PHYTOTOXIC EFFECTS OF INDUSTRIAL AND SEWAGE WASTE-WATERS ON GROWTH, CHLOROPHYLL CONTENT, TRANSPIRATION RATE AND RELATIVE WATER-CONTENT OF POTTED SUNFLOWER PLANTS

Waste water coming from two factories, namely Manquabad (fertilizer) a nd Bani Qura (detergents and oils) factory and Arab El-Madabegh sewage effluents were determined for their phytotoxicities and physicochemic al properties. The effect of the waters on the growth, chlorophyll con tent, transpiration rate and leaf relative water content of sunflower plants was undertaken in pots. In addition, the phytotoxicity present in the waste waters on embryonic radicle growth was also studied. The experiments were repeated each month from January to June, 1992. The t hree waste waters exhibited significant phytotoxic effects on the radi cle growth of sunflower. The phytotoxicity varied with monthly samplin g. The waste water from the fertilizer factory (Manquabad) collected i n February, May and June showed almost 100% inhibition on the radicle growth, while January and April sampling had a stimulatory effect. Mos t of the tested water exhibited significant inhibition on shoot growth . Root growth was significantly enhanced by Arab El-Madabegh sewage wa ter collected in February, March and April and was suppressed in the o ther three months. The three waste waters showed inhibitory effect on chlorophyll content. The inhibition was very high in the January sampl ing. Chlorophyll stability to heat was significantly lower in February and March and higher in May and June water-treated plants. Generally waste water-treated plants showed a lower transpiration rate than the control (tap water). Leaf relative water content of plants grown in th e waste waters was significantly lower in May and June collected water than in the other four months collections. The physicochemical analys is of the waste waters revealed that the amount of Na+, K+ Ca+2, Zn+2, Cu+2, Iron, Cl-, SO4-2 and the degree of electrical conductivity were often above the limits of the standard for irrigation water for agric ultural land, and some of these properties would be severely detriment al to crop growth. Generally waste water coming from the Manquabad fer tilizer factory consistently revealed the highest inhibition, Bani Qur a detergents and oils factory the second and Arab El-Madabegh sewage t he least.