Detailed physico-chemical studies on abattoir effluent using lime, alum, ferrous sulphate and an anionic polyelectrolyte were tried individually and in combination. Among the coagulants tried, lime resulted in good settling of the sludge. At 400 mg l(-1) of lime dose, the Suspended Solids (SS), Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removals were found to be 41.9%, 38.9% and 36.1%, respectively. Best results were obtained with lime and ferrous sulphate in a combination ratio of 400:100 mg l(-1), and the COD reduction of 36.1% at 400 mg l(-1) of lime, further improved to 56.8%. Lime and alum dose of 400:50 mg l(-1) resulted in an increased COD reduction of 42.6% compared to 36.1% at lime dose of 400 mg l(-1). However, the same lime dose with ferrous sulphate addition of 100 mg l(-1) resulted in an increased COD reduction of 56.8% compared to 36.1%. This is a more efficient option for abattoir wastewater treatment and also cost effective. Ferrous sulphate with anionic polyelectrolyte resulted in good removals. Though it is a costly chemical, the dose needed is just half that of lime and just 0.1 mg l(-1) of anionic polyelectrolyte resulted in good reductions in SS, BOD and COD of 54.2%, 49.6% and 43.8% respectively. Studies indicated that the lime and ferrous sulphate in the combination of 400:100 mg l(-1), and ferrous sulphate and polyelectrolyte in the combination of 100:0.1 mg l(-1) are the two feasible options. Lime in combination with alum can also be applied but resultant sludge volume would be more.
Toxic effects of herbal pharmaceutical wastewater on common fish (Lebistes reticulatus) under laboratory conditions were studied. LC50 values for raw, neutralized, and physico-chemically treated effluent for 24, 48, 72, and 96 h ranged between 3.0-9.5%, 5.0-10.5%, and 35-41%, respectively. It was evident from the studies that physico-chemical treatment reduces the toxicity by more than 30%. This article discusses in detail the bioassay evaluation of raw, neutralized, and primary treated effluent. Physico-chemically treated effluent was further subjected to biological treatment by activated sludge system. Effluent from biological treatment revealed no toxic effect even after one month of exposure.
Herbal pharmaceutical industry has grown tremendously in the last few decades. As such, literature on the treatment of this wastewater is scarce. Water pollution control problems in the developing countries need to be solved through application of cost effective aerobic/anaerobic biological systems. One such system-the upflow anaerobic sludge blanket (UASB) process which is known to be cost effective and where by-product recovery was also feasible was applied for treatment of a high strength wastewater for a period of six months in a pilot scale upflow anaerobic sludge blanket (UASB) reactor with a capacity of 27.44 m(3). Studies were carried out at various organic loading rates varying between 6.26 and 10.33 kg COD/m(3)/day and hydraulic retention time (HRT) fluctuating between 33 and 43 hours. This resulted in chemical oxygen demand (COD), biochemical oxygen demand (BOD) and suspended solids (SS) removal in the range of 86.2%-91.6%, 90.0%-95.2% and 62.6%-68.0% respectively. The biogas production varied between 0.32-0.47 m(3)/kg COD added. Sludge from different heights of UASB reactor was collected and subjected to scanning electron microscopy (SEM). The results indicated good granulation with efficient UASB reactor performance.
Herbal Pharmaceutical wastewater was subjected to physico-chemical treatment using conventional coagulants individually and in combination with different anionic, cationic and nonionic polyelectrolytes. Results indicate cationic polyelectrolyte to be the best polymer. Individually Alum did not give good results but Alum with cationic polymer in the ratio of 300:0.25 mg l(-1) resulted in the best removals of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Suspended Solids (SS) of 64.0%, 69.4% and 80.82% respectively. The next combination which resulted in good removals was Lime: cationic polymer in the ratio of 300:0.20 mg l(-1) with COD, BOD, and SS removals of 57.6%, 65.1% and 74.0%, respectively. Overall the studies indicated that the herbal pharmaceutical wastewater needs to be treated by physico-chemical treatment as a primary process to reduce the organic load and increase the performance efficiency of the secondary biological treatment process. This paper discusses in detail the studies carried out using conventional coagulants along with synthetic polyelectrolyte.
The effect of inclusion of trivalent arsenic ions with increasing arsenic concentration on the structural, electrical and thermal properties of the system AsxFe3 – xO4 (x = 0.2, 0.4, 0.6, 0.8 and 1.0), synthesized at ambient temperature have been studied. Thermal measurements from room temperature to 1173 K and DC resistivity measurements with activation energy calculations were used for this purpose. Thermal measurements were carried out on these value added products. This investigation provides evidence for all compounds of the system. In particular: 1) They are stable up to 473 K and further only a small loss in weight was observed for the temperature range of 473 K – 1113 K, 2) In As0.2Fe2.8O4, a strong exothermic peak was observed at around 561 K, which has been shifted to 541 K for AsFe2O4, this shows the phase transition and sample crystallization. X-ray diffraction was used for characterization and DC resistivity measurement from room temperature to 623 K shows semi conducting behavior. The present work reveals that the incorporation of As3+ ions in the lattice of magnetite results in orthorhombic symmetry for arsenic composition x = 0.2 to x = 1.0.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.