Introduction: Analyzing the health risk associated with the microbial contamination of seawater is necessary to ensure that there is not any threat to human or environment. The aim of this study was to evaluate the microbiological quality of Caspian sea water using indicator bacteria. Some Physicochemical parameters were studied to assed their association with the contamination level of Caspian sea water due to the important role in the growth organisms in the seawater.
Materials and Methods: In this study, 100 samples were collected from the northeastern zone of the Caspian sea, Iran, from November 2017 to December 2018. Total coliform, Fecal coliform, E.coli, Fecal Streptococcus and Clostridium perfringens were the indicator bacteria and temperature, pH, electrical conductivity, chloride and turbidity were water physicochemical factors according to standard methods.
Results: The finding showed that the mean of Total coliform, Fecal coliform, E.coli, Fecal Streptococcus, and Clostridium perfringens were 614.72 ± 516.13, 62.11 ± 235.30, 49.69 ± 188.24, 348.02 ± 490.01 and 3.04 ± 5.76 MPN/100 ml, respectively. Furthermore, the mean and SD of temperature, pH, electrical conductivity, chloride, and turbidity were 13.84 ^oC ± 5.62, 8.27 ± 0.45, 17.96 ± 6.56 µs/cm, 5776.95 ± 1996.38 mg/l and 27.48 ± 15.82 NTU, respectively. Statistical analysis showed that microbial qualities were affected significantly by physicochemical factors, but the roles of water temperature were more than others.
Conclusion: The microbiological results revealed that there was a remarkable level of contamination in some areas of Caspian sea. The results suggested that Clostridium perfringens provide better health risk prediction than other analyzed indicator bacteria, particularly in the warm season.

Introduction: Nanoporous silica has received growing interest for its unique application potential in pollutant removal. Therefore, the development of a simple technique is required to synthesize and functionalize the nanoporous materials for industrial application.
Materials and Methods: The synthesis of nanoporous silica was investigated by the template sol-gel method, and it functionalized as an adsorbent for adsorption of malachite green. The morphology and structure of the prepared and functionalized nanoporous silica were studied using X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption-desorption technique. Subsequently, the effective parameters such as solution pH, contact time, and initial concentration on the adsorption process were optimized by adsorption tests.
Results: The results showed that high-order nanoporous silica had been produced with an average diameter of 20.12 nm and average pore volume of 1.04 cm³.g⁻¹. It was found that the optimum parameters of pH, initial concentration and contact time for malachite green adsorption on nanoporous silica were 6.5, 10 mg.l^-1, and 60 min, respectively. The experimental data confirmed the Freundlich model (R² = 0.995) and the obtained kinetic data followed the pseudo-first-order equation. The maximum adsorption capacity calculated by Langmuir isotherm was found to be 116.3 mg.g^-1.
Conclusion: The high adsorption capacity showed that the acid-functionalized nanoporous silica adsorbent can be used as an adequate adsorbent to remove malachite green from aquatic environments. The large surface area can be suggested that the silica nanoporous will have potential application prospects as the adsorbent.

Introduction: The quality of drinking water is of vital importance in breeding chickens. High levels of bacteria, minerals, or other contaminants in the water of poultry farms can have adverse effects on the natural physiology of chickens. Therefore, this study aims to investigate the physical, chemical, and microbial quality of water used in poultry farms in Ardestan, Iran.
Materials and Methods: This descriptive cross-sectional study was conducted on water sources (Wells and Qanats) of 35 poultry farms in Ardestan during the summer of 2021.Water samples were randomly taken and send to laboratory for analysis of physical, chemical, and microbial parameters according to Standard Methods. SPSS 16 software was applied for statistical analysis.
Results: With the exception of sodium, sulfates, and total hardness (TH), all other parameters fell within acceptable standard limits. Some water samples showed elevated levels of total coliforms exceeding the prescribed limits. Furthermore, the mean concentrations of heavy metals, including iron, lead, chromium, and cadmium remained within acceptable levels in all samples.
Conclusion: Although the majority of water quality parameters in the studied poultry farms were compatible with standards limits, testing and monitoring the chemical and microbial quality of water in poultry farms is recommended on a regular basis.

Introduction: A variety of treatment methods, including biological remediation, have been employed to address oil-contaminated wastewater. Bioremediation, which involves using microorganisms to mitigate or eliminate pollutants, is recognized as an environmentally friendly, cost-effective, and evolving technique for removing and breaking down various environmental contaminants, including those from oil industry.
Materials and Methods: This systematic review not only introduces biological treatment but also explores factors contributing to its success. In this study, a search was performed with keywords including petroleum substances, bioremediation, and biological treatment on Scopus, ScienceDirect, Web of Science, and PubMed, and 1349 studies were obtained, and 61 articles were finally chosen according to exclusion and inclusion criteria.
Results: A significant increase was observed in research articles over the past five years, likely reflecting the growing awareness of the need to remediate petroleum pollution in recent years. The nature of petroleum wastewater varies depending on the specific crude oil refining process, and factors that have the greatest effect on biological treatment include temperature, pH, inhibitors, time, oxygen, nutrients, nature, concentration of pollutants, and microorganism type. No single species of microorganism can break down all petroleum compounds.
Conclusion: This study allows decision-makers to evaluate these factors before implementing and investing in this method, ensuring its effectiveness in reducing petroleum pollution concentrations.