Testing Method SOP

How to Measure Nitrite in Water and Wastewater: Methods, Health Risks, and Tips Meta Description: Learn how to accurately measure nitrite in water and wastewater using the Griess method. Understand its environmental impact, health risks, and practical testing tips. Introduction Nitrite (NO₂⁻) might be a minor component in water chemistry, but it plays a critical role in water safety, environmental monitoring, and wastewater treatment . Elevated nitrite levels can be toxic to humans and aquatic life and may indicate issues in water treatment processes. Measuring nitrite accurately is essential for public health, regulatory compliance, and ecosystem protection . This article explains how nitrite forms, why it matters, and the most effective methods for testing it in water and wastewater. What is Nitrite and How Does it Form? Nitrite is an intermediate in the nitrogen cycle , formed during the microbial conversion of ammonia to nitrate: Ammonia → Nitrite → Nitrate In water and wastewater...

  Synthetic Precipitation Leaching Procedure (SPLP) Environmental protection and waste management rely heavily on scientific testing methods to evaluate how pollutants interact with soil, water, and waste materials. One such important analytical method is the Synthetic Precipitation Leaching Procedure (SPLP) . SPLP is widely used to assess the potential for contaminants to leach from solid materials when exposed to acid rain conditions. We will cover a detailed explanation of SPLP, including its purpose, methodology, applications, advantages, and limitations. What Is SPLP? The Synthetic Precipitation Leaching Procedure (SPLP) is a laboratory test designed to simulate the leaching effects of acid rain on solid materials such as soil, waste, sludge, Fly ash and industrial by-products. It was developed by the United States Environmental Protection Agency (EPA) and is described in EPA Method 1312 . Unlike other leaching tests that simulate landfill conditions, SPLP specifically ...

Total Suspended Solids (TSS) in Water and Wastewater Introduction Water quality assessment is a critical aspect of environmental engineering, public health, and industrial processes. Among the various indicators used to measure water quality, Total Suspended Solids (TSS) is one of the most significant. TSS refers to the total amount of solid particles suspended in water that are not dissolved and can be trapped by filtration. These solids include a variety of materials, such as silt, clay, plankton, industrial wastes, and organic detritus. Measuring TSS provides insight into the turbidity, pollution load, and potential environmental impact of water bodies. Definition and Importance of TSS Total Suspended Solids are the particles that remain suspended in water due to the motion of the fluid and are generally larger than 2 micrometers. Unlike dissolved solids, which are in molecular form and pass through a filter, suspended solids can settle over time if water is still. TSS is a key para...

Understanding Hazardous Waste under USEPA and RCRA: Definition, Characterization, and Storage Hazardous waste can pose serious risks to human health and the environment if not properly managed. Under the United States Environmental Protection Agency (USEPA) and the Resource Conservation and Recovery Act (RCRA), hazardous waste is identified, characterized, and regulated through a detailed “cradle-to-grave” system. In this post, we explore what hazardous waste is, how it’s classified, and the rules governing its proper storage and handling. 1. What Is Hazardous Waste? Hazardous waste is broadly defined as a waste with properties that make it dangerous or capable of having a harmful effect on human health or the environment. Under RCRA, a material must first be a “solid waste”—a term that includes liquids, solids, sludges, or contained gases—before it can be evaluated as hazardous.  Once confirmed to be a solid waste, EPA determines whether the material is hazardous by: 1. Listing ...

Standard Operating Procedure (SOP) for TDS Testing in Wastewater (APHA Method 2540C) 1. Purpose: To determine the concentration of total dissolved solids (TDS) in wastewater samples using the gravimetric method as specified in APHA Standard Method 2540C. TDS measures the mass of organic and inorganic substances dissolved in water that pass through a filter, typically after evaporation at 180°C. 2. Scope: This SOP applies to the analysis of wastewater samples (industrial, municipal, or environmental) to quantify TDS for regulatory compliance, treatment efficiency, or environmental monitoring. 3. References APHA, AWWA, WEF. Standard Methods for the Examination of Water and Wastewater 24th Edition, Method 2540C: Total Dissolved Solids Dried at 180°C. 4. Definitions TDS: Total Dissolved Solids, the residual mass of dissolved inorganic and organic substances in water passing through a filter (typically 1–2 µm) after evaporation at 180°C. Gravimetric Method: A technique measuring the dry wei...

Standard Operating Procedure (SOP) Title: Spot Test for Sulphide (Lead Acetate Method) 1. Purpose To qualitatively detect the presence or absence of sulphide (S²⁻) in a sample using the lead acetate spot test. 2. Scope This SOP applies to all solid, semi-solid, or liquid samples received by the laboratory for sulphide screening. 3. Roles and Responsibilities Lab Analyst Perform the test as per this SOP Record observations and results accurately Follow health, safety, and waste disposal requirements Lab Manager / Supervisor Ensure QA/QC compliance Provide training and competency assessment Review and approve records 4. Equipment and Glassware Beaker, 100 mL Watch glass Dropper or pipette 5. Reagents Lead Acetate Solution, 10% (w/v) Dissolve 10 g of lead acetate in distilled water Make up the volume to 100 mL with distilled water Store in a labeled, tightly closed container 6. Health and Safety Wear laboratory gloves, mask, and safety goggles Hand...

Sulfide Analysis in Water and Wastewater A Step‑by‑Step Guide Based on APHA 4500‑S²⁻ (Iodometric Titration) Sulfide testing is a key requirement in water and wastewater quality assessment. Trace levels can generate offensive odors, accelerate corrosion of infrastructure, disrupt treatment operations, and create serious safety concerns due to the release of hydrogen sulfide (H₂S). For dependable measurement, many laboratories rely on the APHA 4500‑S²⁻ iodometric titration method , a classical wet‑chemistry technique with proven reliability. Importance of Sulfide Monitoring In water and wastewater systems, sulfide occurs in three interchangeable forms: Hydrogen sulfide (H₂S) Bisulfide (HS⁻) Sulfide ion (S²⁻) These species coexist depending on pH and temperature, and their combined concentration is reported as total sulfide . Excess sulfide can: Release toxic and flammable H₂S gas Cause persistent odor complaints Attack concrete, iron, and steel pipelines Inhibit biolo...

Introduction  Standard Operating Procedure (SOP) for Oil and Grease Analysis in Water and Wastewater based specifically on APHA 5520B (Standard Methods for the Examination of Water and Wastewater, 23rd Edition). This SOP follows the U.S. EPA's recommended format for SOPs (EPA QA/G-6) to ensure clarity, consistency, and compliance with environmental standards. APHA 5520B uses liquid-liquid extraction (LLE) with n-hexane followed by gravimetric analysis to determine oil and grease concentrations. 1. Purpose This SOP describes the procedures for analyzing oil and grease in water and wastewater samples using liquid-liquid extraction with n-hexane and gravimetric determination, as outlined in APHA 5520B. The method quantifies total oil and grease (n-hexane extractable material) in aqueous samples. 2. Scope and Applicability Scope: This SOP applies to the gravimetric determination of oil and grease in water and wastewater samples (e.g., surface water, industrial effluents, municipal wast...

Understanding EPA SW-846 Method 9034:  Environmental laboratories dealing with solid waste, sediments, and sludges are often required to determine sulfide content for regulatory compliance and risk assessment. One of the most widely referenced procedures in the United States is EPA SW-846 Method 9034 , a titrimetric method designed to measure acid‑soluble and acid‑insoluble sulfides . This article translates the formal method language into a clear, lab‑ready overview , highlighting when to use Method 9034, how it works, and what analysts should watch out for in day‑to‑day practice. What Is SW-846 Method 9034? SW-846 Method 9034 is part of the U.S. EPA’s Test Methods for Evaluating Solid Waste, Physical/Chemical Methods . It is used to quantify sulfides in solid matrices , including: Industrial solid waste Contaminated soils Sediments and sludges The method distinguishes between: Acid‑soluble sulfides (e.g., H₂S, ZnS, FeS) Acid‑insoluble sulfides (e.g., pyrite, FeS₂...