Technologies, challenges and monitoring requirements in waste treatment processes

Global waste generation is rising rapidly due to urbanization, industrialization and population growth – and is projected to reach around 3.4 billion tons per year by 2050 (Source: Global Waste Management Outlook 2024). Traditional disposal routes such as uncontrolled landfilling are no longer sustainable, as they consume land, generate emissions and waste valuable materials and energy.

In parallel, waste streams are becoming more heterogeneous and regulations more stringent. This increases the need for stable, controlled waste treatment processes that balance three objectives:

• Minimize environmental and health impacts
• Maximize material and energy recovery
• Ensure safe, reliable plant operation

Waste treatment therefore is not just a disposal task; it is a critical part of sustainable resource management and energy systems.

Operational risks in waste treatment

At each step of waste treatment, poor control or missing treatment capacity can lead to:

• Increased emissions to air, water and soil
• Odor and noise issues impacting nearby communities and the environment
• Unstable processes such as combustion or digestion
• Loss of valuable materials and energy
• Compliance risks and reputational damage

Engineered waste treatment systems integrate sorting, pre‑treatment, thermal, biological, chemical and final disposal steps to stabilize the material, recover resources and keep emissions within permitted limits.

If not properly designed and operated, waste treatment can pose significant environmental and health risks:

• Air emissions: Harmful gases and particulates, including methane, hydrogen sulfide, ammonia, nitrogen oxides, volatile organic compounds, dioxins and fine particulate matter from improper incineration can contribute to climate change, respiratory and cardiovascular diseases, odor nuisance and explosion or fire hazards.

• Biological risks: Poorly controlled anaerobic digestion and composting sites enable the survival and spread of pathogenic bacteria, viruses and parasites such as E. coli, Salmonella and noroviruses. These risks are amplified through vector attraction (flies, rodents) and the potential presence of antibiotic-resistant microorganisms.

• Soil, ground and surface water contamination: Poorly engineered landfills can lead to the release of heavy metals, persistent organic pollutants, nutrients, hydrocarbons, pharmaceuticals, PFAS and pathogens into soils, groundwater and surface waters. These contaminants degrade ecosystems, pollute drinking water sources, drive eutrophication and create long-term human health risks.

• Worker and community exposure: Communities near inadequately controlled waste treatment sites may experience chronic exposure to air pollution, contaminated water and food-chain pollutants. Health impacts include respiratory and cardiovascular disease, increased cancer risk, infections and neurological effects. Odors and visual impacts also affect quality of life and social acceptance.

Without effective containment, emissions control, continuous monitoring and safe process design, waste treatment becomes a source of risk rather than protection. Underscoring that end-to-end risk mitigation is not an add-on, but a prerequisite for safe, compliant and sustainable waste treatment operations.

Across different treatment technologies, certain process and environmental parameters are particularly important for stable operation and compliance:

• Waste properties: Calorific value, moisture content, particle size and composition (e.g. organics, inerts, metals, plastics)
• Combustion and thermal treatment: Furnace temperature profile, excess oxygen, residence time, flue‑gas composition (e.g. O₂, CO, NOₓ, SO₂, HCl, NH3, HF, TOC), and dust loading
• Biological treatment: Dry solids and volatile solids, temperature, pH, redox conditions, biogas composition (CH₄, CO₂, H₂S), and gas flow rates
• Chemical treatment: pH, conductivity, oxidation‑reduction potential (ORP), reagent dosing and target contaminant concentrations
• Landfill operation and aftercare: Leachate quantity and quality, groundwater levels, surface water quality, and landfill gas flow and composition

By monitoring these parameters, operators can keep processes stable even when feedstock quality or composition fluctuates, while maximizing energy recovery and material yields through more precise control. At the same time, reliable visibility of parameters is essential for demonstrating compliance with environmental permits and operational standards. It helps reduce unplanned downtime or environmental incidents by enabling problems to be identified early and addressed proactively.

Waste treatment has evolved from simple disposal to a key function in sustainable resource and energy management. By combining mechanical, biological, thermal and chemical processes, modern systems can:

• Reduce environmental and health impacts
• Recover materials and energy from residual waste
• Meet stringent regulatory and community expectations

Technologies such as waste‑to‑energy, incineration, biogas & biomethane production and advanced hazardous waste treatment enable operators to turn waste streams into valuable outputs – provided the underlying processes are well engineered, monitored and controlled.