Abstract The PHREEQ-N-AMDTreat aqueous geochemical modeling tools described herein simulate changes in pH and solute concentrations resulting from passive and active treatment of acidic or alkaline mine drainage (AMD). The “user-friendly” interactive tools, which are publicly available software, utilize PHREEQC equilibrium aqueous and surface speciation models and kinetics models for O2 ingassing and CO2 outgassing, iron and manganese oxidation and precipitation, limestone dissolution, and organic carbon oxidation combined with reduction of nitrate, sulfate, and ferric iron. Reactions with synthetic caustic chemicals (CaO, Ca(OH)2, NaOH, Na2CO3) or oxidizing agents (H2O2) also may be simulated separately or combined with sequential kinetic steps. A user interface facilitates input of water chemistry data for one or two (mixed) influent solutions and adjustment of kinetic variables. Graphical and tabular output indicates the changes in pH, metals and other solute concentrations, total dissolved solids, and specific conductance of treated effluent plus the cumulative quantity of precipitated solids as a function of retention time or the amount of caustic agent added. By adjusting kinetic variables or chemical dosing, the effects of independent or sequential treatment steps that have different retention time (volume/flow rate), aeration rate, quantities of reactive solids, and temperature can be simulated for the specified influent quality. The size (land area) of a treatment system can then be estimated using reaction time estimates (volume for a corresponding treatment step is the product of reaction time and flow rate; area is volume divided by depth). Given the estimated system size, the AMDTreat cost-analysis model may be used to compute approximate costs for installation (capital) and annual operations and maintenance. Thus, various passive and/or active treatment strategies can be identified that could potentially achieve the desired effluent quality, but require different land area, equipment, and costs for construction and operation.

中文翻译：

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交互式 PHREEQ-N-AMDTreat 水质建模工具，用于评估酸性矿山排水处理系统的性能和设计

摘要 本文所述的 PHREEQ-N-AMDTreat 水相地球化学建模工具模拟了酸性或碱性矿山排水 (AMD) 的被动和主动处理导致的 pH 值和溶质浓度的变化。“用户友好”交互工具是公开可用的软件，利用 PHREEQC 平衡水和表面形态模型和动力学模型进行 O2 注入和 CO2 放气、铁和锰氧化和沉淀、石灰石溶解以及有机碳氧化与还原结合硝酸盐、硫酸盐和三价铁。与合成腐蚀性化学品（CaO、Ca(OH)2、NaOH、Na2CO3）或氧化剂（H2O2）的反应也可以单独模拟或与连续动力学步骤相结合。用户界面有助于输入一种或两种（混合）进水溶液的水化学数据以及动力学变量的调整。图形和表格输出表明 pH 值、金属和其他溶质浓度、总溶解固体和处理后的流出物的比电导率的变化，以及作为保留时间或添加的苛性剂添加量的函数的沉淀固体的累积量。通过调整动力学变量或化学剂量，可以针对指定的进水质量模拟具有不同保留时间（体积/流速）、曝气速率、活性固体数量和温度的独立或连续处理步骤的影响。然后可以使用反应时间估计（相应处理步骤的体积是反应时间和流速的乘积；面积是体积除以深度）来估计处理系统的大小（面积）。给定估计的系统大小，AMDTreat 成本分析模型可用于计算安装（资本）和年度运营和维护的大致成本。因此，可以确定各种被动和/或主动处理策略，这些策略可以潜在地实现所需的污水质量，但需要不同的土地面积、设备和建设和运营成本。