Assessment of Wastewater Reuse in Kuwait and Its Impact on Amounts of Pollutants Discharged into the Sea

Kuwait has recently implemented a vigorous campaign that aims to reclaim and reuse all treated wastewater in an at- tempt to alleviate water scarcity problem and to preserve seawater quality. This paper assesses the present status of wastewater treatment, reclamation and reuse in Kuwait, and discusses the impact of wastewater reuse on the amounts of pollutants discharged into the sea. Through analysis of the historical records of the wastewater treatment plants, it has been found that reuse of reclaimed wastewater in Kuwait has greatly reduced the amounts of pollutants discharged into the sea. Results showed that more than 50% reduction in volumes of wastewater discharged into the sea had been achieved from year 2000 to year 2010. However, this study has predicted that the amounts of wastewater discharged into the sea will start increasing again by the year 2020 due to shortages of storage capacity for reclaimed wastewater and due to the limitation of wastewater reuse applications to basically agricultural and landscape irrigations. In contrary, the on-going works and future plans of the Ministry of Public Works (MPW) are expected to overcome this problem and lead to a zero discharge of wastewater into the sea.

Cost Evaluation of Compact Dairy Wastewater Treatment System in Kuwait

In Kuwait, wastewater management has gained extra attention in recent years and becomes crucial for sustainable industrial development sector. Among the food industry sector, dairy processing plants generate huge amount of wastewater, which is heavily loaded with organic and other toxic compounds. Disposal of dairy wastewater effluent without sufficient treatment can contaminate aquatic ecosystems. Cost efficient treatment processes that are effective in removing organic load and other contaminants are essential to meet stringent environmental regulations applied in Kuwait. A research study was carried out at the KISR （Kuwait Institute for Scientific Research） to assess the technical viability and economic feasibility of combined microfiltration and biological treatment system. This work presents the economic evaluation of the adopted treatment system. The results show that the cost of the integrated system for large scale is estimated to be US$ 1.575/m3, which is 25% less than the cost of wastewater transportation and treatment in conventional sewage plants.

Controlled drainage in the Nile River delta of Egypt:a promising approach for decreasing drainage off-site effects and enhancing yield and water use efficiency of wheat

North Africa is one of the most regions impacted by water shortage.The implementation of controlled drainage(CD)in the northern Nile River delta of Egypt is one strategy to decrease irrigation,thus alleviating the negative impact of water shortage.This study investigated the impacts of CD at different levels on drainage outflow,water table level,nitrate loss,grain yield,and water use efficiency(WUE)of various wheat cultivars.Two levels of CD,i.e.,0.4 m below the soil surface(CD-0.4)and 0.8 m below the soil surface(CD-0.8),were compared with subsurface free drainage(SFD)at 1.2 m below the soil surface(SFD-1.2).Under each drainage treatment,four wheat cultivars were grown for two growing seasons(November 2018–April 2019 and November 2019–April 2020).Compared with SFD-1.2,CD-0.4 and CD-0.8 decreased irrigation water by 42.0%and 19.9%,drainage outflow by 40.3%and 27.3%,and nitrate loss by 35.3%and 20.8%,respectively.Under CD treatments,plants absorbed a significant portion of their evapotranspiration from shallow groundwater(22.0%and 8.0%for CD-0.4 and CD-0.8,respectively).All wheat cultivars positively responded to CD treatments,and the highest grain yield and straw yield were obtained under CD-0.4 treatment.Using the initial soil salinity as a reference,the soil salinity under CD-0.4 treatment increased two-fold by the end of the second growing season without negative impacts on wheat yield.Modifying the drainage system by raising the outlet elevation and considering shallow groundwater contribution to crop evapotranspiration promoted water-saving and WUE.Different responses could be obtained based on the different plant tolerance to salinity and water stress,crop characteristics,and growth stage.Site-specific soil salinity management practices will be required to avoid soil salinization due to the adoption of long-term shallow groundwater in Egypt and other similar agroecosystems.

Analysis of Sludge Settling and Rising Behavior in Sewage Treatment Plant in Kuwait

All wastewater treatment plants in Kuwait utilize the activated sludge processes in the removal of organic matter and nutrients from domestic sewage.The efficiency of solid liquid separation in the activated sludge system is determined by the ability of sludge constituents to remain flocculated and to settle fast.In Kuwait’s wastewater treatment plants,solids separation problems may occur in activated sludge system,such as bulking sludge,which affects the quality of the secondary effluent.The main aim of this paper is to study and analyze sludge settling and rising behavior in the activated sludge process of Jahra sewage treatment plant.The results indicated that clarifier effluent has significant suspended solids carry-over,which is eventually removed in the sand filtration process.In addition,test results showed poor settlement of clarifier sludge.The poor sludge settling is related to insufficient oxygen level in the aerators.Suggestions were made to raise oxygen level particularly in the aeration unit.

Seasonal Influence on the Ambient Air Quality in Al Jahra City for Year 2010

Eight primary criteria air contaminants were measured continuously for the year 2010 to evaluate ambient air quality in Al Jahra, which is one of the oldest and busiest cities in the state of Kuwait. The state of the art instrumentation was used to record the pollutants concentration to ppb levels maintaining quality control and quality assurance. Hourly base data for Non-Methane Hydrocarons (NM-HC), CH4, CO, CO2, O3, SO2, NO2and Particulate Matter (PM10) were analyzed for year 2010. Meteorological parameters contributing to air pollution, such as (temperature, solar intensity, wind speed and direction) have also been considered. The effect of winter and summer seasonal changes on pollutant concentration levels were analyzed to identify the most probable sources for the application of the futuristic mitigation methods for pollution abatement. The obtained results consistently suggest that the foregoing pollutant concentration levels are higher in winter than summer due to poor dispersion and shallow inversion layer with the exception of O3, CO2and PM10. However, all of the pollutant concentrations are below the allowable standards limits except for NM-HC.

Contribution of the 3D Geological Model to the Study of the High Basin Ziz Jurassic Aquifers Structure (Central High Atlas, Morocco)

The high Ziz’s basin, which is part of the Central High Atlas, contains Jurassic superficial and deep aquifers. The information sheets are still fragmentary and insufficient because of the basin’s large size and its complex geological structure. In order to improve the knowledge of these aquifers and the determination of the structure of aquifers, a 3D geological model was developed in this study. It was constructed from information provided by 200 mechanical soundings and 81 electrical surveys and geological maps. Compiled holes were analyzed, coded and integrated in the software Groundwater Modeling System 6.0 (GMS 6.0). For doing this, five lithostratigraphic units were considered: the Domerian, the Toarcian, the Aalenian, the Bajo-Bathonian and the Quaternary. The operation of the 3D stratigraphic model allowed making it closer to the geometry of Jurassic aquifers.

Stoichiometry design in hierarchical CoNiFe phosphide for highly efficient water oxidation

Rational composition design of trimetallic phosphide catalysts is of significant importance for enhanced surface reaction and efficient catalytic performance.Herein,hierarchical Co_(x)Ni_(y)Fe_(z)P with precise control of stoichiometric metallic elements(x:y:z=(1-10):(1-10):1)has been synthesized,and Co_(1.3)Ni_(0.5)Fe_(0.2)P,as the most optimal composition,exhibits remarkable catalytic activity(η=320 mV at 10 mA cm^(−2))and long-term stability(ignorable decrease after 10 h continuous test at the current density of 10 mA cm^(−2))toward oxygen evolution reaction(OER).It is found that the surface P in Co_(1.3)Ni_(0.5)Fe_(0.2)P was replaced by O under the OER process.The density function theory calculations before and after long-term stability tests suggest the clear increasing of the density of states near the Fermi level of Co_(1.3)Ni_(0.5)Fe_(0.2)P/Co_(1.3)Ni_(0.5)Fe_(0.2)O,which could enhance the OH−adsorption of our electrocatalysts and the corresponding OER performance.

Fabrication of Hydrophilic and Sponge-like PVDF/Brush-like Copolymer Blend Membranes Using Triethylphosphate as Solvent

Porous PVDF blend membranes with good hydrophilicity and a symmetric structure were prepared by the phase inversion method using amphiphilic brush-like copolymers, P（MMA-r-PEGMA）, as hydrophilic additive and triethylphosphate （TEP） as solvent. P（MMA-r-PEGMA） was synthesized by radical polymerization in TEP. Then the obtained amphiphilic copolymer solution was mixed with PVDF and TEP to prepare the dope solution. The effects of P（MMA-r-PEGMA） content and coagulation composition on membrane morphologies were investigated using scanning electron microscopy （SEM）. The results demonstrated that, even blended with amphiphilic copolymers, a symmetric structure can be formed. Hollow fiber membranes with a mainly symmetric structure were also fabricated. The dry hollow fiber membranes showed good hydrophilicity, high flux and good rejection performance because of their hydrophilic surface and pores wall.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

Aims Phosphorus(P)availability and efficiency are especially important for plant growth and productivity.However,the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear.Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency,nitrate(NO3−)and ammonium(NH4+)supply.Important Findings Females had a greater biomass,root length density(RLD),specific root length(SRL)and shoot P concentration than males under normal P availability with two N supplies.NH4+supply led to higher total root length,RLD and SRL but lower root tip number than NO3−supply under normal P supply.Under P deficiency,males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization,exhibiting a better capacity to adaptation to P deficiency than females.Under P deficiency,NO3−supply increased leaf photosynthesis and P use efficiency(PUE)but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4+supply.Females had a better potentiality to cope with P deficiency under NO3−supply than NH4+supply;the contrary was true for males.These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability,especially under NO3−supply,while males adopt more efficient resource use and P remobilization to maximum their tolerance to P deficiency.