Effects of a textile factory effluent on soil and crop plants

Abstract

The effluent of the Modi Textile Factory Ltd, Modinagar, UP(MTF) was analysed and its effects in various concentrations (25, 50, 75 and 100%) on certain physicochemical properties of soil and germination and growth of kidney bean Phaseolus aureus and lady's finger Abelmoschus esculentus crops were studied. The effluent was found to be rich in various types of soilds, BOD, COD, Cl −, SO 4 2−, Na +, K +, Ca 2+ and Mg 2+, deficient in dissolved oxygen and highly alkaline in nature. At all the dilutions tested there was an increase in the water-soluble salts, electrical conductivity, cation-exchange capacity, pH, NH 3-N, phosphorus, organic matter and NH 4O Ac-extractable Na +, K +, Ca 2+ and Mg 2+ of the soil. The greatest changes were recorded with 100% effluent, the most marked increase being in the organic matter of soil, followed by NH 3-N, K +, Na +, P, Ca 2+ and Mg 2+. The other effluent concentrations also changed soil composition accordingly. The top soil supplemented with different dilutions of the effluent had higher concentrations of water-soluble salts and extractable nutrients than the subsoils. The soils supporting crops were found to have lower concentrations of nutrients than those without crops. The plants grown in different effluent concentrations were analysed for Na +, K +, Ca 2+ and Mg 2+. Na + showed a constant and gradual increase with increase in the effluent concentration, whereas K +, Ca 2+ and Mg 2+ concentrations were found to be highest in the plants grown in 50% effluent followed by 25, 75 and 100% effluent. Germination was inhibited and delayed by 100 and 75% effluent, whereas it was normal with other effluent concentrations as compared to water control. Undiluted and 75% effluent retarded the growth of plants whereas 50% effluent enhanced the growth.