碱矿渣胶凝材料固化重金属污泥的研究

主要原材料为高炉矿渣的碱矿渣胶凝材料(HAS)、掺3%沸石的HAS、掺5%沸石的HAS、水泥等4种固化材料被用来固化人工合成含铅、镉、铬等重金属的污泥。污泥固化体中污泥与固化材的掺和比例为4:1。实验结果表明,HAS固化剂对重金属污泥的固化效果要好于水泥,其污泥固化体的无侧限抗压强度高于水泥固化体,同时其固化体的重金属浸出量明显低于水泥。沸石的掺入使HAS固化体的重金属浸出量减小,且随着沸石掺加量的增大,HAS固化体的重金属浸出量相应的减少。

Ultrafiltration Enhanced with Activated Carbon Adsorption for Efficient Dye Removal from Aqueous Solution

In this study, orange G dye was efficiently removed from aqueous solution by ultraflltration （UF） membrane separation enhanced with activated carbon adsorption. The powdered activated carbon （PAC） was deposited onto the UF membrane surface, forming an intact filter cake. The enhanced UF process simultaneously exploited the high water permeation flux of porous membrane and the high adsorption ability of PAC toward dye molecules. The influencing factors on the dye removal were investigated. The results indicated that with sufficient PAC incorporation, the formation of intact PAC filtration cake led to nearly complete rejection for dye solution under opti-mized dye concentration and operation pressure, without large sacnticlng the permeation tlux ot the filtration process. Typically, the dye rejection ratio increased from 43.6% for single UF without adsorption to nearly 100% for the enhanced UF process, achieving long time continuous treatment with water permeation flux of 47 L·m^-2·h^-1. The present study demonstrated that adsorption enhanced UF may be a feasible method for the dye wastewater treatment.

Investigation of Mg^2＋/Li^＋ Separation by Nanofiltration

The Mg2+/Li+/Cl solutions were filtrated with a commercially available DK nanofiltration membrane to investigate the possibility to enrich the lithium component.The investigation was significant as such an approach might be a competing substitute for the present lithium purification industry and the environmental protection purpose.The Donnan steric pore model(DSPM) was implemented for the prediction.The separation of Mg2+/Li+was mainly affected by the working pressure(or the permeation flux) and a limiting separation factor was found around 0.31.The effective membrane charge density was evaluated and its dependence on the permeation flux as well as the ion pattern was discussed.For predicting an actual separation of electrolytes,the experimental investigation seems necessary for the reliability and efficiency.

Concentration of Vinasse Using Membrane Filtration Processes

The application of single nanofiltration （NF） and sequential filtration of microfiltration （MF） and NF for the concentration of vinasse were studied. Filtration experiments were performed at 60 ℃, 500 rpm and different transmembrane pressures using four commercial membranes： MF, PVDF 0.2 μm; NF, PES 300, 500 and 1000 Da. The process effectiveness was evaluated through the permeate flux and the total solids （TS） concentration in the retentate. Because the retention of TS and permeate fluxes were very similar for MF, PVDF-0.2 membrane at 0.10 MPa was selected because of its lower power consumption. The best conditions tested for NF were the following： PES-1000 at 3.50 MPa with a flux of 183.2 kg/m^2 h at a volume reduction factor （VRF） of 2, under which 68% of solids were retained. For the MF ＋ NF, a PES-1000 at 3.50 MPa was selected because a higher permeate flux was achieved at a VRF of 4, and PES-500 at 3.50 MPa because a higher retention of TS was achieved compared to the other experiments. A single NF resulted in a retentate concentration that was almost twice as high as the hybrid MF and NF process, allowing reduced costs in its transportation from distilleries to distant areas.

Wastewater Treatment of a Cardboard Manufacturing Plant by Infiltration Percolation

Different coastal sands of the city of El Jadida are used to filter wastewater from a cardboard manufacturing plant combined with fly ash and bottom ash （by-products of a local power plant）. The performances of five matrices of these elements are compared in infiltration-percolation in vertical columns. The study of particle size sand is performed beforehand. The chemical and mineralogical composition of fly ash and bottom ash are produced by X-ray fluorescence and X-ray diffraction respectively. The wastewater samples were collected during a complete cycle of production of the cardboard. The heavy metals content before and after filtration was obtained by atomic emission spectrometry with inductively coupled plasma （ICP-AES）. The parameters analyzed were： total suspended solids （TSS）, organic matter COD, BODs, the potential hydrogen pH and heavy metals （iron, zinc and arsenic）. The results are very conclusive and respect the essence of control required by Moroccan regulations （law 1606-06） related to discharges from the papermaking and cardboard industry.

Evapotranspiration and Removal Performance in the Treatment of High Salinity LandfilI-Leachate Using HSF

In this study, the water budget in the treatment of high salinity landfill-leachate was estimated and the influence of evapotranspiration （ET） on treatment performance was investigated. The salinity of the inside of horizontal subsurface flow constructed wetland （HSF） of the raw leachate inflow was 15.0± 3.4 g.Cl/L which was in the level of the salinity of the survival limit of reed, and that of the double diluted leachate inflow was 9.3 ± 1.9 g.CI7L. There were large differences in the vegetation between HSF of the raw leachate inflow and that of the double diluted leachate inflow. The dense vegetation bed of double diluted leachate inflow during the growing season （April-October） provided a high ET and a large water loss, which made great contributions to the reduction of the outflow load of COD and T-N. The HSF with die-back reeds in the non-growing season （November-March） provided a slight ET and a small water loss and made less of a contribution to pollutant removal compared to the HSF with dense vegetation bed during the growing season. However, the HSF with die-back reeds during the non-growing season exhibited higher removal performance than the unplanted HSF.

Effects of Biochars and Other Organic Soil Amendments on Plant Nutrient Availability in an Ustoxic Quartzipsamment

A sandy soil, Nampong soil （classified as Ustoxic Quartzipsamment）, was incubated under controlled condition i） to compare the mineralization of major plant nutrients derived from different types of biochars and other organic soil amendments; ii） to examine their effects on soil properties and plant nutrient availability; and iii） to evaluate the plant nutrient losses in leachate from the rooting zone of soil incorporated with the different amendments. The experiment was arranged in a completely randomized design with 3 replications. Five treatments of soil amendments used were cassava stem base biochar （CSB）, rice husk biochar （RHB）, chicken manure （CM）, compost （CP）, and no amendment application （control）. The RHB treatment released the highest amounts of mineralized NO^-N, available P and K （2.30-17.26, 5.50-42.90 and 43.00-187.63 mg kg-1, respectively） while the CM treatment releasing the highest NH4＋-N in the range of 1.86-53.67 mg kg-1. The CSB and RHB treatments showed better continuity of mineralization of nutrients than the treatments of CM and CP, particularly in the case of the CSB treatment. In the soil column incubation experiment, the amounts of NH4＋-N and NO3-N in all treatments barely changed on Day 1 to Day 30 of incubation and then the amounts increased markedly on Day 60. On Day 601 the RHB treatment contained a very high amount of NO3--N （〉 250 mg kg-1）. This suggests that N would become more available 30 d after the incorporation. The CM treatment gave the highest amounts of organic matter and available P in the ranges of 4.64-8.94 g kg-1 and 14.41-36.33 mg kg-1, respectively, during the 60-d column incubation. The CSB treatment tended to have higher available K throughout the measuring period. The NO3--N was leached from the soil column quite quickly on Day 1 of incubation while the loss of NH^-N decreased slightly from Day 1 until the end of the measurement. The amounts of P and K losses varied with the type of soil amendments, and the pattern of the loss was irregular.