Background and Purpose Discharge of industrial wastewater to urban wastewater system is a way of its management, especially within the cities. If it is not done in proportion to the system’, s capacity and under supervision, it may damage urban collection, transfer and treatment systems. Material and Methodology In this study, impacts of industrial discharges on urban wastewater facilities and the related standards and regulations in the selected countries are reviewed. Finding The study shows Canada, Mexico, Argentina, Singapore, USA, and Australia and New Zealand consider 13, 10, 14, 22, 34 and 29 variables of industrial wastewater in their standards, respectively. Moreover, USA limits the flow ratio of industrial discharges to urban wastewater. In contrast, Iran has no standard for industrial discharges to urban wastewater facilities and there is just one guideline to regulate discharges in industrial towns, which consists eight variables. Moreover, the lack of assessment of urban wastewater network and treatment capacity to accept industrial discharges which, often due to deficiency of information and experience in this field, can disrupt sewage transmission and treatment processes. Discussion and Conclusion As a result, setting national standard and guideline up to regulate industrial discharges to urban wastewater system, assessment of network and treatment plant capacity for accepting industrial discharges, and monitoring and supervision of these discharges to discover and prevent unauthorized discharges are critical measures to manage industrial wastewater especially within the cities in Iran.

In this study, the energy consumption of Nasirabad Industrial Park (NIP) treatment plant was evaluated. A combination of up-flow anaerobic baffled reactor (UABR) and aerobic integrated fixedbed activated sludge (IFAS) processes were employed in NIP. To find out the average electrical energy use per m3 influent wastewater, the rate of energy usage of the plant was calculated by data derived from the monthly utility bills in 2013 and 2014. The energy consumption was estimated to be 10. 4 and 10. 7 kWh. day-1. m-3 in 2013 and 2014, respectively. In addition, the electrical energy consumption of different electromechanical equipment of the plant was separately assessed. The average daily electrical energy consumed by treatment processes (effective energy) in both 2013 and 2014 was estimated at 7. 2 kWh. day-1. m-3, while the average energy consumption by other parts of the treatment plant (ineffective energy) was 3. 2 and 3. 5 kWh. day-1. m-3 in 2013 and 2014, respectively. The rate of electrical energy usage per kg COD removal was found to be 4. 9 and 5. 1 kWh. day-1 in 2013 and 2014, respectively. Finally, it was inferred that energy use in NIP was not being managed in a suitable manor. Given the significance of energy, price risings, and the decline of resources by which energy is generated, it is imperative to take effective managerial actions to reduce electrical energy consumption in wastewater treatment plants. Also, the designers of water and wastewater treatment plants should consider less energy-intensive processes to improve their energy efficiency.

Textile industry is the major source of water consumption and wastewater pollution. There are various treatment techniques to remove textile wastewater pollution. Coagulationflocculation is a widely used process to remove pollution due to suspended particles. In this research, different coagulants like Alum, Lime, FeCl3, FeSO4 and MgCl2 were applied to select the suitable ones with optimum removal efficiency of sulfuric dyes. Settling characteristics of flocs formed in the coagulation process were studied in a laboratory scale settling column unit. Parameters such as color, COD, TSS, turbidity and settled sludge volume have been evaluated. The optimum coagulant dose and pH value were determined by comparing the effectiveness of these coagulants.Results showed other coagulants except lime could eliminate color and COD. In this case, FeSO4 was chosen as an optimum coagulant for color removal because of the lowest required coagulant dose, minimum settled sludge volume and maximum de-colorization.

Introduction: Treatment of Wastewater due to product and consumption of material cleaning with special physicochemical characteristics is difficult, and therefore can cause significant environmental problems such as eutrification, toxicity, algae bloom and etc. To stop these consequences, assessing the quality characteristics of this wastewaters is necessary. To investigate about the appropriate method of treatment, Paksan Factory producing 30 percent of Iran detergents was selected.Materials& Methods: This study was a descriptive-cross-sectional one in which 30 wastewater composite samples24hr (obtained by combining portions of 720 grab samples) were taken during a five month period. The samples were properly preserved with acid and kept under 4oC during experimentation and transported to laboratory. The chemical characteristics were determined. Data analyzed using descriptive statistics.Results: The results of the samples showed that the wastewater temperature was 40.84±12.31 and the pH was 10.56±2.96. It also showed that the concentrations of the organic loading of wastewater were very high, expressed as COD, ranging from 6254-13040 mg/l, concentration of BOD was 2459-3200 mg/l and concentration of MABS ranging from 245-1120 mg/l. The results indicated that the BOD5/COD ratio was 0.34±0.09 and the mean of phosphorus was 88.13 mg/l.Conclusion: temperature and pH in wastewater of this factory have ringed with very changes and organic load was high. In most of samples BOD5/COD ratio was proper for biological treatment but in the samples that were not proper for biological treatment this problem would be solved with combination treatment of industrial wastewater and domestic one This wastewater has high concentration of foaming that prohibit of oxygen infiltration in wastewater and nonbiodgredable material. These results indicated that the wastewater is not easily subjected to conventional system of biological treatment; therefore such wastewater can cause some environmental problems.

In this research, horseradish peroxidase for phenol removal was utilized. First, the process was studied at the laboratory scale using a synthetic phenol solution (1-10) mM. Results showed that horseradish peroxidase (HRP) could effectively remove phenolic compounds from wastewater and that the catalytic capability of the enzyme was maintained for a wide range of pH, temperature, and aromatic concentration levels. The performance conditions were optimized for at lease 95% and 100% removal of phenolic compounds for both actual and synthetic wastewaters under high and low phenol concentrations (1 and 10 mM). The phenolic wastewater used was an olive mill effluent with a phenol concentration of 1221 mg/L (13 mM) and a pH value of 3.5. At the end of the reaction, the phenolic compounds changed to insoluble polymers and precipitated. Each enzyme/wastewater system was optimized for the following chemical dosages: hydrogen peroxide, enzyme, polyethylene glycol (PEG), and buffer. Furthermore, the reaction time to achieve at least 95% phenol removal was determined. According to the results, COD and BOD reduced to 58% and 78%, respectively. Experimental results showed an increase in H2O2 concentration beyond the optimum dose resulting from enzyme inactivation, thus reducing the phenol removal efficiency. On the other hand, increasing the enzyme, PEG, and/or reaction time beyond the optimum values resulted in only a marginal increase in removal efficiency.

Industrial effluents are a menace to the environment and the fact that their characteristics vary from industry-to-industry only adds to the complex challenge they offer to the engineers and scientists. Resource-efficient and environmentfriendly solutions to this hazard are a call of the hour. Coagulation, by synthetic chemicals, has been used as a cost-effective and efficient method for managing the effluents generated by a large number of industries. However, the synthetic chemicals themselves are a cause of concern due to their non-native nature, non-degradability, and health conditions associated with their left-over residues. Natural coagulants offer a cost-effective, environment-friendly, and sustainable alternative to the application of synthetic chemicals. Such natural coagulants, despite their demonstrated effectiveness in treating the industrial wastewaters, have their own limitations and are yet to be investigated for large-scale applications. The current work presents a state-of-the-art review of the natural coagulants’ application in treating industrial wastewaters and their relative advantages and disadvantages as compared to the chemical coagulants. Future research areas have also been identified that may ultimately lead to the large-scale commercial application of natural coagulants and will result in an environment-friendly and sustainable solution to the problems created by industrial effluents and synthetic chemical coagulants.

The effluents of polymerization plants are acidic due to the use of sulfuric acid as flocculation agent and their wastewater contains high amounts of sulfate ions. In wastewater industry, several physical, chemical and biological treatment methods are used. The main purpose of this study is to examine the feasibility of anaerobic biological treatment of sulfate in industrial effluents by using sulfate-reducing bacteria. The research method is quantitative, and experiments and data collection from 2017-2020. The main variables of this research are temperature, effluent pH and the population of microorganisms. Experiments at two temperature levels of 25 and 60 oC and two different pHs, 7.5 and 8.5, were performed and four series of experiments were done. The results showed that by increasing the temperature of the solution from 25° to 60 °C at a concentration of 50 mg/L sulfate ion and a pH of 7.5, microorganisms showed 17.6% better performance. Also, the performance of microorganisms in anaerobic biological treatment at concentration of 50 mg/L of sulfate ion was 45.3% minimum and 49.9% at maximum. Comparison of experimental results at two different pHs of 7.5 and 8.5, indicates that at the same temperatures of 25 and 65°C, with increasing pH, the performance of microorganisms has improved by 16.4%. The efficiency of wastewater treatment increases 19.6% by changing pH from 7.5 to 8.5. Results showed that the correlation between temperature and sulfate ion concentration follows the 1st degree equation. Also, the weak pH environment provides suitable conditions for the removal of ions in the effluents, and the correlation between increasing the pH of the solution and decreasing the concentration of sulfate ions is a 2nd degree equation. Study showed that temperature and pH are the two effective factors in the process of biological treatment of effluents.