The production of industrial wastewater is increasing worldwide due to the drastic advances in production and manufacturing processes. The adverse industrial activities discharged contaminated wastewater directly into the water bodies that contain toxic substances such as heavy metals and metalloids. Due to the continuous use of these effluents in the agricultural sector may decrease the soil fertility and crop growth. The mobility and availability of these contaminants affect their toxicity and biogeochemistry. The present study was conducted to investigate the toxic effects of marble industrial waste water on Zea mays L under the exogenous application of citric acid (CA) with different combinations such as T1; 25 % marble effluent (M.E) diluted with distilled water, T2; 50% M.E diluted with water, T3; 100% M.E, T4; citric acid (5mM), T5; 25% M.E + C.A, T6; 50% M.E + C.A, T7; 100% M. E+ C.A. The results showed significant decrease in the growth of Zea mays with increasing concentration of marble effluent. The maximum reduction in plant height, root length, number of leaves, leaf area and fresh and dry biomass of leaf, stem and root was observed at the application of 100% M.E as compared to control. Similar to growth conditions the photosynthetic machinery (Chlorophyll a, b, carotenoids), gas exchange attributes (net photosynthetic rate, water use efficiency, stomata conductance, transpiration rate) and the activities of antioxidant enzymes (SOD, POD, APX, CAT) was also decreased with increasing concentration of M.E. The application of CA significantly alleviated the M.E induced toxic effect on Zea mays and ameliorated the growth, biomass, photosynthesis, gas exchange attributes and antioxidant enzymes activities by reducing the production of reactive oxygen species (ROS) and electrolyte leakage. The C.A application also enhanced the metal content and accumulation such as lead (Pb), cadmium (Cd), iron (Fe) in different parts of Zea mays. The results concluded that the Zea mays tolerant verities can be the potential candidate for the M.E irrigated soil and might be suitable for the phyto-extraction of Pb, Cd and Fe. Future studies are required to investigate the suitability of Zea mays for the phyto-extraction of heavy metals.