盐渍水再利用处理及其在泡青菜上的应用研究

采用絮凝工艺对高浓度盐渍水进行预处理,通过单因素分析和正交实验,考察絮凝剂用量、絮凝时间、絮凝温度对盐渍水澄清效果的影响,确定了絮凝澄清盐渍水最佳工艺参数:当絮凝剂添加量为0.012%,絮凝时间为140min、絮凝温度为18℃时,能够将初始盐度为15%、透光率为21.17%的盐渍水,处理成盐度为14.58%,透光率为83.7%,絮凝澄清效果最好;将采用上述工艺得到的回收盐渍水,进行泡青菜的盐渍中试实验,并与同浓度食盐水渍菜进行对比,动态跟踪了盐渍青菜盐度、酸度、亚硝酸盐的变化情况,同时进行感官评价,发现回收盐渍水渍菜色泽、滋味、脆度更接近成熟泡青菜,发酵风味浓厚。

无花果盐渍水回收处理技术研究

采用活性炭和硅藻土联合处理高盐度无花果盐渍水,即用活性炭对无花果盐渍水进行前处理后,再用硅藻土助滤处理。通过单因素分析和正交试验,考察活性炭处理无花果盐渍水时的添加量、作用时间、作用温度和硅藻土的添加量对无花果盐渍水处理效果的影响,以盐度和白度(Wh)为指标,确定其最佳工艺参数。当活性炭的添加量为2.2%,作用时间为65min,处理温度为50℃时,硅藻土添加量为2.0%,能够将盐度为22.67%、Wh值为87.08的无花果盐渍水处理成盐度为21.87%、Wh值大于95.0的盐渍水。数据说明盐分保留高同时脱色澄清效果好。再将处理后的无花果盐渍水中的盐,通过蒸发浓缩结合烘干工艺进行回收,回收率:76.31%;纯度:98.12%;Wh≥85。

盐渍水灌溉条件下水稻的生产量及化学成分

用沿海盐碱土进行的“花盆”试验表明，水稻在分蘖和开花的早期阶段对盐渍水灌溉非常敏感。水稻在生长早期阶段用盐渍水灌溉后是严重的，经常用盐渍水灌溉，不论其盐碱度如何，都会缩短水稻的生长期、减少产量和禾杆中氮、磷、钾的成份。在水稻生长的后期阶段用盐水灌溉较为适应。

盐渍土地区钢筋混凝土施工用水处理研究

通过对西北盐渍地区水的含盐量分析,指出了该地区钢筋混凝土结构严重破坏腐蚀的原因,详细阐述了解决这个问题的反渗透法,即处理钢筋混凝土结构的施工用水——盐渍水,此技术具有简单高效、除盐率高和运行费用低等优点,很适合在经济落后的西部地区推广使用。

海带盐渍加工尾水处理菌株筛选及生物处理工艺研究

目的筛选海带盐渍加工尾水处理菌株,并研究其生物处理工艺。方法将海水来源微生物通过初筛、复筛,以甘露醇去除率为主要指标,筛选出2株目标菌株应用于海带尾水处理,经PCR扩增鉴定目标菌株,以化学需氧量(chemical oxygen demand,COD)(即CODMn去除率)为指标,通过单因素、正交实验优化2个菌株的最佳培养条件,而后将混合菌株应用于海带盐渍加工尾水中,研究生物处理前后海带盐渍加工尾水中CODMn去除率、生化需氧量(biochemical oxygen demand,BOD)(即BOD5去除率)的变化。结果本研究筛选2株耐高盐的海带盐渍加工尾水处理菌株分别为二尖梅奇酵母(Metschnikowia bicuspidata)和季也蒙毕赤酵母(Meyerozyma guilliermondii),优化条件分别为二尖梅奇酵母菌培养温度25℃、接种量8%和培养转速100 r/min;季也蒙毕赤酵母菌培养温度28℃、接种量5%和培养转速200 r/min;2种菌株混合对尾水处理优化条件为接种量3%,最佳培养时间60 h,CODMn去除率85.98%。结论耐高盐菌株经扩繁对海带盐渍加工尾水进行了生物处理,混合菌株生物处理降低了盐渍海带尾水中的CODMn值,CODMn去除率为81.35%;BOD5含量降低了98.70%。技术解决了褐藻加工行业高盐尾水难以处理的问题,可为后续酵母菌处理高盐尾水提供依据。

耐盐菌的筛选及在裙带菜加工尾水中的应用

目的筛选应用于裙带菜盐渍加工尾水处理的耐盐菌。方法以裙带菜盐渍加工尾水为培养基,根据CODMn去除率、甘露醇去除率以及生物量筛选出4株耐盐菌株。将这4株菌株分别应用于裙带菜盐渍加工尾水中,以CODMn去除率为主要指标测定72 h生长曲线,优选出各菌株的最佳培养时间。然后将这4株菌株混合应用于裙带菜盐渍加工尾水,确定最佳接种量和培养时间。结果经鉴定4株菌株分别为二尖梅奇酵母菌(Metschnikowiabicuspidata)、鞘氨醇菌(Sphingomonas)、胶红酵母菌(Rhodotorulamucilaginosa)、盐单胞菌(Cobetia)。各菌株对裙带菜加工尾水处理后CODMn去除率均在48h后达到最大值,去除率分别为84.90%、77.40%、79.20%、70.80%。4种混合菌株在28℃、150 r/min摇床反应条件下的最佳接种量为3%,最佳培养时间为60 h, CODMn去除率达到83.49%。结论本研究中筛选出的耐盐菌株有效的降低了裙带菜漂烫尾水的CODMn,对于实际应用有重要意义。

Salt-Water Dynamics in Highly Salinized Topsoil of Salt-Affected Soil During Water Infiltration

Continuous monitoring of salt and water movement in the soil profile of highly salinized topsoil under steadystate infiltration was conducted.It gives that salt and water dynamics during convection-diffusion period can be divided into three stages:1.formation of a salt peak,2.the salt peak moving downwards till the appearance of the summit of the salt peak,3.the salt peak moving further downwards with the peak value decreasing.Results show that the maximum salt peak appears at the same depth if soil texture and outflow condition are the same.Factors affecting salt and water movement and ion components in the outflow solution underinfiltration are discussed.

Characteristics of Channeling Flow in Cultivated Horizon of Saline Rice Soil

By applying bromide ion as tracer, the channeling flow has been quantitatively described in saline rice soil and alkaline soil of Da＇an City, Jilin Province of China. Breakthrough curves of bromide ion in the saline rice soils after 1-year cultivation and 5-year cultivation and alkaline soil have been attained. Results show that the rice cultivation practice can improve the alkaline soil structure, however, it can accelerate the development of channeling flow pathway. Therefore, the channeling flow pathway has been developed widely in saline rice soil, but rarely in the alkaline soil. Three models of convection-dispersion equation （CDE）, transfer functional model （TFM） and Back-Progation Network （BP Network） were used to simulate the transportation process of bromide ion. The peaks of probability density function of saline rice soil are higher with left skewed feature compared with that of the alkaline soil. It shows that the TIM and CDE can simulate the transportation process of the bromide ion in saline rice soil after 5-year cultivation, however, some deviation exists when it was used to simulate transportation process of bromide ion in saline rice soil after 1-year cultivation and alkaline soil; BP network can effectively simulate transportation process of bromide ion in both saline rice soil and alkaline soil.

Removal of Nitrogen and Phosphorus from Saline Wastewater Using Up-Flow Sludge Blanket Filtration Process

There is recent trend of providing additional treatment of wastewater beyond tertiary level. The purpose is to refine water to a quality that is safe for reuse for unrestricted irrigation and other non potable uses. For this purpose, Kuwait has built and operated an advanced wastewater treatment plant with capacity of 500,000 m3·dl. This plant providing treatment beyond tertiary utilizes the process of Ultra Filtration （UF） and Reverse Osmosis （RO）. The reject water of this unit contains high concentration of total nitrogen and total phosphate. Safe disposal of this water into the environment or possible reuse needs substantial reduction of these chemicals. In this study, a bench scale up-flow sludge blanket filtration system was investigated. The system operated with an average Hydraulic-Retention Time （HRT） of 19 h, whereas, sludge age varied within the range of 14 days to 16.5 days. The results show that the average removal efficiencies of the system for Biological Oxygen Demand （BOD）, Chemical Oxygen Demand （COD） were over 86% and 82% respectively. The phosphate and nitrogen＇s average removal were found to be 50% and 45% respectively.

Managing Salinity in Tunisian Oases

The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance between water, soil and man, which is now changed by modem irrigation and drainage systems. The oases pump most of their water from deep aquifers and only to a small degree from shallow aquifers. The quality of the irrigation water and the presence of a shallow saline water table are the main causes of salinization of the oases. Concerning the salt-affected landscapes and hydro-saline dynamic, the authors distinguish an equilibrium dynamic of salts to the parcel which depends on water management, and an equilibrium dynamic at the level of the basin watershed which is powered by drilling and ending in hypersaline depressions. For the management of salinization and waterlogging, a combination of agricultural management techniques are used, the first being modem methods of irrigation and drainage. Other, less used methods are sandy amendment, the reuse of drainage waters, geothermal waters and of treated wastewater.

Estimation of New Wheat Genotypes for Salt Tolerance Which Induced through Plant Breeding Programs

Salinity of soils or water poses an increasing threat to food production due to climate change. Plant breeding programs were applied to improve salt tolerance in new wheat genotypes to overcome this problem. The aim of this research work is to estimate the realized improvement in salt tolerance of the selected genotypes through plant breeding programs. The comparison experiments were conducted in salinized soils at two locations for two years as compared with two local cultivars. All the selected genotypes derived from F2 populations after six cycles of exposure to high salinity level were tested for salt tolerance during all growth stage. At harvest stage, seed yield and its components were studied for the comparison. Results showed that there were significant differences between all selected genotypes and local eultivars in their overall sensitivities to soil salinity. All selected genotypes were superior in seed yield and its components at maturity to those of the local cultivars at the two location and years. Clearly, all the selected genotypes exhibited more than twice seed yield/m2 compared with that obtained from local cultivars. The results also indicated that there were differences among selected genotypes in their responses to soil salinity between locations and years, but not significant. Important thing is significant improvement in selected genotypes was achieved in their salt tolerance through six cycles of screening and selection to high salinity level. The conclusion is a strong possibility to improve salt tolerant genotypes of wheat with high salt tolerance through plant breeding programs.

Study on Hatching Rate of Artemia fanciscana Cysts in Different Sources of Saline

A comparison of Arternia cysts hatching （Artemia franciscana） were conducted on bleaching and non-bleaching with sodium hypochloride on five dilution of salt solution by using sea water, sea salt solution, artificial sea salt solutions, iodine added cooking salt solution, and rock salt solutions. All solutions were adjusted at 30 ppt of salinity in 1 litter cylinder. The experiment was carried out with Factorial Experiment in CRD. After 24 hours, a randomized count of living Artemia was taken a photograph of Artemia size by stereo microscope. A statistic analysis showed that all data of bleaching and non-bleaching were no significant difference （P 〉 0.05）. The hatching ability of Artemia cysts in solutions was examined and the results showed that sea salt solution was 327.33 × 103.4. 28,536.5263 Nauplii/liter, sea water 316 ×10^3± 20,420.5779 Nauplii/liter, artificial sea salt solutions 314.33× 10^3 ± 34,268.5473 Nauplii/liter, iodine added cooking salt solution 309.66 ± 10^3 .4- 22,898.3260 Nauplii/liter, and rock salt solutions 305.33 ± 10^3 ± 25,579.9401 Nauplii/liter, respectively. The body length of Artemia was compared and the data showed that there was no significant difference （P 〉 0.05）. The highest body length was found in sea salt solution 527.32 ± 4.70μm, sea water 521.65±8.51 μm, artificial sea salt solutions 522.08 ± 10.04 μm, iodine added cooking salt solution 522.67 ±7.87 μm, and rock salt solutions 516.33 ±11.15μm, respectively.

Calcium Addition Affects Germination and Early Seedling Growth of Sweet Sorghum under Saline Conditions

[Objective] This study aimed to determine the interactive effects of supple- mental Ca amendment and salinity on germination of sweet sorghum seeds in saline solution culture medium, and investigate the effects of different combinations of Na/Ca ratio in saline soils on the early growth of sweet sorghum plants. [Method] A germi- nation test and a greenhouse pot experiment were conducted to assess the interac- tive effects of calcium addition to culture medium on the germination and seedling growth of sweet sorghum （Sorghum saccharatum Moench） in saline soils with a range of NaYCa ratios. In the germination test, seeds were treated with different combinations of five calcium levels [0, 5, 10, 15, and 20 mmol/L Ca（NO3）2] and five salinity levels （0, 50, 100, 150, and 200 mmol/L NaCI）. In the greenhouse experi- ment, seeds were sown in potting soils containing 3 salinity levels （2.3, 4.7 and 7.0 dS/m） and three Na：Ca ratios （10：0, 10：1, and 5：1）. [Result] In the germination test, Ca addition at 5 mmol/L promoted germination by 5.5%, 9.9%, and 17.0% at the 3.4, 6.7 and 10.1 dS/m salinity levels. The higher Ca level （10 mmol/L） also in- creased germination by 9.1% and 7.8% at the 3.4 and 6.7 dS/m salinity levels. Then even higher Ca addition at 15 and 20 mmol/L appeared to promote germina- tion when culture media had high salinity （10.1 and 13.4 dS/m）. In the greenhouse pot experiment, saline soil amended with supplemental Ca at the 2.3 and 4.7 dS/m salinity levels significantly promoted early seedling growth, with an increase of 6.8% to 28.2% in plant height and 14.3% to 67.9% in whole plant weight. From 28 to 42 d after seeding, the relative growth of seedling was increased by Ca addition, with a reduction of 49.5% to 66.0% in plant height and 4.8% to 61.9% in whole plant weight. From 42 to 56 d after seeding, however, the relative growth of seedling was significantly inhibited by Ca amendment. [Conclusion] Results of this study indicate that appropriate supplemental Ca could improve sorghum germination and early seedling growth in saline soils.

Biodiversity in Saline and Non-Saline Soils Along the Bohai Sea Coast,China

A plethora of information is available on the effects of salinity on plant growth and soil physico-chemical properties,but the effects on soil organisms are often neglected.Thus,a systematic investigation of how soil biodiversity,including bacteria,nematodes,mites,and earthworms,changes along saline gradients was conducted along the Bohai Sea coast at Laizhou City,Shandong Province,China,with 30 soil samples randomly selected and classified by salinity into two categories:saline and non-saline.Testing revealed a significantly higher abundance of the surveyed organisms in non-saline soils.The redundancy analysis showed that a negative correlation was observed between electrical conductivity and soil organism abundance in saline soil,but not in non-saline soil.Soil organic matter,available nitrogen,and total nitrogen all positively affected organism abundance in both saline and non-saline soils.The richness and Shannon diversity of nematodes were significantly higher in non-saline soils,but were not significantly different between soil types for other organisms.None of the environmental factors surveyed was obviously related to soil organism diversity.Consequently,our results suggested that soil electrical conductivity only negatively affected soil organisms in saline soil,while soil fertility positively affected soil organisms in both saline and non-saline soils.

Impact of Irrigation Methods on Soil Salt Content and Their Differences in Whole Cotton Growing Season in Arid Area of Northwest China

Research for changes of soil water and salt is an important content of land sciences and agriculture sciences in arid and semi arid regions. In this paper, sampling in actual agricultural fields, laboratory analysis of soil samples and statistical analysis methods are used to quantitatively analyze soil salinity changes under different ir- rigation methods throughout the cotton growing season in Shihezi reclamation area. The results show that irrigation methods play an important role in soil salt content in the surface soil （0-20 cm） and sub-deep soil （40-60 cm）, fol- lowed by deep soil layer （60-100 cm） and root soil layer （20-40 cm）. Furrow irrigation yields the maximum soil salt content in deep layer （60-100 cm） or sub-deep layer （40-60 cm） and the maximum salinity occurs in the first half of the cotton growing season （June or earlier）. In contrast, drip irrigation yields the maximum soil salinity in the root layer （20-40 cm） or sub-deep （40-60 cm）, and this usually appears in the second half growing season （July or af- ter）. The ratio of chloride ion to sulfate ion （Cl-/SO2- 4） and its change in the soil are on the rise under furrow irrigation while the value first increased and then decreased with a peak point in June under drip irrigation. This suggests that furrow irrigation may shift the type of soil salinization to chloride ion type moreso than drip irrigation. Potassium and sodium ion contents of the soil show that soil sodium＋potassium content will drop after the first rise under furrow irrigation and the value is manifested by fluctuations under drip irrigation. Potassium＋sodium content change is relatively more stable in the whole cotton growth period under irrigation methods. The maximum of sodium and potassium content of the soil usually occur in deep soil layer （60-100 cm） or sub-deep soil layer （40-60 cm） in most sample points under furrow irrigation while it is inconsistent in different sample points under drip irrigation. A non- parametric test for paired samples is used to analyze differences of soil salt content under different irrigation methods. This analysis shows that the impact of irrigation on soil salinity is most significant in July, followed by August, June, May, and April in most sample points. The most significant impact of irrigation methods occurs in the surface soil layer （0-20 cm）, followed by deep layer （60-100 cm）, root layer （20-40 cm） and sub-deep （40-60 cm）. These conclusions will be benefitial for mitigation of soil salinization, irrigation and fertilization and sustainable land use.

Effect of Combined Use of Brackish Water and Nitrogen Fertilizer on Biomass and Sugar Yield of Sweet Sorghum

Soil salinization and non-point source pollution are among the most important and widespread environmental problems in European Mediterranean regions. Sweet sorghum （Sorghum bicolor （L.） Moench var. saccharatum） is a moderate to high salinity tolerant crop with low water and nutrient needs, seen as an alternative to grow in the water scarce regions. A three-year multifactorial study was conducted in southern Portugal to evaluate the combined effects of saline water and nitrogen application on the dry biomass （total, stems, and leaves）, sugar content （total reducing sugars and sucrose eontents） and sugar yield （here defined as the product of total reducing sugars and stems dry biomass） functions of sweet sorghum. Sorghum dry biomass and sugar yield showed diminishing returns for each incremental change of nitrogen. The use of saline irrigation waters also led to yield reduction. Exception was sucrose content which increased with increasing levels of sodium in the soil. Nitrogen need decreased as the amount of sodium applied increased. Stem dry biomass, sucrose content, and sugar yield progressively increased with progress in the experiment. The effect could be attributed to the increase of the amount of irrigation applied throughout the years, thus increasing the leaching fraction which promoted salt leaching from the root zone, reduced the salinity stress, increased plant transpiration, nitrogen uptake and biomass yield.

Assessment of Terrestrial Ecosystem Sensitivity and Vulnerability in Tibet

The Tibetan Plateau serves an important shelter function for the ecological security of Asia, and especially China. Here, we proposed and improved indicators and methods for assessing the ecological sensitivity and vulnerability of the terrestrial alpine Plateau ecosystems and assessed the freeze-thaw erosion, land desertification, water-caused soil loss, and land salinization sensitivity, together with ecological vulnerability, from the overall ecological sensitivity, ecological pressure, and elasticity aspects in Tibet. The results indicate that the terrestrial ecosystem of Tibet is quite sensitive to freeze-thaw erosion, land desertification and water-caused soil loss. Extremely and highly sensitive regions account for 9.62% and 83.69%, respectively, of the total area of the Tibet Autonomous Region. Extremely and highly vulnerable areas account for 0.09% and 52.61%, respectively, primarily distributed in the Himalayan and Gangdise mountain regions in west Tibet; the Nyainqentanglha, Tanggula, Hoh Xil, and Kunlun mountain regions; and the northwest and northern regions of the Changtang Plateau. The results will aid the development of customized protection schedules according to different ecological issues in each region.

Dynamics of ^(14)C-labelled Glucose and NH_4^+ in a Regularly Flooded Extremely Alkaline Saline Soil

Flooding an extremely alkaline(pH 10.6) saline soil of the former Lake Texcoco to reduce salinity will affect the soil carbon(C)and nitrogen(N) dynamics.A laboratory incubation experiment was done to investigate how decreasing soil salt content affected dynamics of C and N in an extremely alkaline saline soil.Sieved soil with electrical conductivity(EC) of 59.2 dS m^(-1) was packed in columns,and then flooded with tap water,drained freely and conditioned aerobically at 50%water holding capacity for a month.This process of flooding-drainage-conditioning was repeated eight times.The original soil and the soil that had undergone one,two,four and eight flooding-drainage-conditioning cycles were amended with 1000 mg glucose-^(14)C kg^(-1) soil and 200 mg NH_4^+-N kg^(-1)soil,and then incubated for 28 d.The CO_2 emissions,soil microbial biomass,and soil ammonium(NE_4^+),nitrite(NO_2^-) and nitrate(NO_3^-) were monitored in the aerobic incubation of 28 d.The soil EC decreased from 59.2 to 1.0 dS m^(_1) after eight floodings,and soil pH decreased from 10.6 to 9.6.Of the added ^(14)C-labelled glucose,only 8%was mineralized in the original soil,while 24%in the soil flooded eight times during the 28-d incubation.The priming effect was on average 278 mg C kg^(-1) soil after the 28-d incubation.Soil microbial biomass C(mean 66 mg C kg^(-1) soil) did not change with flooding times in the unamended soil,and increased 1.4 times in the glucose-NH_4^+-amended soil.Ammonium immobilization and NO_2^- concentration in the aerobically incubated soil decreased with increasing flooding times,while NO_3^- concentration increased.It was found that flooding the Texcoco soil decreased the EC sharply,increased mineralization of glucose,stimulated nitrification,and reduced immobilization of inorganic N,but did not affect soil microbial biomass C.