The main task of this work is related with the design of a class of SISO robust control law for the regulation of substrate concentration (CDO) of an Industrial Activated Sludge Wastewater Plant. The control design is related with an uncertainty estimator (reduced order observer) based Active Control. Departing from the tracking error between the desired and the current substrate concentrations trajectories a control law is designed and the plant is regulated to the corresponding set point of the COD concentration. To be realizable the controller needs model information related with the kinetic term of COD consumption which is provides with a reduced order observer, these coupled structure (observer based controller) is robust against model uncertainties. The performance of the proposed control law is illustrated with numerical simulations employing a mathematical model of an Industrial Activated Sludge Wastewater Plant tuned with industrial data.

Bioremediation of metal pollutants from industrial wastewater using metal resistant bacteria is a very important aspect of environmental biotechnology. In this study, three species of Pseudomonas aeruginosa were isolated from active sludge of a food factory in the city of Kerman. The bacterial identity was determined by various biochemical tests. Among them, isolate number one could grow on Muller-Hinton agar medium containing 6mM cadmium ion (Cd2+) and was therefore selected for further study. The isolates were subjected to mutation by two mutagenic agents (Acridine Orange and Acriflavine) using gradient plate and SIC techniques. The Minimum Inhibitory Concentration of Cd2+ for the isolate one after mutation was increased to 7mM. Removal of Cd2+using mutated and wild type strains of this bacterium was carried out at different time intervals (10-300 minutes). It was observed that within 60 minutes, 94.7% of cadmium was removed in 30mg/L of Cd2+ solution. However, with 60mg/L Cd2+ solution, only 53.58% and 38.68% Cd2+ removed were achieved by mutated and wild type bacteria, respectively. The equilibrium data was fitted by Langmuir isotherm equation and the related parameters for Cd2+ were derived. Based on the data obtained in this study, it can be concluded that biomass of this bacterium can be used for bioremediation of cadmium from industrial waste processing plants with high efficiency.

The objective of this study was to investigate the effect of various active carbon weights (100 and 150 g)and sizes (0.3, 1.5 and 4 mm) on the remediation of soil hydrocarbon pollution and monitor the negative impacts of petroleum hydrocarbons on parameters such as C/N, electrical conductivity (EC) and hydrophobicity of aggregates in petroleum polluted soil. This pilot study was conducted over 60 days as a split-plot in time experiment based on a completely randomized design with three replicates and included seven treatments (W100S0.3, W100S1.5, W100S4, W150S0.3, W150S1.5, W150S4, C), in which w and s indicated active carbon weight (g) and size (mm), respectively. The results showed that the application of active carbon at smaller sizes resulted in a significant decrease in the concentrations of C, N, C/N, pH, and total petroleum hydrocarbons )TPH(.. Active carbon treatment with 150 g weight and 0.3 mm size was the most effective treatment in TPH biodegradation, reduction of organic carbon content and C/N ratio in the polluted soil. Also, this treatment decreased aggregate hydrophobicity and dispersible clay percentage by TPH degradation.

The removal of four pharmaceutically active compounds, i.e., anti-inflammatory painkiller diclofenac (DCF), lipid-regulating agent clofibric acid (CFA), epilepsy drugs carbamazepine (CBM), and broad-spectrum anti-bacterial agent triclosan (TCS), present in sewage sludge was investigated using anaerobic digestion processes in the mesophilic and thermophilic modes. Sludge retention times (SRTs) were set at 10, 15, and 20 days, respectively, for the mesophilic mode and 7, 15, and 20 days, respectively, for the thermophilic mode. The effective isolation and purification pre-treatment to extract the target compounds from the sewage sludge samples were firstly established, followed by gas chromatography-mass spectrometer analysis to identify and quantify them. The removal efficiencies of the target compounds could be raised to a certain extent with the increase on SRTs, especially under the mesophilic condition. The removal of CFA and TCS under thermophilic condition hardly varied when the SRTs were above 15 days. All the compounds could be partly removed from the sewage sludge under the two temperature conditions, particularly TCS that was reduced by about 74%. Besides, CFA, firstly reported in this study, could be reduced by maximal 65%. On the whole, the thermophilic mode was more conducive to the removal of CBM and TCS, but did not have a noticeable effect on the removal of CFA. Furthermore, DCF could be better removed in the mesophilic mode. In addition, NH3-N accumulation in this measured range might positively affect the removal of the selected compounds, particularly in the mesophilic mode.