Effect of industrial waste water on physicochemical properties of vegetation and its remediation with coagulants and flocculants

In order to assess the levels and impact of different trace metals on human health, a study was carried out to determine the levels of different trace heavy metals present in commonly edible vegetables grown in fresh water and industrial waste water of Faisalabad region. There is great variation in moisture, crude fiber (CF), protein content (CP) of fresh and wastewater grown vegetables and their leaves as well as edible part. In our present investigation fresh water showed high mean CP than waste water irrigated vegetable but wastewater grown vegetables exhibited more CF content to those of fresh water grown vegetables. The order of heavy metals in different trends of heavy metals in vegetables were in order of Cu greater than Zn greater than Mn greater than Ni greater than Pb greater than Cd. In nitric acid method, Pb and Ni showed more recovery of metal than samples digested by dry ash procedure. Statistically significant differences (p less than 0.05) were obtained between fresh water and wastewater irrigated samples. Higher accumulation of heavy metals was noted in leaves than their respectable edible parts. Chemical coagulants (peanut husk, sodium citrate and ferric chloride) were immobilized into bead form using sodium alginate to treat industrial wastewater samples. The maximum reduction of different physico-chemical characteristics such as EC, TSS, TSS, COD, SO4-2, Cl-1 phenolphtalein and total alkalinity was showed by ferric chloride at coagulant dose 2 g/L and pH 7.6. The morphology, size and elemental composition of individual immobilized ferric chloride and peanut husk were examined using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX). The particles analyzed in the study were mostly of large size, with equivalent diameters ranging from 2 to 70 mum. The promising results of the present study demonstrate that immobilization of chemical coagulants can make them more effective for wastewater treatment.