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Petrochemical industrial wastewater presents a challenge when treated, employing the conventional activated sludge process, such as in the activated sludge process, the loss of biomass due to the harsh wastewater conditions and the inhibition caused by the elevated levels of industrial compounds. Hybrid biological reactors may present a resource to be tapped in the operation of an industrial wastewater treatment facility if integrated optimally in the treatment sequence. This paper examines possible integration scenarios of hybrid reactors in a petrochemical wastewater treatment plant in order to improve its organic removal efficiency. A pilot hybrid biological reactor was constructed using high surface area biological carrier and was operated using real wastewater streams from a wastewater treatment plant at two flow rates (400 ml/min and 240 ml/min), two dissolved oxygen levels (2.0 mg/l and 4.0 mg/l), and anaerobic conditions. The reactor was tested using raw, primary, secondary, and effluent streams from the wastewater treatment plant. The reactors were primed with wastewater from the aeration tank of the wastewater treatment plant and was operated for 10 d afterward (total 24 runs). The chemical oxygen demand cumulative removal was used to identify best integration scenario and to benchmark its performance against domestic wastewater. The best performing scenarios were identified as anaerobic (400 ml/min) for raw wastewater treatment and [(400 ml/min and dissolved oxygen (DO) 2.0 mg/l)] for secondary wastewater polishing. The results reflected the unfavorable conditions for biodegradation after the primary chemical treatment. This conclusion was confirmed upon benchmarking the hybrid reactor performance using domestic wastewater.

Introduction Bacteria in most environments exist as communities of sessile cells in a selfproduced polymeric matrix known as biofilms. Biofilms are responsible for more than 80% of infections, including urinary tract infections (UTI). UTI is the most common hospital acquired infection, caused mainly by Escherichia coli (E.coli). E. coli can readily form biofilm in such infections, specially in the presence of indwelling urinary catheter. It’s difficult to eradicate bacteria in biofilms, since they are shielded from the host defense mechanisms as phagocytes and antibodies, as well as antibiotics. Searching for alternative or adjuvant substances for prevention and eradication of biofilm associated infections are therefore urgently needed. Aim of the work Studying the efficacy of the trans-cinnamaldehyde (TC) for preventing E. coli biofilm formation. Materials and methods Thirty isolates of E.coli were obtained from urine samples. To test the effect of TC on E.coli biofilm formation and preformed biofilms, microtitre plates (MTP) were inoculated with the isolated E.coli and were treated with different concentrations of TC and incubated at 37° C. A colorimetric assay was used to assess biofilm inhibition and inactivation and optical densities (OD) were compared before and after adding different TC concentrations. Results The mean OD of the isolated E.coli biofilms was 1.3 and significantly decreased when mixed with TC different concentrations. TC had high activity in inhibition of preformed E.coli biofilms, where no biofilm was detected on MTP treated with 1.25% and 1.5% TC. Conclusion TC inhibited the biofilm forming ability of E.coli isolates could fully inactivate formed biofilms, suggesting its possibility to be used as an anti-biofilm agent or adjuvant in preventing and treating UTI caused by biofilm producing E.coli.

Public interest in radioactivity and radionuclides distribution in the environment has increased significantly due to their toxicity, health effects, and related environmental impacts. One of the concerns for wastewater treatment and reclamation is the presence and distribution of contaminants that are not removed by the wastewater treatment plant in case its effluent is reused, particularly, for irrigation or direct potable reclamation. Radionuclides are contaminants that are not effectively removed by wastewater treatment plants. To address radionuclides in wastewater treatment plants of Kuwait, a survey was planned and conducted in five wastewater treatment plants to investigate the presence and distribution of radioactivity in wastewater. The results of gamma, alpha, and beta surveys indicated that the wastewater treatment plants investigated showed normal level of radioactivity concentrations that were below the International Atomic Energy Agency (IAEA) recommended limits for unrestricted use of the treated wastewater. It was found that radionuclides had different fates in treatment plants. Radionuclides like 40K, total 210Pb, 137Cs, 226Ra, 228Ra, 238U, and 235U would likely partition onto sludge and biosolids than be discharged in the liquid effluents. In contrast, 131I would more likely remain in the liquid effluent than partition onto the sludge. Its short half-life of 8 days would, however, mean that it would have limited effects even if the treated wastewater is widely used. Storage to segregate these radionuclides may not be feasible because it will require long periods due to the long half-lives of some of them (e.g., half-life of 137Cs is 30.7 years).

The Kuwait Oil Company currently pumps about 10 Mm3/yr from one of its well fields in central Kuwait (Eocene Aquifer) and plans to increase this rate to 30 Mm3/yr to meet its water demand. The objective of this study is to investigate the sustainability of brackish groundwater resources for oil operations in the mentioned well field in a way to identify the consequences of increasing the pumping rates on groundwater levels and groundwater salinity. A suitable methodology to assess the sustainability of brackish groundwater utilization has been developed based on pumping tests in addition to flow and salinity numerical modeling. Extensive hydrogeological and salinity field investigations were also conducted. The results show that pumping rate should not be increased above 20 Mm3/yr in the aquifer of the study, otherwise a sharp decline in groundwater levels and a significant increase in groundwater salinity will occur. The results of the pumping tests show that the hydraulic properties of the Eocene Aquifer can support regional utilization of the aquifer, but any additional pumping wells should be located within a wider area than the current well field. The salinity variation analysis shows that a mixing process between brackish and saline water is taking place.

Data was collected on the quality and quantity of wastewater discharged from different petroleum and nonpetroleum industrial sources in Kuwait over a period of one year. A field survey included 75 factories distributed in three industrial areas (Sabhan, Kuwait City, and Shuaiba). Among the industries contacted only 41 agreed to participate in field measurements and wastewater sampling campaign. The questionnaire feedback obtained indicated that the activities of these industries can be categorized into 20 categories including 4 and 37 petroleum and nonpetroleum industries, respectively. The mean quality of wastewater generated in Sabhan industrial area were found to be higher than those of Kuwait City and Shuaiba areas. The inorganic results indicated that high values of total suspended solids (TSS), total dissolved solids (TDS), sulfide, free chlorine, and fluoride were observed in the wastewater of petroleum factories of Shuaiba, while high values of total phosphate, ammonia, total Kjeldahl nitrogen, total nitrogen, and floatables were observed in the wastewater of nonpetroleum factories of Kuwait City. Additionally, organic results indicated that high values of chemical oxygen demand (COD), biochemical oxygen demand (BOD), oil and grease, and total petroleum hydrocarbons (TPHs) were observed in the wastewater of petroleum factories of Shuaiba area. GIS maps were generated for 25 wastewater parameters for the participating 41 factories using ArcView GIS software.

Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO3 and WO3-graphene oxide (GO) nanocomposites has been performed through the sol-gel method. Then, platinum (Pt) nanoparticles were deposited onto the WO3 and WO3-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites. X-ray diffraction (XRD) findings exhibit a formation of monoclinic and triclinic WO3 phases. Transmission Electron Microscope (TEM) images of Pt/WO3-GO nanocomposites exhibited that WO3 nanoparticles are obviously agglomerated and the particle sizes of Pt and WO3 are ~10nm and 20-50nm, respectively. The mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue (MB) as a probe molecule under visible light illumination. The findings showed that mesoporous Pt/WO3, WO3-GO and Pt/WO3-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO3. The photodegradation rates by mesoporous Pt/WO3-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO3, WO3-GO, and Pt/WO3, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO3-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO3 and GO sheets, in addition to the Pt nanoparticles that act as active sites for O2 reduction, which suppresses the electron hole pair recombination in the Pt/WO3-GO nanocomposites.

This paper presents a long-term assessment of the quality of the final product water of Sulaibiya Wastewater and Reclamation Plant (SWTRP), which is the world’s largest reverse osmosis (RO) wastewater plant. The assessment was based on 10 years of the plant’s monthly records of the effluent quality. The results obtained indicated that the final product water had met targeted design values all the times without a single incidence of violation. However, statistical analyses have shown that some of the parameters have seasonal patterns, and most of them are characterized by high variability. Further, the distributions of the effluent data were found to be highly skewed. In general, the distributions of the effluent data were found to neither follow normal nor log normal distributions. Knowledge of effluent distribution is of fundamental importance in assessing the reliability of existing wastewater treatment plants. It is also basic for design of new plants.

Groundwater in North Kuwait was polluted by hydrocarbons from destroyed oil wells during the 1991 Gulf War, and by salts derived from seawater used for fighting oil fires. The results of eight rounds of monitoring the groundwater chemistry over the years 2012–2015 have been assessed, based mainly on the presence of organic matter derived from petroleum hydrocarbons and on the total dissolved solids content of groundwater. Good correlations between these two parameters suggest that there is simultaneous movement of hydrocarbons and salts that are leached from the surface soil by the infiltration of surface runoff. It has been concluded that although these parameters have shown some periodical fluctuations in their values, there has been no significant change in the overall extent and severity of groundwater contamination over the period of the study. The fluctuations observed are possibly the results of seasonal addition of pollutants that are carried downwards by the infiltration of rainfall; the effects of biogeochemical reactions within the aquifer; and the movement of pollutants with groundwater flow and dilution by mixing with unpolluted groundwater within the aquifer. The removal of the sources of pollution (oil lakes, oil pits and polluted surface soil) from the study area has been recommended before the adoption of any remedial measures to avoid seasonal addition of pollutants to the treated groundwater.

Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO

A study was carried out to determine the optimum soil depth for the removal of coliphage viruses from treated wastewater. Treated wastewater containing viruses was passed through soil columns filled with soil collected from Sulaibiya area, Kuwait. The soil column experiments were under operation for eight months during the period from August 2004 to March 2005. Three soil depths were used in these experiments. These are 0.1, 0.2, 0.4, and 0.8 m of natural Sulaibiya soil. For each experimental condition, two identical columns were set up, so that the changes of the results can be evaluated, producing total of eight columns. For all columns, the coliphage tests were studied only under alternating 1 d flooding and 1 d drying conditions. Influent and effluent coliphage samples were collected and analyzed following cycles of flooding periods. The coliphage virus count in the treated wastewater ranged between 0 and 62,800 pfu/100 ml. The laboratory results revealed that coliphage removal for Sulaibiya s...

A laboratory study was carried out to determine the best domestic water filter with respect to cost, volume of treated water, and effectiveness in improving the quality of potable water. Six types of filters were tested including sand, five micron cartridge, ceramic, carbon block, ultra violet (UV) sterilization unit, and reverse osmosis combined filters. Water samples were collected upstream and downstream of each type of filter. These samples were analyzed for pH, EC, TDS, TSS, turbidity, TOC, chlorine concentration, and various bacteria. Also, the volume of treated water produced by each type of filter was measured. The laboratory results indicated that inlet water had low salinity (TDS value 275–438 mg/l), low TSS (0–7 mg/l), chlorine (0.13–0.78 mg/l) contents, and high content of bacteria (1–1212 MPN/100 ml). The results revealed that the membrane of the RO combined filter set was exposed to severe damage by the residual chlorine in the water, rendering the membrane unable to reduce water sal...

Laboratory and field experiments have been carried out to find an optimum method for the treatment of hydrogen sulfide-rich groundwater that often occurs at comparatively shallow depths (15–40 m from the surface) in the urban areas of Kuwait City and is pumped to the surface during dewatering of the construction sites. The treatment would be necessary to remove the gas from the pumped groundwater before its disposal, either on the surface or to the stormwater network, to avoid health and environmental hazards created by the release of the hydrogen sulfide gas, which is toxic, to the atmosphere or to the sea. Based on these experiments, it has been recommended that an economic and reliable hydrogen sulfide treatment facility for groundwater pumped at the study area should consist of sand filters, followed by aeration units for the removal of major part (60–70%) of hydrogen sulfide. Chlorination or activated carbon adsorption can be utilized as a polishing process to remove the residual hydrogen sul...

Passing treated wastewater through soil is a natural and economic means to improve the quality of wastewater. The United Agricultural Production Company (UAPCO) farm located in the Sulaibiya area of Kuwait has been irrigated with tertiary treated wastewater since 1976. A field investigation at the farm has been conducted by the Kuwait Institute for Scientific Research (KISR) to assess the applicability of the natural soil treatment method, in the long term, to improve the quality of the treated wastewater under the conditions prevailing in Kuwait. The collected data have been analyzed to assess the degree of improvement in quality of the infiltrated water with respect to the tertiary wastewater used for irrigation. The data analysis indicates that in spite of low clay content of the soil, improvement in the quality of the tertiary treated wastewater through soil aquifer treatment by the removal of ammonia (>90%), iron (>80%), organic carbon (>90%), biological oxygen demand (BOD) (100%) and bacteria (50–100%, depending on its type), can be expected over a long-term period. Soil leaching, however, tends to increase the total dissolved solids of the infiltrated water and the nitrification process increases the nitrate content.

A study, aimed at characterizing the nature of anthropogenic and biogenic hydrocarbon contamination in the groundwater of Kuwait, was carried out using fluorescence spectroscopy and other analytical techniques. The results of these analyses have demonstrated that the groundwater in certain areas of northern Kuwait has been significantly impacted by contamination originating from the oil-contaminated surface soils. The study revealed that a water-soluble fraction (WSF) of the crude oil surface contamination appeared to be slowly leaching into the freshwater lenses located in the area. The study also showed that hydrocarbon pollutants were practically absent in the brackish water areas of central and southern Kuwait, except for a few isolated sites. However, nonpetroleum hydrocarbons, with ultraviolet-visible absorption characteristics and fluorescence characteristics typically associated with humic substances, were observed at a few sites in the brackish water fields.

Hydrogen sulfide occurs in high concentration (10–200 mg/l) in different parts of Kuwait City and its suburbs at relatively shallow depths (15–40 m from the surface). This was revealed by drilling through the aquifer system underlying the city and sampling and analyzing the ground water at the drilled locations. The near-absence of coliform bacteria in the sulfide-rich zones, the presence of sulfur-reducing bacteria in the deep (>80 m) Dammam Formation aquifer and a linear positive relation between the concentration of hydrogen sulfide and the total dissolved solids content suggested non-anthropogenic origin of the sulfide in the ground water of Kuwait. The upward movement of sulfide-rich water from depth and its differential flushing by surface recharge through outcrops of the aquifers appear to have given rise to the present distribution of hydrogen sulfide in the aquifers underlying the Kuwait City.

Porosity and hydraulic-conductivity measurements were carried out on conventional core samples from Eocene Dammam Formation, penetrated by a well in the northwest Shigaya water-well field of Kuwait. The main objective was to identify any potential adverse effects (mainly reduction of porosity and permeability) that the injection of desalinated water in the formation material would have before attempting any artificial recharge project.

Originally introduced in the 1990s, bimodal HDPE, pipe resins are still finding new niches today, including even nuclear power plants. HDPE pipe grades are used to make strong, corrosion resistant and durable pipes. High density polyethylene, PE 4710, is the material of choice of the nuclear industry for the Safety Related Service Water System. This grade of polymer is characterized by a Hydrostatic Design Basis (HDB) of 1600 psi at 73 °F and 1000 psi at 140 °F. Additionally bimodal high density PE 4710 grades display >2000 hours slow crack growth resistance, or PENT. HD PE 4710 grades are easy to extrude into large diameter pipes; fabricate into fitting and mitered elbows and install in industrial settings. The scope of this paper is to describe the bimodal technology which produces HDPE pipe grade polymer; the USA practices of post reactor melt blending of natural resin compound with black masterbatch; and the attributes of such compound and its conformance to the nuclear industry’s Safety Related Service Water System.