Synthesis of NaY zeolite from a submolten depolymerized perlite:Alkalinity effect and crystallization kinetics

NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred crystallizer.Effects of alkalinity ranging from 0.38 to 0.55(n(Na_(2)O)/n(SiO_(2)))on the relative crystallinity,textural properties and crystallization kinetics were investigated.The results show that alkalinity exerts a nonmonotonic influence on the relative crystallinity and textural properties,which exhibit a maximum at the alkalinity of 0.43.The nucleation kinetics are studied by fitting the experimental data of relative crystallinity with the Gualtieri model.It is shown that the nucleation rate constant increases with increasing alkalinity,while the duration period of nucleation decreases with increasing alkalinity.For n(Na_(2)O)/n(SiO_(2))ratios ranging from 0.38 to 0.55,the as-synthesized NaY zeolites exhibit narrower crystal size distributions with the increase in alkalinity.The growth rates determined from the variations of average crystal size with time are 51.09,157.50,46.17 and 24.75 nm·h^(-1),respectively.It is found that the larger average crystal sizes at the alkalinity of 0.38 and 0.43 are attributed to the dominant role of crystal growth over nucleation.Furthermore,the combined action of prominent crystal growth and the longer duration periods of nucleation at the alkalinity of 0.38 and 0.43 results in broader crystal size distributions.The findings demonstrate that control of the properties of NaY zeolite and the crystallization kinetics can be achieved by conducting the crystallization process in an appropriate range of alkalinity of the reaction mixture.

Effect of Saline Water on Soil Acidity, Alkalinity and Nutrients Leaching in Sandy Loamy Soil in Rwamagana Bella Flower Farm, Rwanda

The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K+), Magnesium (Mg2+), Sulphur (S), CN ratio and Sodium (Na+) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.

Effects of Soil Salinity and Alkalinity on Grain Quality of Tolerant,Semi-Tolerant and Sensitive Rice Genotypes

Soil salinity and alkalinity adversely affects the productivity and grain quality of rice. The grain quality of 19 rice genotypes characterized as salt tolerant （T）, semi-tolerant （ST） and sensitive （S） was assessed in lysimeters containing saline and highly alkaline soils. Head rice recovery was reduced by salinity stress whereas it was not affected by alkalinity stress. The ratio of length to width （grain dimensions） was significantly reduced in the T genotype even at low electrical conductivity （EC, 4 mS/cm） and alkalinity （pH 9.5）, whereas in the ST genotype, it was significantly reduced at high salinity （EC 8 mS/cm）. There was no significant effect of any levels of salinity or alkalinity on grain dimensions in the S genotype. Amylose content was significantly reduced in T and ST groups even at low EC （4 mS/cm） and alkalinity （pH 9.5） and the effect in the S genotype was only at high salinity. Starch content showed significant reduction at high salinity and alkalinity （EC 8 mS/cm and pH 9.8） in the T and ST genotypes and no significant effect was observed in the S genotype. The effect of both levels of salinity （EC 4 and 8 mS/cm） and high alkalinity （pH 9.8） on gel consistency was observed only in the S genotype. The tolerant genotypes IR36 under high salinity, and CSIR10 and CSR11 under alkali stress showed less reduction in amylose content. The T genotype BR4-10, and ST genotypes CSR30, CSR29 and CSR13 showed better gel consistency under saline and alkali stress. Amylose content was affected even at low salinity stress and thus important to be considered in breeding rice for salt tolerance. Overall, the grain quality of T and ST genotypes was less affected by saline and alkali stress compared to S ones.

Industrial wastes applications for alkalinity regulation in bauxite residue: A comprehensive review

Bauxite residue is a highly alkaline material generated from the production of alumina in which bauxite is dissolved in caustic soda.Approximately 4.4 billion tons of bauxite residues are either stockpiled or landfilled,creating environmental risks either from the generation of dust or migration of filtrates.High alkalinity is the critical factor restricting complete utilization of bauxite residues,whilst the application of alkaline regulation agents is costly and difficult to apply widely.For now,current industrial wastes,such as waste acid,ammonia nitrogen wastewater,waste gypsum and biomass,have become major problems restricting the development of the social economy.Regulation of bauxite residues alkalinity by industrial waste was proposed to achieve‘waste control by waste’with good economic and ecological benefits.This review will focus on the origin and transformation of alkalinity in bauxite residues using typical industrial waste.It will propose key research directions with an emphasis on alkaline regulation by industrial waste,whilst also providing a scientific reference point for their potential use as amendments to enhance soil formation and establish vegetation on bauxite residue disposal areas(BRDAs)following large-scale disposal.

Spatial and temporal variations in pH and total alkalinity at the beginning of the rainy season in the Changjiang Estuary, China

The results of field observation carried out in May 2003 were used to examine pH and total alkalinity behaviors in the Changjiang Estuary. It was showed that pH and total alkalinity took on clear spatial variations in values with the minima in the low salinity region. Like salinity, transect distributions of pH and total alkalinity （TA） in a downriver direction had a sharp gradient each. These gradients appeared in such a sequence that the TA gradient was earlier than salinity and pH gradients, and the salinity gradient was earlier than the pH gradient. These distribution characteristics seemed to be strongly influenced by the mixing process of freshwater and seawater, for both pH and total alkalinity had significant linear relationships with salinity and temperature. For pH, phytoplankton activities also had a significant impact upon its spatial distribution. During a period of 48 h, pH and total alkalinity changed within wide ranges for every layer of the two anchor stations, namely, Stas 13 and 20, which were located at the mixed water mass and seawater mass, respectively. For both Stas 13 and 20, pH and TA fluctuation of every layer could be very wide during a 4 h period. As a whole, the data of the two anchor stations showed that neither variations in salinity and temperature nor phytoplankton activities were the main factors strongly influencing the total alkalinity temporal variability on a small time scale. The data of Sta. 20 implied that both salinity variation and phytoplankton activities had a significant influence on pH temporal variability, but the same conclusion could not be drawn from the data of Sta. 13.

Decolorization of azo dyes with high salt concentration by salt-tolerant mixed cultures under anaerobic conditions

Because the lack of detailed study of biological decolorization in high salt dye wastewater, it is still difficult to evaluate the biological treatment on high-salinity dye wastewater. The experiments were carried out to study the salt-tolerant bacteria, which is useful in the treatment of high-salinity colored wastewater. Simulated wastewater containing 5-150 g/L salt （NaCI） and 50-2000 mg/L Reactive Brilliant Red K-2BP was treated with three salt-tolerant mixed cultures （CAS, TAS, DSAS）, which were under a gradually acclimated procedure. With the increase of concentrations of salt and dye, the decolorization became low. The abilities of decolorization of dyes wastewater by three mixed cultures （CAS, TAS, DSAS） were studied, CAS and DSAS mixed cultures showed more active for the treatment of high-salinity colored wastewater than TAS mixed cultures. The results suggested that there might be a simple process for the high salt wastewater treatment, which could be incorporated into conventional activated sludge plants.

Generation and analysis of expressed sequence tags from the salt-tolerant eelgrass species, Zostera marina

Zostera marina, a monocotyledonous angiosperm, is one of the most important seagrass species. To inves- tigate the salt-tolerance mechanism and discover salt-tolerant genes in Z. marina, a cDNA library was con- structed. Single-pass sequencing of the 5＇ ends of 4 081 clones yielded 4 002 high quality expressed sequence tags （ESTs）, which were assembled into 241 contigs and 1 673 singletons, representing 1 914 unigenes. The average length of the ESTs was 582 bp, with sizes ranging from 100-1 500 bp. Basic Local Alignment Search Tool （BLASTX） analysis revealed that 1 664 unigenes had significant homology to known genes in the Na- tional Center for Biotechnology Information （NCBI） non-redundant （nr） database （E-value≤5-10）. Among them, the two most abundant genes encoded metallothionein （157 ESTs） and chlorophyll a/b-binding pro- tein （38 ESTs）, accounting for 7.1% and 1.7% of the total ESTs, respectively. Using Kyoto Encyclopedia of Genes and Genomes （KEGG）, 1 462 unigenes were assigned to 1 161 pathways （E-value≤5-10）. A total of 938 unigenes were assigned Gene Ontology （GO） terms based on the GO hierarchy analysis, and InterProScan searches recognized 1 003 InterPro families. Three genes for metallothionein in Z. marina that belonged to Class II was identified. Results of this study will improve understanding of the molecular mechanisms of saline tolerance in Z. marina.

Separation of sulfide lead-zinc-silver ore under low alkalinity condition

A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10^-4 % Ag （mass fraction） from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb^2＋ and has a sulfidation on oxidized lead minerals. The results also show that NazCO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.

A novel salt-tolerant Micrococcus sp. DUT_AHX capable of degrading nitrobenzene

A novel strain of Micrococcus sp.DUT_AHX,which was isolated from the sludge of a nitrobenzene(NB)-manufacturing plant and could utilize NB as the sole carbon source,was identified on the basis of physiological and biochemical tests and 16S ribosomal DNA(rDNA)sequence analysis.It can grow at the temperature up to 40℃or in the presence of NaCl concentration up to 12 g/L in Luria-Bertani(LB)medium.The optimal degradation conditions are as follows:temperature 37℃,pH 7.0,and shaking speed 150 r/min.The strain involves a partial reductive pathway due to the release of ammonia and can also utilize 2-aminophenol as the sole carbon source.Furthermore,the enzyme activity tests show that crude extracts of NB-grown strain DUT_AHX mainly contain 2-aminophenol 1,6-dioxygenase activity.The exploitation of salt-tolerant bacteria will be a remarkable improvement in NB bioremediation and wastewater treatment at high salinity and high temperature.

Alkalinity stabilization behavior of bauxite residue:Ca-driving regulation characteristics of gypsum

Alkaline anions,include CO3^2–,HCO3^–,Al(OH)4^–,OH^–,continuously released from bauxite residue(BR),will cause a potential disastrous impact on surrounding environment.The composition variation of alkaline anions,alkaline phase transformation pathway,and micro-morphological transition characteristics during the gypsum addition were investigated in an attempt to understand alkalinity stabilization behavior.Results demonstrated that alkaline anions stabilization degree in leachates can reach approximately 96.29%,whilst pH and alkalinity were reduced from 10.47 to 8.15,47.39 mmol/L to 2 mmol/L,respectively.During the alkalinity stabilization,chemical regulation behavior plays significant role in driving the co-precipitation reaction among the critical alkaline anions(CO3^2–,HCO3^–,Al(OH)4^–,OH^–),with calcium carbonate(CaCO3))being the most prevalent among the transformed alkaline phases.In addition,XRD and SEM-EDX analyses of the solid phase revealed that physical immobilization behavior would also influence the stability of soluble alkali and chemical bonded alkali due to released Ca^2+from gypsum which aggregated the clay particles and stabilized them into coarse particles with a blocky structure.These findings will be beneficial for effectively regulating strong alkalinity of BR.

Salt-tolerant mechanism of marine Aspergillus niger cellulase cocktail and improvement of its activity

The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.

Summertime freshwater fractions in the surface water of the western Arctic Ocean evaluated from total alkalinity

As a quasi-conservative tracer, measures of total alkalinity （TA） can be utilized to trace the relative fractions of freshwater and seawater. In this study, based on the TA and related data collected during the third Chinese National Arctic Research Expedition （JulySeptember 2008, 3rd CHINARE-Arctic） and the fourth Chinese National Arctic Research Expedition （JulySeptember 2010, 4th CH1NARE-Arctic）, fractions of sea-ice meltwater, river runoff, and seawater within the surface water of the western Arctic Ocean were determined using salinil~~ and TA relationships. The largest fraction of seeL-ice meltwater was found around 75~N within the Canada Basin during both surveys, which is located at the ice edge. Generally, it was found that the frac- tion of river runoff was less than that of sea-ice meltwater. The river runoff, composed mainly of contributions from the Yukon River carried by Bering inflow water and the Mackenzie River, was influenced by the currents, leading to two peak areas of its fraction. Our results show that the dilution effect of freshwater carried by Bering inflow water during the 3rd CH1NARE-Arctic in 2008 expedition period may be stronger than that during the 4th CH1NARE-Arctic in 2010 expedition period. The peak area of sea-ice meltwater fraction during the 4th CH1NARE-Arctic was different from that of the 3rd CHINAR-E-Arctic, corresponding to their sea-ice condition.

Activity origin and alkalinity effect of electrocatalytic biomass oxidation on nickel nitride

Electro-oxidation of 5-hydroxymethylfurfural(HMFOR)is a promising green approach to realize the conversion of biomass into value-added chemicals.However,considering the complexity of the molecular structure of HMF,an in-depth understanding of the electrocatalytic behavior of HMFOR has rarely been investigated.Herein,the electrocatalytic mechanism of HMFOR on nickel nitride(Ni3 N)is elucidated by operando X-ray absorption spectroscopy(XAS),in situ Raman,quasi in situ X-ray photoelectron spectroscopy(XPS),and operando electrochemical impedance spectroscopy(EIS),respectively.The activity origin is proved to be Ni^(2+δ)N(OH)ads generated by the adsorbed hydroxyl group.Moreover,HMFOR on Ni3 N relates to a two-step reaction:Initially,the applied potential drives Ni atoms to lose electrons and adsorb OH-after 1.35 VRHE,giving rise to Ni^(2+δ)N(OH)ads with the electrophilic oxygen;then Ni^(2+δ)N(OH)ads seizes protons and electrons from HMF and leaves as H_(2) O spontaneously.Furthermore,the high electrolyte alkalinity favors the HMFOR process due to the increased active species(Ni^(2+δ)N(OH)ads)and the enhanced adsorption of HMF on the Ni3 N surface.This work could provide an in-depth understanding of the electrocatalytic mechanism of HMFOR on Ni3 N and demonstrate the alkalinity effect of the electrolyte on the electrocatalytic performance of HMFOR.

Impacts of Alkalinity Drops on Shifting of Functional Sulfate-Reducers in a Sulfate-Reducing Bioreactor Characterized by FISH

Alkalinity is one of the most important parameters that influence microbial metabolism and activity during sulfate-laden wastewater biological treatment. To comprehensively understand the structure and dynamics of functional microbial community under alkalinity changes in sulfate-reducing continuous stirred tank reactor （CSTR）, fluorescent in situ hybridization （FISH） technique was selected for qualitative and semi-quantitative analysis of functional microbial compositions in activated sludge. During 93d of bioreactor operation, the influent alkalinity was adjusted by adding sodium bicarbonate from 4000mg·L^-1 down to 3000mg·L^-1, then to 1500mg·L^-1, whereas other parameters, such as the loading rates of chenucal oxygen demand （COD） and sulfate （SO4^2-）, hydraulic retention time （HRT）, and pH value, were continuously maintained at 24g·L^-1·d^-1 and 4.8g·L^-1·d^-1, 10h,and about 6.7, respectively. Sludge samples were collected during diflerent alkalinity levels, and total Bacteria, tlae sulfate-reducing bacteria （SRB）, and four SRB genera were demonstrated with 16S ribosomal .RNA-targeted oligonucleotide probes. The results indicated that bioreactor started-up successfully in 30d. The two instances ot drop in alkalinity resulted in the fluctuation of sulfate removal rate. The diversity of SRB community showed significant shift, and the alteration of microbial community directly resulted in the corresponding statuses of bioreactor. The dominant genera during the bioreactor start-up and alkalinity drops were Desulfovibrio, Desulfobacter, Desulfovibrio, Desulfobacter, and Desulfovibrio, respectively. In addition, the acetotrophic SRB sutterecl more trom me reduction of alkalinity than the non-acetotrophic SRB. This strategy can present the functional microbial community structure during start-up and alkalinity drop stages, and provides a powerful theoretical guideline for optimization and adjustment of bioreactor, as well.

Distributions of dissolved inorganic carbon and total alkalinity in the Western Arctic Ocean

The third Chinese National Arctic Research Expedition （3rd CHINARE-Arctic in 2008） was carried out from July to September 2008. During the survey, numerous sea water samples were taken for CO2 parameter measurement （including total alkalinity TA and total dissolved inorganic carbon DIC）.The distribution of COs parameters in the Western Arctic Ocean was determined, and the controlling factors are addressed. The ranges of summertime TA, normalized TA （nTA）, DIC and normalized DIC （nDIC） in the surface seawater were 1 757 2 229 umol.kg 1 2 383-2 722 umol.kg-1, 1 681 2 034 pmol.kg 1, 2 119--2 600 umol.kg-1, respectively. Because of dilution from ice meltwater, the surface TA and DIC concentrations were relatively low. TA in the upper 100 m to the south of 78°N had good correlation with salinity, showing a conservative behavior. The distribution followed the seawater-river mixing line at salinity 〉30, then followed the seawater mixing line （diluted by river water to salinity = 30） with the ice meltwater. The DIC distribution in the Chukchi Sea was dominated by biological production or respiration of organic matter, whereas conservative mixing dominated the mixed layer TA distribution in the ice-free Canada Basin.

Rheological properties of salt-tolerant HPAM solutions with ultrahigh molecular weight

The rheological properties of salt-tolerant partially hydrolyzed polyacrylamide(HPAM)solutions with molecular of 2.5×107 g/mol at different concentrations were measured in steady-state shear flow mode by Haake Rheostress 150 rheometer.Three constitutive equations(Oldroyd four constant model,Guesekus model and FENE-P model) were used for describing the apparent viscosity and first normal stress difference.The apparent viscosity of salt-tolerant HPAM solutions appears a first Newtonian zone when the shear rate is approximately lower than 0.2 s-1.At high shear rate,the HPAM solutions show shear-thinning and elasticity.The results show that the FENE-P model has the best agreement between theoretical and experimental data within the available shear rate range.The material parameters are useful for numerical analysis of polymer solution flow fields.

Sulfate-Exchange Alkalinity of Ferralsol Colloid

The amount of OH- replaced by sulfate, i.e., sulfate-exchange alkalinity, from the electric double layer of ferralsol colloid was measured quantitatively in different conditions with an automatic titration equipment.The amount of OH- release increased with the amount of Na2SO4 added and decreased with raising pH in the suspension of ferralsol colloid. The exchange acidity was displayed as PH was higher than 5.6. If the negative effect of sodium ions was offset, the amount of OH- replaced by sulfate was larger than the original amount of OH- released in the PH range of lower than 5.8. The amount of OH- released decreased rapidly as PH was higher than 6.0 and dropped to zero when PH reached 6.5. In the solution of 2.0 mol L-1 NaClO4, the amount of OH- replaced by sulfate from the surface of ferralsol colloid could be considered as the amount of OH- adsorbed by ligand exchange reaction. The amount of OH- released in the solution of NaClO4 concentration below 2.0 mol L-1 from which the amount o f OH- adsorbed by ligand exchange reaction was subtracted could be considered as the OH- adsorbed by electrostatic force. The OH- adsorbed by electrostatic force decreased with increases in the concentration of NaClO4 and PH and increased almost linearly with the increasing amount of Na2SO4 added. The percentages of OH- adsorbed by electrostatic force in water and in the electrolyte solutions of 0.05 and 0.5 mol L-1NaClO4 in the total OH- released were calculated, respectively.

High-yield Cultivation Technique of Salt-tolerant Spartina and Rice in Coastal Mudflat

Directing at the characteristics of coastal mudfiat saline and alkaline land, the yield of salt-tolerant Spartina and rice could reach 5 925-8 280 kg/hm^2 by the techniques of land and water resource utilization, farming improvement, construction of matched water system, seed selection and treatment, water direct seeding, seedling raising on seedbed, field transplanting, weeding, nutrient and water management, and disease and pest control, providing a scientific basis for the cultivation of Spartina and Rice in coast mudflat.

Germination and Photosynthetic Responses to Salinity and Alkalinity in Avicenna marina Propagules

Avicenna marina(Forssk.)Vierh is a halophytic mangrove.The reproductive unit is green and has photosynthetic propagules.Mangroves are naturally exposed to fluctuations in some abiotic factors at the soil surface,including salinity and alkalinity.The objective of this study was to determine the effects of two salts including NaCl and NaHCO_(3)on germination processes and discuss the relationships between cotyledon photosynthesis and embryo axis growth in A.marina propagules.These propagules came from Al Birk,located on the shoreline of the Saudi Red Sea.The results showed that the studied salts did not affect neither the final germination percentage nor the embryo axis growth.However,rooting and root growth were delayed by both salts at 300 mM and were strongly inhibited by 600 mM NaHCO_(3).Both NaCl and NaHCO_(3)reduced the photosynthetic activity.These two salts did not affect the other photosynthetic parameters,including stomatal conductance,net transpiration,and intercellular CO_(2).Thereafter,the reduction in net photosynthesis was not related to any limitation of stomatal conductance.The early germination phase was independent of cotyledon photosynthesis,whereas rooting and root growth may be limited by reduced photosynthesis under NaCl and NaHCO_(3).

Research progress on plant tolerance to soil salinity and alkalinity in sorghum

Sorghum is an important source of food, feed and raw material for brewing, and is expected to be a promising bioenergy crop. Sorghum is well known for its strong resistance to abiotic stress and wide adaptability, and salt tolerance is one of its main characteristics. Increasing sorghum planting acreage on saline-alkalien land is one way to effectively use this kind of marginal soil. In this paper, domestic and overseas research on plant tolerance to soil salinity and alkalinity in sorghum, including salt-tolerant genetics and breeding, physiology, cultivation, and identification of tolerant germplasms, are reviewed. Suggestions for further studies on salinity and alkalinity tolerance in sorghum are given, and the prospects for sorghum production in saline-alkalien land are discussed.