Background and Objective: Proper management of sewage is one of the most important environmental issues, organic matter and nutrients, including phosphorus compounds, are the potential pollutants of the receiving waters. Release of phosphorus from municipal wastewater treatment plant effluent to the environment is one of the main reasons for the phenomenon of the Eutrophication. Therefore, the aim of this study was to determine the amount of nutrients and organic matter in wastewater of Yasouj city and efficient removal of nutrients such as total phosphorus by modified Bardenpho system.Method: This is a cross-sectional study. The sampling method as Composite Sampling and study population was samples of treatment system input (after screening system) and output of treatment system (after sedimentation). In order to identify of affecting factors on phosphorus removal use of modified Bardenpho pilot. The amount of nitrate, total phosphate, COD and BOD5 removal for 9 months was evaluated. The collected data were analyzed by using SPSS software (version 16). Findings: According to the results, the average of input COD in system (674.55±228.54), input phosphorous (21.26±4.8), input nitrate (25.91±19.63), input BOD (378.33±106.66) mg per liter and the input pH (7.22±0.35). There is a significant Relationship between the input COD and percentage of phosphorus removal (P.value=0.004), but there is not significant relationship between the pH input and phosphorus removal percentage (P.value=0.339). Most phosphorus removal was observed in Solids Retention Time (SRT) of 15 days (69.72%). Internal recycle of 200 percent (68.96%) showed the highest percentage of phosphorous removal.Discussion and Conclusion: According to obtained information, the optimum conditions for phosphorus removal showed SRT =15, HRT =0.5-1 in anaerobic tank, the internal recycle percentage of 200%, recycled activated sludge (75%) and keep the DO =2-3. Therefore, for removal of phosphorus addition of physical and chemical methods can use of modified biological processes. In this systems, by replacing of an anaerobic stage at the beginning of the process, improve phosphorus removal. This method can be a good alternative to treatment plants with activated sludge system.

In this research, an experimental study to evaluate nutrient removal from synthetic wastewater by a labscale moving bed biofilm process was investigated. Also, kinetic analysis of the process with regard to phosphorus and nitrogen removal was studied with different mathematical models. For nutrient removal, the moving bed biofilm process was applied in series with anaerobic, anoxic and aerobic units in four separate reactors that were operated continuously at different loading rates of phosphorus and nitrogen and different hydraulic retention times. Under optimum conditions, almost complete nitrification with an average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.92 g NOx-N (NOx-N=NO2-N +NO3-N) produced/kg volatile suspended solids. Hour (VSS.h). Denitrification rate increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed good correlation with the anaerobic phosphate release rate. Under optimum conditions, the average total nitrogen and phosphorus removal efficiencies were 80.9% and 95.8%, respectively. As a result of the moving bed biofilm process (MBBR) kinetic analysis, the Stover- Kincannon model was chosen for modeling studies and experimental data analysis. The Stover-Kincannon model gave high correlation coefficients for phosphorus and nitrogen removal, which were 0.9862 and 0.986, respectively. Therefore, this model could be used in predicting the behavior or design of the moving bed biofilm process.

Objective Root structure modification is associated with the efficient water uptake and the nutrient utilization. It also provides structural support for the anchoring in soil. Genetic engineering for the improvement of plant root structure may help to maintain higher yields under drought conditions. The aim of this study was to modify the root structure of rice in order to improve drought tolerance and the efficiency of nutrient uptake. For this purpose, simultaneous transformation of Deeper Rooting1 or OsDRO1 gene, which is involved in the regulation of growth angle of the root in order to adapt to drought conditions, and Phosphorus-Starvation Tolerance1 or OsPSTOL1 gene, which is effective in increasing phosphorus uptake and improving root structure, were considered for rice root structure modification. Materials and methods The OsDRO1 and OsPSTOL1 genes derived from the wild rice cultivars were cloned together in a single construct under the control of the root specific and the ubiquitin promoters, respectively. The resulting construct, pUhrDroPstol is transformed into the Agrobacterium tumefactions strain EHA105 and used for the gene transformation into Hashemi cultivar. Putative transgenic plants, survived on 50 mg/L Hygromycin during tissue culture steps, are transplanted into the Yoshida solution and then into the pots until they set seeds. Construct specific and gene specific PCR analysis are used to confirm the transgenic plants. Results In this study, 12 putative transgenic rice events were obtained, of which 10 showed the presence of both OsDRO1 and OsPSTOL1 genes in the PCR analysis. Transgenic plants show stronger root structure compared to the non-transgenic ones. Molecular analysis in the T1 and T2 generations determined the homozygous events. Conclusions In this study, two candidate genes affecting root structure, nutrient uptake and drought tolerance were transferred to the Hashemi rice using genetic engineering. So far, simultaneous transfer of these two candidate genes have not been reported. Transgenic plants present better root system compared to the control plants. The mentioned construct can be used for the transformation of other crops to improve their root structure, nutrient uptake and their drought tolerance. It is hoped that the production of the transgenic rice with modified root structure and efficient phosphorus uptake increases its drought tolerance and reduce water consumption in rice cultivation.

The use of bio-fertilizers is a global approach to reduce chemical inputs pollution to increase the quantity and quality of plant products in line with sustainable agriculture. In this study in order to compare the effects of biological and chemical phosphorus fertilizer on phosphorus uptake and yield of ornamental calendula, a factorial experiment with two factors: 1 - Application of biological phosphorus fertilizer at four levels: M1 (without using biological phosphorus manure), M2 (inoculated seed with biological phosphorus fertilizer), M3 (inoculated roots with biological phosphorus fertilizer), M4 (inoculated seed and roots with biological phosphorus fertilizer) and (2) the amount of phosphorus in the form of triple superphosphate at four levels P1 (zero), P2 (100), P3 (200), P4 (300 mgl-1), based on a randomized complete block design with 16 treatments and 5 replicates with 5 pot per treatment was performed. The results showed that of the biological phosphate fertilizer application methods, M4 to most of the traits such plant height (35.53 cm), flower diameter (66.58 mm), flower number (9.15), number of leaves per plant (64.25), shoot fresh weight (29.9 g) and shoot P (% 3.45) was effective and efficient and phosphorus fertilizer consumption has reduced. Whereas in most of the characteristics M4P3 treatment had no significant difference with M4P4 treatment. Therefore, it is advisable to reduce consumption of chemical phosphorus fertilizer.

Desert growth in Iran is a major problem. A large part of the country is surrounded by vulnerable areas at risk of desertification, so that about 75% of the ecosystems of arid and semi-arid regions of the country, face the effects and consequences of desertification. Effects such as the drying up of inland lakes, sandstorms, dust and intensification of wind erosion are a clear manifestation of the growing rate of desertification in recent years in the country. In arid and semi-arid ecosystems, there is little vegetation due to lack of moisture and other adverse climatic conditions. As a result, soils are more prone to degradation, but in some of these areas, despite the lack of soil moisture, high temperatures and other unfavorable ecological conditions, the distances between plants are often covered by a community of microscopic plants, and this Communities are known as biological soil crusts. Biological soil crusts are the association of soil mineral particles with cyanobacteria, algae, fungi, lichens, or bryophytes and are common coverings in open spaces around vascular plants in arid and semi-arid regions. Biological crusts significantly affect early ecosystem processes and have been described as ecological engineers in arid regions.

The up-flow Sludge Blanket Filtration (USBF) is a novel and efficient wastewater treatment process which is a modification of conventational activated sludge system. The purpose of this study was to determine the efficiency of USBF process in biological phosphorus removal and to achieve the optimized hydraulic retention time according to the maximum phosphorus removal in the system. The experiments were carried out using a pilot scale USBF plant with a total volume of 60 liters by operating in different hydraulic retention times with flow rates of 0.57, 0.67, 0.8, 1.0, 1.33 and 2L per hour and the COD/P ratio around 50 at pH from 6.5 to 7.8 and room temperature (i.e.20±2oC). The experiments results according to the phosphorus removal showed that the system could commonly achieve steady state in a short time in flow rates of 0.8 and 0.67, and the phosphorus removal efficiency of more than 90 percent, but in the flow rates of 1.0, 1.33 and 2L per hour it would take a longer time to achieve the steady state and the desired phosphorus removal rate. At the end statistical analysis were carried out to determine an economical option for the hydraulic retention time for the biological phosphorus removal in this process, that it was 10 h for the hydraulic retention time in the clarifier.

To survey the effects of chemical and biological phosphorus on the yield and essential oil of Satureja hortensis L. as an important medicinal plant, factorial experiment was conducted based on randomized complete block design with three replicates at Research Station of Faculty of Agriculture, Urmia University in 2011. The treatments were chemical phosphorus fertilizer with four levels (0, 50, 100 and 150 kg/ha P as triple supper phosphate) and biological phosphorus fertilizer with four levels (0, 100, 200 and 300 g/ha Pseudomonas putida Strain P13 and Bacillus lentus Strain P5). The results of ANOVA showed the significant interaction effect between chemical and biological phosphorus on the yield of fresh weight, biological yield, stem dry weight, and the yield of drug and essential oil. There was non-significant effect of chemical and biological phosphorus on the essential oil percent, harvest index of drug and harvest index of essential oil. The highest amounts of total fresh weight (23327 kg/ha), biological yield (5282 kg/ha), stem dry weight (2523 kg/ha) and yield of drug (2759 kg/ha) and essential oil (79 kg/ha) were obtained from 200 g/ha of biological phosphorus without chemical fertilizer. The minimum amounts of total fresh weight, biological yield, stem dry weight, the yield of drug and essential oil were observed in higher than 200 g/ha of biological phosphorus.

In this research, a pilot consisting of two Sequencing Batch Reactors (SBR) used to remove phosohorus biologically. Both reactors were in operation in a 12 hours cycle and they were controlled by a computer. The blank one had no primary anaerobic stage and its aeration time was 9.5 hours. The other one had the primary anaerobic stage with no change in the total reaction time (9.5 hours). The average concentration of influent phosphorus and COD in reactors were 7.5 and 800 milligram per litre respectively. In two months periods, the average effeciencies of phosporus removal for the blank reactor and the second reactor with anaerobic reaction times of 2,3, and 4.5 hours were 16%, 26%, 64%, and 99% respectively.In the reactor with anaerobic reaction time of 4.5 hours, increasing the sludge age from 5 days to 10 days resulted in decreasing of phosphorus removal efficiency from 99% to 87%.In general, the result of this investigation show that the increases of anaerobic reaction time can increase the efficiency of phosphorus removal, because of the prevalence of phosphorus removing microrganisms over other species. Also, the accurate control of additional sludge volume (sludge age) has an appropriate effect on the removal efficiency.

Background and objectives: Phosphorus (P) is one of the most important components and a limiting factor for the growth of plants due to its low mobility and availability in soil. Application of organic materials such as biochar is one of the main choices to increase the availability of P in soil. Biochar is a carbon-rich material derived from pyrolysis of organic feedstocks under limited or no oxygen conditions. Biochar can influence the availability of P by improving the physicochemical, biological, and enzymatic conditions of soil, in addition to directly increasing the concentration of nutritional elements, particularly P. Soil pollution by heavy metals such as Cadmium (Cd) has been one of the environmental concerns in the last several decades. Cadmium alters the activity and diversity of soil microbial communities, and it also lessens soil function by decreasing the activity of enzymes related to nutrient cycling. Application of organic materials such as biochar in contaminated soil can reduce the availability of heavy metals in the soil, and as a result, increase the biological properties. It is hypothesized that application of biochar in heavy metal-contaminated soil influences the availability of P not only directly but also indirectly by improving microbial and enzymatic activity. This issue depends on the type of biochar and soil. Therefore, this study was conducted to investigate the interaction effect of biochar (cow manure and wheat straw) and Cd on microbial respiration, acid and alkaline phosphatase activity and available P in two soils with different physicochemical characteristics.Materials and methods: A factorial experiment was conducted using a completely randomized design with three replicates. The experimental factors included 4 levels of Cd contamination (0, 5, 10 and 20 mg kg-1), 3 levels of biochar (control, wheat straw and cattle manure biochar) and 2 types of soil (corck sofla and research center). Two types of soil contaminated with different amounts of Cd from CdCl2, were amended with 2.5% of the biochar, then were incubated for 14 and 90 days at laboratory temperature and 70% field capacity. At the end of each incubation time, available Cd and P, basal respiration and acid and alkaline phosphatase activity were measured. Results: The application of cattle manure and wheat straw biochar in soil reduced the available Cd by 70-86% and 61-85%, respectively. At all levels of Cd contamination, the amount of available Cd in the research center soil with sandy loam texture was higher than that of the Kark Sefala soil with clay texture. Higher concentrations of Cd also reduced the microbial respiration and the enzyme activities in the research center (31-46%) more than in the corck sofla (21.5-35.5%) soil. The decrease in microbial respiration and enzyme activities due to Cd contamination in the soil without biochar (10-41.5%) was more than the soil amended with wheat straw (5-39.8%) and cow manure (0.8-37.9%) biochar. The results also showed that available P increased with biochar addition and decreased with increasing Cd concentration in soil, so that the highest amount of available P was observed in the soil amended with cow manure biochar and without Cd contamination. Positive and significant correlation between available P with microbial respiration (r=0.385-0.604), alkaline (r=0.764-0.879) and acid (r=0.761-0.883) phosphatase activity was obtained, indicating that microbial activity and the enzymes involved in P cycling, play a significant role in the availability of P in the soil.Conclusion: These findings indicated that the application of biochar in Cd-contaminated soils can increase the bioavailability of P in the soil by decreasing the availaility of Cd and increasing microbial activity and alkaline and acid phosphatase activity. This issue was affected by the biochar and soil type.