Improved Cu and Zn sorption on oxidized wheat lignocellulose

We studied the effect an oxidizing treatment of a lignocellulosic substrate, extracted from wheat bran, on the sorption of Cu and Zn. Oxidizing agents, such as potassium permanganate (KMnO₄) or sodium periodate (NaIO₄), creates oxygenated functions, e.g. alcohol and carboxylic acid, which increase the density of functional sites and the binding capacity of lignocellulose towards copper and zinc. We found that the treatment with KMnO₄ is the most efficient, with an increase of about 30–40% metal ion binding, compared to 15–25% using NaIO₄. The investigation of the oxidation process shows that the efficiency of KMnO₄ can be attributed to its affinity towards insaturated double bonds of lignin entities. Oxidized lignocellulose is thus a promising, efficient, and cheap biomaterial for the decontamination of wastewater.     

Growth, yield and elements content of wheat (Triticum aestivum) grown in composted municipal solid wastes amended soil

A commercial formulation of composted municipal solid wastes (MSW) was used for amending soil at 0, 50, 100, 150, 200 and 250 kg ha⁻¹ in which wheat had been grown (field experiments) and element residues of amended soil and plant parts were enumerated. MSW amendment caused a significant improvement in soil quality. Growth (shoot length, leaf number, leaf area, tiller number, plant dry weight and chlorophyll contents of leaves) and yield (length of panicle, number of panicles per plant and grain yield per plant) of wheat increased gradually up to the MSW-amendment level of 200 kg ha⁻¹. Elements, Ni, Zn, Cu, Cd, Cr, and Pb accumulated in plants from MSW amended soil, but the degree of metal accumulation was the least in seeds in comparison to other plant parts (root, stem and leaf). Moreover, Ni, Zn, Cd and Pb, were in high concentration in all plant parts. It is recorded that the level of 200 kg ha⁻¹ MSW amendment caused better growth and yield of wheat, but progressive levels of metal accumulation in plant parts were recorded due to increase in amendment levels. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Use of agricultural waste for the removal of nitrate-nitrogen from aqueous medium

The effectiveness of wheat straw charcoal (WSC) and mustard straw charcoal (MSC) as adsorbents for the removal of nitrate-nitrogen from water has been investigated. Commercial activated carbon (CAC) was used as a standard for comparison. The adsorption effectiveness of MSC was highest followed by CAC and WSC irrespective of the concentration of nitrate-nitrogen in the range of 0-25mg/l. The effects of temperature in the range of 15-28 degrees C on adsorption by WSC and MSC have also been investigated. It was observed that the temperature dependence of the adsorption effectiveness of MSC was higher than that of WSC and CAC. It is concluded that the MSC can be used for the in situ treatment by adsorption of nitrate-nitrogen in underground and surface water.     

Microbial community structures in an integrated two-phase anaerobic bioreactor fed by fruit vegetable wastes and wheat straw

The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.     

米糠与氧化钙、过磷酸钙联用钝化Pb污染土壤

研究了生物质材料米糠及其与氧化钙、过磷酸钙联用对土壤中重金属Pb的钝化作用.结果表明,向土壤中加入米糠可增大土壤pH值,增加土壤中重金属Pb的稳定性.米糠投加量每增加2%,土壤pH值增大约0.3.米糠投加量增大,Pb稳定效率也随之增大,6%米糠投加量60 d时,Pb稳定化效率达到38.06%,弱酸提取态降低28.90%.6%米糠+2%氧化钙联用、6%米糠+0.6%过磷酸钙联用均可对土壤中Pb产生较好的钝化效果,60 d时的稳定效果分别为47.36%、44.85%.6%米糠+2%氧化钙对Pb污染土壤有较好的钝化调节作用,可增大土壤pH,从而促进酸可提取态Pb向其他稳定形态转变.     

污水土地处理模拟试验比较分析

通过温室条件下，冬小麦３种不同种植密度下（Ａ、Ｂ、Ｃ３组分别为０．０２０８、０．１０４２、０．１４１５株／ｃｍ＾２），氮污染物运移转化吸收模拟试验，分析不同污水土地处理强度下植物生长、根系生长与分布、根系对氮污染物吸收规律以及根系部分吸收与土壤中氮去除过程，探讨最佳的污水土地处理条件和强度。试验结果是，Ａ组单株吸氮量最大达４９．９０ｍｇ／株；Ｂ组种植密度下，土壤中氮累计减少量与随灌水累计加入量相等     

Nuclear War Investigation Related to a Limited Nuclear Battle with Emphasis on Agricultural Impacts in the United States

A limited battle involving the nuclear arsenals of India and Pakistan would have significant climatic impacts upon agricultural crop production in the United States; corn, soybeans, and winter wheat yields would be significantly reduced in the Corn Belt region of the US. The most severe impacts would occur during the second year after the modeled nuclear battle.     

Effects of Stonewalled Terracing Techniques on Soil-Water Conservation and Wheat Production Under Mediterranean Conditions

A field plot experiment was conducted in the Palestinian Autonomous Areas to study the effect of stonewalled terracing on soil and water conservation as compared to the nonterraced areas. Effects of the wheat canopy were considered as a second treatment. The experiment was undertaken over a period of two seasons (2000 and 2001). The results of the experiment found that the mean soil erosion was significantly lower (P < 0.05) in the terraced plots than in those that were nonterraced (182 kg/ha and 3525 kg/ha during the first season, 1769 kg/ha and 5057 kg/ha during the second season for terraced and nonterraced plots, respectively). A similar trend was observed with respect to runoff in areas under the same treatments. The wheat canopy showed lower, but not significant runoff and erosion in most of the cases for both seasons. Due to better soil and water conservation, the terraced plots obtained significantly higher total plant dry matter than nonterraced plots (1570 and 630 kg/ha in 2000, 2545 and 889 kg/ha in 2001 for terraced and nonterraced treatment, respectively). The runoff coefficient was 20% and 4% for the nonterraced and terraced plots, respectively. Rainstorms with intensity ≥4 mm/hand rainfall ≥10 mm are more likely to cause runoff and erosion.     

米糠炭吸附水中镉的研究

文章研究了米糠炭的用量、溶液温度、Cd^2＋浓度、溶液pH值和吸附时间对米糠炭吸附Cd^2＋性能的影响。实验结果表明,米糠炭对Cd^2＋具有很好的吸附效果,吸附率达94．6％。其最佳吸附条件为：米糠炭用量20g／L,温度30℃,pH=3,Cd^2＋质量浓度低于50mg／L,吸附平衡时间30min。     

浅谈稻米加工副产品的深度开发利用

通过对黑龙江垦区稻米加工副产品稻壳7种综合利用方式和米糠4种深度开发方式的介绍,结合垦区稻米加工产业对上述两种副产品的利用现状,从资源有效利用和保护环境的角度阐述了此项工作在黑龙江垦区的重要性及良好发展前景.