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) and Bani Qura (detergents and oils) factory and Arab El-Madabegh sewage effluents were determined for their phytotoxicities and physicochemical properties. The effect of the waters on the growth, chlorophyll content, 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 three waste waters exhibited significant phytotoxic effects on the radicle growth of sunflower. The phytotoxicity varied with monthly sampling. The waste water from the fertilizer factory (Manquabad) collected in February, May and June showed almost 100% inhibition on the radicle growth, while January and April sampling had a stimulatory effect. Most of the tested water exhibited significant inhibition on shoot growth. Root growth was significantly enhanced by Arab El-Madabegh sewage water collected in February, March and April and was suppressed in the other three months. The three waste waters showed inhibitory effect on chlorophyll content. The inhibition was very high in the January sampling. 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 the waste waters was significantly lower in May and June collected water than in the other four months collections. The physicochemical analysis 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 agricultural land, and some of these properties would be severely detrimental to crop growth. Generally waste water coming from the Manquabad fertilizer factory consistently revealed the highest inhibition, Bani Qura detergents and oils factory the second and Arab El-Madabegh sewage the least.