ng potential of pro­duction of distillery and paper mill effluents, their char­acteristics, impact of use of these effluents on soi l, crop and waterbodies, treatment of these effluents for safe disposal, their manurial potential and strategies as we ll as constraints in the use of these effluents in agriculture.

Quantity and Characteristics of Effluents

Distillery Effluents Presently, there are 285 disti lleries in India '. Most

of these di stilleries are concentrated in the states of

CHHONKAR el al.: IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 35 1

Maharashtra, Uttar Pradesh and Karnataka2• According to the recent estimates, the alcohol production in India has reached 2 .7 billion litre mark. The proportion of waste water, generally known as spentwash, is nearly 15 times of the total alcohol production . This massive quan­tity, approximately 40 billion litre of effluents, if dis­posed untreated, can cause considerable stress on the water courses, leading to widespread damage to aquatic life.

A high organic load (50,000 mg L" BOD and 95,000 mg L" COD) has been recorded in spentwash, whereas the post-methanation effluents had considerably lower organic load (5,000 mg L" BOD and 25,000 mg L-' COD)' _ The spentwash contained 1,000 mg L-' lIitro­gen, 40 mg L-' phosphorus, 11,000 mg L-' potassium and 1,500 mg L-' sulphate with 15 dS m-I electrical conduc­tivity (EC) and 4_5 pH. The nutrient concentration Elnd EC decreased while pH increased in post-methanation effluents as compared to those in spentwash_ It contained 300 mg L-' nitrogen, 20 mg L- phosphorus, 6,000 mg L-' potassium and 900 mg L-' sulphate with 8.5 dS m l EC and 5.9 pH. Zalawadia and Raman4 also recorded similar nutrient content of disti!kry effluents. Organic compounds extracted from spentwash by alkaline re­agents are of humic nature and similar to those found in the so il except that fuivic dcid predominates over humic acid·l . The presence of sugars (2-20 %) and proteins (lO­II per cent) in the dry spentwash along with p.lineral components has also been reported6

. Metals (in mg L-) like Fe-34.8, Mn-12 .7, Zn-4.61, Cu-3 .65, Cr-O.64 , Cd-0.48 and Co-0.08 are also found7 in spentwash with elec­trical conductivity in the range 15-23 dS m-I.

Paper Mill Effluents The first paper mill in India was established in 1867

at Bali , West Bengal. After independence, there has been a tremendous growth of paper industry and as in 1989, there were 305 paper and paper board mills in India, with the installed capacity of 3 million tonnes per an­num (TPAY. Large paper mills with capacity more than 55 tonnes per day account for 51 per cent of the total installed capacity. A number of small paper mills with 10-30 tonnes per day capacity and using agricultural resi­dues and waste paper have been set up all over the coun­try since 1975 and account for 49 per cent of the installed capacity. Water requirement is high in paper industry and it varies from 250 to 400 m' per tonne of paper in large paper mills while in small paper mills, the requirement of water is 200 to 350 m' per tonne of the product.

The major chemicals used by most of the paper and pulp mills are: sodium sulphate, sodium hydroxide, sodium sulphide, sodium carbonate, calcium hypochlo­rite and magnesium bisulphate. Obviously, the waste waters also contain these chemicals in various amounts. Lignin and its derivatives are highly res istant to degra­dation due to the presence of carbon to carbon linkages and some lignin derivatives possess mutagenic proper­ties _ The conventional pollutants in the paper mill efflu­ents relate to BOD, suspended solids, COD and pH, whereas, the non-conventional pollutants are colour and settleable solids . A large paper mill (LPM), on an aver­age, generates 220 m' of waste water per tonne of paper made, which contains 168 kg suspended soilds, 65 kg BOD load and 246 kg COD load~. The high pollution in a small paper mill (SPM) is due to non-recovery of chemi­cals from black liquor which is reported to be uneco­!10mical. As such each tonne of paper produced in SPM generates 2.65 time~ the pollution load discharged per tonne of paper made in LPM. Lignin and its deri vatives responsible for the brown colour in the waste wCl.ter, are not readily biodegradable and thus constitute recalc itrant pollutants. The intensity of colour is proportional to the black liq~lor losses in the mill. A number of toxic pollut­ants have been identified in waste water from this in­dustry, particularly from the pulp washing and bleach­ing operations . These include resins, acids, chlorinated lignins and chloro-f3tty acids . Other toxic pollutants in­clude tri- and penta-chloro~)henols, used in slimicide and biocide formulations in the mills. Beside these, on an average, LPM ancI SPM effluents~, contain (in mg L-') N, 6; P, 1.5; K, 10; Ca, 200; Mg, 35; and Na, 75 .

Current Mode of Disposal of Effluents

Distillery Effluents The environmental significance of distilleries is

recognised as the polluting units generating large vo l­ume of foul smelling and co lour waste water known as spentwash. Generally, the waste water is discharged into the "vater courses under untreated or partiall y treated conditions. Sometimes, the spentwash is recycled to pro­duce methane, which supplements the energy needs of the distillery as a boiler fuel. Attempts have also been made to produce potash fertilizer from distillery efflu­ents, in which the effluent is concentrated, dried and in­cinerated in specially designed mult i feci boilers . The energy generated can be used for the drying process or distillation and the steam can be used to generate power.

352 J SCI IND RES VOL 59 MAY 2000

Techniques have also been developed to use spentwash obtained from the distilleries for mass scale production of earthworms which are good soil conditioners and find use in agriculture. However, these technologies could not get enough public attention because the processes are not economically lucrative.

Paper Mill Effluents

The volume of effluents discharged per tonne of paper produced depends on the water economy fol lowed in the mill through recycling and reuse. Assuming a value of 6000 gallons of effluents per tonne of all kinds of paper products, the total volume of effluents di scharged by the industry has been estimated to be 131 million gallons per day 10. Practically major portion of effluents emanating from various pulp and paper industries in our country is being discharged into various rivers II.

Impact of Use of Effluents on Soil Health

Distillery Effluents The soils of tropical regions are low in organic car­

bon content. Therefore, the addition of organic matter is always beneficial for improving the soi l fertility status. But it is feared that the application of large amounts of organic m~tter, i.e. the material with high BOD and COD, may have an adverse effect on soi l health by increasing pC02 and temperature, and forming organic acids dur­ing decomposition which lead to the net immobilization of plant nutrients . However, these ill-effects are tempo­rary in nature and after a certain period, the system gets stabilized and adverse effects get nullified through deg­radation of organic acids. Since the post-methanation

effluents have nearly 60 per cent less organic load and higher pH values (7-7.5) than the spentwash (pH 4-5), possibilities of utilizing the effluents in a more benefi­cial way have increased, as this contains the essential nutrients such as nitrogen, phosphorous and potassium. It is also quite likely that the application of nutrients in the form of effluent irrigations may be more effective in respect of the bioavailability of nutrients to plants as compared to the synthetic inorganic fertilisers .

The effluent irrigations increased the pH, EC, OC, SAR, PAR, exchangeable Na and exchangeable K and available nutrient contents, i.e. N, P and K of the soils under sugarcane than with normal water at the same level of fertilizer application, showing that the potass ium fer­tilizer could be withdrawn from the fertilizer sched­u le4

.12

.u. Devarajan et af. U further concluded that the dis­

tillery wastes can be safely used as liquid manure at the rate of 125 to 250 t h,rl. An appreciable increase in the available K status in the post-harvest soi l after wheat crop was observed in effluents-treated plots, as compared to the control plot (Tab le I). As compared to the EC in the post-harvest soil after the wheat crop, the EC of the soi l after rice crop decreased . This may be due to the leaching of the salts during rice cu ltivation as water at 5 cm level is usually maintained. However, hi gher EC was recorded at higher levels of effluent application. The stud­ies conducted for four years at IARI farm on continuous application of PMEalong with irrigation on wheat and maize showed a steady ri se in soil EC and avai lable po­tassium (Figure I) . However, the EC has been found to decline significantly in the surface layer on discontinua­tion ofPME application during the experiment on wheat

Table I - Chemical properties of the post harvest soi ls following eflluent treatment'"

TreatmenT EC pH Organic C Available K Bulk density Volumetric water (dS m") (%) (kg ha" ) (g em') content

Wheat Rice Wheat Rice Wheat Rice Wheat Rice Wheat Rice Wheat Rice

CONTROL 0.20 0.10 7.50 8.40 0.50 0.73 191.4 271.0 1.53 1.52 0.37 0.40

10% PME 0.20 0.16 8.80 8.20 0,74 0.81 416.0 341.0 1.41 LSO 0.39 0.41

20% PME 0.44 0.15 7.90 8.30 1.08 0.96 880.0 572.0 1.41 1.52 0.4 1 0.41

30% PME 0.64 0.35 7.40 8.20 0.94 0.99 2006.0 1210.0 1.35 1.49 0.40 0.42

40% PME 0.79 0.55 7.60 8.30 1.00 0.99 2365.0 1375.0 1.36 1.42 0.44 0.41

CD (0.05) 0.14 0.06 NS NS 0.37 NS 183.0 141.0 0.13 NS 0.05 NS

~

CHHONKAR el at.: IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 353

. ~ frl

o .

:g 0.4 en

o.

Surface soil (0-15 cm)

-+-10% PME

--30% PME

Soli profile (90 em)

Control -+- 10% PME

20% PME .... 30% PME

40% PME

o.o~------------------------------~ 0.0 '------------_____ .......J

E Q..

4

1500

.~1000 ~

a 17 22

No. of Irrigations ~.

Surface soil (0-15 cm)

Control -+- 100/0 PME

20% PME -30% PME

40% PME

26 4 8 17 22

No. of IrrIgatIons

Soil profile (90 cm)

Control -+- 10% PME

20% PME - 30% PME

40% PME

26

0'-----------------------------------' 4 a 17 22 26 8 17 22 26

No. of Irrigations No. of Irrigations

Figurc I - Changes in soil EC and available potassium duc to long-term PME application in crop sequence , wheat, rice. sugarcanc. ratoon , ricc and wheat at Oudh Distillery (Unpubli shed IARI study)

(Figure 2). This suggests that the discontinuation of PME applicati on fo r 1-2 crop seasons, would be more suit­able and environment-friendly. However, no signi ficant change in so il pH due to the application of effluents in the post-harvest so il after wheat as well as ri ce crops was recorded (Table I), as the effluents do not conta in any strong salt which on di ssociati on cou ld change the pH signifi cantl y. Further, an increase in the organic car­bon was observed with effluent irrigations in post-har­vest so il which is asc ribed to the add iti on of organic matter through the effluents. Reduction in bulk density

after wheat was recorded, while after rice, bulk density was not reduced significant ly due to application of ef­fluents. As a consequence, increase in volumetric water content in effluent-treated plots was observed only after wheat. Bes ides, Singh et al. 15 found that add ition of spentwash without dilution was very effecti ve in increas­ing the water intake rate of the sodic calcareous soi l. Escolar l 6 had earlie r observed changes in hydraulic conducti vity, aggregate stabil ity and improvement in infiltration rate by the addition of di st illery slops and molasses to the columns of saline sodic soi l.

354 1 SCIIND RES VOL 59 MAY 2000

Years: • 1997 E3 1998 r-------------------------~0.8r_------------------------~

. ~ :!:!.,O.2

f:rl

0.1

][0.6

~ <...> ...., 0 . 4

0.2

0 . 0

0-15 30-45

Depth (0.,.,)

20% PME

0-'1:5 30-45

80-75 0-115

0 . 8

0 . 6

0.4

0 . 2

o 60-7:5 0-1:5

10% PME

30-45

Depth (ern)

30% PME

30-45

80-715

60-7CS

Depth (ern) Depth (ern)

~.2r-------------------------_,

~

40% PME 0 . 8

0 . 4

0 . 2

o 0-"15 30-4:5 60-75

Depth (ern)

Figure 2 - Changes in soil EC on di scontinuing PME application (U npubli shedlARI study)

Purushottam et at. 17 noticed the absence of nitro­gen fixing bacteria from the soil s treated with distillery effluents. Irrigat ion with pre-methanated distillery waste water (PRM) and diluted PRM resulted in overall low bacterial count. However, the popUlation of fungi and actinomycetes showed an increasing trend. When post­methanation distillery waste water (PME) was applied, the effect on the bacterial population was not to that ex­tent as with PRM, because pH ofPME is in the range 7-8 (optimum for bacteria) and it also contains relati ve ly less organic load due to transformation of the organic matter into methane IX . However, Nashikar"} reported that irrigation with high BOD waste waters did not adversely

affect the nitrificati on acti vity in soil. The effluent at low concentrations ( 1- 10 % v/v) and at proper pH levels (7.0-8.0) increased the growth and N-fixing abi lities of Anabaena, a blue green algae20

.

Paper Mill Effluents A few ev idences are avai lable to show the impact

of pulp and paper mill effluents on soil health. Seshayee Paper and Board Ltd (Pallipaayam) dicharges about 35 million litres of effluents every day and these have been used for rai sing sugarcane for the past 15 years in sandy loam soil s21

. Cation exc hange capac ity, CaC01 , ex­changeable cations, available K and available micronutri-

, 1

CHHONKAR e/ al.: IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 355

Table 2- Effect of continuous irrigation with paper factory effluents on soil propertiesll

Property Duration of irrigation

2 years

01

pH 7.6 EC (dS nl'l ) 0.7 Organic carbon (g kg·l) 0.4 CaCO) (g kg·l) 0.5 CEC [cmol (p+) kg·I ] 13.1

Exchangeable ca tions [ cmol (p+ ) kg·1 J

Na 1.2 Ca 5.1 Mg 3.4 K 1.0

Available lIIacmnll/riell /S (kg h[(I)

N P K

270 13. 1 224

Available l11iCf'OllUlrien/s (mg kg·l)

Fe 7.0 Mn 27.9 Zn 2.1 ClI 0.3

02

7.5 0.6 0.3 1.1 10.3

0.9 4.2 2.2 0.7

239 9.5 176

6.5 2 1.1 1.7 0.2

15 years

01

7.8 1.5 0.4 1. 7 17.3

2.4 7.2 5.5 1.9

243 12.9 328

2 1.1 23 .6 2.9 0.5

01 and O

2 denote 0.15 and 0.15-0.30 m depth of sampling

02

7.7 0.6 0.3 1.5 13.4

1.4 5. 3 3.8 1.3

180 10.0 202

22. 1 12. 1 0.4 0.4

ents of soils irrigated with paper factory effluents for IS years were reported to have increased over 2 year-efflu­ent irrigated soils (Table 2). Inspite of load ing the soil s with 2 ha-m of effluents (20 million litres) every year for 15 years, the available micronutrient level did not reach the toxic level. However, there was practically no significant change in most of the so il properties. Simi­larly, irrigati on of sugarcane c rop with combined pulp and paper mill effluents has been found to increase pH, organic carbon, N , P and K status of so ils22 . The applica­tion of effluents over a period of IS years has been found to increase the exchangeable Na by 4 .5-fo ld , compared with control (well water irrigated so ils), which ultimately raised the Na adsorption ratio of the so il s.

Impact of Use of Effluents on Crops

Distillery Effluents Crops like sugarcane have been found to withstand

the application of concentrated effluents without show-

ing reduction in the yield, whereas cereal s like wheat and rice grow well after dilution to BOD levels of 500-1000 mg L·'. Significant higher yields of sugarcane and an the increase in available N content of soil were ob­tained with 200 kg N per ha supplied through spentwash; however, the yield and available N-content decreased when 300 kg N per ha was applied through spentwash23.24 .

Dongale and Savant2S opined that spentwash was as good as KCI as a source of potassium for sorghum. Kulkarni et aUe, classified spentwash as a dilute liquid organic fertilizer with high potassium contents and whose nitro­gen mostly in the colloidal form, behaves as a slow re­lease fertilizer better than most of the inorganic nitrogen sources. Two-thirds of phosphorus is al so in organic form, the metabolic availability of which is more than that from inorganic sources. Moreover, it contains large amounts of important secondary elements like Ca, Sand Mg as well as trace e lements , viz. Cu , Mn and Zn. Zalawadia and Raman4 have reported that with 75 per cent of the recommended fertilizer application and di s­ti lIery waste water irrigation , the yield is at par with 100 per cent recommended dose of fertilizer with normal water irrigation. The percentage utilization of applied N, P and K through fertilizer is more in distillery waste water irrigation with 75 per cent fertilizer dose than with normal water irrigation with 100 per cent fertilizer dose. A four year experiment with wheat and maize conducted at IARI clearly demonstrated that there was no di scern­ible toxic effect of effluent application on wheat and maize up to 30 per cent PME (Table 3).

Further, inves tigations at various locations con­ducted by IARI have shown that most of the field crops, viz. sugarcane, rice , wheat and mustard showed positive response to post-methanation effluents application with irri gation water. Even after the 20th consecuti ve irrig::l­tion with effluents, none of the crops showed any tox ic­ity symptoms up to 30 per cent post methanati on efflu­ents (PME) application. The sugarcane crop receivi ng nine irrigations followed by ratoon crop rece iving five irri gations up to 30 per cent PME showed better yie lds as compared to the normall y irri gated crop . The kharif crops like mai ze and rice have been found to respond well to PME irrigation even up to 40 per cent level, stress symptoms were visible in the case of wheat crop irri­gated with 40 per cent PME continuously for three yea rs.

Paper Mill Efj7uents Mishra and Behera27 have reported that the expo­

sure of seeds of rice to paper mill effluents retard the growth of rice seedlings . The adverse effect was more

356 J SCI INO RES VOL 59 MAY 2000

Table Y-Grain yield of maize and wheat crops grown at IARI under PME irrigati on (l ARI Study, 1993-98 )

Treatments

Wheat 94-95 Maize 95 Wheat 95-96 (HO-2285) (GS-2) (HO-2285)

Cont ro l 3.65 2.90 2.85

10% PME 5.82 3. 14 3.27

20% PME 5.64 3. 19 3.26

30% PME 4.73 3. \0 3.\ 2

40% PME 4. 24 3. \8 2.68

pronounced where a higher concentration of effluents was used and protein content of rice seedling was ad­versely affected. Measurement of protein may therefore provide a useful criterion for the evaluation of phyto­toxic ity of effluents released from pulp and paper indus­try. In a laboratory experiment, seed germination of rice was studied in soil polluted with paper mill effluents1X

;

it was observed that the polluted soil caused a de lay in seed germination and reduction in final germination by 12.5 per cent compared with seeds in unpolluted soils. Srivastava2Y has reported that the seed germination of radi sh and onion was adversely affected by the use of paper mill effluents.

A case study conducted by Narashimharao and Naras imhara030 revealed that rice and cotton crops grown on sandy loam soils irrigated with paper mill effluents at Sarapaka vill age of Andhra Pradesh did not show any defi ciency or tox icity symptoms. However, the leaves of chilli and tobacco crops turned yell ow and it was con­cluded that the effluents were unsuitable for irrigating these crops mainly due to high salinity.

Kamalakar et al. 31 reported that the germination of maize seed was 100 per cent in nutrient solution and 91 per cent in undiluted effluents; the corresponding fig­ures for sunflower were 96 and 80 per cent. Subsequently, plant growth in both the species decreased with increas­ing effluents concentration from 25 to 100 per cent com­pared to nutrient solution. In similar studies, Kannan and Obli sami 32 have compared the effect of raw and treated effluents irrigation on vigour indices of some crops grown on red loam soils and have reported that treated efflu­ents did not affect seed germination in any species, while undiluted raw effluents decreased the seed germination

Yield (t ha·')

Maize 96 Wheat 96-97 Maize 97 (Hyb. Navjyot) (HD-2285) (GS-2)

1.54 2.80 2.61

1. 80 3.06 3.80

2.32 2.82 4.44

2. \8 3.26 3.87

1.62 2.6 \ 3.7\

of rag i, cowpea and cotton . Further, raw effluents re­tarded the seedling growth and vigour in maize, cowpea and cotton , while growth ofragi was highest with 75 per cent effluents. Optimum concentration s of treated efflu­ents for growth and vigour were worked out to be 100, 75 , 50 and 25 per cent for mai ze, rag i, cow pea and cot­ton , respectively. However, for groundnut the optimum concentration of paper mill effluents was assessed to be 25 per cent in respect to germination as well as dry mat­ter accumulation" . Leaf chlorophyll content of wheat has also been reported to decrease with increasing con­centration of paper mill effluents34

.

Impact of Effluents on Water Bodies Distillery Effluen.ts

Distillery waste waters pose a serious threat to the water quality in seve ral regions of the country. Lower­ing pH value of the stream, increase in organic load, depletion of oxygen content , di scolouration, des truction of aquatic life and bad smell are some of the maj or pol­lution problems due to distillery waste water. The addi­tion of distillery effluents to river Wain Ganga results in high concentration of organic matter and salts in the ri ver which is responsible for decrease in the di ssol ved oxy­gen and pH and the increase in BOD, COD leve ls and total dissolved solids in river water3) . In stances of large scale fi sh mortality in river Gomti due to distillery efflu­ents have been reported3fi

• Verma and Dalela37 found high sensitivity of some freshwater fi sh to diluted spentwash. Joshi et al.' noticed groundwater contamination by ef­fluents with hi gh BOD and salt content near the lagoon sites in most of the distilleries . In some cases , parti cu­larly in Maharashtra, the colour problem in ground wa-

.~

CHHONKAR el at.: IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 357

Table 4 - Pollution load from pulp and paper industry on various ri vers"

Statel pl ace Quantity of paper BOD di scharged Ri vers receiving pollution produced/yr per day (kg)" (tonnes)

West Bengal 132544 18157 Ganga, Damodar, Hooghl y

Madhya Pradesh 1208 19h 1655 1 Sone, Tapti, Khan, Chambal

Orissa 104279 14258 Ib, Tel, Nagavali

Andhra Pradesh 79207 10850 Godavari , Pranahita

Mysore 77234 10580 Kali , Cauvery, Bhadra reservoir

Maharashtra 76307 10453 Bhima, Wardha, Vait arn a

Bi har 56754 7775 Sone

Haryana 47587 65 19 Yamuna

Tamil Nadu 3905 1 5349 Cauvery

Uttar Pradesh 323 10 4426 Yamuna, Ganga

Gujarat 2 1400" 293 1 Tapti , Sabarmati, Mervi, Bhadar

Kerala 10285 1409 Chli yar, Koll ado

, An average value of 50 kg BOD/tonne of paper made is used for calcul ating BOD load h Include the national Newsprint Factory (4000 tonnes/yr) " Does not include the pul p produced by the Cent ra l Pulp Mill

ter is so acute that distille ri es have to prov ide potable water to the surrounding villages. This problem has been overcome at some of the sites by lining the lagoons and ensuring regular use of e ffluents for irrigati on on a larger area under well dev ised agronomic pl an, resulting in minimum retention time in the lagoons3

.

Paper Mill Effluents The po llution load from the pulp and paper indus­

tryon various rivers as estimated by Subrahmanyam and Mohan Rao tt, is g iven Table 4. M ost of our ri vers are be ing polluted by effluents emanating from thi s indus­try. Agarwal to has indicated the location specific prob­lems of ri ver po llution, such as complete deoxygenat ion of water of Ib river up to atleast 3 km downstream at Brajrajnagar during summers due to the di scharge of liq­uid wastes by Orient Paper Mill , Ori ssa. Simi larl y, hi gh concentrations of CI (7. 55-1 9 mg L-t) and sulphide (0 .82-12.2 mg L-t

) have been detected even up to 18 km down­stream from Bhadra confluence into Tunga ri ver. Other evidences of ri ver inc lude settling down of a lot of fine pulp fibres and sludge to a depth of I metre on the ri ver bed of Cauvery due to the di sposal of huge volume of efflu e nt s fro m Ses hayee Pulp a nd Boa rd Ltd , Pa llipa layam . Di sso lved oxygen leve l of wa ter of

Godavari was found to reduce due to the disposal of ef­fluents from Andhra Pradesh Paper Mill. The average di ssol ved oxygen in the upstream is 8 mg L-t, which gets re du ced to 5 .5 mg L -t a t I km d o wn s trea m of Tungabhadra ri ver due to the discharge of effluents fro m pulp and paper mill at Gondiparla village in Kurnool of Andhra Pradesah . Biochemical oxygen demand and COD in the upstream of thi s ri ver are 3.7 and 20 mg L-t

, re­specti ve ly, the corresponding values at I km downstream be ing 12 and 56 mg L-t

•

Quality Standard for Disposal of Distillery and Paper Mill Effluents

The pH and suspended so lids of treated distill e ry effluents should be 5 .5-9.0 and 100 mg L-t, respecti ve ly as specified by the Central Po llution Contro l Boarepx. The max imum limit of BOD for disposal into inland sur­face waters and on land for irrigati on has been fixed at 30 and 100 mg L-t, respecti ve ly. It a lso states that co lour and unpleasant odour of effluents are to be removed as far as practicable . However, amendments in environment protecti on rules a ll ow to di scharge distillery effluents on land hav ing BOD up to 1000 mg L·t where land appl ication is envisaged as a secondary treatment sys­tem for furth er re moval of BOD. Bes ides, I imits of BOD

358 1 SCIIND RES VOL 59 MAY 2UUU

Table 5 - Minimum national Standards for di sposal of eftluents from pul p and paper industry)'

Parameter SPM LPM

Discharge illfO illlalld sill/ace wafer

pH 5.5-9.0 7.0-8.5 Suspended solids (mg L-I) 100 50 BOD (mg L-I) 30 30 COD (mg L-I) 350

Disposa l all lalld

pH 5.5-9.0 Susrendcd solids (mg L-I) 100 BOD (mg L-I ) 100 SAR 26

as 30 mg L-t and 10 mg L-t of NO; (expressed as N) are prescribed for drainage water emanating from such sec­ondary treatment systems. Similarl y, upper-limits of BOD and NO,- have been fixed at 3 and 10 mg L-t for net addition t; ground water quality. It is very difficult to bring down BOD of di stillery effluents from 50,000 to 30 mg L-t. Therefore, application of di stillery efflu­ents on land seems to be a better propositi on. Thi s will not only help to protect the water bodies from pollution but also augment the crop productivity as the effluents contain significant amounts of nutrients. It is likely that these effluents due to their nutrient composition may fac ilitate better yields in the beginning but the continu­ous or indiscriminate use may also cause accumulation of salts in the so il , endangering its productivity and sustainability. Hence, proper management practices have to be developed for successful use of these effluents in ag riculture.

The Central Pollution Control Board has developed different Minimum Nationa l Standards (MINAS) for SPM and LPM after looking into pract ical difficulties , limitations, techno-economic feasibility and economic impact on the industry (Table 5). The bas ic consider­ations were the characteristics of effluents from small pulp and paper mills without chemical recovery systems, achievability and techno-economic feasibility of vari­ous waste water treatment alternatives and maintained ratio of annualized cost to the turn over of the industry.

Treatment of Distillery and Paper Mill Effluents

The characteristics of spentwash do not allow its direct di scharge into a water body, hence it requires treat­ment. In India most of the distilleri es use molasses, a by-product of sugar industri es, as a raw materi al for the

production of alcohol. The treatment of molasses di s­tillery waste waters is a serious problem as it has very high values of COD, BOD and salt load . Physico-chemi­cal treatment such as sedimentation with the addition of coagulant and other additives such as alum, lime, ferric chloride, activated charcoal, etc. has been found to be unsati sfactory. During the last decade there was a sig­nificant development in the treatment of waste waters from the alcohol industries through adoption of anaero­bic digestion. In thi s process spentwash is recycled to produce methane which supplements the energy needs of the distillery as boiler fuel. However, the post-meth a­nation effluent (PME) from the di stilleries is again faced with the problem of disposal as it still has considerable amount of organic and salt load. Hence, the problem of treating PME has not been solved as yet.

The processes of treatment of waste water fro m agricultural residue based paper mill are equali sation of flow from pulp wash section , primary clarification for combined waste water, secondary biological treatment and sludge drying beds or lagoons for primary sludge, depending on the avai lability of land3~. Further, it is sug­gested that a rotating biological contactor can be used for the treatment of the settled combined waste water where BOD is expected to reduce by over 90 per cen t3~.

Manurial Potential of Distillery and Paper Mill Effluents

The total effluents generated by 285 Indian di still­eries in a year amount to nearly 40 bil lion litres which can provide 480,000 t of K, 52000 t of Nand 8,000 t of P annually. Thus, the manurial potential of the efflu ents can be estimated by the fact that one year's effluents can meet the potass ium requirement of 3 million hectare of land , nitrogen requirement of 0.25 million hectare land and phosphorus requirement of 0.2 million hectare land , if two crops are taken in a year. Although, N, P and K contents in post-methanation effluents are reduced by 50-70 per cent, still the effluents contribute 240,000 t of K, 12,000 t ofN and 800 t ofP annually which can meet the K requirement of 1.5 million hectare of land, N re­quirement of 70,000 hectare of land and P requirement of 20,000 hectare of land annually. The manurial poten­tial of post-methanation distillery effluents in different states of India has been estimated by Joshi e! aU for Maharashtra, Uttar Pradesh and Madhya Pradesh . The manurial potential of di stillery effluents is quite signifi­cant and so the spec ial efforts are needed to harness thi s potential by pragmatic use of effluents in agriculture, particularly in these states. The addition of nutrients like

CHHONKAR et ClI.: IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 359

N, P, K and S will vary with the practice of pre-sown treatment and with different level s of diluted PME ef­fluents . Dilution to an extent of I : 10 will supply 72, 4.8 , 1440 and 240 kg ha-1 of N, P, K and S , respectively2. This may save the application of potassium and sulphur completely and partial saving of N to an extent of 60 per cent. Dilution at other levels may also save the inorganic N complete ly. Thus, the practice of applying the PME in agricultural fields either as pre-sown or post-sown seems to be beneficial. Looking at the potential of effluents in terms offertilizer requirement, the other factors such as, accumulation of salts in soil, changes in so il mechanical impedance, edaphic factors, soil moi sture and its ther­mal regime should not be overlooked.

If about 10 cm of PME is given at one time in pre­sown treatment or five post-sown irrigations with 4-5 times dilution , the area requirement for disposal of the effluents in agricultural fields comes to about 70,000 hectare. Assuming two crops per year in rab; and kharif seasons and fixing N requirement of about 200 kg ha-1

,

the total nitrogen requirement comes to 10125 tonnes. By followin g this practice, the N content which is avail­able to the root zone through effluent amounts to about 12210 tonnes, thereby indicating that there may not be any requirement of inorganic fertilizer application for supplying nitrogen. However, such practice may lead to excess application of potass ium. Although I iterature in­dicates that there is no significant reduction in the growth and yield response in cereals due to excessive potass ium but chlorides and sulphates associated with it pose seri­ous threat to the soil environment under long-term use. It becomes essential to look into the dynamics of high salt load in so il , groundwater and atmosphere continuum system. The detailed investigation in this regard may help in evaluating the sustainability and stability of the sys­tems response in re lation to practice of applying the PME distillery effluents in agricultural fields.

To hamess the K supplying potential of the effl u­ents fully, it is des irable that the total effluents gener­ated during a year should be used on 1.5 million hectare of land. But the Nand P requirements of the cropping system cannot be met fully through the effluents and the deficit has to be applied by the farmers . Although th is option may solve the problem of salt loading in the crop fields , it seems very difficult. as the large area required for ferti-in-igation may not be available with any dis­tillery individually. Therefore, cooperation of the farm­ers is essential for utilisation of effluents collectively in their field s. This also offers the best eco-friendly use of

the effluents without posing any threat to the soil envi­ronment besides hamessing its full manurial potential. However, there is a scope for reducing the area require­ment by exploring the thresholds for rate of application of effluents but in that case, potass ium which is abun­dantly present in the effluents may be wasted . Similarly, bes ides a source of irrigation water, the pulp and paper factory effluents also contain appreciable amount of plant nutrients, viz. N, P, K, Ca, Mg, S , etc. which can be

utilised in crop production.

Strategies for Utilisation of Distillery and Paper Mill Effluents in Agriculture

The best strategy for utili sation of industrial effl u­ents for in-igation of agricultural crops should emerge from the reali sation by all the concemed agencies - pollution control agencies, industries, farmers and research organisations. The use of industrial effluents, particularly spentwash for pre-sown treatment of agri­cultural land, although seems lucrative, should be dis­continued as the production of biogas from it offers a cheap and pollution-free source of energy. The post­methanation effluent has lower CN ratio and so it would degrade more sw iftly in the soil than in spentwash. Hence, there should be no problem with its utilisation in agriculture. Although BOD is an important parameter with res pect to water pollution but for the agroecosystems, the high salt load of the effluent is more important due to impending salinity problems after con­tinued use of effluents on the agricultural land, while the organic content of the effluents as indicated by BOD and COD values, is degraded fast by the soil microbes. The expensive energy consuming secondary treatment techniques aiming at reduction in BOD and ineffic ient in reducing the sa lt load of the effluent become irrel­evant with respect to agricultural use of the effluents . Thus, it is imperative to draw a line between agrocycling and water pollution control strategies. Another option is th e tran sformation of distilllery effluents int o a biofertili ser for which costly but viable technologies are ava ilable. Bes ides, composting with pres s mud , vermiculture are a few altematives which can be ven­tured to utili se the manurial potential of the di stillery effluents .

Constraints in Irrigation with Distillery and Paper Mill Effluents

Since the colour of the distillery effluents i dark brown, it induces e lement of psychological fear amongst

360 J SCI IND RES VOL 59 MAY 2000

the fanners. Sometimes, untreated effluent is drained into the channels which if applied on to the standing crops, damages the crop. Such incidences generates negative popularity towards the industrial effluents . Similarly, farmers hesitating to use the effluents bearing high salt and organic load for irrigation in the absence of fool­proof technology. Finally, lack of adequate attention to the propagation of usefulness of effluents in agriculture prevents the fanners to mobilise their collective strength to accept the practice of irrigating their field s with efflu­ents.

Conclusion The distillery and paper industries concentrated

mainly on the bank of various rivers in our country, re­ceive huge amount of industrial waste waters . These in­dustrial effluents are characterized by high BOD and COD levels and contain high percentage of different or­ganic and inorganic materials, depending upon the sources of their origin . Though impact of use of these waste waters on soil, plant and waterbodies has been evaluated, database is not adequate to elucidate the in­fluence of long-term use of these effluents to agriculture as well as environment as a whole. The conventional approach of in-plant treatment of industrial waste water even up to secondary and tertiary levels and its disposal in surface water does not provide an environmenta ly compatible solution to waste water management. Agri­cultural utilization of waste waters offers a low cost al­ternative. In doing so the manurial and irrigational po­tential of various types of waste waters which invari­ably have a considerable economic value in context of present energy and nutrient crisis and lately felt need for water conservation deserve to be primarily considered. However, it is equally important that potential toxicants in the waste waters should be identified. A waste water agrocycling package should have inh e re nt safety machanism so that the resultant product in the form of food grain, fodder or allied products such as milk or meat should be safe for consumers and the sustainability of agroecosystems . To ensure this , it is imperative that in­dustrial waste water should not be allowed to be dis­charged on land outside the framework of widely tested

agronomic package.

Acknowledgement Authors thank Prof. R.B . Singh, Former Director,

fA Rl, New Delhi, at present Asst. Director General , FAa, Bangkok, for his suggestion to take Lip thi s project and advice.

References AIDA, All India Distillery Associ ation Circu la r, June 1995, New Delhi, India, pi O.

2 Joshi H C, Pathak H, Choudhary A & Kalra N, Distillery eftl u­ents as a source of plant nutrient: Problems and prospects, Fer/if News, 41( II) ( 1996) 41-47.

3 Joshi H C, Kalra N, Chaudhary A & Dev 0 L, Environmental issues related with distillery effluent utilisati on in agriculture in India, Asia Pac J Environ Develop. 1(2) (1994) 92-103.

4 Zalawadia N M & Raman S, Effect of distillery waste water with graded fertilizer levels on sorghum yield and soil proper­ties, J Indian Soc Soil Sci. 42 (4) ( 1994) 575-579.

5 Corri C C, Pole A, Andreux F, Lobo M & Eduardo B P, Or ­ganic residues of the cane agro-industry I. Physical and chemi ­cal characteristics, STAB. 6(3) ( 1988) 34-37.

6 Kulkarni A D, Yewale A V & Jadhav S J, Cattle feed from spent wash, Bhartiya SlIg, 16 (2) (1990) 39-40.

7 Patil G D, Characterization of Spent Waslt/spent SllIrr.\'­pressmlld Compost and Their Effect on Yield. Nutrient VIJ/ake by Maize (Zea mays L.) and Soil Properties, PhD Thesis , MPKV, Rahuri, Maharasht ra, India, 1994.

8 Subrahmanyam P V R, Waste management in pulp and paper industry, J Indiall Ass Enviroll M{l/wge , 17 (2) ( 1990) 70-04.

9 Upadhyaya J S & Singh B. Decolourisation of el11uent from paper and pulp industry, Indian .I En viroll HI!h , 33 (3) ( 100 I) 350-356.

10 Agarwal S K. IlIdllstrial Environment - Assessment and SI/'{/[­egy (A PH Publishing Corporation. New Delhi 11001 2). 1996.

II Subrahmanyam P V R & Mohan Rao G J, Pulp and paper mill waste treatment , FIAWPC Symp En viron Pol/III , ( 1973 ). pp. 120-136.

12 Jad hav H D & Savant N K, Inlluence of added spent wash (d is­tillery waste) on chemical and physical propert ies of soil . In­dian J Agric Cit em, 8 ( I &2) ( 1975) 73-84.

13 Deverajan L, Rajannan G, Ramanathan G & Oblisailli G. Ef­fect of one time application of treated distillery ertl uents on soi I fertility status , yield and quality of sugarcane, S ISSTA Sligar J, 21 (3) ( 1994) 133- 135.

14 Pathak H, Joshi H C, Choudhary A, Kalrn N & Dwi ved i 1'vI . Distillery eflluents as so il amendment for wheat and ricc. J 111-dian Soc Soil Sci. 46 ( I ) ( 1998) 155-1 58.

15 Singh R, Singh N T & Arora Y, The use of spent wash for the reclamation of sodic soils, J Indian Soc Soil Sci. 28 ( I) ( 1980) 38-4 1.

16 Escolar R P, Stability of aggregates treated with distillery slop or black strap molasses , J Agric Vniv P Rico , SO ( 1966 ) 174-185.

17 Purushottalll D. Gunasekarah & Oblisami G, Effect of distill ery erlluent on certain microbial qualiti es of soil and plant growth . Proc Symp AMI, held at Nagpur. India, 18-20 Dec, 1986.

18 Juwarkar A, Dutta SA & Pandey R A. Effect of distill ery waste water irrigation on nodulation and nutritional qual ity of ground­nut, J IAEM , 17 ( I) ( 1990) 24-25.

19 Nashikar V J. Effect of reuse of BOD waste waters for crop irrigation on soil nitrification , Env Int. 19 ( 1993) 63-60.

20 Adhikari S P & Sahu J, Effect of distillery dIluen t on the growth of blue green algae, Anabaena in li ght and dark, Environ Ecol. 3 (4) ( 1985) 580-590.

CHHONKAR et al. : IMPACT OF DISTILLERY & PAPER MILL EFFLUENTS ON AGRICULTURE 361

2 I Palaniswami C & Sree Ram.ulu U S, Effec ts of continuous irri­gation with paper fac tory eftluent on soil properties, J Indian Soc Soil Sci, 42 (1994) I 39-140.

22 Kannan K & Oblisami G, Influence of irrigati on with pul p and paper mill eftluents on soil chemical and mi crobiological prop­erties , Bioi Fert Soil, 10 (3) ( 1990) 19 7-20 I.

23 Agarwal M L & Dua S P, Proc Seminar on Treatment and Disposal oj Effluent Jrom Sligar and Distillery Industries, held at Bangalore, 1976, pp 26-29.

24 Baj pai P D & Dua S P, Studies on the utility of di still ery efflu ­ent (spent wash) for its manuri al value and its effect on soil prop­erti es, Indian Sugar, 21 (5) (1972) 687-690.

25 Dongale J H & Savant N K, Potassium availability in spentwash (distill ery wastes), J Maharastra Agric Un iv, 3 (2) (1978) 138-139.

26 Kulkarni A D, Modak H M & Jadhav S J, Fertilizer fro m spentwash- A review, Bhartiya Sug, 12 (9) (1987) 17-20.

27 Mishra R N & Behera P K, The effect of paper industry efflu ent on growth , pigments, carbohydrates and proteins of ri ce seed­lings, En viroll Pollut, 72 (1991 ) 159-1 67.

28 Baruah B K & Das M, Effect of paper mill effluents on seed germinati on of crop, Envi/'On Ecol, 15(4) (1997) 904-906.

29 Sri vastava R K, Effect of paper mill effluents on seed germina­ti on and early growth perfo rmance of radi sh and onion, J Ecotoxicol EnvilVn Monit, 1 ( I ) (199 1) 13-1 8.

30 Narashimharao P & Narasimharao Y, Quality of effl uent water discharged from paper board industry and its effect on allu vial soil and crops , Indiwl J Agric Sci, 62 ( I) ( 1992) 9- 12.

31 Kamalakar J A, Sharma D & Melkania U, Effect of paper and pulp factory effluents on growth and development of maize and sunfl ower, Int J EnvilVl1 Studies, 39 (1-2) (1980) 55-63.

32 Kannan K & Oblisami G, Effec t of raw and treated paper mi ll efflu ent irrigation on vigour indices of certain crop plants, Ma­dras Agric J, 79 ( I ) ( 1992) 18-2 1.

33 Kannan K & Oblisami G, Effect of paper mill effluent irrigation on drymatter accumulation in groundnut, Madras Agric J, 79 ( I ) (1992) 59-6 1.

34 Chaturwed i Charu , Zaidi P H, Agarwal S R & Chaturwedi C, Effect of industrial effluent and aging on the chl orophyll con­tent of wheat plants, J Recent Ad Appl Sci, 10 (1-2) (1995) 65-69.

35 Chauhan A, Effect of distillery eftluent on ri ver Wain Ganga, Indian J Env Hlth, 33 (2) (199 1) 203-207.

36 Joshi H C, Environmental constraints in management of fi sher­ies in open water system, Proceedings oJthe National Sellli/wr 0 11 Management oj Fisheries in Inland Opell Water Systellls oj India , Barrackpore, West Bengal, India, Dec 1988, 1990, pp 23-30.

37 Verma S R & Dalala R C, Toxici ty of dis tillery waste to Pllntills sophore (ham) and Mystus villalus (bloch) (Pi sces: Cyprinidae: Bagridae) Part 3. Bioassay studies and TLm determination . A C/a

HydlVchim HydlVhiol, 4 (1976) 547.

38 Environment (Protection) Rules, 1986, in Pollution ContlVl Acts, Rules and Notifications Issued Thereundel; Pollution Cont ro l Series : PCU 2/ 1992, Vol I, CPCB, 1996.

39 Comprehensive Industry Document Series : COI NDS/ 23/ 85, Minimal Nati onal Standards, Small Pulp and Paper Industry, Central Board for the Prevention and Control of Water Pollution, New Delhi.