Characterization of Digestates from Anaerobic Co-Digestion of Manioc Effluent, Human Urine and Cow Dung

This study focused on the characterization of digestates resulting from anaerobic digestion of manioc effluents from attiéké factories. Two types of digestate were characterized, one consisting of manioc effluent + urine and another composed of manioc effluent + urine + cow dung. As a result, these residues of bio-digestion rich in nutrients (NPK) can be used as agricultural fertilizer. Moreover, the determination of some microorganisms and heavy metals digestates allowed to better appreciate its fertilizing quality. These parameters remained in accordance with the quality standards of a digestate prescribed. These results show that digestates from anaerobic co-digestion of manioc effluents, urine and cow dung can be used without fear as an agricultural biofertilizer.

木薯渣基生物质炭对水中Cd^(2+)Cu^(2+)的吸附行为研究

以木薯渣为原料,制备不同温度(350、450、550℃)的生物质炭(BC350、BC450、BC550),对其性质进行表征,探究吸附时间、溶液初始浓度、温度、p H对生物质炭吸附Cd^(2+)、Cu^(2+)作用的影响。结果表明:生物质炭对Cd^(2+)、Cu^(2+)的吸附平衡时间随着生物质炭热解温度的升高而缩短,伪二级动力学模型能较好地描述吸附动力学特性(R2>0.983)。吸附等温线符合Freundlich模型和Langmuir模型,但Freundlich模型拟合的线性更好,R2分别在0.951~0.998和0.992~0.998之间,说明生物质炭对Cd^(2+)、Cu^(2+)的吸附为多层吸附。lg KF值表示吸附能力,随生物质炭热解温度的升高而增大,说明BC550吸附效果最好,对Cd^(2+)、Cu^(2+)的最大吸附量分别为15.55和5.44 mg·g-1。生物质炭对Cd^(2+)、Cu^(2+)的吸附具有自发的特性,吸附量随p H的增加先增加后下降,最适p H分别为5.5和6.5。

木薯粉与糖蜜混合发酵柠檬酸的研究

利用木薯粉进行柠檬酸发酵,研究了发酵温度、起始糖浓度、起始pH值、摇瓶发酵的装液体积对柠檬酸发酵的影响,确定了柠檬酸批式发酵的优化条件,即:35℃的发酵温度,50ml的摇瓶发酵装液体积,5.0的发酵起始pH值,12%的起始糖浓度。在此优化条件下进行了木薯粉与糖蜜混合配比的发酵实验,最终确定了木薯粉与糖蜜混合的最佳配比为9:1。

红薯渣和木薯渣对生长獭兔的营养价值评定

为评定红薯渣和木薯渣在生长獭兔上的营养价值,本试验选择30只100日龄平均体重(1.78±0.20)kg的健康白色獭兔,随机分为3组,每组5个重复,每个重复2只。试验饲粮用替代法进行配制,红薯渣和木薯渣在基础饲粮中的替代比例均为15%;采用全收粪法进行消化试验,预试期和正试期各5 d。结果表明:1)红薯渣和木薯渣中的总能(GE)以及干物质(DM)、粗蛋白质(CP)、粗纤维(CF)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、酸性洗涤木质素(ADL)、粗脂肪(EE)、粗灰分(Ash)、钙(Ca)、磷(P)、无氮浸出物(NFE)含量分别为13.49 MJ/kg、90.08%、2.63%、10.66%、16.90%、13.27%、4.56%、2.77%、8.74%、1.12%、0.17%、65.29%和14.30 MJ/kg、95.76%、2.39%、16.85%、16.64%、13.08%、2.67%、4.41%、3.05%、0.91%、0.07%、69.07%。2)红薯渣和木薯渣在生长獭兔中的表观消化能分别为11.47和13.06 MJ/kg,生长獭兔对红薯渣和木薯渣中的GE、DM、CP、CF、NDF、ADF、ADL、EE、Ash、Ca、P、NFE的表观消化率分别为85.00%、74.64%、92.60%、20.84%、30.13%、10.69%、41.47%、9.25%、34.16%、47.33%、51.13%、80.57%和91.36%、89.92%、88.94%、58.08%、30.09%、5.39%、27.02%、7.24%、84.27%、70.30%、27.43%、96.25%。由此可见,生长獭兔对红薯渣和木薯渣中的不同营养成分消化率存在一定差异,结合饲料原料营养物质含量总体分析,木薯渣对生长獭兔的营养价值要高于红薯渣。

Earth Mothers

All around Zamakoue,a small town about 35km from Cameroon's capital Yaounde,there are vast manioc fields that extend as far as the eye can see.This entire area is under the responsibility of a single woman,Ernestine Mballa.The fertile manioc fields provide her with a substantial income and contribute effectively to her personal growth,as well as that of her family as a whole.Manioc, or cassava,is a tropical vegetable widely grown and consumed in Africa.